The two companies with International Space Station commercial cargo delivery contracts, Orbital Sciences Corporation and SpaceX, are at different stages in their efforts to carry out those contracts, with SpaceX having already completed one of its twelve contracted missions while Orbital continues to prepare for the first launches of its Antares launch vehicle and Cygnus spacecraft. Both companies, though, will be active over the next several months.
SpaceX is preparing for its second Commercial Resupply Services (CRS) cargo mission, CRS-2, now planned for March 1. “I don’t see anything that would keep that from happening,” NASA ISS program manager Mike Suffredini said at a press conference last week in Houston about upcoming ISS activities. The Dragon will berth with the station two days later, ISS flight director Tony Ceccacci said at the same press conference, and is currently scheduled to remain at the station until April 2.
The CRS-2 launch was originally scheduled for January, but was delayed by the investigation into the failure of an engine on the first stage of the Falcon 9 that launched the CRS-1 Dragon mission in October. Last month SpaceX officials said the investigation into the engine shutdown was wrapping up, but few additional details regarding the cause of the problem have been released.
Suffredini said the investigation was not “completely closed” but sounded confident that the problem was resolved. “It was hard to find a specific smoking gun to point to, but a number of things were believed to be contributors that have been looked at,” he said, without going into much detail about those contributing factors. One factor, he suggested, might have been the large amount of testing done on the engine prior to launch. The engines on the CRS-2 mission have been limited to acceptance testing, he said.
Another issue with the CRS-1 flight was the loss of power to a freezer carrying biological samples on the spacecraft upon splashdown. Suffredini said that none of the samples were compromised by the loss of freezer power. He said SpaceX was working to limit water intrusion into those systems. “The fix that was necessary was to a better job of sealing up the boxes,” he said. Those components will be sealed up better for CRS-2, with an “ultimate” redesign planned for CRS-3.
While SpaceX makes fixes to its launch vehicle and spacecraft, Orbital is making slow progress towards demonstrating its systems. Orbital earlier this week released an updated test schedule for the Antares and Cygnus, starting with a hot fire test on the pad now planned for February. A test flight of the Antares, carrying a “heavily instrumented mass simulator” in place of a Cygnus spacecraft, is slated for March, four to six weeks after the hot fire test. The full Antares/Cygnus COTS demo mission to the ISS would follow in April and May, and the first of eight CRS missions in the third quarter.
Those scheduled have been slipping, in part because of delays in getting the Antares launch site at Virginia’s Mid-Atlantic Regional Spaceport (MARS) completed, but Suffredini sounded confident those launches would take place close to the current schedule. “That’s going very well,” he said of the current Antares pad tests. “Many things have come together with getting the pad ready and the vehicle ready to go fly. They’ve overcome a number of hurdles, so the schedule’s started to stabilize on that system.”