grinner
06-23-2004, 08:10 AM
'Anomalies' in first private spaceflight revealed
12:27 22 June 04
NewScientist.com news service
The flight of the first private astronaut was not as perfect as it first appeared – a number of glitches occurred during the flight, some potentially catastrophic.
The revelations were made by Burt Rutan, designer of SpaceShipOne, which on Monday became the world's first privately funded craft to enter space. Until the team fully understands exactly what went wrong during the flight, he said, they will not go ahead with the pair of flights needed to claim the $10 million Ansari X-Prize.
Luckily, the glitches did not prevent a successful flight. But pilot Mike Melvill said that a partial failure of the system controlling the spacecraft's orientation could have been disastrous if it had occurred just slightly earlier in the flight.
The problem struck at the end of the rocket engine's firing time of about 70 seconds, just as Melvill reached space. "As I came out of the atmosphere I no longer had any attitude control," Melvill told New Scientist and other reporters. "If that had happened earlier, I would never have made it and you all would be looking sad right now."
Big bang
Although that was the most serious anomaly, it was not the only frightening moment for the 63-year-old test pilot. There was also a loud bang behind him while the rocket engine was firing.
The team believes this was caused by aerodynamic stresses crumpling a composite material fairing around the engine nozzle. However, Dick Rutan, Burt's brother and a famed test pilot himself, said that fairing could have fallen off completely without endangering the craft.
Melvill's first frightening moment on the historic flight came at the very instant he flipped the switch to turn on the hybrid rocket motor. The craft suddenly lurched over 90° to the right, and as soon as he brought it back to level it then rolled 90° to the right.
"I was ready to hit the switch" to turn off the motor and abort the flight, he said, but the craft remained steady and he was able to continue and achieve the 100 kilometre altitude that officially makes him an astronaut. This difficulty appears unrelated to the later failure of attitude control, Melvill said.
Despite Melvill's 25 years of piloting experimental craft, he found even the normal operation of the rocketship alarming, as it travelled faster and higher than any previous privately-built craft.
Speeding bullet
SpaceShipOne was travelling "faster than an M-16 rifle bullet", Rutan said, about around 2400 km/h (1500 mph) or mach 3.2. As it reentered the atmosphere, falling like a badminton shuttlecock almost straight down, the rushing air sounded like a hurricane, said Melvill.
"Coming down is frightening, because of that roaring sound," he said. "You can really hear how that vehicle is being pounded."
Until the exact causes of the anomalies are understood, there will be no X-Prize attempt, Rutan said: "There's no way we would fly again without knowing the cause and being sure we had fixed it."
But despite the problems, the mood among the team remained extremely buoyant about their success. Melvill recounted how, as he became weightless, he opened a bag of M&M chocolates to watch them float around the cabin.
But it was the sublime view that affected him the most. "The sky was jet black, with light blue along the horizon - it was really an awesome sight," he said. "You really do get the feeling that you've touched the face of God."
David L Chandler, Mojavelink (http://www.newscientist.com/news/news.jsp?id=ns99996052)
12:27 22 June 04
NewScientist.com news service
The flight of the first private astronaut was not as perfect as it first appeared – a number of glitches occurred during the flight, some potentially catastrophic.
The revelations were made by Burt Rutan, designer of SpaceShipOne, which on Monday became the world's first privately funded craft to enter space. Until the team fully understands exactly what went wrong during the flight, he said, they will not go ahead with the pair of flights needed to claim the $10 million Ansari X-Prize.
Luckily, the glitches did not prevent a successful flight. But pilot Mike Melvill said that a partial failure of the system controlling the spacecraft's orientation could have been disastrous if it had occurred just slightly earlier in the flight.
The problem struck at the end of the rocket engine's firing time of about 70 seconds, just as Melvill reached space. "As I came out of the atmosphere I no longer had any attitude control," Melvill told New Scientist and other reporters. "If that had happened earlier, I would never have made it and you all would be looking sad right now."
Big bang
Although that was the most serious anomaly, it was not the only frightening moment for the 63-year-old test pilot. There was also a loud bang behind him while the rocket engine was firing.
The team believes this was caused by aerodynamic stresses crumpling a composite material fairing around the engine nozzle. However, Dick Rutan, Burt's brother and a famed test pilot himself, said that fairing could have fallen off completely without endangering the craft.
Melvill's first frightening moment on the historic flight came at the very instant he flipped the switch to turn on the hybrid rocket motor. The craft suddenly lurched over 90° to the right, and as soon as he brought it back to level it then rolled 90° to the right.
"I was ready to hit the switch" to turn off the motor and abort the flight, he said, but the craft remained steady and he was able to continue and achieve the 100 kilometre altitude that officially makes him an astronaut. This difficulty appears unrelated to the later failure of attitude control, Melvill said.
Despite Melvill's 25 years of piloting experimental craft, he found even the normal operation of the rocketship alarming, as it travelled faster and higher than any previous privately-built craft.
Speeding bullet
SpaceShipOne was travelling "faster than an M-16 rifle bullet", Rutan said, about around 2400 km/h (1500 mph) or mach 3.2. As it reentered the atmosphere, falling like a badminton shuttlecock almost straight down, the rushing air sounded like a hurricane, said Melvill.
"Coming down is frightening, because of that roaring sound," he said. "You can really hear how that vehicle is being pounded."
Until the exact causes of the anomalies are understood, there will be no X-Prize attempt, Rutan said: "There's no way we would fly again without knowing the cause and being sure we had fixed it."
But despite the problems, the mood among the team remained extremely buoyant about their success. Melvill recounted how, as he became weightless, he opened a bag of M&M chocolates to watch them float around the cabin.
But it was the sublime view that affected him the most. "The sky was jet black, with light blue along the horizon - it was really an awesome sight," he said. "You really do get the feeling that you've touched the face of God."
David L Chandler, Mojavelink (http://www.newscientist.com/news/news.jsp?id=ns99996052)