Following the loss of the CRS-3 resupply mission last October, Orbital ATK has made steady progress in repairing and rebuilding their ground facilities at Wallops and the Mid-Atlantic Regional Spaceport. Despite the always difficult mishap recovery process, Orbital ATK is now on track to return an upgraded version of their Antares rocket to flight in the early part of 2016.

Returning Antares and Cygnus to flight:

While an official cause of the October 2014 failure of Antares has yet to be released, Orbital ATK is taking steps toward the implementation of an upgraded version of their Antares rocket, the Antares 200 series.

Under the 200 series design, which is slated to debut early next year as the company moves to return the Antares to flight status, the vehicle’s original twin AJ-26 engine configuration will be replaced with twin RD-181 engines for the core stage.

Together, the RD-181 engines will be capable of providing up to 100,000 lbf more than the dual AJ-26 combination was capable of producing.

In an exclusive interview with NASASpaceflight.com, Vice President and General Manager of Orbital ATK’s Antares Program, Mike Pinkston, stated that this new engine configuration for Antares has led to five areas of significant engineering work.

This includes the certification of the new engine itself; modifications to the core propellant tanks and structures and commodity systems; changes to the structure that’s used to adapt the engine to the core itself; changes to avionics and software that control the engines; and new propellant feed lines that take propellants from the core to the engines.

In the intervening months since the mishap, Orbital ATK teams have made significant progress in their work across these five areas.

“On all five of those fronts, we’ve made outstanding progress — to the point where, by the end of this month, we will have new, modified hardware for all of those systems at Wallops and into integration of the first vehicle,” stated Mr. Pinkston.

“So that’s all really come along well and come along as planned.”

This steady work on Antares has been paralleled with impressive work on the ground systems the were damaged or destroyed when the Antares rocket failed shortly after liftoff from the Mid-Atlantic Regional Spaceport.

When the failure occurred, the rocket’s remains thankfully missed numerous crucial elements of the launch pad itself.

Following the completion of the initial phases of the accident investigation, repairs to Pad 0A and the surrounding facilities at Wallops have progressed on schedule.

According to Mr. Pinkston, “Pad repairs are going well. Things are going to plan. And the plan is to have the pad repaired and ready for us in the fall.”

Orbital ATK currently estimates that pad repairs will be completed around the end of September/beginning of October and that the company will have a fully-functional pad well ahead of the planned hot fire test of the new Antares configuration.

When that hot fire test will occur is contingent upon the completion of Antares upgrade work.

“The pace we’re on today still supports getting to a hot fire test sometime between the end of this year and the very early part of next year,” said Mr. Pinkston.

“That’s been our plan all along, and we’re still on it. But precise dates will come out when we get a little deeper into the flow.”

When it occurs, this hot fire test will help Orbital ATK validate the changes and enhancements made to the Antares rocket and will ultimately allow the company to return their Cygnus spacecraft to flight operations on the Antares.

But Orbital ATK isn’t waiting for Antares’ return to flight before flying Cygnus again.

Instead, the company is utilizing Cygnus’ unique ability to fly on other launch vehicles to perform their OA4 mission to the ISS this December onboard a United Launch Alliance (ULA) Atlas V rocket.

Using the Atlas V for the OA4 mission will not only allow Orbital ATK to fly Cygnus without Antares, but will also allow for a maximization of pressurized cargo lofted to ISS in the new Enhanced Cygnus spacecraft via the Atlas V’s powerful core stage engines and Centaur upper stage.

With the Enhanced Cygnus and Atlas V combo, the December OA4 flight will haul roughly 3,500 kg of supplies to the orbital outpost and laboratory.

And OA4 will not be the only Cygnus mission hitching a ride to the ISS on an Atlas V.

Under Orbital ATK’s current schedule, 2016 will consist of three Cygnus missions: the OA5, OA6, and OA7 missions.

Two of these three 2016 missions will fly on the company’s newly-upgraded Antares rocket, with the remaining flight going uphill on another Atlas V rocket.

According to Mr. Pinkston, “Prior to the second Atlas [purchase], there was always a plan to build enough hardware to support three Antares missions in 2016. And that plan isn’t changing.

“We will have all the hardware in place with the first mission ready to fly in the early part of 2016. None of that changes [with the purchase of a second Atlas]. The Atlas, nominally, would pick up one of those three missions.”

Mr. Pinkston stressed that the exact schedule of flights for 2016 has not been firmly decided and that it’s unclear at this time which one of the three 2016 Cygnus flights will be on Atlas V instead of Antares.

Adding to this, Frank DeMauro, CRS Program Director for Orbital ATK, stated that “The key thing is the coordination we do with NASA and when they want which mission.

“We’re continuing to work with NASA on their flight planning for next year. So there’s some uncertainty as to when we’ll actually fly that second Atlas mission.”

Importantly, Mr. DeMauro confirmed to NASASpaceflight.com that the newly purchased second Atlas V will launch one of the already planned three Cygnus missions of 2016 and will further help the company meet its cargo up-mass contract requirements to NASA.

Moreover, while initial reports following last October’s loss of the Antares rocket stated that Orbital might purchase as many as three Atlas V rockets from ULA, Mr. DeMauro confirmed that Orbital has no plans to purchase future Atlas V flights for Cygnus beyond the two that are already contracted.

“Our plan is just the two Atlas missions, then we’re back on Antares as our launch vehicle,” stated Mr. DeMauro.

(Images: via L2’s Antares/Cygnus Section – Containing presentations, videos, a vast set of unreleased hi-res images, interactive high level updates and more, with additional images – including the new Atlas V with Cygnus via L2 artist Nathan Koga. Other images via Orbital ATK and NASA).

(Click here: http://www.nasaspaceflight.com/l2/ – to view how you can support NSF and access the best space flight content on the entire internet).