Officials with UP Aerospace have pinpointed what went wrong with their maiden rocket launch last year. They say they have fixed a problem with the rocket鈥檚 fins, and that their Spaceloft XL rocket could return to flight as early as April 2007.
UP Aerospace, based in Hartford, Connecticut, US, was the first company to use Spaceport America, the budding launch site near Truth or Consequences, New Mexico. Their Spaceloft rocket took off on 25 September 2006 鈥� but did not make it into space (see New Mexico鈥檚 first commercial rocket crashes after launch).
Jerry Larson, UP Aerospace鈥檚 president and chief technology officer, says that the problem with last year鈥檚 launch was caused by aerodynamic instability after the rocket reached four times the speed of sound (Mach 4). The rocket鈥檚 three fins did not provide enough stability at these high speeds.
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An amateur shows a definite wobble about 10 seconds into the flight (approximately 6 minutes into the footage).
Stable spin
Computer models did not accurately predict what the rocket would experience in flight, and the young company could not afford expensive wind-tunnel tests beforehand to put their rocket through the rigours of a mock flight.
鈥淯ntil you fly it, you don鈥檛 really know,鈥� Larson told New 杏吧原创. 鈥淐omputer models are only so good and can never replace real-world experience.鈥�
With the data gathered from that first flight, UP鈥檚 engineers decided they needed to add a fourth fin. They also decided to increase the tilt of the rocket鈥檚 fins from one-tenth of a degree from vertical to half a degree. Tilting the fins will make the rocket spin, which should stabilise its flight.
However, the addition comes at a price. The fourth fin weighs about 2.3 kilograms, so UP Aerospace had to compensate by reserving a little less mass for cargo. Overall, the vehicle can carry a payload of approximately 50 kg.
Eclectic cargo
The 6-metre-tall rocket is designed to fly on a sub-orbital trajectory to the edge of space 鈥� an altitude of at least 100 kilometres. Its payload should release and then parachute back to Earth for a landing at the neighbouring White Sands Missile Range.
The next flight, scheduled for late April, is expected to carry some interesting payloads. The ashes of James Doohan, who played Scotty in the original Star Trek series, and the ashes of Mercury astronaut Gordon Cooper will take a trip on the suborbital rocket. It will also carry students鈥� scientific experiments and a commercial payload for an Italian company.
UP Aerospace hopes to make six to eight launches in 2007. Despite their optimism, company officials are being realistic about the difficulty of sending things into space.
鈥淲ith the launch vehicle business, there鈥檚 always risk involved,鈥� Larson says. 鈥淲e鈥檝e solved this problem. We鈥檝e done a lot of testing with our motors, [but] we haven鈥檛 returned with parachutes and things like that.鈥�
