After a spectacular 12 months, which saw both its Cygnus cargo ship and its home-grown Antares booster return to flight, after a lengthy hiatus, Orbital ATK has announced that its next delivery mission to the International Space Station (ISS) will likely fly next spring, atop a United Launch Alliance (ULA) Atlas V 401. The decision apparently stems from NASA concerns about the potentially damaging impact of having both of its Commercial Resupply Services (CRS) partners—the Dulles, Va.-headquartered Orbital ATK and the Hawthorne, Calif.-based SpaceX—out of action for a protracted period of time, as was the case for several months from October 2014 and June 2015. It thus serves to satisfy the agency’s requirement for “enhanced schedule assurance” for cargo deliveries and maximizes the capacity of critical supplies destined for the station in 2017. Current plans call for Orbital ATK to launch three Cygnuses to the ISS next year.
“Following a successful Antares launch for the recent OA-5 Commercial Resupply Services mission and subsequent rendezvous and berthing of the Cygnus spacecraft with the International Space Station, Orbital ATK has responded to NASA’s needs for enhanced schedule assurance for cargo deliveries and maximum capacity of critical supplies to the space station in 2017 by once again partnering with United Launch Alliance to launch Cygnus aboard an Atlas V for the upcoming OA-7 mission in the spring timeframe,” noted an Orbital ATK statement, seen by AmericaSpace. “The company will be ready to support three cargo resupply missions to the station next year and will work with NASA to finalize the flight schedule.”
When Orbital Sciences Corp. (as it was back then) and SpaceX signed the inaugural CRS1 contracts with NASA in December 2008, both launch providers were expected to complete their respective number of missions by December 2016. Each would transport a total of 44,000 pounds (20,000 kg) of payloads and supplies to miscellaneous ISS crews, via eight Cygnus and 12 Dragon cargo vehicles. As circumstances transpired, both partners met with significant delay: SpaceX did not stage its inaugural Dragon to the station until May 2012 and in Orbital’s case it was September 2013 before an ISS crew first caught sight of an incoming Cygnus. This fulfilled a core CRS1 requirement of staging a “Demonstration” flight, before the partners were able to press ahead with their contracted haul of dedicated resupply missions. In SpaceX’s case, its first dedicated mission (CRS-1) took place in October 2012 and that of Orbital (ORB-1) came in January 2014.
More recently, the catastrophic explosion of Orbital’s Antares booster, seconds after liftoff on the ORB-3 mission in October 2014, and the high-altitude breakup of SpaceX’s Falcon 9 whilst en-route to deliver CRS-7 to the space station in June 2015, placed the CRS program in the dire situation of having both commercial partners simultaneously out of action. Matters were worsened yet further by the failure, earlier in 2015, of a Russian Progress cargo ship, which carried the potential of adversely impacting the ISS crew.
In the weeks after its Antares failure, Orbital Sciences Corp.—which merged with elements of ATK Thiokol in early 2015 to become “ATK Thiokol”—contracted with ULA to deliver at least two future Cygnus missions atop the highly reliable Atlas V 401 booster. This served to close the gap in flight operations before an anticipated resumption of Antares launches in mid-2016. A pair of Cygnuses were successfully launched atop Atlas vehicles in December 2015 and March 2016, before Antares triumphantly lofted OA-5 last month. In the meantime, SpaceX successfully returned its Falcon 9 to flight in December 2015 and launched a pair of Dragons to the ISS in April and July 2016.
However, it has since met with a further setback, when a Falcon 9 exploded on the launch pad on 1 September, ahead of a standard static-firing of its first-stage engines. The incident totally destroyed the rocket and its commercial payload, the $195 million Amos-6 communications satellite. According to SpaceX founder Elon Musk, SpaceX anticipates a return to flight no sooner than December 2016, although the failure adds yet more delay to the CRS program.
It is understood that the current risk-level associated with the Antares 230 booster, whose first stage is propelled by a pair of Russian-built RD-181 engines, has been met with some concern by NASA. This apparently prompted the space agency to request Orbital ATK to utilize ULA’s Atlas V, which benefits from a more rapid launch capability and offers a more promising outlook in terms of schedule adherence. As for SpaceX, it remains to be seen if the failures which triggered the CRS-7 high-altitude break-up in June 2015 and the on-pad explosion of Amos-6 last September are related. Orbital ATK brought Antares back to operational status only after several months of delays through the summer of 2016. Excluding their Demonstration flights, Orbital ATK has now flown five fully successful Cygnus missions and SpaceX has conducted eight fully successful Dragon missions. Last year, the original CRS1 allocation was extended for both partners and in January 2016 both were selected by NASA—along with Sierra Nevada Corp.—for the follow-on CRS2 contract, which will continue to resupply space station crews through the anticipated end of ISS operations in 2024.
Novosti Kosmonavtiki has noted that next year’s trio of Cygnus missions, numbered OA-7 through OA-9, are targeted to fly in March, June and October, with each cargo ship remaining berthed at the space station for approximately two months, ahead of departure and a destructive re-entry into Earth’s atmosphere. “The plan is to fly our Enhanced Cygnus on an Atlas V in the spring and all four remaining CRS1 missions will be flown on our own Antares,” Orbital ATK told AmericaSpace on Monday. “We are still working to finalize the details of this change to fly on Atlas in the spring. While we expect it to go forward, we’re still working through the final details.”