Two weeks from today the newest Orbital ATK Cygnus cargo freighter is scheduled to launch NASA’s next resupply run to the International Space Station (ISS), and today (March 8) members of the media were invited to visit the spacecraft in the Kennedy Space Center “Payload Hazardous Servicing Facility” clean room, prior to moving to its beachside launch pad for flight.
The mission, OA-6, is scheduled to fly to orbit atop a United Launch Alliance (ULA) Atlas-V 401 booster from Cape Canaveral’s Launch Complex-41 shortly after 11 p.m. ET on March 22, bringing with it 3,513 kg (7,700 lbs.) of crew supplies, hardware, and science experiments to support the Expedition 47 and 48 crews onboard the ISS.
The name “S.S. Rick Husband” has been given to Cygnus OA-6, in honor of the late astronaut who commanded the final voyage of Shuttle Columbia, STS-107, in 2003. The mission is the first one to be named after an astronaut who actually participated in construction of the ISS.
The spacecraft, when encapsulated in its 13-foot-diameter (4-meter) bullet-like payload fairing, weighs in at over 16,500 pounds, making it the heaviest Atlas-V payload ULA will have ever flown, slightly heavier even than the previous OA-4 Cygnus “SS Deke Slayton II” (confirmed to AmericaSpace by ULA this afternoon). Both surpass the 7.5-ton weight of the NAVY’s Mobile User Objective System (MUOS) satellites launched over the last several years from the same pad, which held the title previously.
The launch window March 22 opens at 11:05 p.m. and extends to 11:35 p.m. EDT, unusually long for an ISS chase, which comes courtesy of the performance and capability of ULA’s workhorse Atlas-V. The same was true for the previous Cygnus OA-4 Atlas flight last December.
Jim Sponnick, ULA’s vice president for Atlas and Delta programs, provided the following explanation at the time:
“Instantaneous launch windows are the standard way to accomplish a rendezvous mission with a low-earth object like the ISS, and this approach can significantly limit the probability of an on-time launch. We always strive to implement longer launch windows in our mission designs, to maximize the probability of a first-day launch for our customers. We have been enhancing our mission design capabilities and operational processes for years in order to make good use of the launch vehicle performance to provide the flexibility to accomplish launch window objectives.”
Orbital ATK’s own rocket, the now upgraded Antares, is currently preparing for its own series of tests and Return-to-Flight later this year with “new” Russian RD-181 engines. But until then the company, who holds a multi-billion dollar Commercial Resupply Services (CRS-1) contract with NASA, is dependent on the Atlas-V to continue fulfilling their commitment to the ISS until Antares is ready to fly Cygnus again.
The OA-6 spacecraft as a whole marks the second flight for Orbital ATK’s new enhanced version of the original Cygnus, featuring an extended Pressurized Cargo Module (PCM), a lighter Service Module (SM), and new lightweight Ultraflex solar arrays—upgrades which will enable the SS Rick Husband to fly nearly as much weight as the last three Cygnus missions combined (prior to OA-4).
“We had a great mission on CRS-4 (OA-4)”, said former astronaut Dan Tani, now senior director of Missions and Cargo Operations for Orbital ATK. “There were a few workarounds we needed to do, but it was so minor we didn’t make any changes to this vehicle.
Cygnus will be transported to nearby pad 41’s beachside Atlas Vertical Integration Facility (VIF) to meets its rocket in the coming days (usually 7-10 days before scheduled T-0). Following final integrated testing and closeout preparations for launch, SS Rick Husband and its Atlas booster will roll to their nearby launch pad on the morning on March 21.
ULA noted in comments to AmericaSpace today that the Atlas booster itself is processing well with no issues reported.
Some of the payloads include:
- Strata-1: An investigation into the properties and behavior of regolith on small, airless bodies.
- Gecko Grippers: An investigation testing a gecko-adhesive gripping device that can stick on command in the harsh environment of space.
- Spacecraft Fire Experiment-I (Saffire-I): An experiment to intentionally light a large fire inside Cygnus after it leaves the ISS, measuring flame growth, oxygen use and more to improve understanding of fire growth in microgravity and safeguard future space missions.
- Meteor: The first space-based observations of the chemical composition of meteors entering Earth’s atmosphere.
“It’s like Christmas,” said Dani as he recalled his own experiences with resupply spacecraft arriving at the ISS in 2007 and 2008. “It’s exciting to watch another vehicle approach and dock. It’s like opening a big box of goodies and finding some stuff that you’ve been wanting and finding some surprises you didn’t know about.”
The one-time use cargo ship will remain attached to the ISS for approximately two months, before departing for pieces at the bottom of the Pacific Ocean.
Orbital ATK’s CRS-1 contract with NASA, signed in December 2008, required the Dulles, Va.-based company to fly eight dedicated Cygnus missions to the ISS by 2016 to deliver a total of 44,000 pounds of payloads and other items. To date, Orbital ATK has delivered 7,300 kg (16,093 lbs) of cargo to the ISS over the course of four successful missions under the current CRS-1 contract.
The contract has since since been extended, and NASA has since given Orbital ATK two additional missions under CRS-1, missions OA-9e and OA-10e, giving Cygnus 10 flights under CRS-1 instead of the original eight.
However, the increased capability of the ULA Atlas-V compared to the Orbital ATK Antares means ULA can haul 35 percent more cargo to orbit, which would have allowed Orbital ATK to fulfill their original CRS-1 contract in seven flights instead of eight. Now, with the contract extended to 10 flights, it is expected that Orbital ATK will only really need nine, with the 10th Cygnus CRS-1 contract flight optional depending on the needs of NASA and the ISS.
Orbital ATK also recently secured a CRS-2 contract for ISS resupply missions through the first half of the 2020s, providing NASA the option to use both the Antares and Atlas-V based on payload weight.
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