With the first flight of the Commercial Resupply Services 2 (CRS2) contract for NASA, Northrop Grumman debuted an upgraded Antares rocket. The new Antares 230+ permits greater up-mass capability to the International Space Station to meet the CRS2 contract requirements from NASA.
Launch of the NG-12 Cygnus mission from the Mid-Atlantic Regional Spaceport in Virginia occurred at the opening of a 5-minute launch window at 09:59:47 EDT (13:59:47 UTC) on Saturday, 2 November 2019.
Starting the CRS2 contract:
The start of the CRS2 contract is a huge milestone for Northrop Grumman and NASA.
Northrop Grumman is the first of the three CRS2 providers to begin the contract flights, with SpaceX to follow in 2020 and Sierra Nevada in 2021.
For Northrop Grumman, the road to CRS2 has been one filled with success, lessons, and change.
“This is a special time for us,” noted Frank DeMauro, Vice President and General Manager of Space Systems Division at Northrop Grumman, in a one-on-one interview with NASASpaceflight.
“We’ve actually been working on the CRS2 contract for a few years now in preparation for this particular mission. On the Cygnus side, what’s been so rewarding for our team is not only being able to support the ISS and the crew getting their scientific experimentation and doing their work, but it’s that over the course of the CRS1 contract and now moving into CRS2 we’ve had to continually upgrade the capabilities of the vehicles with the goal of doing more and more support for NASA science efforts on the ISS.
“The capabilities that have been added to Cygnus in order to support that science is very exciting to all of our team.”
Among the changes are an increase to the amount of payload Cygnus can lift to the International Space Station and – crucially – how much unneeded equipment or used experiments Cygnus can dispose of at the end of its Station missions.
Speaking to the significance of the start of the CRS2 contract, Kurt Eberly, Antares Program Manager, said in a one-on-one interview with NASASpaceflight, that “CRS1 was awarded in late 2008 before we had even developed either the rocket or the spacecraft or the launch pad.
“And to get them all developed and operating and start flying in 2013 and finishing the NG-11 mission (last CRS1 contract flight) in early 2019 and then being awarded CRS2 in early 2016, that really kicked off the development of all the key features to bring forward important new capabilities for NASA in CRS2.
“To have that come to fruition is a great feeling, and the Antares teams are really excited to be demonstrating all these capabilities and executing this first launch of CRS2.”
Upgraded Antares 230+ variant:
From the rocket side of the equation, CRS2 is the first flight of the upgraded Antares 230+ variant.
According to Mr. Eberly, “The biggest thing we did was strengthen the airframe of the first stage core. And that was just adding a little bit of metal to a couple of locations. And that allows us to not have to throttle down at MaxQ anymore and just fly at 100% throttle up until we reach the G-force limit, and then we throttle back.
“We now let the Gs ride up a little higher. So we were a little over 4 Gs on the 230 and now we’re a little over 5 Gs for the 230+. That netted us most of the [increased up-mass for CRS2] to just not have to throttle down.”
Additionally, the teams also stripped unneeded inert mass from both the first and second stages to reduce Antares’ mass as well as altered the trajectory the rocket will fly.
“We determined we could lower the perigee of the injection orbit a little bit, and that allows us to take more mass to that lower injection orbit,” noted Mr. Eberly. “Because Cygnus has a very capable bi-propellant system with a high ISP, we could trade that lower injection for more propulsion at a higher ISP and yield a higher mass to orbit capability.”
Greater up-mass on CRS2:
That higher mass to orbit comes in very handy for another new part of the CRS2 contract: the ability to perform cargo late-load at the launch pad less than 24hrs before launch.
For the CRS1 contract, this was not required for Cygnus and Antares because NASA did not mandate it.
But since 2008 when those CRS1 contracts were awarded, NASA realized they needed late-load capability on all their cargo craft, and so the agency made it a CRS2 contract requirement.
Northrop Grumman responded by proposing a redesign to the Antares’ faring to allow for access to Cygnus at the launch pad. They debuted this CRS2 requirement on the final CRS1 flight back in April.
The fairing redesign includes the ability to take the top part, or tip, of the fairing off while inside a mobile cleanroom environment that is wheeled up to Antares after it is taken horizontal at the launch pad.
Late load underway for Antares NG-12. pic.twitter.com/zyHBhHMd4g
— Michael Baylor (@nextspaceflight) November 1, 2019
When the top part of the fairing is removed, crews have access to the forward hatch of Cygnus, which is also then removed, work platforms installed, and late-load cargo items placed inside Cygnus and secured for launch.
Back on NG-11 in April, crews performed late-load operations even though it was not part of the contract for that mission, demonstrating the ability to take six mid-deck experiment lockers up on Cygnus with four of those lockers powered.
For the current NG-12 mission, the number of late-load mid-deck lockers has risen to 10, with six of them powered.
“This is one of the things NASA really wanted: the ability to get time-sensitive cargo to the Station as quickly as possible from the time they deliver to us,” said Mr. DeMauro. “And so from NG-11 to NG-12, we’ve gone up by a significant amount of that final cargo which is primarily the science cargo.”
An additional item from Mr. DeMauro was a note on how well the Antares and Cygnus sides of the team work together.
“The Cygnus and Antares teams have always worked closely together supporting NASA for these missions. But the late load capability with the pop-top fairing and the Mobile Transport Facility [cleanroom], working with the Cygnus team on the timeline and the Antares team on how to get that final cargo load there, that’s one of the best examples of the teamwork that has gone on between the Antares and Cygnus teams to support NASA in their goals. And we’re extremely proud of what they’ve accomplished this year.”
Even more impressive is the ability for the Antares and Cygnus teams to support a swap out or refreshment of late-load, time-sensitive scientific experiments or crew supplies in the event of a 24-hour launch scrub and turn around.
Mr. Eberly noted that “We have the capability to do a 24-hour scrub turn around with refreshing the cargo. It actually turns out to be roughly 23 and a half hours because of the orbit precession [of the ISS]. So, yes, we have that, and we demonstrated it in a pathfinder” earlier this year.
Late-load for this current NG-12 mission began 24 hours ahead of launch, at roughly 10:00 EDT (14:00 UTC) Friday at the Mid-Atlantic Regional Spaceport in Virginia.
Late-load ran through the late-morning and early-afternoon hours local time, before teams moved on to finalize securing of the payload inside Cygnus and close up Cygnus’ forward hatch.
After final hatch mate and pressure checks were complete, the top of the Antares fairing was reinstalled inside the mobile cleanroom environment before that truck rolled away from Antares and the rocket was once again prepared to go vertical.
Antares remained in the horizontal position at the launch pad through the early-night hours before going vertical in the middle of the night just a few hours before the start of countdown operations.
The count began at 05:00 EDT (09:00 UTC) ahead of the opening of the launch window at 09:59:46 EDT (13:59:46 UTC).
Antares is set to lift off tomorrow morning taking the Cygnus, filled with science and supplies, to the International Space Station.
Stay tuned for our coverage here and on YouTube!
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The window ran for 4 minutes and 59 seconds closing at 10:04:45 EDT (14:04:45 UTC).
Sunday’s launch window opened at 08:37 EST (13:37 UTC) and closed five minutes later at 08:42 EST (13:42 UTC).
After launch, Cygnus will raise its orbit to that of the International Space Station’s and – assuming a Saturday launch – perform a two day chase of the Station before rendezvousing with the outpost Monday for grapple by the Station’s Canadarm2 at 05:45 EST (10:45 UTC) ahead of berthing operations.