Orbital Sciences’ Antares space launch vehicle is being developed to carry cargo payloads to and from the International Space Station under a NASA Commercial Orbital Transportation Services contract.
Its first stage is powered by two Aerojet AJ26-62 LOX/kerosene engines, and the second stage is an ATK Castor 30B.
It will be test fired from the new Mid Atlantic Regional Spaceport on Wallops Island, Va. There have been delays associated with the new facilities, and most recently, a stand down because of Hurricane Sandy.
The pre-storm precautionary procedures the team put in place were successful. The Antares first stage weathered the storm in good condition, as did the launch pad and supporting facilities. The operations are getting back to normal. First up will be a cold flow test, involving fueling and de-fueling of the engines. It is anticipated to be completed within a few weeks. There will then be two additional wet dress rehearsals.
A hold-down test firing will next take place. This will be a full thrust 30 second firing. Once these tests are complete and data is analyzed, a launch date for the test flight of Antares will be determined. The flight will carry an instrumented mass to represent the Cygnus cargo capsule. This first test flight is penciled in for early 2013. It is hoped that the first cargo flight to the ISS may be in April 2013. However, Orbital has not disseminated a schedule after the Hurricane Sandy delay, and NASA officials think that April is too optimistic
SpaceX has a similar COTS contract, which was granted earlier than the Orbital contract.
It completed its first cargo delivery and return mission Oct. 28, 2012. However the next mission has been delayed until at least March 2013. The overall success of SpaceX’s first operational cargo mission to the ISS overshadowed the fact that the mission also encountered several problems, including the failure of one of the nine Falcon 9 engines.
Speaking to the NASA Advisory Council’s Human Exploration and Operations Committee on Nov 14, ISS program manager Mike Suffredini said that Space X is still trying to determine what happened to the engine. NASA is participating in the investigation, he said, and a fault tree analysis is underway.
Several other problems also arose during the mission. While berthed to the space station, one of the three computers on the Dragon spacecraft failed. Dragon can operate with only two computers, and SpaceX chose to proceed with the two functioning units rather than trying to fix the faulty unit while on orbit.
Dragon experienced other anomalies because of radiation as well. One of three GPS units, the Propulsion and Trunk computers and Ethernet switch all experienced ”suspected radiation hits,” but all were recovered after a power cycle. Suffredini said that SpaceX is considering whether it needs to use radiation-hardened parts instead, but noted that “rad-hardened” computers, for example, not only are more expensive, but slower. He speculated that the company would ultimately decide to use rad-hardened components in the future unless it is cost-prohibitive.