Alliant Techsystems' latest target date for the first test of a five-segment solid rocket motor is 13 August. The motor will become NASA's Ares I crew launch vehicle's first stage.

ATK says the 133-day postponement for the test of development motor (DM)-1 was to allow improved manufacturing processes to be used. The test had been scheduled for 2 April and the postponement allows the company to increase certain operations' temperatures and permit more x-ray inspection.

ATK says: "Since the first stage was well ahead, this change was deemed to be prudent and without impact [to the schedule]. Several changes were undertaken to enhance programme reliability, [for example] patching thermal couple wires."

The company now plans testing for DM-2 and DM-3 for June 2010 and April 2011, respectively. In March 2008 ATK said that DM-2 and DM-3 would be in August 2010 and February 2011. The gap between each test is partly due to there being only one test stand.

ATK says that "it wanted to stress that there is no impact to the [Ares I] programme and these enhancements were implemented because the schedule allowed this flexibility". NASA has delayed its first five-segment Ares I first stage test flight, Ares I-Y, from the first half of 2012 to the third quarter of 2013.

Source: Flight International