[HN Gopher] Student rocket group shatters amateur space record
___________________________________________________________________
Student rocket group shatters amateur space record
Author : wallflower
Score : 237 points
Date : 2024-11-27 18:15 UTC (6 days ago)
(HTM) web link (viterbischool.usc.edu)
(TXT) w3m dump (viterbischool.usc.edu)
| tromp wrote:
| > 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.
| brudgers wrote:
| Or 7.662481e-14 parsec/sec, 1467.9126 Newtons, and
| 4.4041166e-16 light years.
|
| Because space.
| 7734128 wrote:
| You can't turn mass into force, especially not in space.
| brudgers wrote:
| For the metrically challenged, pounds are a unit of force
| not mass.
| littlestymaar wrote:
| 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)
| two_handfuls wrote:
| 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.
| stouset wrote:
| 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.
| M3L0NM4N wrote:
| I think it's used as both. Foot-pounds is used as a unit
| of work, so it's a force in that context.
| delta_p_delta_x wrote:
| 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.
| brudgers wrote:
| Your comment is ambiguated.
|
| https://en.wikipedia.org/wiki/Pound
| beAbU wrote:
| 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.
| brudgers wrote:
| 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.
| nordsieck wrote:
| > 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.
| foxglacier wrote:
| 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.
| merek wrote:
| > For the imperially challenged
|
| You mean everyone in the world expect for the Americans,
| Liberians and Burmese? :)
| foooorsyth wrote:
| Making this joke falls flat in the comments section of a
| rocket science article about Americans continuing to dominate
| space.
| lionkor wrote:
| 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.
| etiennebausson wrote:
| It's mostly because the US was the only nation to survive
| WW2 with its infrastructure intact.
|
| Same story as computing, really.
| kortilla wrote:
| Nope, that's a lazy excuse. The US space industry was
| dead in the early 2000s. Astronauts went to the ISS on
| Soyuz.
| conductr wrote:
| 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.
| mrguyorama wrote:
| 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_launc
| her...
|
| 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.
| lionkor wrote:
| Which is easy to do when you enter at the end and capture
| the highest skill scientists.
| trompetenaccoun wrote:
| 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.
| lupusreal wrote:
| 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.
| lionkor wrote:
| 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?
| trompetenaccoun wrote:
| 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.
| aguaviva wrote:
| _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.
| eps wrote:
| Not to beat the dead horse but NASA predominantly uses
| metric units.
| Aaargh20318 wrote:
| 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.
| firesteelrain wrote:
| 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/Lumi
| nar...
|
| 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.
| _0ffh wrote:
| I took a look at the code, and I found references to both
| metric (meters, kgs) and imperial units (lbs) in there.
| huhtenberg wrote:
| _(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/...
| delta_p_delta_x wrote:
| > 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_.
| vasco wrote:
| "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!
| fragmede wrote:
| 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.
| willvarfar wrote:
| Space is pretty big. Is it fair to say that the USA
| dominates up to, say, Earth's Ionosphere?
| lupusreal wrote:
| Earth orbit is the only useful part of space.
| arijun wrote:
| "Americans dominate the space industry" is presumably
| what they meant, and not inaccurate. On the other hand,
| even the American space industry uses metric.
| gorlilla wrote:
| Hubble wasn't so sure.
| dspillett wrote:
| 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".
| dakr wrote:
| Not a consequence of units used: https://en.wikipedia.org
| /wiki/Hubble_Space_Telescope#Flawed_...
| cossatot wrote:
| It's space in the SV context, i.e. the competitive arena
| or market. Americans dominate the space space.
| gdhkgdhkvff wrote:
| 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!
| bumby wrote:
| 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.
| tshaddox wrote:
| You might as well complain about the name of the World
| Cup, since it's also only teams from Earth.
| lupusreal wrote:
| 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.
| mp05 wrote:
| Dominated by a company that is led by an African-American
| man no less!!
| brudgers wrote:
| How many HP is your Eurorack case?
| snakeyjake wrote:
| What's the highest posted speed limit on the M1/M6 from
| London to Birmingham?
| delta_p_delta_x wrote:
| 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...
| nordsieck wrote:
| > 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?
| rors wrote:
| The UK government doesn't mandate units for reporting
| your own weight. The examples listed are required by law.
| adolph wrote:
| > The UK government doesn't mandate units for reporting
| your own weight.
|
| Wait, you can just use a unit-less value?
| UK Govt Official Weight Form Weight: well-nourished
| dspillett wrote:
| _> 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.
| 2ap wrote:
| 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.
| dspillett wrote:
| 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.
| finnh wrote:
| 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.
| bigfatkitten wrote:
| 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.
| lostlogin wrote:
| 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
| bombela wrote:
| Americans also measure gun powder and hard water content
| in barley corn :) That's what the unit "Grain" is.
| snakeyjake wrote:
| You forgot that whenever the temperature exceeds 37C
| everyone says "it's 100 degrees out!"
|
| edit: also, every _proper_ cookbook.
| HPsquared wrote:
| 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).
| btilly wrote:
| 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.
| lucozade wrote:
| It's definitely less than Mach 5.5 given all the roadworks.
| sandworm101 wrote:
| Nobody knows. There has never been a gap in traffic
| sufficient for a normal vehicle to exceed the limit.
| HPsquared wrote:
| "National Speed Limit"
| BoxOfRain wrote:
| 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.
| thechao wrote:
| 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.
| BoxOfRain wrote:
| 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.
| jszymborski wrote:
| 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)
| johnmaguire wrote:
| Yet a 2 x 4 isn't 2" x 4". :P
| lostlogin wrote:
| Ahh, rough sawn versus dressed.
|
| Deeply frustrating when you assume sizing matches
| description.
| bombela wrote:
| 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.
| sandermvanvliet wrote:
| 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...
| physhster wrote:
| Probably because you're stuck with sub-par 110v appliances
| made for the US market...
| esterly wrote:
| Most electric ovens and dryers are 240V in the US
| https://us-electric.com/how-to-install-an-electric-stove-
| out...
| bombela wrote:
| 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.
| LorenPechtel wrote:
| 110v is a lot less likely to kill you if you do
| accidentally touch it.
| marssaxman wrote:
| 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.
| lostlogin wrote:
| 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.
| dang wrote:
| " _Eschew flamebait. Avoid generic tangents._ " -
| https://news.ycombinator.com/newsguidelines.html
| dragonwriter wrote:
| > 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.)
| soneca wrote:
| 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
| variaga wrote:
| It is true:
|
| https://en.wikipedia.org/wiki/Comparison_of_the_imperial_an
| d...
| analog31 wrote:
| 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.
| daemonologist wrote:
| 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.
| jjmarr wrote:
| Altitudes for aircraft use feet worldwide, to be fair.
| dj_gitmo wrote:
| TV screens and monitors are also measured in inches.
| -\\_(tsu)_/-
| delta_p_delta_x wrote:
| 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.
| Tepix wrote:
| In Germany you have to always mention the metric size.
| Luckily.
| delta_p_delta_x wrote:
| > 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_Aviati
| on_O...
| Tepix wrote:
| No, and this is not an aircraft, is it?
| HPsquared wrote:
| Imperial units fit nicely here: 1.00 mile/sec.
| tw04 wrote:
| Can I get that in stone and hands please?
| saagarjha wrote:
| 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?
| kevmo314 wrote:
| At some point the label of amateur starts costing more than the
| value the achievements bring.
| WalterBright wrote:
| The value is in educating the next generation of rocketmen.
| saagarjha wrote:
| 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!
| WalterBright wrote:
| Working through the equations, and then building a
| working machine from it, is very educational.
| lmm wrote:
| 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.
| plugger wrote:
| 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.
| echoangle wrote:
| > 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.
| plugger wrote:
| 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.
| monksy wrote:
| 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.
| plugger wrote:
| 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.
| xyx0826 wrote:
| 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.
| plugger wrote:
| > 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.
| accurrent wrote:
| 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".
| plugger wrote:
| 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.
| plugger wrote:
| Actually, they have a team bio on their site. They look
| quite young to me.
|
| https://www.uscrpl.com/the-team
| accurrent wrote:
| 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.
| xyx0826 wrote:
| > 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.
| potato3732842 wrote:
| >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.
| jeffbee wrote:
| Isn't their main advantage that every student at USC is
| rich AF? It's one of the wealthiest student bodies in the
| land.
| asdff wrote:
| At schools like that a pretty decent amount of students
| are on partial or full rides from scholarship or
| financial aid fwiw.
| jeffbee wrote:
| 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.
| hackernewds wrote:
| not to mention you are way more motivated when your grades
| are tied to an outcome
| saagarjha wrote:
| I don't think they are doing this for a class?
| littlestymaar wrote:
| 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).
| Rebelgecko wrote:
| I don't think RPL is tied to any sort of academic grades
| potato3732842 wrote:
| 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.
| Onavo wrote:
| 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.
| relistan wrote:
| 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.
| plugger wrote:
| Good advisor, yes. But knowledge retention is critical.
| They've been at it for nearly 20 years, not 5.
| relistan wrote:
| Great, that strengthens my point.
| serjester wrote:
| Depends on the team. They also have the virtue of being
| able to get almost any alumni to talk to them.
| Haugsevje wrote:
| Well, I would guess the knowledge is burned into the mind
| of the students?
| asdff wrote:
| They probably have all their documentation going back years
| on a usc google drive account.
| bragr wrote:
| 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/
| pfdietz wrote:
| 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.
| hoseja wrote:
| Feds are gonna come and talk to you very sternly, at first.
| chasd00 wrote:
| 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/
| LorenPechtel wrote:
| 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.
| mclau156 wrote:
| 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
| snowwrestler wrote:
| You mean like SpaceX, which is a well-resourced and determined
| civilian team?
| s1artibartfast wrote:
| Notably not an amateur team.
| carabiner wrote:
| 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.
| WalterBright wrote:
| Dang. I would have loved to be on that team as a student.
| cespare wrote:
| 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.)
| LarsDu88 wrote:
| Get these kids a DoD contract.
|
| That rocket probably exceeds the range of the ATACMS rocket and
| may have enough range to hit the Crimean bridge from Southern
| Ukraine.
| zakki wrote:
| Why DoD (US) instead of Ukraine Gov?
| plugger wrote:
| ITAR
| TrainedMonkey wrote:
| Or we could avoid weaponizing kids and let them explore space
| for the sake of exploration. Give them a no strings attached
| grant and let them decide later on what they want to use
| acquired experience for.
| walrus01 wrote:
| serious answer but without a dod contract and appropriate
| licensing, putting any kind of guidance system other than "keep
| it pointed straight up" on a rocket like this definitely makes
| it fall within a few things:
|
| ITAR (international traffic in arms regulations)
|
| EAR (export administration regulations)
|
| CCL (commerce control list)
|
| BIS (bureau of industry and security)
|
| MTCR (missile technology control regime)
|
| Just to start... Let's just say if you want to _guide_
| something like this you 'd better be sure that the federal
| government absolutely knows who you are and what you're
| building, and for what purpose, and that everyone is a US
| citizen who is eligible to get a security clearance.
|
| I guess I didn't even get into the other explosives/munitions
| related licensing and certifications and storage/preparation
| facility requirements for very large solid rocket motors (ATF)
| bragr wrote:
| With what payload?
|
| >The comparatively lightweight rocket amounted to 330 pounds
|
| That's a total weight less than any warhead available for
| ATACMS: https://en.wikipedia.org/wiki/ATACMS#Comparison
|
| And then there are the engineering challenges of flying very
| specific trajectories capable of single digit meters of CEP at
| those ranges, surviving a ballistic reentry to ground rather
| than parachuting, and being robust enough to survive being
| bounced around in a sealed canister for years at a time with no
| maintenance and then successfully launching in anger at short
| notice.
| vkou wrote:
| Not to mention the challenges of mass production and quality
| control on a budget.
| pjc50 wrote:
| They're not expensive or well-connected enough to get DoD work.
| Would have to promise to build different sections of the rocket
| in different swing states, etc.
| trhway wrote:
| Ukraine does have "Smerch" rockets - the engine part is about
| 500kg, 6m length, 0.3m diameter. In the dumb version it carries
| 280kg payload to 70km. The high-precision version carries 170kg
| to 120km. You can decrease payload further - to about 60kg -
| and hit the bridge (not that 60kg would destroy it, yet given
| the cheapness and availability of the rocket, one can use it to
| say regularly hit military cargo trains and trucks on the
| bridge while also damaging the rails/pavement for several hours
| in a row, and also one can use it to attack the S-400 defending
| the bridge, etc.)
|
| I think what Ukraine hits, be it with own or Western weaponry,
| isn't just the matter of capability. I think they are trying to
| be very careful to not trigger nuclear response (my personal
| opinion is that this fear is overblown - of course i have this
| opinion while sitting comfortably in an armchair in CA). Also i
| think they are trying to not scare the Western partners as a
| country which, just to name a few, was the powerhouse of the
| USSR space and ICBM programs and has several working plutonium
| producing nuclear stations, and thus definitely has very
| interesting options of its own strategic defense.
| dragonwriter wrote:
| The entire rocket is smaller than the (smallest) warhead of an
| ATACMS; for a missile, you need to be able to deliver a useful
| payload at range, range without that is meaningless.
|
| (Also, DoD has plenty of missiles with a longer range than the
| ATACMS.)
| hshshshshsh wrote:
| Why this obsession to get the world sleep walk into world war3?
| LarsDu88 wrote:
| Why this waffling around helping a western democracy defend
| itself against an enemy that purposefully bombs children's
| hospitals, is run by a dictatorship, and spews active
| measures disinformation campaigns all around the world?
|
| Let me remind you that World War 2 effectively happened from
| the western democracies repeatedly appeasing the dictator's
| territorial ambitions and doing absolutely nothing to defend
| countries like Czechoslovakia and Poland, not from
| "sleepwalking into war"
| pjc50 wrote:
| > enemy that purposefully bombs children's hospitals
|
| While I support Ukraine, we should also watch out for the
| US ally that purposefully bombs hospitals on flimsy
| pretexts.
| LarsDu88 wrote:
| I agree!
| pjc50 wrote:
| The war's already happening, it's a matter of who it's
| allowed to spread to.
| mrguyorama wrote:
| The problem with disarmed pacifism is that if Russia decides
| it wants a european conquest, there is no possibility for
| peace. You cannot prevent war from only one side. There MUST
| be attempts at peace from the other side. If they do not
| believe in reasonable peace terms, for example as the Nazis
| and Japanese did in WW2, there is no amount of pacifism or
| disarmament or neutrality or "war is bad" can prevent war.
|
| In fact, if your adversary wants war, insisting we do nothing
| to protect ourselves and allies IS "sleepwalking into WW3"
|
| Peace REQUIRES buy in from the other party. Without that buy
| in, there is NOTHING you can do to prevent it. Russia right
| now insists to it's people that they are fighting NATO. The
| people of Russia insist they are in a war with NATO. It does
| not matter what WE want or believe or insist, if Russia
| insists on a war with NATO, they will get it. You don't get
| to just dig your head into the sand and pretend it's not
| happening.
|
| Armed neutrality is the only option.
|
| People love to point out WW2 as the obvious example, but I
| think WW1 is a better example honestly. Austria-Hungary
| wanted to go to war with Serbia. They were committed to doing
| so well before the Archduke was assassinated. They drew up
| ten absurd demands that they expected Serbia to reject so
| they would have a pretense for war. Serbia surprised everyone
| by agreeing to 9/10 of the demands. Austria-Hungary still
| invaded, because they wanted conquest, not whatever made up
| demands they had submitted. There was nothing Serbia could
| have done to prevent the war other than capitulate entirely,
| and that would not have gone well for millions of people.
| eps wrote:
| In metric: previous record was 116 km, this launch was 143 km.
| Tepix wrote:
| Thanks. I can't believe they're giving the speed in ft/second,
| i've never seen that... _horrible!_
| eterevsky wrote:
| 470'000 ft = 140 km altitude
| niteshpant wrote:
| thank you - this was the comment I was looking for
| hoseja wrote:
| >through anodization
|
| That was just oxidation.
| gus_massa wrote:
| 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)
| Haugsevje wrote:
| Are they as high up that it could start orbiting?
| phaedrus wrote:
| Orbiting has more to do with velocity than altitude.
| jvanderbot wrote:
| Specifically, you need to be moving approx 10 km/s which
| 22,000 mph or mach 30.
| Haugsevje wrote:
| Ahh yes, of course! I guess they are not high enough for geo
| stationary orbit?
| jadyoyster wrote:
| 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
| Haugsevje wrote:
| That's a very clarifying video! Suddenly i remembered my
| pre-college physics:)
| marcyb5st wrote:
| 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...
| pavon wrote:
| 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.
| nordsieck wrote:
| > 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
| zamadatix wrote:
| 30 km/s is ~the speed at which Earth orbits the Sun. For
| orbiting Earth you just need a _mere_ <8 km/s.
| nordsieck wrote:
| Thanks for the correction.
| steviedotboston wrote:
| 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.
| ceejayoz wrote:
| 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.
| lostlogin wrote:
| 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?
| ceejayoz wrote:
| Wait for it to come back down, then fine you.
| Loudergood wrote:
| 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.
| LorenPechtel wrote:
| 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.)
| pclmulqdq wrote:
| 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.
| iandanforth wrote:
| 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.
| sklargh wrote:
| ITAR and amateur rocketry YouTube have a strained relationship.
| mrguyorama wrote:
| 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.
| bragr wrote:
| 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.
| edm0nd wrote:
| 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.
| rangestransform wrote:
| 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
| r00fus wrote:
| 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?
| ceejayoz wrote:
| > 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.
| wbl wrote:
| 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.
| foota wrote:
| 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.
| ceejayoz wrote:
| The Shahed drones were entirely within Russian capacity to
| design and produce. They just needed them _now_.
| kylehotchkiss wrote:
| > 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)
| jltsiren wrote:
| 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.
| amelius wrote:
| As with anything, progress is great until a point. E.g. when
| amateurs can print biological viruses at home then things get
| scary.
| kylehotchkiss wrote:
| 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.
| LorenPechtel wrote:
| 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.
| bastloing wrote:
| Bright kids, great support, can't wait to see what they can do
| with their careers! Bravo!
| WhitneyLand wrote:
| How much did it cost them?
|
| Using ensemble model estimation resulted in a guess of $400,000.
| boringg wrote:
| 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?
| mryall wrote:
| 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.
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