Rough ride won't stop next X Prize shot

 作者:兀官时秋     |      日期:2019-03-03 06:17:04
By Maggie McKee, Mojave (Image: David L Chandler) The rolling experienced by SpaceShipOne on its first Ansari X Prize flight on Wednesday will not jeopardise the team’s chances of winning the $10 million purse, team members said in a post-flight briefing. The cause of the rolling is now being investigated. Initial radar measurements suggest the rocket reached an altitude of 103 kilometres (337,500 feet), which, if confirmed, means it passed the required 100 km (328,084 ft) threshold for reaching space. The spacecraft, designed by Scaled Composites of Mojave, California, will now have to repeat the feat by 13 October to take the prize. Company president Burt Rutan says he will announce on Thursday whether the team will make its second run as scheduled on 4 October. “One down, one to go,” said X Prize Foundation founder Peter Diamandis, after the flight. The craft and its pilot, Mike Melvill, touched down safely at California’s Mojave Airport at 0834 PDT (1634 BST) on Wednesday. But the flight did not go completely according to plan. After SpaceShipOne separated from its carrier airplane, White Knight, at 14,150 metres (46,400 feet) and fired its engine, the rocket began to roll as it shot upward. Beginning at about 48,770 m (160,000 ft), the ride became rough, said Melvill. He said the craft made about 20 turns at the top of the climb – rolling about once every two seconds. The air is so thin at those altitudes that Melvill had to use a specially designed system of air jets to stop the rolling until the rocket could change its wing orientation to freefall stably back to Earth, as planned. The rolling made for some tense moments for spectators watching close-up video of the flight. “Your heart is really in your throat when these things happen,” said Microsoft co-founder Paul Allen, who provided an estimated $20 million for the rocket’s development. Rutan and others in the flight control room also got worried and asked Melvill to cut short the planned 88-second engine burn. Melvill checked that the rocket would reach 100 km, then shut off the rocket 11 seconds ahead of schedule. “He didn’t feel as uncomfortable as we did so he let it run another couple seconds. He wants to win the X Prize, too,” said Rutan. “I didn’t have any discomfort – I thought it was kind of cool,” Melvill said, adding that he even took a moment to snap some digital photos after the rocket had stabilised. The cause of the rolling is unknown. “It probably was something I did,” Melvill suggested, like accidentally stepping on a rudder. He also explained that he was probably the main cause of the rocket going about 35 km off course on a 21 June flight into space, possibly by overcompensating for wind shear. In fact, high wind shear at 60,960 m (200,000 ft) may have contributed slightly to the rolling, Rutan said. Since the rocket’s first flight, engineers have noticed the craft is prone to roll when exposed to wind, and Rutan says he will fix this by modifying the craft’s shape in future models. “This is a prototype,” said Alex Tai, a representative from Virgin Galactic, the new company begun by airline entrepreneur Richard Branson that has licensed SpaceShipOne’s technology for $21 million. “There are going to be a lot more [improvements] that are going to make me sleep better,” he told New Scientist. The flight is a landmark even though it is just the first of two required to win the Ansari X Prize. “If you look at it in terms of opening the door to a new era of commercial human spaceflight, you have already succeeded,” said George Nield, an official at the US Federal Aviation Administration. Indeed, officials mentioned plans for future spaceflight prizes – possibly with their own reality TV shows – after the X Prize is won. More on these topics: