NASA's first firing test of the five-segment solid rocket motor, DM-1, for the Ares I crew launch vehicle, has been delayed by up to six months from 2 April to August or September.
Ares I uses a solid rocket motor for its first stage and its prime contractor Alliant Techsystems, which provides the Space Shuttle Programme's four-segment motor, won the development contract in 2007. ATK says a six-month delay is possible because it needs to be "sure the first test is right and there is no critical path impact" - meaning the CLV's development will not be set back by the delay.
After DM-1 ATK had planned to test its demonstration motors DM-2 and -3 in August and September, respectively. Those tests are now likely to be delayed toward the end of the year, if not to 2010.*
The Ares I's first stage differs from the Shuttle solid rocket boosters as it has a modified solid fuel, new insulation materials for the segments and igniter - itself a solid rocket - and it will have a longer nozzle for lunar missions.
Due to exhaust vortices generating an oscillation through the entire vehicle, the Ares' first stage will have mass dampers at the its base and other mitigation systems at its top. The first stage's base will also have additional small motors to initiate a tumbling motion for its descent profile.
On 19 March the company delivered the four first-stage motor segments for the Ares I-X for its test flight, scheduled for 11 July. The segments are from the Space Shuttle Programme. Ares I-X is a test vehicle representative of the final Ares CLV rocket.
This month ATK placed a $257 million contract with the Boeing/Lockheed Martin joint venture United Space Alliance for Ares I-X and CLV support work. The alliance carries out ground operations for the Space Shuttle Programme.
*CORRECTION: Alliant Techsystems has informed Flightglobal.com that DM-3 is scheduled for 2011 and DM-2 is planned for 2010. Flight's 7 March 2008 story reported that DM-2 was planned for September 2009, ATK did not question that at the time.