With their OA7- mission underway and currently berthed at the International Space Station, Orbital ATK is pressing forward with plans for the series of CRS-1 extended contract missions which are set to begin later this year. The company is also proceeding with planning for their six contracted CRS-2 resupply missions to the Space Station, a contract that now offers NASA three different variants of Cygnus vehicles.

CRS-2 contract – three Cygnus options for increase Station needs:

As part of the effort to continue resupply services to the International Space Station following the expiration of the first round of Commercial Resupply Services contracts, CRS-1, NASA announced to potential bidders on 10 April 2014 a series of requirements that would be included for companies to bid on for the delivery and disposal of pressurized and unpressurized cargo to and from the ISS.

The requirements included the delivery of approximately 14,000 to 17,000 kg (31,000 to 37,000 lb) per year of pressurized cargo; the delivery of 24-30 powered lockers per year, requiring continuous power of up to 120 watts at 28 volts, with cooling and two-way communication services; the delivery of approximately 1,500 to 4,000 kg (3,300 to 8,800 lb) per year of unpressurized cargo, consisting of 3 to 8 items, each item requiring continuous power of up to 250 watts at 28 volts, with cooling and two-way communication services; the return/disposal of approximately 14,000 to 17,000 kg (31,000 to 37,000 lb) of pressurized cargo; and the disposal of 1,500 to 4,000 kg (3,300 to 8,800 lb) per year of unpressurized cargo, consisting of 3 to 8 items.

Orbital ATK was one of five companies that submitted contracts for CRS-2 in July 2014 and one of three companies awarded contracts on 14 January 2016 for resupply mission slated to begin in 2019.

To meet NASA’s requirements for the CRS-2 contract, Orbital ATK put together a bid that included three different variants of its Cygnus spacecraft to meet the various requirements for the contract.

In an interview with NASASpaceflight.com, Frank DeMauro, Vice President of Human Space Systems and Space Logistics & CRS Program Director for Orbital ATK, discussed these three Cygnus variants as well as other considerations for the CRS-2 contract.

“With CRS-2, you had to bid pressurized missions and an unpressurized mission,” noted Mr. DeMauro. “So we offered NASA two different types of spacecraft.”

The first version of Cygnus for the CRS-2 contract is similar to the current version of Cygnus, upgraded to carry 10 to 15% more pressurized cargo than CRS-1 Cygnus vehicles can.

But Orbital ATK didn’t stop there. “We also offered a bigger version with an even larger PCM (Pressurized Cargo Module) that would have to use an Atlas V rocket,” stated Mr. DeMauro.

“We did that to give NASA maximum flexibility in picking and choosing the types of missions they want.

In essence, what Orbital ATK proposed for their CRS-2 contract was an Antares-based Cygnus design and an Atlas-based Cygnus to take advantage of both vehicles lifting capabilities – placing the smaller Cygnus on Antares and the larger Cygnus with more cargo on an Atlas V.

Moreover, the third Cygnus option is one that has yet to fly – the unpressurized cargo Cygnus.

“We also bid a mission that was dedicated to unpressurized cargo for ORUs (Orbital Replacement Units) and things like that,” added Mr. DeMauro.

The unpressurized Cygnus would berth just like the current vehicles to one of the ports on ISS.

Then, just as with JAXA’s HTV missions, the Station’s robotic arm – the SSRMS – would grab the unpressurized cargo from Cygnus.

In this configuration, the unpressurized Cygnus would look different than its pressurized counterparts, with a cargo carrier taking the place of the PCM.

“So that’s our portfolio,” noted Mr. DeMauro. “We were selected for the contract, and now NASA has the job to pick and choose and tell us which mission types they want.

“They’ve [already] turned us on for one of the six guaranteed [CRS-2] missions, and that’s an Antares mission. But they haven’t picked the other five.

“So they can come back and say ‘We want all Antares missions’, or ‘We want all Atlas missions,’ or ‘We want two and three.’ And they can throw in a non-pressurized mission if they want.

“NASA has options, and then they tell us what they want to do.”

For the pressurized versions of Cygnus, the modules will be capable of much more than just carrying additional upmass to the Station.

“We are also going to be carrying more science capability,” stated Mr. DeMauro.

“One of the things NASA really wanted was more powered mid-deck lockers, places where they could put payloads that required power to either operate experiments in transit or to keep experiments cool or frozen from the time they’re placed in the vehicle to when they get to ISS.”

Moreover, CRS-2 Cygnus vehicles will carry the ability to accommodate late-stow activities within a day of launch.

The current Cygnus fleet does not carry that capability.

To add these capabilities, Mr. DeMauro noted that CRS-2 Cygnus vehicles will have a larger power supply and additional commanding and telemetry capabilities for the payloads they carry.

“Right now, when we put the payloads in and turn them on, the next time we really talk to them is when we get to the ISS. So in CRS-2, we’ll be able to actually command those experiments ‘on’ or ‘off’ and to monitor telemetry from them constantly – which we can’t do right now.”

Like the current Cygnus fleet, the CRS-2 line of Cygnus vehicles will use the Ultra-flex Solar Arrays and will carry a 60-90 day stay at ISS requirement, though Mr. DeMauro notes that the vehicles will be capable of staying on orbit for longer than 90 days to allow for post-Station experiments and checkouts.

Moreover, the guarantee from NASA for six CRS-2 flights will allow Orbital ATK and the PCM supplier, Thales Alenia Space, to better streamline the Cygnus production process.

“As with any manufacturer, you can get economies of scale in terms of production rates and building things more quickly through the factory,” notes Mr. DeMauro.

“One of the benefits of NASA saying ‘We’re going to give you a minimum of six missions’ is that we can plan for building six of the same or close to the same [spacecraft]. And that helps with the suppliers who can build more efficiently if they’re doing them all at the same time.”

According to the latest-available Flight Panel Integration Planning document, available for download on L2, the first CRS-2 mission for Orbital ATK is slated for July 2019.

(Images: NASA, Jacques Van Oene, and L2 including renders from L2 artist Nathan Koga – The full gallery of Nathan’s (SpaceX Dragon to ITS, SLS, Commercial Crew and more) L2 images can be *found here*)