By Rob Coppinger in London
SpaceShipTwo (SS2) could have a different rocket fuel, a 140km (87 mile) apogee, increased down range, 7g re-entry loading and reclined passenger seats, SpaceShipOne (SS1) pilot Brian Binnie and Virgin Galactic president Will Whitehorn told last week’s Royal Aeronautical Society space tourism conference.
SS2, which now carries six passengers and two pilots, and its carrier aircraft White Knight 2 (WK2), are under construction. However, neither will be unveiled until late 2007, when flight tests are expected. WK2, with a wingspan expected to be 34-38m (112-124ft), would air launch SS2 1h into the flight. When the new hybrid rocket motor is fired, passengers will experience 4g on the ascent to an apogee of 140km.
The two pilots, Binnie and Mike Melvill, who flew the 2004 SS1 flights, experienced a howling sound for about 20s and shuddering for 5s, just before main engine cut-off. “The shuddering was due to the valve situated in the oxidiser tank. We can fix that, but it might not eliminate the shuddering entirely,” says Binnie, who is also a Scaled Composites programme manager overseeing SS2’s cockpit.
The shuddering was caused by intermittent injection of oxidiser from its tank due to the low levels left. Because of its slim design margins it is unlikely SS2 will be able to retain enough oxidiser to prevent that.
During the 5min of weightlessness, passengers could float around, but for the descent they will have to be back on their reclined seats, needed for passengers to cope with the expected 7g re-entry loads.
SS2’s increased down range could enable it to land at Roswell instead of the New Mexico South West Regional Spaceport near Las Cruces, from where it will launch in 2009.
Source: Flight International
