The two companies in the lead to fly crewed suborbital spacecraft announced milestones earlier this week towards the beginning of powered flight tests of their vehicles. On Friday, Virgin Galactic released images of an oxidizer tank being installed in SpaceShipTwo. The tank is a major element of the spacecraft’s hybrid propulsion system, which uses nitrous oxide as a liquid oxidizer along with a solid fuel.
The tank installation also inspired a blog post on the corporate Virgin website by Sir Richard Branson. In it, he drops a hint that the current hybrid propulsion system, which Virgin has billed as being environmentally friendly, might be replaced by something even more benign. “We’re now looking at some exciting future plans which could radically lower each flight’s remaining environmental footprint. More on that in due course!”
As for when that first powered test flight might take place, Virgin Galactic has, as it has done so for years, emphasized they’re focused on safety rather than making schedule. Even Branson didn’t offer much in his post. “[W]e’re leaving no stone unturned as we approach the first supersonic, rocket-powered flights of SpaceShipTwo,” he writes. “Our amazing engineers and pilots are preparing right now for the first powered spaceship flight, which should be followed with a fairly quick build up to Virgin’s first proper step across the final frontier!”
In a talk last month at the AIAA Space 2012 conference in Pasadena, California, Steve Isakowitz, executive vice president and chief technology officer of Virgin Galactic, said the company had set an “aggressive” goal of an initial powered flight by the end of the year. That, however, he added that schedule would be paced on how things were coming together.
As Virgin gets SpaceShipTwo ready at one area of Mojave Air and Space Port in California, in another area XCOR Aerospace is getting making progress on its Lynx Mark 1 prototype spaceplane. At the International Symposium for Personal and Commercial Spaceflight (ISPCS) in Las Cruces, New Mexico, on Thursday, XCOR COO Andrew Nelson announced that the company had completed another major test just Wednesday: firing the liquid oxygen and kerosene engines while mounted in a “flight-weight fuselage” with “real” pumps. The engines were “spewing out fire at our test site in Mojave,” he said. “It was an exciting day for XCOR.” Video of the engine test, he said, should be released in the next week.
XCOR had previously indicated they planned to start low-level (“air under the gear”) flight tests, part of a larger series of incremental tests of the Lynx, by late this year. Those flights appear to have slipped into early next year, based on Nelson’s comments at ISPCS. “We are progressing quickly on building and fielding the Lynx and flying it in the new year,” he said.