The left rear landing gear on Virgin Galactic's WhiteKnight Two failed during a test flight in the Mojave desert 19 Aug.
The quad-engine jet that will be the mothership carrying Virgin's passenger spaceship was on its 37th test flight. The spaceship was not attached at the time of the incident. No one was injured.
The gear failure was a "very, very minor incident" says Virgin Galactic, and will have "no impact on the project at all."
Virgin has said the test programme is expected to run through most of 2011 before commercial operations begin. More than 300 would-be astronauts have paid for or put down a deposit for a $200,000 ticket with Sir Richard Branson's space tourism venture.