Student rocket group shatters amateur space record
viterbischool.usc.edu
viterbischool.usc.edu
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.
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'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".
But I'll ask them now, and get a real answer.
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 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.
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).
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.
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...
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.
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.
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.
How about Armadillo Aerospace: better example?
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.)
A little higher (150km) and this would've been out of the realm of amateur rocketry entirely.
I’m sure you would get punished but what are they going to do about your rocket once it’s up there?
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
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 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 Shaheds are probably most useful not for advanced tech (they aren’t!) but for the ability to produce them while under global sanctions.
Such sanctions are new to Russia, but Iran had a decade or two to figure out how to evade them.
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)
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?
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.
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.
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.)
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.
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...
What sources have you checked for (1)? A counter example I would put forward is a police officer. They are not a civilian, nor are they military. What are they?
Civilians in government can be a thing to distinguish military, but the actions of civilians on behalf of government are not civilian actions. Eg: "I am a civilian, I work for the government. When I do things on behalf of the government, it is not as a civilian."
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
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...
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?
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.
Using ensemble model estimation resulted in a guess of $400,000.
That was just oxidation.
For the imperially challenged, that's a velocity of 1.6 km/s, weight of 150kg, height of 4m and 20cm diameter.
Because space.
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.
The pound a unit of force. It is also a unit of mass. Both units share the same name.
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 don’t know how to make the point any clearer that there are two units of measurement, both with the same name.
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.
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.
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.
And pressure in PSI and torque in foot-lbs because pounds are a unit of weight (i.e. force) not mass.
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.)
And if so, I will upvote your pedantry
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...
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.
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.
You mean everyone in the world expect for the Americans, Liberians and Burmese? :)
Deeply frustrating when you assume sizing matches description.
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.
You think you got the right size fitting, lol nope, it’s actually conical not straight…
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.
[1]: https://www.legislation.gov.uk/uksi/2016/362/pdfs/uksi_20160...
Do 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.
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.
But it seems to change when people are old enough to be talking about their own weight.
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’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
Wait, you can just use a unit-less value?
UK Govt Official Weight Form
Weight: well-nourishededit: also, every proper cookbook.
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.
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!
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.
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.
https://ukma.org.uk/why-metric/myths/metric-internationally/...
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.
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.
How is that not arguably imperialism related?
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.
Same story as computing, really.
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.
Those are moribund programs that were being kept alive solely by the government because it wanted to ensure the US had launch capabilities for NRO and other classified missions. There was absolutely no innovation coming out of them to drive down costs or increase payloads.
The sector was dead from an innovation perspective and a failure from a competitive perspective.
Your screed about businesses taking credit for stuff is mostly unfounded. The internet’s foundation in DARPA is very well understood and acknowledged. However, all of the advancements to scale up to the scale of the internet today were pushed by Silicon Valley and academia.
DARPA and the military never cared about scale and still doesn’t because it’s not a goal.
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.
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.
gallon 2^0
half-gallon 2^-1
quart 2^-2
pint 2^-3
cup 2^-4
gill 2^-5
jill 2^-6 -- invented half-gill
ounce 2^-7
tbsp 2^-8
half-tbsp 2^-9
dram 2^-10
peck 2^1
half-bushel 2^2
bushel 2^3
half-barrel 2^4
barrel 2^5
hogshead 2^6
??? 2^7
??? 2^8