World's Largest Amateur Rocket Prepares For Second Attempt 76
Plammox writes "Last year, non-profit, volunteer-based Copenhagen Suborbitals failed at launching what they call the world's largest amateur rocket, because of a frozen LOX-valve. This year, the sea launch platform 'Sputnik' has become self-propelled, eliminating the need for their home-built submarine(!). Sputnik is on its way into the Baltic Sea right now and a launch attempt is expected on Friday. However, one of the founders warns that even if ignition should occur, it might very well look like this."
Appropriate name (Score:5, Interesting)
Sergei Korolev [wikipedia.org], the chief designer of the Sputnik program (and every subsequent Soviet space vehicle until 1965), started out designing amateur gliders in his backyard when he was a teenager. I suspect many a great aerospace engineer started out as an amateur aircraft or rocket designer.
Today's amateur is the man who takes us to Mars tomorrow.
Not the first failure due to a frozen LOX valve (Score:4, Interesting)
I worked on the American Rocket Company's [wikipedia.org] proof of concept hybrid launch vehicle in 1989, which went under various names in the press, but the working name in house was Single Engine Test One (SET-1) [globalsecurity.org].
SET-1 failed on the pad at VAFB, also due to a frozen LOX valve. There's a good account of the Oct 1989 vehicle accident attached to the Original Post here [nasaspaceflight.com]. I'll summarize from my experience.
All of the engine testing took place at Edwards AFB, where the humidity was approx 10% on average. At Vandenburg, humidity was more like 100% during cryo fill/drain operations in the mornings. I suspect that similar condensation and freezing problems affected the Copenhagen Sputnik valve.
After two days of dry-run fill/drain ops, there was a nice casing of ice around the 4" gate valve that separated the He-pressurized LOX tank from the polybutadeine rubber fuel cast into the combustion chamber, so it only opened about 10% of full -- just enough to ignite the engine but not enough to produce any effective thrust.
The LOX valve failure was listed as the "cause," but it was only the proximate cause, and could have been predicted and/or mitigated. But a number of other contributing factors (human error, subcontractor interference from competing companies, and design shortcomings) led to the thrust vector control fuel, 60% hydrogen peroxide, pooling in the flame bucket and catching fire. As a result, the outside of the vehicle caught fire, and eventually the whole thing became a burning mess on the pad, sending a huge black cloud of smoke over Santa Maria, CA.
The proof of concept failure was the direct cause of the failure of the AMROC startup. I joined in Feb 1989 when the staff was about 50. By the time of (company President and chief inspirational figure) George Koopman's death in July, the staff was four times as large. By the end of the year, the company was only 25 people, and closed its doors a year or so later, selling its IP to Westinghouse, which then transferred it to SpaceDev. So some of the work we performed did prove useful, eventually. And we succeeded in proving that hybrid rockets were "safer" than solid -- during SET-1 development, some Rocketdyne folks down the road at EAFB dropped a solid rocket section from a crane. The resulting explosion killed 2 people iirc. The SET-1 accident caused only $2000 of minor damage to the pad at Edwards.
I was a young engineer just out of college. It was an awesome experience to work at a startup like that, and I have dozens of entertaining stories to tell as a result, and learned many lessons I used regularly over the next two decades. I'll never forget it.
Re:I don't get it. . . (Score:4, Interesting)
I was going to point out Scripps' awesome FLIP [ucsd.edu] platform, which works on the same principle. You start what amounts to a long section of pipe, flood one end of the pipe. When it flips into the vertical position you have a floating stanchion whose buoyancy is dominated by the part that's well below the level of wave action. Of course the submersible part of FLIP is some 100m long, but for the purposes of launching a rocket the platform probably doesn't have to be as stable as FLIP.
IIRC, the Copenhagen Suborbitals group used a submarine they'd successfully designed and built as a tug to position their launch platform. From that I'd have to conclude they have the engineering capability to produce an inertially stable launch platform. If they haven't, it's most likely because it's not needed for this vehicle and mission.