Any idea what kind of permitting or permission they had to go through to launch this? I'm assuming you can't just take what's basically a missile and go into the dessert and shoot it without the FAA knowing about it.
You need FAA waivers to send stuff up there. There comes an altitude (18k IIRC) above which all airspace is controlled, you're not supposed to be up there without following the directions of the relevant tower and carrying a transponder that they can talk to. But an amateur rocket has no ability to follow such directions so you have to get FAA permission to get exclusive access to a chunk of airspace.
Of course the FAA doesn't give out such waivers willy nilly, they expect the amateur rocket community to minimize the need. Thus there are launch sites in the middle of nowhere that have launch windows where the big stuff is allowed.
They also self-regulate on availability of the big motors. The guys who make them won't sell them to anyone who isn't certified, other than as part of a launch to get said certification which is done under the supervision of someone who is certified. They don't have the force of law but so far it's worked. (And there's the separate issue of the hazmat rules about those big motors--most people can neither legally store nor transport them. Take delivery at the launch site and use them.)
Note that this record setting flight to 143km did not use an off the shelf motor. They built their own motor, integrated into the airframe for lightness and to reduce the cross section. Ammonium perchlorate propellant.
I have participated in a few high-altitude balloon launches before, and those basically all have a transponder on them, as well. You have to let the FAA know the time window and get a waiver on the "launch" site, but those can be unpredictable in the atmosphere (some have limited steering of altitude), and you have a (very low) chance of getting somewhere a commercial flight might want to be.
I misinterpreted your comment initially, you’re citing the FAA: ‘To qualify as an amateur rocket, the launch must be suborbital, not have any humans onboard, remain under 150 km (93.2 statute miles), and have a total impulse under 200,000 lb-sec (889,600 Newton seconds).’
I’m sure you would get punished but what are they going to do about your rocket once it’s up there?
This was launched under a FAA waiver. Black Rock Desert is one of the places to go in the US if you want to do this. They'll open up a cylinder to the sky. I wasn't there, but I venture that this was done with support from Tripoli Rocketry Association at BALLS.
Launching at BRD is where I first met Elon Musk where he was there with 5 sons (at the time) to watch them launch golfball nosecone rockets with 3d printed fin cans.
There is an annual competition that precedes the main event called ARLISS.org
A local rocketry club has standing clearance to 10,000ft and I know lots of college teams come from 6 hours away to take advantage of it.
Check your local clubs, you can see impressive launches on at least 1 weekend a month.
Honest question by someone who is not familiar with this space: what prevents a well-resourced by determined civilian team from beating them? Like, yes, this is rocket science…but it's rocket science done by a team of college students. Surely there are other groups interested in this kind of thing? Does the government step in at some point and go "that's enough" when you try to do significantly better?
I think college student teams strike a combo of time, talent and resource that would be surprisingly hard to come by in the larger “civilian world.” In college, you have a bunch of freshly educated, similarly minded people in one place with a whole bunch of free time to put towards one project, highly motivated because it’s both an extracurricular escape and a career prep achievement. And these teams are often financially supported by their school departments or fundraisers. If you fail, there are little if any consequences on your life. All these motivators improve the likelihood of making something truly impressive.
Sure, we can make an arrangement like this out of college. Call up your ex-rocket club teammates, who have all now graduated and making banks at rocket startups. Spend the Thanksgiving week grinding out the CAD, code and circuit boards then test everything out in a desert. But projects like this are a huge time investment and with work and family in the way, they can often be very difficult to coordinate and pull off.
Even if your rocket does end up shooting off and breaking a record, does it truly “beat them”? I find it a bit hard to compare a team of similarly educated college students to a group of adults, usually with relevant professional backgrounds. Maybe the closest we can get are YouTuber collabs. Sometimes I miss my days spent on my college team; it’s pretty hard for me to get an exciting, rewarding, comradely and occasionally traumatizing experience like that ever again.
> I think college student teams strike a combo of time, talent and resource that would be surprisingly hard to come by in the larger “civilian world.”
The flip-side of this that you have a bunch of very smart young people absolutely dripping with theory knowledge and close to zero relevant real world experience in anything applicable in this space. The ability of college university teams to make exceptionally bone headed f ups is very well known. I've mentored a couple of university rocket teams for over 5 years now and I can tell you it's often an exercise in 'unknown unknowns'.
USC RPL has been at this for almost 20 years now. Their main competitive advantage (besides in-house cf cased motors) is documentation and knowledge transfer. As I'm sure you can imagine there are probably no founding team members actively involved today. I was at Balls in 2013 (IIRC it was 13) when they launched their first Traveler rocket, which was their first space shot attempt. They didn't actually reach that goal until April 2019.
I used to be part of a very successful competitive robotics team. You'll be surprised at how many student teams have this one guy who has been doing his PhD forever/startup founder who spun off from your team and mentors it that exist in the more successful teams.
I've seen PhDs whove mastered the art of being in the same uni team. One of them I knew has followed the path from undergrad (4 years), masters (2 years), RA (2 years), Phd (7 years), Post-doc (2 years).
Another is a startup founder who started the team in undergrad, worked as an RA for 4 years, then spun-off his own company over the next 6 years.
For the most part its beneficial for the uni to retain such talent. Especially, cause they are better grounded than some of the professors who claim to be "experts".
Unless they turn faculty I kinda doubt it. Not to sully your robot team, but I expect many of these students to want to progress to bigger and better things in the commercial space launch sector which they can't do at USC. Also, money.
Founded in 2005. They probably have a very strong Knowledge transfer system and alumni network in place (useful for funding). This is something I can attest to when I go back to my college days.
> you have a bunch of very smart young people absolutely dripping with theory knowledge and close to zero relevant real world experience
For sure! And that’s perhaps the #1 reason these teams are so valuable: it’s an environment to get hands dirty in. If something sticks, that’s great and goes on the resume. If something awful happens, just walk away with a cool story assuming you didn’t blow up a school building or anything like that. Either way the experience and hopefully learnings stick with these young people like me for a long time.
Somewhat but it's still such a wealthy student body that if everyone in the photo was from a family worth millions that would not even be a very unlikely statistical anomaly.
Making it graded tends to F it up bigtime. You waste soooo much time doing overkill process for the sake of proving that you can to get the grade. CAD models will be made. Simulations will be run. Powerpoints will be made to convey the results. When in reality all you needed was one dude to spend two hours prototyping both so that they could be evaluated and the more viable path of development chosen.
Heh, grades served as a good barometer for me to know how much effort I needed to put into the boring classes to pass them. My transcript is a nightmare, high 50s and low 60s in the "easy classes", high 90s in the hard/interesting classes. And then a bunch of really fun/challenging extracurricular stuff that used to get a line or two on my resume when I was a fresh grad.
Thank goodness that the only employer to have ever cared was one where many of my extracurricular friends already worked and vouched for me. The only other time my transcript has actually mattered was when I went back to grad school; my overall average was about 2% too low for the good funding and I had to spend a semester working a lot of hours at the undergrad homework help desk until my first semester MSc. grades came in and qualified me for a significantly better stipend with less hours spent on other people's homework.
The biggest issue with college teams is that there is no institutional knowledge retention. Once they are done padding their resumes, they will move on. The next batch of club members will usually reinvent the wheel again. There is little incentive for good management and long term innovation beyond proving out one or two ideas that are immediately relevant to their academic research.
This is so frustrating to me. I was involved in a cyber security club that just started in my university. Both complete incentive misalignment and lack of focus. In the first committee meeting I was excited and pitched a plan to go from "zero to one", setting up training curriculums, building talent pipelines (esp from year 1s) from the student populace to us, institutional knowledge retention to keep and grow knowledge, getting mentors/research links with professors etc. After drawing everything on a white board, I turned around to find a glassy eyed committee. Every single one said "nah, let's just meet every week and uh, talk about a ctf or something". The president looked around and agreed with them. Over the semester I realized the president was far more interested in going to events and introducing himself as president than actually having any impact. As I predicted at the start, the initial hype and momentum gave way to lethargy and indifference. Participation from both non members and members fell off a cliff.
I think we can see that this isn’t true in this case. They are building on successful work from 2019’s record setting attempt, implying plenty of continuity. And these are undergrads so they are not generally doing heavy research. They are likely well advised.
If a 21 century rocketry group takes 20 years to reach the Karman line, college students or not, they are the definition of incompetent. Maybe they should all get internships at the United Launch Alliance; good for lapping out of the gravy train and not much else.
A lot of these college teams are mentored by someone in the HPR (high powered rocketry) hobby. Many of the college level competitions require it.
HPR hobbyists have flown above 300k feet, and once you’ve reached 100k going higher it largely a propellant cost problem. 100k feet is a goal for many hobbyists because you’re above Mach2, doing staging, plus recovery and altimeters have to work differently at that altitude. However, going higher just means more propellant.
There’s an annual event called BALLS out in Nevada where HPR flyers can go as high as they want. There’s also a site called FAR (friends of amateur rocketry) where you can fly above 100k ft as well as liquid biprop engines if you want.
It's not just more propellant. Note the engineering that went into keeping the thing from burning up. Or look at the MESOS rocket--the guy who built that took the choice of delayed ignition of the second stage, accepting the extra gravity loss in exchange for less drag loss.
And if you don't have a guidance system you have to complete your burn low enough that aerodynamic forces keep your rocket pointed up during the burn. The bigger your burn the more of an issue that becomes.
Amateur rocketry is relatively common, although space shots are a considerable engineering effort. A good example is BPS.space (Joe Barnard) on youtube [1], who is making significant progress towards a space shot (over the karman line) and documenting it in detail, though he's definitely not the first to do a space shot. He's doing everything himself including his own solid propellent, nozzles, casings, flight computers, control surfaces, cameras, and flight computer. On the regulatory side, the FAA has a regulatory regime to support these kinds of activities. There are amateur launch facilities like the Friends of Amateur Rocketry [2] in the Mojave Desert that support these kinds of launches, although they do require you progress through successful launches of smaller rockets to get permission to fly larger rockets, so you can't just rock up with a huge rocket the first time.
The old saying goes 'Rocket science is easy. Rocket engineering is hard.'. You need a lot of expertise and experience to build a rocket that is light and strong enough to get anywhere near this sort of altitute and also be recoverable afterwards. So many things can go wrong.
Nothing. The FAA in the US is pretty good about these things and as long as you stay below 490,000 ft AGL and are flying a sounding rocket (eg not trying to make orbit).
With that said, well-resourced doesn't matter too much, it's more knowledge and experience. CSXT attempts were done by a team of aerospace engineers experienced in these types of things in their day jobs. They reached space (above 100km AGL) twice. USCRPL has been doing this for well over a decade, and have also reached space twice. And they've had heaps of failures along the way.
TLDR; Going Mach 5 in fairly thick atmosphere is exceptionally hard to do without encountering a rapid unscheduled disassembly. Flying a two stage to space is more efficient and less rough on the rocket, but no one has done that yet as it's quite a bit harder that a relatively dumb 4fnc rocket.
This is the amateur record, not the civilian one. And while the group may be "student-run", if you check their sponsors page it's funded partly by the university and partly by a who's who of the aerospace industry (Boeing and SpaceX are prominent), which I suspect is much easier for a college student group (who make a good feel-good cause, and those companies are implicitly courting to come and work for them) than a group of working adults.
The biggest hurdle (besides knowledge) in an endeavor like this is cost. Those sponsors aren't providing technical expertise.
The main 'competitive advantage' USC RPL has developed that enabled this space shot is their in house filament wound carbon fibre cased ammonium perchlorate motors. By swapping comparatively heavy/over engineered aluminum motor casings that are reusable they make single use cf cased motors.
I'm pretty sure Boeing and SpaceX aren't the places you go for solid motors.
> Those sponsors aren't providing technical expertise.
Do you know that about this specific case? Because I personally know a similar student team where the sponsor absolutely is giving guidance on technical matters.
Look, did they use industry to help them with things like xraying their motor grains to check to confirm they had no voids? possibly. But this team has been at this for nearly 20 years and made their first spaceshot attempt over a decade ago (Traveler I).
All of their in house designed and built GPS and radio triangulation electronics failed. It was the COTS stuff that gave them good data. I would think if private industry was doing any heavy lifting for them that wouldn't have occurred.
They've blown up a lot of their motors in testing to get to their R class motor they used here. I also doubt that would have been the case if they were getting private sector assistance.
Not only that but they're a self organizing team. Unlike the professional world they want to be there, they're not getting selected out due to vibe checks/leetcode proficiency or filtered out due to comp ask. Also they don't have business dictating design or trying to ban engineering practices.
This is not traditional rocket science of turbines and cryogenic fluids, this is igniting solid propellant and ensuring your rocket is strong enough to not explode
idk what "value" people expect out of a model rocket, anyway. Of course SpaceX or NASA is sending things to orbit. The value is you get to have fun launching things into space yourself!
Mostly tooling, machining. Autoclaves to cure the carbon, lathes, CNC fab. Total cost not including the space is easily over $100k. Few hobbyists can do this, but a university can sponsor it when it'll be used by multiple groups and for research.
What's weird about student/amateur rocketry is how, at a certain point, knowledgeable people have to say "I'm not allowed to help you." If you get too good at this hobby you run straight into arms treaties.
I can't wait until arms export controls are challenged under first amendment grounds, we already came close that one time with encryption algorithms being published as a book
If college kids can do it, there's no knowledge that terrorists in even backwater shitholes (a lot of al-qaeda were engineers by training) can't quickly obtain. We might as well drop the pretense that the knowledge itself is something so valuable to building weapons that speaking it to foreigners should be illegal
I don't think this is an accurate statement. Consider for instance that the Sinaloa Cartel is currently hiring college students to try and reproduce chemical precursors for the production of Fentanyl. This is something that's probably trivial for a real company with resources to do, but because it's not public knowledge it's difficult for them.
I think the same could likely be said for this kind of production of rocketry.
For another example, consider how Russia had to rely on Iran for the production of their Shahed drones (until Iran showed them how to produce them), despite Russia being a longtime producer of weaponry.
I think this particular engineering department has a very exceptional group of college kids. I don't hear much about students in other schools in other states much less other countries accomplishing near this much. I know "American Exceptionalism" probably is not a view that HN audience would give much merit to, but we are still one of the only places in the world where smart students are given opportunities like this. Our culture seemed to give "opportunity" a good balance (even when we see the many downfalls, ie the entire crypto space)
I find your choice of words interesting. "Students are given opportunities" sounds pretty much the way things were done in the USSR. The Western way is (or at least used to be) treating students as adults who have the independence and the agency to create opportunities for themselves.
Iran/China/Russia all have more advanced missiles than the US has deployed like, ever. Iran and Russia have demonstrated recently hypersonics that are effectively unblockable.
What kind of knowledge do these arms export controls really do other than make it more difficult to compete with defense contractors?
> Iran/China/Russia all have more advanced missiles than the US has deployed like, ever.
This is somewhat true for China's, on paper at least. Maybe.
Russia's Kinzhals got intercepted by 1980s Patriots.
Iran's are just boring old ballistic missiles.
> Iran and Russia have demonstrated recently hypersonics that are effectively unblockable.
The US has plenty of similar ballistic missiles; ATACMS is similarly tough to intercept. Doubly so in large numbers, which was how Iran got some through.
Fortunately, the economics of the marketplace have driven it towards big gene-printing firms. It's cheaper to outsource to a high-capital, low-cost-operating company than it is to do in house with a low-capital, high-cost-operating approach. Thus the low end of the market pretty much died and the big guys check all orders against a slew of thou-shalt-not-print genes.
You don't need to print really, more a question of culturing them like a kombucha. Luckily that ends up being a self limiting problem since the amateur doesn't know containment well enough to protect themselves.
I don't think it's that strained. BPS Space for example spends a lot of time talking about how "This is not a tutorial" but there's a massive gulf between what is currently published information that is available to people like him and what is actually meaningful to regulation.
If you are buying your propellant components in small bags off the internet and mixing it yourself in stand mixers and casting it yourself in your garage and using niche open market servos to build your stuff with homemade guidance, the gov is not looking at you. ITAR isn't about keeping every precocious kid from building small volume guided munitions; It's about keeping shithole states from building ICBMs. It's about keeping former SpaceX personnel from spending time in Best Korea.
This is especially true in a post FPV drone world, where putting 1kg of explosive anywhere you want in a 10km radius is a $500 purchase off alibaba. Precision munitions have accidentally been democratized.
I'm not sure that's an accurate characterization. He's specifically voiced concerns about the ambiguity of whether what he's doing violates ITAR, even with the "this isn't a tutorial, I've left out information" and that if the feds launched an investigation, he'd be crushed by the process even if they found no wrongdoing in the end.
Yet anyone can buy a consumer drone and strap homemade explosives on it and do a lot more damage VS a college kid with an engineering background who is into rocketry.
I was trying to understand how an altitude of 470,000 ft compares to other things, so I looked up a few numbers.
470k feet is 143 km. The altitude record for an air-breathing aircraft is 38 km. There are some very low earth orbit satellites that orbit in the sub-200 km range (https://en.wikipedia.org/wiki/Very_low_Earth_orbit). The ISS orbits at about 400 km and typical LEO is 800 km. ICBMs have an apogee altitude of 1000 km or more.
(Of course, the energy required to get up to some altitude is only a small fraction of the energy required to get into orbit at that altitude. https://what-if.xkcd.com/58/ is a relevant read.)
> Aftershock II is believed to be the world’s first civilian-built rocket to reach an altitude of 470,000 feet.
Surely this first line, bolded and right below the byline, isn't correct for our normal understanding of "civilian", is it? Like most rockets aren't military-built.
1. I've checked multiple places and consistently "civilian" is defined in contrast to military / armed forces/ police, but not in contrast to government in general.
2. But even among non-governmental groups, this claim doesn't make sense. Northrop Grumman, Arianespace and a bunch of other companies that are not governmental organizations (but may have government customers).
Is the core challenge on amateur rocketry the amount of fuel that you can put on board the rocket. Essentially a cost equation on the design components?
It would be super fun to do but isn't that the big different -- design and shape certainly make a difference but are they not mostly determined at this point with subtle iterations?
The key challenges called out are a) fuel, b) robust airframe, c) active guidance to handle varying conditions, d) funding for testing and robust components. The article goes into a good amount of detail on each.
> Are they as high up that it could start orbiting?
1. No
2. Orbit is more about speed than height. You have to get high enough that the atmosphere doesn't aggressively degrade your velocity, but the key is to hit ~8km/s, although that number changes depending on your altitude.
You only need to be moving ~7.5-8km/s, but getting to orbit tends to take 9.5-10km/s of total delta-v due to needing to ascend, aerodynamic drag, and other losses.
Orbiting however is more about radial velocity. You are sort of constantly falling towards Earth, but you are moving so fast that you always miss it and so you end up orbiting it. A great animation on the subject: https://www.reddit.com/r/Damnthatsinteresting/comments/1btbn...
Even for geostationary you still need to gain a ton of horizontal velocity, more than LEO. You are staying over the same spot on the earth, but the earth is rotating and you need to match that same angular velocity. Being at a higher altitude you need a faster linear velocity to match that angular velocity, since you have a larger circle to travel in the same amount of time.
Even if they were high enough they would just fall back to earth. There are lots of videos explaining orbit, this one looks good: https://www.youtube.com/watch?v=bcvnfQlz1x4
> Aftershock II reached a velocity of 5283 ft/s and Mach 5.5. The comparatively lightweight rocket amounted to 330 pounds, at a height of 13 ft and 8” diameter.
For the imperially challenged, that's a velocity of 1.6 km/s, weight of 150kg, height of 4m and 20cm diameter.
Wikipedia disagrees with you[1], and if pounds were a unit of weight that'd be very unpractical from a legal PoV to have things being labeled in pounds since the same object have a different weight in Puerto Rico (close to the Equator) and Fairbanks (close to the North Pole).
To be very pedantic, the pound is a unit of both force and mass, and it's because the unit evolved before the Newtonian understanding of weight versus mass. That's why there exists the pound-mass, and the pound-force.
Of course, in SI this is very straightforward: the unit of mass is the kilogram and the unit of force is the newton, which is the force acting on a mass of one kilogram experiencing an acceleration of one metre per second per second in an inertial frame of reference.
In case you didn't understand the other reply, you can't use newtons in this context. Kilograms is perfectly fine here. The thrust of the engine can (and should) be measured in newtons though.
Also, 4 decimal points of precision is completely overkill. Maybe one decimal point at most would be more than enough, but most wouldn't even bother with that.
The problem is the 8 significant figures, not 4 decimal places - 0.3300 kip and 1467.9126 N both have 4 decimal places but one is much worse than the other.
Even if 330 lb was exact, all those digits in 1467.9126 N aren't even correct. It should be 1467.9131 N using standard gravity. It looks like brudgers used 1 lbf = 4.44822 N which is what Google says but is only rounded to 6 s.f. so can't be used to generate an 8 s.f result.
> The thrust of the engine can (and should) be measured in newtons though.
It's very common to measure engine thrust in ton-force because it makes it easy to compare the thrust to the weight of the rocket, which is a critical metric.
Many CIS countries and China use metre flight levels[1] and kilometres per hour for indicated speed reporting. Additionally, the ICAO has recommended transiting to metre flight levels since 1979[2]. More additionally, the Airbus A300 had flight levels initially set up to be metric (obviously, since it was an effort spearheaded by the French), but to appeal to American airlines the Airbus consortium switched to feet. Although I am positive that Airbus engineers work exclusively in SI.
METARs worldwide except in North America use SI units for reporting weather.
They are decidedly not. They are marketed in inches of the diagonal (a supremely brain-dead decision, if you ask me), but they are engineered, manufactured, and even programmed only in SI units.
If you look at your display's EDID output, the diagonal doesn't even factor in; what you do have are vertical, horizontal, and per-pixel dimensions; all in millimetres. This is what all panel manufacturers (LG, AUO, Samsung, Innolux, BOE, TCL, and so on) do.
US customary units are a distinct system from imperial units (some of the individual units overlap, and several others have the same names but different definitions.)
It's interesting that I'm perfectly fluent in both US and metric units, yet I don't have a personal frame of reference for the magnitude of many of the numbers given in the article, in either unit system. For instance, how they compare to rockets that are actually in practical use.
Compare to New Shepard (Blue Origin suborbital passenger vehicle): 1 km/s top speed, 100-120 km max altitude. Of course it also carries a payload of six passengers and (the rocket part) lands propulsively.
Compare to orbital rockets: (low earth) orbital velocity is 7.8 km/s, the ISS orbits at about 400 km, the lowest satellites are at about 200 km.
Note that the Americans never adopted the imperial system, which was established after US independence; US customary units are their own thing, based on the older English customary units which preceded the Imperial standardization.
I use a German MRI scanner and they have clearly thought about this too. I can enter patient height and weight in ‘metric’ centimetres and kilograms or in ‘US’ feet, inches and pounds.
Canadians mostly use imperial when describing one's height and weight. Folks also tend to bake using imperial measures in my experience, and idk if it's different for large projects, but home demos are very much the domain of imperial standard objects (like a 4' x 8' panel of drywall or a 2" x 4" x 8' beam)
Americans love inventing field specific nomenclature. Like piping sizes, wire sizes, metal sheet thickness, plywood router bit size, construction wood size, furniture/raw wood size, etc
I have always thought it was just a side effect of capitalism. The more messy the units, the harder it is to enter a field without requiring the help of an expert sales.
There are only three things the UK uses Imperial units for: road signage (speed limits, distances, and vehicle dimension restrictions; and since 2016 all new dimension restriction signage has to be in dual-SI and Imperial units[1]), beer, and milk, the latter two of which are also sold in half-litre and litre measurements.
> There are only three things the UK uses Imperial units for: road signage (speed limits, distances, and vehicle dimension restrictions; and since 2016 all new dimension restriction signage has to be in dual-SI and Imperial units[1]), beer, and milk
Do people not weigh themselves in stones and pounds?
> Do [UK] people not weigh themselves in stones and pounds?
Older people, usually yes.
Younger people, more often that not, not. Even at 48 I use Kg for my own weight, but those only a half a decade older more routinely use stone/measurements.
Though there is a sizable range of people who use one unit system by default but have a reasonable intuition of the other.
Unlike some things, there are no legal mandates dictating which set of measures to use for this.
Another difference in weight scales: we don't tend to work with just pounds when we use imperial measurements. When a US TV show gives a weight as, for example, “172 pounds”, many will need to do a little mental arithmetic (this may be subconsciously, not actively calculating but the process delaying understanding) to convert to X stone & Y pounds rather than naturally having an intuition of the weight from the single number.
I'm a paediatrician. No parent has ever asked me for their baby's weight in kg - they are all pounds and ounces. So much so that I can do this niche conversion almost in my head, at least at the start of the day, as we weigh them in kg.
What's weird is my pediatrician here in Seattle uses kg for my ~10 year old kids' weights but inches for their heights. Why the kg? They always translate to pounds for discussion, but the record is in kg.
It was always pounds and ounces when they were babies though. Not sure when it switched to kg; probably when we switched from "baby specialist" to "standard pediatrician" so around toddler age.
SI has been the standard for decades in Australia, but people almost always
ask for baby weights in pounds and ounces.
Adult heights are the other exception, those are often in feet and inches. My 14 year old knows she's 5'2" but her knowledge of imperial measurements doesn't go much further than that.
I’ll add tyre pressures - cyclists seem wedded to PSI.
I’m in New Zealand and we use imperial for baby weights, tyre pressure and height.
Baking uses some measure like cups (US or imperial?) and teaspoons/tablespoons which I dislike, grams is preferable.
Surely the dumbest though is UK shoe sizing. The increments are barley corns length, a unit of measure which is hilarious. This is for males and children, women’s shoe sizing is apparently US. What a shambles.
Also the British, we're metric on paper for most things but in practice we use both systems interchangeably for a lot of things. In a few cases like the roads and draught beer imperial units are mandated.
Since this comes as a surprise to many of my first-time British colleagues: US customary and Imperial use the same names, but are different units. The US customary volume units (cups, gallons, etc.) are on two scales: the "tablespoon scale" which is all powers-of-two, and the "teaspoon scale" which is a third of some nearby tablespoon scale.
I used to have a handy chart of the mapping of "prefix" to power-of-two, for 2^-7 to 2^7.
Also, the US foot was supposed to be exactly 30cm, but the French couldn't get their shit together, in time.
Another fun fact is that UK gallons are based on the volume occupied by ten pounds of water. Combined with the fact there's 20 ounces in UK pint this means a fluid ounce of water weighs an ounce, and a pint of water weighs a pound and a quarter.
Not that you're very likely to encounter British fluid ounces any more, the smallest imperial unit of volume I generally run into is the half-pint.
"Americans dominate space" is the most American sentence I've read in a while. Imagine that, a few humans from a little corner of the universe dominating space!
"Americans dominate the space industry" is presumably what they meant, and not inaccurate. On the other hand, even the American space industry uses metric.
Nor was Mars Polar Lander – the most likely cause of its loss was a mistake in units that resulted in it using too short a deceleration burn as it prepared to land, meaning it hit the surface far faster than intended (IIRC we don't know for sure if it impacted in one piece, broke apart during descent). Tabloid headlines of the time dubbed the mission as a “close encounter of the thud kind”.
The EU was dominating space for around twenty years or so, but that has long passed and at this rate will never come again. The ESA and Arianespace dropped the ball so badly, books will be written about it.
Thanks to Starlink, something like 70% of the 7500 satellites orbit Earth are American. Or course by mass, nature still wins by a landslide, but as always, it's all in how in count things.
There are 31 extra-planetary human objects/, 19 of which are American, and 12 are Japanese/Soviet/European/Chinese/Indian, so maybe a bit further than the ionosphere?
For clarity, Americans claim the WORLD champions of baseball. The championship series is called the World Series. In American football, it's just called the Super Bowl.
Also, they got their lead in space tech mainly because of a German scientist (Werner von Braun).
On the Apollo program, all the calculations were done in metric (obviously). The computers all worked in metric internally and then converted to imperial for display. They actually had to waste some of their very limited cpu cycles on converting to imperial because the US astronauts couldn’t handle the metric system.
Your comment contains a series of partial truths, falsehoods and misconceptions.
So Werner built the rockets and all the subsystems too or was just the technical fellow/consultant?
Sure, the US was in a better position post WW2. But Werner has been dead for years and the US still dominates space 10x or even 100x times. Engineering in the US is top notch.
As far as your other assertion- what’s your source?
NASA primarily used the imperial system (feet, pounds, and seconds) for the Apollo program. The Apollo Guidance Computer (AGC) and other systems were designed using imperial units because the entire spacecraft and mission control infrastructure were built around the U.S. customary system.
There was no wasting of CPU cycles. We even have the source code on GitHub to go look at:
(AGC) calculations were carried out using the metric system, but display readouts were in units of feet, feet per second, and nautical miles – units that the Apollo astronauts were accustomed to.
There is a direct lineage from the Nazi German V2 rockets to Saturn V. Wernher von Braun and his rocketry friends were involved at all levels of American rocketry and ballistic missile programs, and I am happy to say the latter wouldn't have gotten off the ground as early as they did without von Braun's guidance at all levels. At least until the end of WW2, British (and even German) aerospace was considerably further along than American equivalents. And even afterwards, the Europeans, Canadians, Brazilians and the Soviets have remained very productive in terms of civilian and military aerospace. This legacy continues today.
> the US still dominates space 10x or even 100x times. Engineering in the US is top notch
Good for the USA, but this has very little at all to do with unit systems and much more to do with just how much capital there is in the USA. And as everyone else has said, NASA uses SI. I bet these college students did, too.
Keep in mind that the metre is barely younger than the US itself, having been formalised in the 1790s.
What does that have to do with rockets? The main resources you need for spaceflight are intellectual capacity and engineering skills. Plus a government that allows it to happen. Besides the US, China and Russia, the 4th place for number of launches in 2023 is shared by India and New Zealand. The latter can hardly be described as imperialist by any measure. All you need is a single company like Rocket Lab. It could easily happen in other places too, under the right circumstances.
Prior to losing WW2 for example Germany dominated the space and they were latecomers in imperialism with very little control over anything outside their own territory. In fact getting pushed around by more powerful colonial nations, and the economic sanctions that were put on them, were the main reason leading to the fascist takeover and ultimately the war.
One could argue the US entering into WW2 is imperialism. Von Braun and a large number of other highly skilled and important people came from that, which directly migrated German rocket and Spacecraft innovation to the US.
Not to start a big discussion about WW2 but the US was passive until they were attacked. Over 2000 Americans were killed in Pearl Harbor. For a nation of its size and power, the US was decidedly un-imperialist up until then. Even after they'd beat the Nazis and Imperial Japan, they actually helped rebuild their economies instead of exploiting them. Granted, that might have been the smarter thing to do anyway and turned out a win-win. But it wasn't how most leaders thought at the time. Look at the Soviet Union and how they ended up oppressing the territories they "liberated". The Western allies also wanted to keep Germany down, as did some in the US government (see the Morgenthau Plan for example). Had they prevailed there might soon have been another war.
For a nation of its size and power, the US was decidedly un-imperialist up until then.
Its empire was never on the scale of the major European Powers. But by that point in time, it still maintained explicit colonial control over the Philippines, Puerto Rico, Hawaii (still fairly recently subjugated) and numerous Pacific islands. Along with the Panama Canal Zone (which had its own postcal code, CZ).
It also exerted considerable influence over the affairs of many nominally independent countries in the hemisphere (Cuba quite notably), and engaged in several major military interventions up until 1933 (Mexico, Haiti, Dominican Republic, Nicaragua). It also intervened substantially in the Russian Civil War, up until 1925, and was still engaged in wars of suppression against its indigenous population through the middle of that decade as well.
One could say its imperial project took a breather of sorts in the mid-1930s, and decided to rest on its laurels for a bit.
Rocket Lab is mostly an American company these days. Headquartered in America, most of their employees in America, traded on an American stock exchange, doing contracts for the American military.
It was more of an exploration lull and not much industry had came out of it quite yet as privatization was being implemented and so it’s the case the industry was actually just being born.
You are simply wrong for anything other than human rated flight. They didn't have the kind of PR that NASA and Space X have, and they were never human rated, but private satellites never stopped flying on Atlas, Delta, and Titan programs that variously went from the 1960s all the way up until the 2020s. All three of those rocket programs are direct descendants of ICBM programs.
I disagree with the premise that it was lack of bombing of US infrastructure related though. Space programs are very simply the public output of ICBM programs. Most of the modern day is simply a direct descendant of ICBM programs. You like distributed and reliable communication networks like the internet? Built so ICBM silos could command each other even if certain hubs were nuked. You like the miniaturization of solid state electronics? That capability was paid for entirely by the US Air Force who wanted powerful computers under 100 pounds for advanced planes and precision ICBMs. Satellite navigation was also explicitly invented for nuclear missiles fired out of submarines to have an accurate fix for guidance purposes.
Basically the entirety of the modern world exists because the US of the cold war pumped trillions of dollars into producing ICBMs and planes that were genuinely "next gen" while every single private business takes the credit for stuff they never paid for. Computer and telecommunications companies would never have built this stuff on their own: They were fine with computers taking up an entire facility that they could rent out (cf modern clouds) and fully switched networks that were reliant on a big company to manage. None of them needed to sell you a "personal computer". None of them wanted a distributed, uncontrolled network like the Internet.
Any idea what kind of permitting or permission they had to go through to launch this? I'm assuming you can't just take what's basically a missile and go into the dessert and shoot it without the FAA knowing about it.
You need FAA waivers to send stuff up there. There comes an altitude (18k IIRC) above which all airspace is controlled, you're not supposed to be up there without following the directions of the relevant tower and carrying a transponder that they can talk to. But an amateur rocket has no ability to follow such directions so you have to get FAA permission to get exclusive access to a chunk of airspace.
Of course the FAA doesn't give out such waivers willy nilly, they expect the amateur rocket community to minimize the need. Thus there are launch sites in the middle of nowhere that have launch windows where the big stuff is allowed.
They also self-regulate on availability of the big motors. The guys who make them won't sell them to anyone who isn't certified, other than as part of a launch to get said certification which is done under the supervision of someone who is certified. They don't have the force of law but so far it's worked. (And there's the separate issue of the hazmat rules about those big motors--most people can neither legally store nor transport them. Take delivery at the launch site and use them.)
Note that this record setting flight to 143km did not use an off the shelf motor. They built their own motor, integrated into the airframe for lightness and to reduce the cross section. Ammonium perchlorate propellant.
I have participated in a few high-altitude balloon launches before, and those basically all have a transponder on them, as well. You have to let the FAA know the time window and get a waiver on the "launch" site, but those can be unpredictable in the atmosphere (some have limited steering of altitude), and you have a (very low) chance of getting somewhere a commercial flight might want to be.
You need a waiver over 18k feet. https://www.faa.gov/space/licenses/amateur-rockets / https://www.faa.gov/air_traffic/publications/atpubs/pham_htm...
A little higher (150km) and this would've been out of the realm of amateur rocketry entirely.
I misinterpreted your comment initially, you’re citing the FAA: ‘To qualify as an amateur rocket, the launch must be suborbital, not have any humans onboard, remain under 150 km (93.2 statute miles), and have a total impulse under 200,000 lb-sec (889,600 Newton seconds).’
I’m sure you would get punished but what are they going to do about your rocket once it’s up there?
Wait for it to come back down, then fine you.
Ah, so either explode or go even further, got it.
This was launched under a FAA waiver. Black Rock Desert is one of the places to go in the US if you want to do this. They'll open up a cylinder to the sky. I wasn't there, but I venture that this was done with support from Tripoli Rocketry Association at BALLS.
Launching at BRD is where I first met Elon Musk where he was there with 5 sons (at the time) to watch them launch golfball nosecone rockets with 3d printed fin cans.
There is an annual competition that precedes the main event called ARLISS.org
A local rocketry club has standing clearance to 10,000ft and I know lots of college teams come from 6 hours away to take advantage of it. Check your local clubs, you can see impressive launches on at least 1 weekend a month.
Honest question by someone who is not familiar with this space: what prevents a well-resourced by determined civilian team from beating them? Like, yes, this is rocket science…but it's rocket science done by a team of college students. Surely there are other groups interested in this kind of thing? Does the government step in at some point and go "that's enough" when you try to do significantly better?
I think college student teams strike a combo of time, talent and resource that would be surprisingly hard to come by in the larger “civilian world.” In college, you have a bunch of freshly educated, similarly minded people in one place with a whole bunch of free time to put towards one project, highly motivated because it’s both an extracurricular escape and a career prep achievement. And these teams are often financially supported by their school departments or fundraisers. If you fail, there are little if any consequences on your life. All these motivators improve the likelihood of making something truly impressive.
Sure, we can make an arrangement like this out of college. Call up your ex-rocket club teammates, who have all now graduated and making banks at rocket startups. Spend the Thanksgiving week grinding out the CAD, code and circuit boards then test everything out in a desert. But projects like this are a huge time investment and with work and family in the way, they can often be very difficult to coordinate and pull off.
Even if your rocket does end up shooting off and breaking a record, does it truly “beat them”? I find it a bit hard to compare a team of similarly educated college students to a group of adults, usually with relevant professional backgrounds. Maybe the closest we can get are YouTuber collabs. Sometimes I miss my days spent on my college team; it’s pretty hard for me to get an exciting, rewarding, comradely and occasionally traumatizing experience like that ever again.
> I think college student teams strike a combo of time, talent and resource that would be surprisingly hard to come by in the larger “civilian world.”
The flip-side of this that you have a bunch of very smart young people absolutely dripping with theory knowledge and close to zero relevant real world experience in anything applicable in this space. The ability of college university teams to make exceptionally bone headed f ups is very well known. I've mentored a couple of university rocket teams for over 5 years now and I can tell you it's often an exercise in 'unknown unknowns'.
USC RPL has been at this for almost 20 years now. Their main competitive advantage (besides in-house cf cased motors) is documentation and knowledge transfer. As I'm sure you can imagine there are probably no founding team members actively involved today. I was at Balls in 2013 (IIRC it was 13) when they launched their first Traveler rocket, which was their first space shot attempt. They didn't actually reach that goal until April 2019.
I used to be part of a very successful competitive robotics team. You'll be surprised at how many student teams have this one guy who has been doing his PhD forever/startup founder who spun off from your team and mentors it that exist in the more successful teams.
I've seen PhDs whove mastered the art of being in the same uni team. One of them I knew has followed the path from undergrad (4 years), masters (2 years), RA (2 years), Phd (7 years), Post-doc (2 years).
Another is a startup founder who started the team in undergrad, worked as an RA for 4 years, then spun-off his own company over the next 6 years.
For the most part its beneficial for the uni to retain such talent. Especially, cause they are better grounded than some of the professors who claim to be "experts".
Unless they turn faculty I kinda doubt it. Not to sully your robot team, but I expect many of these students to want to progress to bigger and better things in the commercial space launch sector which they can't do at USC. Also, money.
But I'll ask them now, and get a real answer.
Actually, they have a team bio on their site. They look quite young to me.
https://www.uscrpl.com/the-team
Founded in 2005. They probably have a very strong Knowledge transfer system and alumni network in place (useful for funding). This is something I can attest to when I go back to my college days.
> you have a bunch of very smart young people absolutely dripping with theory knowledge and close to zero relevant real world experience
For sure! And that’s perhaps the #1 reason these teams are so valuable: it’s an environment to get hands dirty in. If something sticks, that’s great and goes on the resume. If something awful happens, just walk away with a cool story assuming you didn’t blow up a school building or anything like that. Either way the experience and hopefully learnings stick with these young people like me for a long time.
>Their main competitive advantage
Their advantage is institutional buy in and resource allocation.
A collegiate team that has to piss a huge fraction of their man hours on overhead tasks and fundraising has no chance of success.
Isn't their main advantage that every student at USC is rich AF? It's one of the wealthiest student bodies in the land.
At schools like that a pretty decent amount of students are on partial or full rides from scholarship or financial aid fwiw.
Somewhat but it's still such a wealthy student body that if everyone in the photo was from a family worth millions that would not even be a very unlikely statistical anomaly.
not to mention you are way more motivated when your grades are tied to an outcome
Making it graded tends to F it up bigtime. You waste soooo much time doing overkill process for the sake of proving that you can to get the grade. CAD models will be made. Simulations will be run. Powerpoints will be made to convey the results. When in reality all you needed was one dude to spend two hours prototyping both so that they could be evaluated and the more viable path of development chosen.
That's not how motivation works usually, no.
Grades are good to push a large group of people, including many otherwise unmotivated ones, up to a minimum threshold.
But you don't achieve exceptional results from grades alone (and in fact, grades can be harmful when dealing with otherwise highly passionate people).
Heh, grades served as a good barometer for me to know how much effort I needed to put into the boring classes to pass them. My transcript is a nightmare, high 50s and low 60s in the "easy classes", high 90s in the hard/interesting classes. And then a bunch of really fun/challenging extracurricular stuff that used to get a line or two on my resume when I was a fresh grad.
Thank goodness that the only employer to have ever cared was one where many of my extracurricular friends already worked and vouched for me. The only other time my transcript has actually mattered was when I went back to grad school; my overall average was about 2% too low for the good funding and I had to spend a semester working a lot of hours at the undergrad homework help desk until my first semester MSc. grades came in and qualified me for a significantly better stipend with less hours spent on other people's homework.
I don't think RPL is tied to any sort of academic grades
I don't think they are doing this for a class?
The biggest issue with college teams is that there is no institutional knowledge retention. Once they are done padding their resumes, they will move on. The next batch of club members will usually reinvent the wheel again. There is little incentive for good management and long term innovation beyond proving out one or two ideas that are immediately relevant to their academic research.
This is so frustrating to me. I was involved in a cyber security club that just started in my university. Both complete incentive misalignment and lack of focus. In the first committee meeting I was excited and pitched a plan to go from "zero to one", setting up training curriculums, building talent pipelines (esp from year 1s) from the student populace to us, institutional knowledge retention to keep and grow knowledge, getting mentors/research links with professors etc. After drawing everything on a white board, I turned around to find a glassy eyed committee. Every single one said "nah, let's just meet every week and uh, talk about a ctf or something". The president looked around and agreed with them. Over the semester I realized the president was far more interested in going to events and introducing himself as president than actually having any impact. As I predicted at the start, the initial hype and momentum gave way to lethargy and indifference. Participation from both non members and members fell off a cliff.
I think we can see that this isn’t true in this case. They are building on successful work from 2019’s record setting attempt, implying plenty of continuity. And these are undergrads so they are not generally doing heavy research. They are likely well advised.
Good advisor, yes. But knowledge retention is critical. They've been at it for nearly 20 years, not 5.
Great, that strengthens my point.
If a 21 century rocketry group takes 20 years to reach the Karman line, college students or not, they are the definition of incompetent. Maybe they should all get internships at the United Launch Alliance; good for lapping out of the gravy train and not much else.
They probably have all their documentation going back years on a usc google drive account.
Depends on the team. They also have the virtue of being able to get almost any alumni to talk to them.
Well, I would guess the knowledge is burned into the mind of the students?
A lot of these college teams are mentored by someone in the HPR (high powered rocketry) hobby. Many of the college level competitions require it.
HPR hobbyists have flown above 300k feet, and once you’ve reached 100k going higher it largely a propellant cost problem. 100k feet is a goal for many hobbyists because you’re above Mach2, doing staging, plus recovery and altimeters have to work differently at that altitude. However, going higher just means more propellant.
There’s an annual event called BALLS out in Nevada where HPR flyers can go as high as they want. There’s also a site called FAR (friends of amateur rocketry) where you can fly above 100k ft as well as liquid biprop engines if you want.
https://www.tripoli.org/content.aspx?page_id=4002&club_id=79...
https://friendsofamateurrocketry.org/
It's not just more propellant. Note the engineering that went into keeping the thing from burning up. Or look at the MESOS rocket--the guy who built that took the choice of delayed ignition of the second stage, accepting the extra gravity loss in exchange for less drag loss.
And if you don't have a guidance system you have to complete your burn low enough that aerodynamic forces keep your rocket pointed up during the burn. The bigger your burn the more of an issue that becomes.
Amateur rocketry is relatively common, although space shots are a considerable engineering effort. A good example is BPS.space (Joe Barnard) on youtube [1], who is making significant progress towards a space shot (over the karman line) and documenting it in detail, though he's definitely not the first to do a space shot. He's doing everything himself including his own solid propellent, nozzles, casings, flight computers, control surfaces, cameras, and flight computer. On the regulatory side, the FAA has a regulatory regime to support these kinds of activities. There are amateur launch facilities like the Friends of Amateur Rocketry [2] in the Mojave Desert that support these kinds of launches, although they do require you progress through successful launches of smaller rockets to get permission to fly larger rockets, so you can't just rock up with a huge rocket the first time.
[1] https://www.youtube.com/@BPSspace/videos
[2] https://friendsofamateurrocketry.org/
Tom Mueller (#1 hire at SpaceX) and friends had been working on big amateur liquid fueled rockets in his garage before Musk got him to leave TRW.
The old saying goes 'Rocket science is easy. Rocket engineering is hard.'. You need a lot of expertise and experience to build a rocket that is light and strong enough to get anywhere near this sort of altitute and also be recoverable afterwards. So many things can go wrong.
Nothing. The FAA in the US is pretty good about these things and as long as you stay below 490,000 ft AGL and are flying a sounding rocket (eg not trying to make orbit). With that said, well-resourced doesn't matter too much, it's more knowledge and experience. CSXT attempts were done by a team of aerospace engineers experienced in these types of things in their day jobs. They reached space (above 100km AGL) twice. USCRPL has been doing this for well over a decade, and have also reached space twice. And they've had heaps of failures along the way.
TLDR; Going Mach 5 in fairly thick atmosphere is exceptionally hard to do without encountering a rapid unscheduled disassembly. Flying a two stage to space is more efficient and less rough on the rocket, but no one has done that yet as it's quite a bit harder that a relatively dumb 4fnc rocket.
There is an interesting documentary about a team from Sheffield University and their attempt to reach the Karman line:
https://www.youtube.com/watch?v=6ZUuVvpgoCU
This is the amateur record, not the civilian one. And while the group may be "student-run", if you check their sponsors page it's funded partly by the university and partly by a who's who of the aerospace industry (Boeing and SpaceX are prominent), which I suspect is much easier for a college student group (who make a good feel-good cause, and those companies are implicitly courting to come and work for them) than a group of working adults.
The biggest hurdle (besides knowledge) in an endeavor like this is cost. Those sponsors aren't providing technical expertise. The main 'competitive advantage' USC RPL has developed that enabled this space shot is their in house filament wound carbon fibre cased ammonium perchlorate motors. By swapping comparatively heavy/over engineered aluminum motor casings that are reusable they make single use cf cased motors. I'm pretty sure Boeing and SpaceX aren't the places you go for solid motors.
> Those sponsors aren't providing technical expertise.
Do you know that about this specific case? Because I personally know a similar student team where the sponsor absolutely is giving guidance on technical matters.
Look, did they use industry to help them with things like xraying their motor grains to check to confirm they had no voids? possibly. But this team has been at this for nearly 20 years and made their first spaceshot attempt over a decade ago (Traveler I). All of their in house designed and built GPS and radio triangulation electronics failed. It was the COTS stuff that gave them good data. I would think if private industry was doing any heavy lifting for them that wouldn't have occurred. They've blown up a lot of their motors in testing to get to their R class motor they used here. I also doubt that would have been the case if they were getting private sector assistance.
Not only that but they're a self organizing team. Unlike the professional world they want to be there, they're not getting selected out due to vibe checks/leetcode proficiency or filtered out due to comp ask. Also they don't have business dictating design or trying to ban engineering practices.
This is not traditional rocket science of turbines and cryogenic fluids, this is igniting solid propellant and ensuring your rocket is strong enough to not explode
At some point the label of amateur starts costing more than the value the achievements bring.
The value is in educating the next generation of rocketmen.
idk what "value" people expect out of a model rocket, anyway. Of course SpaceX or NASA is sending things to orbit. The value is you get to have fun launching things into space yourself!
Working through the equations, and then building a working machine from it, is very educational.
You mean like SpaceX, which is a well-resourced and determined civilian team?
Notably not an amateur team.
Mostly tooling, machining. Autoclaves to cure the carbon, lathes, CNC fab. Total cost not including the space is easily over $100k. Few hobbyists can do this, but a university can sponsor it when it'll be used by multiple groups and for research.
Feds are gonna come and talk to you very sternly, at first.
In metric: previous record was 116 km, this launch was 143 km.
Thanks. I can't believe they're giving the speed in ft/second, i've never seen that... horrible!
Historical background:
https://www.youtube.com/watch?v=JYqfVE-fykk
What's weird about student/amateur rocketry is how, at a certain point, knowledgeable people have to say "I'm not allowed to help you." If you get too good at this hobby you run straight into arms treaties.
I can't wait until arms export controls are challenged under first amendment grounds, we already came close that one time with encryption algorithms being published as a book
If college kids can do it, there's no knowledge that terrorists in even backwater shitholes (a lot of al-qaeda were engineers by training) can't quickly obtain. We might as well drop the pretense that the knowledge itself is something so valuable to building weapons that speaking it to foreigners should be illegal
I don't think this is an accurate statement. Consider for instance that the Sinaloa Cartel is currently hiring college students to try and reproduce chemical precursors for the production of Fentanyl. This is something that's probably trivial for a real company with resources to do, but because it's not public knowledge it's difficult for them.
I think the same could likely be said for this kind of production of rocketry.
For another example, consider how Russia had to rely on Iran for the production of their Shahed drones (until Iran showed them how to produce them), despite Russia being a longtime producer of weaponry.
The Shahed drones were entirely within Russian capacity to design and produce. They just needed them now.
If that was true, why are they now producing shahed drones domestically instead of a homegrown drone?
> If college kids can do it
I think this particular engineering department has a very exceptional group of college kids. I don't hear much about students in other schools in other states much less other countries accomplishing near this much. I know "American Exceptionalism" probably is not a view that HN audience would give much merit to, but we are still one of the only places in the world where smart students are given opportunities like this. Our culture seemed to give "opportunity" a good balance (even when we see the many downfalls, ie the entire crypto space)
I find your choice of words interesting. "Students are given opportunities" sounds pretty much the way things were done in the USSR. The Western way is (or at least used to be) treating students as adults who have the independence and the agency to create opportunities for themselves.
Makes complete sense.
Iran/China/Russia all have more advanced missiles than the US has deployed like, ever. Iran and Russia have demonstrated recently hypersonics that are effectively unblockable.
What kind of knowledge do these arms export controls really do other than make it more difficult to compete with defense contractors?
> Iran/China/Russia all have more advanced missiles than the US has deployed like, ever.
This is somewhat true for China's, on paper at least. Maybe.
Russia's Kinzhals got intercepted by 1980s Patriots.
Iran's are just boring old ballistic missiles.
> Iran and Russia have demonstrated recently hypersonics that are effectively unblockable.
The US has plenty of similar ballistic missiles; ATACMS is similarly tough to intercept. Doubly so in large numbers, which was how Iran got some through.
We bought Russian anti-ship missiles in the 1990s and they were unable to meet our requirements for our testing missiles, so we had to improve them.
As with anything, progress is great until a point. E.g. when amateurs can print biological viruses at home then things get scary.
Fortunately, the economics of the marketplace have driven it towards big gene-printing firms. It's cheaper to outsource to a high-capital, low-cost-operating company than it is to do in house with a low-capital, high-cost-operating approach. Thus the low end of the market pretty much died and the big guys check all orders against a slew of thou-shalt-not-print genes.
You don't need to print really, more a question of culturing them like a kombucha. Luckily that ends up being a self limiting problem since the amateur doesn't know containment well enough to protect themselves.
ITAR and amateur rocketry YouTube have a strained relationship.
I don't think it's that strained. BPS Space for example spends a lot of time talking about how "This is not a tutorial" but there's a massive gulf between what is currently published information that is available to people like him and what is actually meaningful to regulation.
If you are buying your propellant components in small bags off the internet and mixing it yourself in stand mixers and casting it yourself in your garage and using niche open market servos to build your stuff with homemade guidance, the gov is not looking at you. ITAR isn't about keeping every precocious kid from building small volume guided munitions; It's about keeping shithole states from building ICBMs. It's about keeping former SpaceX personnel from spending time in Best Korea.
This is especially true in a post FPV drone world, where putting 1kg of explosive anywhere you want in a 10km radius is a $500 purchase off alibaba. Precision munitions have accidentally been democratized.
I'm not sure that's an accurate characterization. He's specifically voiced concerns about the ambiguity of whether what he's doing violates ITAR, even with the "this isn't a tutorial, I've left out information" and that if the feds launched an investigation, he'd be crushed by the process even if they found no wrongdoing in the end.
Yet anyone can buy a consumer drone and strap homemade explosives on it and do a lot more damage VS a college kid with an engineering background who is into rocketry.
I was trying to understand how an altitude of 470,000 ft compares to other things, so I looked up a few numbers.
470k feet is 143 km. The altitude record for an air-breathing aircraft is 38 km. There are some very low earth orbit satellites that orbit in the sub-200 km range (https://en.wikipedia.org/wiki/Very_low_Earth_orbit). The ISS orbits at about 400 km and typical LEO is 800 km. ICBMs have an apogee altitude of 1000 km or more.
(Of course, the energy required to get up to some altitude is only a small fraction of the energy required to get into orbit at that altitude. https://what-if.xkcd.com/58/ is a relevant read.)
> Aftershock II is believed to be the world’s first civilian-built rocket to reach an altitude of 470,000 feet.
Surely this first line, bolded and right below the byline, isn't correct for our normal understanding of "civilian", is it? Like most rockets aren't military-built.
Civilian vs government - notably including NASA; not just military.
1. I've checked multiple places and consistently "civilian" is defined in contrast to military / armed forces/ police, but not in contrast to government in general.
2. But even among non-governmental groups, this claim doesn't make sense. Northrop Grumman, Arianespace and a bunch of other companies that are not governmental organizations (but may have government customers).
https://en.wikipedia.org/wiki/List_of_spacecraft_manufacture...
Dang. I would have loved to be on that team as a student.
Somewhat related: A video about buildng a carbon fiber, solid fuel rocket by Xyla Foxlin: https://www.youtube.com/watch?v=ZQvK8EFJQzw ("only" 7Km, 23Kft)
Is the core challenge on amateur rocketry the amount of fuel that you can put on board the rocket. Essentially a cost equation on the design components?
It would be super fun to do but isn't that the big different -- design and shape certainly make a difference but are they not mostly determined at this point with subtle iterations?
This article has a good summary:
https://www.apogeerockets.com/Peak-of-Flight/Newsletter533
The key challenges called out are a) fuel, b) robust airframe, c) active guidance to handle varying conditions, d) funding for testing and robust components. The article goes into a good amount of detail on each.
Did this rocket have active guidance?
Thanks!
Are they as high up that it could start orbiting?
> Are they as high up that it could start orbiting?
1. No
2. Orbit is more about speed than height. You have to get high enough that the atmosphere doesn't aggressively degrade your velocity, but the key is to hit ~8km/s, although that number changes depending on your altitude.
edit: 30km/s -> 8km/s
30 km/s is ~the speed at which Earth orbits the Sun. For orbiting Earth you just need a mere <8 km/s.
Thanks for the correction.
Orbiting has more to do with velocity than altitude.
Specifically, you need to be moving approx 10 km/s which 22,000 mph or mach 30.
You only need to be moving ~7.5-8km/s, but getting to orbit tends to take 9.5-10km/s of total delta-v due to needing to ascend, aerodynamic drag, and other losses.
Ahh yes, of course! I guess they are not high enough for geo stationary orbit?
Geo stationary orbit is 36000 km give or take.
Orbiting however is more about radial velocity. You are sort of constantly falling towards Earth, but you are moving so fast that you always miss it and so you end up orbiting it. A great animation on the subject: https://www.reddit.com/r/Damnthatsinteresting/comments/1btbn...
Even for geostationary you still need to gain a ton of horizontal velocity, more than LEO. You are staying over the same spot on the earth, but the earth is rotating and you need to match that same angular velocity. Being at a higher altitude you need a faster linear velocity to match that angular velocity, since you have a larger circle to travel in the same amount of time.
Even if they were high enough they would just fall back to earth. There are lots of videos explaining orbit, this one looks good: https://www.youtube.com/watch?v=bcvnfQlz1x4
That's a very clarifying video! Suddenly i remembered my pre-college physics:)
470'000 ft = 140 km altitude
thank you - this was the comment I was looking for
How much did it cost them?
Using ensemble model estimation resulted in a guess of $400,000.
Bright kids, great support, can't wait to see what they can do with their careers! Bravo!
>through anodization
That was just oxidation.
> Aftershock II reached a velocity of 5283 ft/s and Mach 5.5. The comparatively lightweight rocket amounted to 330 pounds, at a height of 13 ft and 8” diameter.
For the imperially challenged, that's a velocity of 1.6 km/s, weight of 150kg, height of 4m and 20cm diameter.
Or 7.662481e-14 parsec/sec, 1467.9126 Newtons, and 4.4041166e-16 light years.
Because space.
You can't turn mass into force, especially not in space.
For the metrically challenged, pounds are a unit of force not mass.
Wikipedia disagrees with you[1], and if pounds were a unit of weight that'd be very unpractical from a legal PoV to have things being labeled in pounds since the same object have a different weight in Puerto Rico (close to the Equator) and Fairbanks (close to the North Pole).
[1]: https://en.wikipedia.org/wiki/Pound_(mass)
To be very pedantic, the pound is a unit of both force and mass, and it's because the unit evolved before the Newtonian understanding of weight versus mass. That's why there exists the pound-mass, and the pound-force.
Of course, in SI this is very straightforward: the unit of mass is the kilogram and the unit of force is the newton, which is the force acting on a mass of one kilogram experiencing an acceleration of one metre per second per second in an inertial frame of reference.
Your comment is ambiguated.
https://en.wikipedia.org/wiki/Pound
I distinctly remember reading how I would weigh a different amount on the moon. This only makes sense if the pound is a unit of force.
You would weigh a different amount on the moon, but that is completely independent of how we label our units of measurement.
The pound a unit of force. It is also a unit of mass. Both units share the same name.
It's not independent because if I'm 80kg here, I'm still 80kg on the moon. Because gravity does not affect mass.
If I weigh 160lb on earth I'm told that I would weigh 26lb on the moon.
That makes sense if lb measures force because gravity affects force.
In short, this commonly shared "fact" is consistent with pounds being a unit of force, not of mass.
Or, I suppose, of lb at least sometimes being a unit of force.
I think it's used as both. Foot-pounds is used as a unit of work, so it's a force in that context.
In case you didn't understand the other reply, you can't use newtons in this context. Kilograms is perfectly fine here. The thrust of the engine can (and should) be measured in newtons though.
Also, 4 decimal points of precision is completely overkill. Maybe one decimal point at most would be more than enough, but most wouldn't even bother with that.
The problem is the 8 significant figures, not 4 decimal places - 0.3300 kip and 1467.9126 N both have 4 decimal places but one is much worse than the other.
Even if 330 lb was exact, all those digits in 1467.9126 N aren't even correct. It should be 1467.9131 N using standard gravity. It looks like brudgers used 1 lbf = 4.44822 N which is what Google says but is only rounded to 6 s.f. so can't be used to generate an 8 s.f result.
> The thrust of the engine can (and should) be measured in newtons though.
It's very common to measure engine thrust in ton-force because it makes it easy to compare the thrust to the weight of the rocket, which is a critical metric.
The force of a rocket engine can be measured in pounds.
And pressure in PSI and torque in foot-lbs because pounds are a unit of weight (i.e. force) not mass.
Altitudes for aircraft use feet worldwide, to be fair.
> use feet worldwide, to be fair
Many CIS countries and China use metre flight levels[1] and kilometres per hour for indicated speed reporting. Additionally, the ICAO has recommended transiting to metre flight levels since 1979[2]. More additionally, the Airbus A300 had flight levels initially set up to be metric (obviously, since it was an effort spearheaded by the French), but to appeal to American airlines the Airbus consortium switched to feet. Although I am positive that Airbus engineers work exclusively in SI.
METARs worldwide except in North America use SI units for reporting weather.
[1]: https://en.wikipedia.org/wiki/Flight_level#Metre_flight_leve...
[2]: https://en.wikipedia.org/wiki/International_Civil_Aviation_O...
No, and this is not an aircraft, is it?
TV screens and monitors are also measured in inches. ¯\_(ツ)_/¯
In Germany you have to always mention the metric size. Luckily.
They are decidedly not. They are marketed in inches of the diagonal (a supremely brain-dead decision, if you ask me), but they are engineered, manufactured, and even programmed only in SI units.
If you look at your display's EDID output, the diagonal doesn't even factor in; what you do have are vertical, horizontal, and per-pixel dimensions; all in millimetres. This is what all panel manufacturers (LG, AUO, Samsung, Innolux, BOE, TCL, and so on) do.
> For the imperially challenged,
US customary units are a distinct system from imperial units (some of the individual units overlap, and several others have the same names but different definitions.)
I dont know if you were downvoted for being pedantic or for being wrong. But I’d love to know if this is true.
And if so, I will upvote your pedantry
It is true:
https://en.wikipedia.org/wiki/Comparison_of_the_imperial_and...
Can I get that in stone and hands please?
It's interesting that I'm perfectly fluent in both US and metric units, yet I don't have a personal frame of reference for the magnitude of many of the numbers given in the article, in either unit system. For instance, how they compare to rockets that are actually in practical use.
Compare to New Shepard (Blue Origin suborbital passenger vehicle): 1 km/s top speed, 100-120 km max altitude. Of course it also carries a payload of six passengers and (the rocket part) lands propulsively.
Compare to orbital rockets: (low earth) orbital velocity is 7.8 km/s, the ISS orbits at about 400 km, the lowest satellites are at about 200 km.
Imperial units fit nicely here: 1.00 mile/sec.
> For the imperially challenged
You mean everyone in the world expect for the Americans, Liberians and Burmese? :)
"Eschew flamebait. Avoid generic tangents." - https://news.ycombinator.com/newsguidelines.html
Note that the Americans never adopted the imperial system, which was established after US independence; US customary units are their own thing, based on the older English customary units which preceded the Imperial standardization.
I use a German MRI scanner and they have clearly thought about this too. I can enter patient height and weight in ‘metric’ centimetres and kilograms or in ‘US’ feet, inches and pounds.
Canadians mostly use imperial when describing one's height and weight. Folks also tend to bake using imperial measures in my experience, and idk if it's different for large projects, but home demos are very much the domain of imperial standard objects (like a 4' x 8' panel of drywall or a 2" x 4" x 8' beam)
Yet a 2 x 4 isn't 2" x 4". :P
Ahh, rough sawn versus dressed.
Deeply frustrating when you assume sizing matches description.
Even rough sawn is not 2" by 4".
Americans love inventing field specific nomenclature. Like piping sizes, wire sizes, metal sheet thickness, plywood router bit size, construction wood size, furniture/raw wood size, etc
I have always thought it was just a side effect of capitalism. The more messy the units, the harder it is to enter a field without requiring the help of an expert sales.
After 10 months of house renovation it’s my experience that plumbers are the worst offenders when it comes to sizing weirdness.
You think you got the right size fitting, lol nope, it’s actually conical not straight…
Probably because you're stuck with sub-par 110v appliances made for the US market...
Houses are fed split phase 240v. All big appliances have a dedicated electrical run with 240V and 20A to 50A.
Common 120V outlets are 15A max, with devices usually limited to 13A for some breathing room. That's 1.8kW and 1.5kW.
In France, the common 240V outlet is 16A. With devices at 13A max that's 3.8kW and 3.1kW.
So yes it sucks for tools. But cooking is just fine.
It sucks for anything with heating elements. 240v kettles and hair dryers are really awesome.
Most electric ovens and dryers are 240V in the US https://us-electric.com/how-to-install-an-electric-stove-out...
110v is a lot less likely to kill you if you do accidentally touch it.
That's the only advantage.
What's the highest posted speed limit on the M1/M6 from London to Birmingham?
There are only three things the UK uses Imperial units for: road signage (speed limits, distances, and vehicle dimension restrictions; and since 2016 all new dimension restriction signage has to be in dual-SI and Imperial units[1]), beer, and milk, the latter two of which are also sold in half-litre and litre measurements.
[1]: https://www.legislation.gov.uk/uksi/2016/362/pdfs/uksi_20160...
> There are only three things the UK uses Imperial units for: road signage (speed limits, distances, and vehicle dimension restrictions; and since 2016 all new dimension restriction signage has to be in dual-SI and Imperial units[1]), beer, and milk
Do people not weigh themselves in stones and pounds?
> Do [UK] people not weigh themselves in stones and pounds?
Older people, usually yes.
Younger people, more often that not, not. Even at 48 I use Kg for my own weight, but those only a half a decade older more routinely use stone/measurements.
Though there is a sizable range of people who use one unit system by default but have a reasonable intuition of the other.
Unlike some things, there are no legal mandates dictating which set of measures to use for this.
Another difference in weight scales: we don't tend to work with just pounds when we use imperial measurements. When a US TV show gives a weight as, for example, “172 pounds”, many will need to do a little mental arithmetic (this may be subconsciously, not actively calculating but the process delaying understanding) to convert to X stone & Y pounds rather than naturally having an intuition of the weight from the single number.
I'm a paediatrician. No parent has ever asked me for their baby's weight in kg - they are all pounds and ounces. So much so that I can do this niche conversion almost in my head, at least at the start of the day, as we weigh them in kg.
What's weird is my pediatrician here in Seattle uses kg for my ~10 year old kids' weights but inches for their heights. Why the kg? They always translate to pounds for discussion, but the record is in kg.
It was always pounds and ounces when they were babies though. Not sure when it switched to kg; probably when we switched from "baby specialist" to "standard pediatrician" so around toddler age.
SI has been the standard for decades in Australia, but people almost always ask for baby weights in pounds and ounces.
Adult heights are the other exception, those are often in feet and inches. My 14 year old knows she's 5'2" but her knowledge of imperial measurements doesn't go much further than that.
Yes, I've never heard a baby weight given in Kg.
But it seems to change when people are old enough to be talking about their own weight.
I’ll add tyre pressures - cyclists seem wedded to PSI.
I’m in New Zealand and we use imperial for baby weights, tyre pressure and height. Baking uses some measure like cups (US or imperial?) and teaspoons/tablespoons which I dislike, grams is preferable.
Surely the dumbest though is UK shoe sizing. The increments are barley corns length, a unit of measure which is hilarious. This is for males and children, women’s shoe sizing is apparently US. What a shambles.
I’m sure there are more niche hangovers. https://en.m.wikipedia.org/wiki/Barleycorn_(unit) https://en.m.wikipedia.org/wiki/Shoe_size
Americans also measure gun powder and hard water content in barley corn :) That's what the unit "Grain" is.
The UK government doesn't mandate units for reporting your own weight. The examples listed are required by law.
> The UK government doesn't mandate units for reporting your own weight.
Wait, you can just use a unit-less value?
You forgot that whenever the temperature exceeds 37C everyone says "it's 100 degrees out!"
edit: also, every proper cookbook.
Also an American saying "sub-zero" means it's really very cold. Basically the difference between a fridge (approx 0 degC) and a freezer (-18 degC).
Very specifically, cold enough for salt water to freeze.
Useless trivia. If you dump salt into ice water, it reliably goes from 32 F to 0 F. Which makes it cold enough to make ice cream with.
It's definitely less than Mach 5.5 given all the roadworks.
Nobody knows. There has never been a gap in traffic sufficient for a normal vehicle to exceed the limit.
"National Speed Limit"
Also the British, we're metric on paper for most things but in practice we use both systems interchangeably for a lot of things. In a few cases like the roads and draught beer imperial units are mandated.
Since this comes as a surprise to many of my first-time British colleagues: US customary and Imperial use the same names, but are different units. The US customary volume units (cups, gallons, etc.) are on two scales: the "tablespoon scale" which is all powers-of-two, and the "teaspoon scale" which is a third of some nearby tablespoon scale.
I used to have a handy chart of the mapping of "prefix" to power-of-two, for 2^-7 to 2^7.
Also, the US foot was supposed to be exactly 30cm, but the French couldn't get their shit together, in time.
Another fun fact is that UK gallons are based on the volume occupied by ten pounds of water. Combined with the fact there's 20 ounces in UK pint this means a fluid ounce of water weighs an ounce, and a pint of water weighs a pound and a quarter.
Not that you're very likely to encounter British fluid ounces any more, the smallest imperial unit of volume I generally run into is the half-pint.
Making this joke falls flat in the comments section of a rocket science article about Americans continuing to dominate space.
"Americans dominate space" is the most American sentence I've read in a while. Imagine that, a few humans from a little corner of the universe dominating space!
"Americans dominate the space industry" is presumably what they meant, and not inaccurate. On the other hand, even the American space industry uses metric.
Hubble wasn't so sure.
Nor was Mars Polar Lander – the most likely cause of its loss was a mistake in units that resulted in it using too short a deceleration burn as it prepared to land, meaning it hit the surface far faster than intended (IIRC we don't know for sure if it impacted in one piece, broke apart during descent). Tabloid headlines of the time dubbed the mission as a “close encounter of the thud kind”.
Not a consequence of units used: https://en.wikipedia.org/wiki/Hubble_Space_Telescope#Flawed_...
It's space in the SV context, i.e. the competitive arena or market. Americans dominate the space space.
The EU was dominating space for around twenty years or so, but that has long passed and at this rate will never come again. The ESA and Arianespace dropped the ball so badly, books will be written about it.
Thanks to Starlink, something like 70% of the 7500 satellites orbit Earth are American. Or course by mass, nature still wins by a landslide, but as always, it's all in how in count things.
Space is pretty big. Is it fair to say that the USA dominates up to, say, Earth's Ionosphere?
There are 31 extra-planetary human objects/, 19 of which are American, and 12 are Japanese/Soviet/European/Chinese/Indian, so maybe a bit further than the ionosphere?
Earth orbit is the only useful part of space.
Americans: we dominate space and are the WORLD champions of football.
The thing I love best about jokes like this is that it changes based on your perspective.
Americans reading this: “f—- yeah, we do!” Upvote!
Non-Americans reading this: “lmao perfect parody of an American!” Upvote!
For clarity, Americans claim the WORLD champions of baseball. The championship series is called the World Series. In American football, it's just called the Super Bowl.
You might as well complain about the name of the World Cup, since it’s also only teams from Earth.
Not to beat the dead horse but NASA predominantly uses metric units.
Also, they got their lead in space tech mainly because of a German scientist (Werner von Braun).
On the Apollo program, all the calculations were done in metric (obviously). The computers all worked in metric internally and then converted to imperial for display. They actually had to waste some of their very limited cpu cycles on converting to imperial because the US astronauts couldn’t handle the metric system.
Your comment contains a series of partial truths, falsehoods and misconceptions.
So Werner built the rockets and all the subsystems too or was just the technical fellow/consultant?
Sure, the US was in a better position post WW2. But Werner has been dead for years and the US still dominates space 10x or even 100x times. Engineering in the US is top notch.
As far as your other assertion- what’s your source?
NASA primarily used the imperial system (feet, pounds, and seconds) for the Apollo program. The Apollo Guidance Computer (AGC) and other systems were designed using imperial units because the entire spacecraft and mission control infrastructure were built around the U.S. customary system.
There was no wasting of CPU cycles. We even have the source code on GitHub to go look at:
https://github.com/chrislgarry/Apollo-11
Look in this assembly code. It is imperial.
https://github.com/chrislgarry/Apollo-11/blob/master/Luminar...
Then, there are design documents and other engineering standards that tell us everything was in imperial units.
I am not buying what you are saying.
(AGC) calculations were carried out using the metric system, but display readouts were in units of feet, feet per second, and nautical miles – units that the Apollo astronauts were accustomed to.
https://ukma.org.uk/why-metric/myths/metric-internationally/...
> was just the technical fellow/consultant?
There is a direct lineage from the Nazi German V2 rockets to Saturn V. Wernher von Braun and his rocketry friends were involved at all levels of American rocketry and ballistic missile programs, and I am happy to say the latter wouldn't have gotten off the ground as early as they did without von Braun's guidance at all levels. At least until the end of WW2, British (and even German) aerospace was considerably further along than American equivalents. And even afterwards, the Europeans, Canadians, Brazilians and the Soviets have remained very productive in terms of civilian and military aerospace. This legacy continues today.
> the US still dominates space 10x or even 100x times. Engineering in the US is top notch
Good for the USA, but this has very little at all to do with unit systems and much more to do with just how much capital there is in the USA. And as everyone else has said, NASA uses SI. I bet these college students did, too.
Keep in mind that the metre is barely younger than the US itself, having been formalised in the 1790s.
I took a look at the code, and I found references to both metric (meters, kgs) and imperial units (lbs) in there.
Not sure if I would necessarily say that the reason the US is pretty good at space stuff is imperial measurements. Its probably imperialism, instead.
What does that have to do with rockets? The main resources you need for spaceflight are intellectual capacity and engineering skills. Plus a government that allows it to happen. Besides the US, China and Russia, the 4th place for number of launches in 2023 is shared by India and New Zealand. The latter can hardly be described as imperialist by any measure. All you need is a single company like Rocket Lab. It could easily happen in other places too, under the right circumstances.
Prior to losing WW2 for example Germany dominated the space and they were latecomers in imperialism with very little control over anything outside their own territory. In fact getting pushed around by more powerful colonial nations, and the economic sanctions that were put on them, were the main reason leading to the fascist takeover and ultimately the war.
One could argue the US entering into WW2 is imperialism. Von Braun and a large number of other highly skilled and important people came from that, which directly migrated German rocket and Spacecraft innovation to the US.
How is that not arguably imperialism related?
Not to start a big discussion about WW2 but the US was passive until they were attacked. Over 2000 Americans were killed in Pearl Harbor. For a nation of its size and power, the US was decidedly un-imperialist up until then. Even after they'd beat the Nazis and Imperial Japan, they actually helped rebuild their economies instead of exploiting them. Granted, that might have been the smarter thing to do anyway and turned out a win-win. But it wasn't how most leaders thought at the time. Look at the Soviet Union and how they ended up oppressing the territories they "liberated". The Western allies also wanted to keep Germany down, as did some in the US government (see the Morgenthau Plan for example). Had they prevailed there might soon have been another war.
For a nation of its size and power, the US was decidedly un-imperialist up until then.
Its empire was never on the scale of the major European Powers. But by that point in time, it still maintained explicit colonial control over the Philippines, Puerto Rico, Hawaii (still fairly recently subjugated) and numerous Pacific islands. Along with the Panama Canal Zone (which had its own postcal code, CZ).
It also exerted considerable influence over the affairs of many nominally independent countries in the hemisphere (Cuba quite notably), and engaged in several major military interventions up until 1933 (Mexico, Haiti, Dominican Republic, Nicaragua). It also intervened substantially in the Russian Civil War, up until 1925, and was still engaged in wars of suppression against its indigenous population through the middle of that decade as well.
One could say its imperial project took a breather of sorts in the mid-1930s, and decided to rest on its laurels for a bit.
But "decidedly un-imperalist" it was not.
Rocket Lab is mostly an American company these days. Headquartered in America, most of their employees in America, traded on an American stock exchange, doing contracts for the American military.
It's mostly because the US was the only nation to survive WW2 with its infrastructure intact.
Same story as computing, really.
Nope, that’s a lazy excuse. The US space industry was dead in the early 2000s. Astronauts went to the ISS on Soyuz.
It was more of an exploration lull and not much industry had came out of it quite yet as privatization was being implemented and so it’s the case the industry was actually just being born.
You are simply wrong for anything other than human rated flight. They didn't have the kind of PR that NASA and Space X have, and they were never human rated, but private satellites never stopped flying on Atlas, Delta, and Titan programs that variously went from the 1960s all the way up until the 2020s. All three of those rocket programs are direct descendants of ICBM programs.
https://en.wikipedia.org/wiki/Comparison_of_orbital_launcher...
I disagree with the premise that it was lack of bombing of US infrastructure related though. Space programs are very simply the public output of ICBM programs. Most of the modern day is simply a direct descendant of ICBM programs. You like distributed and reliable communication networks like the internet? Built so ICBM silos could command each other even if certain hubs were nuked. You like the miniaturization of solid state electronics? That capability was paid for entirely by the US Air Force who wanted powerful computers under 100 pounds for advanced planes and precision ICBMs. Satellite navigation was also explicitly invented for nuclear missiles fired out of submarines to have an accurate fix for guidance purposes.
Basically the entirety of the modern world exists because the US of the cold war pumped trillions of dollars into producing ICBMs and planes that were genuinely "next gen" while every single private business takes the credit for stuff they never paid for. Computer and telecommunications companies would never have built this stuff on their own: They were fine with computers taking up an entire facility that they could rent out (cf modern clouds) and fully switched networks that were reliant on a big company to manage. None of them needed to sell you a "personal computer". None of them wanted a distributed, uncontrolled network like the Internet.
Which is easy to do when you enter at the end and capture the highest skill scientists.
Dominated by a company that is led by an African-American man no less!!
How many HP is your Eurorack case?