Orbital ATK resumes U.S. cargo missions to ISS

An Atlas V rocket is targeting a 4:44 p.m. Sunday launch from Cape Canaveral Air Force Station with a Cygnus cargo spacecraft bound for the International Space Station.

If it succeeds, this will be the fourth Orbital ATK mission (OA4) of approximately 10 as part of their commercial resupply services contract to deliver 28,700 kilograms (63,272 pounds) to the International Space Station.

Poor weather scrubbed launch attempts Thursday and Friday, and caused a third try on Saturday to be postponed.

“Within a few days [of the failed launch last year], we had a plan”, Frank Culbertson, Space Systems Group president at Orbital ATK and retired NASA astronaut, said in a press briefing Wednesday (Dec. 2). The mission marks Orbital’s first return to space since its Antares rocket blew up shortly after take off at NASA’s Wallops Flight Facility in October 2014. NASA’s other commercial supplier, SpaceX, is also sidelined by a launch accident.

In addition, Cygnus will deliver replacement cargo items including a set of Microsoft HoloLens devices for use in NASA’s Sidekick project, a safety jet pack astronauts wear during spacewalks known as SAFER, and high pressure nitrogen and oxygen tanks to plug into the station’s air supply network. Once on its own, the space swan will spread its new, Ultraflex solar arrays and upgraded power systems to arrive at the station on December 9th.

Orbital’s Cygnus spacecraft is expected to reach the orbiting station, traveling at 17,500 mph some 250 miles high, later in the week. The station’s robotic arm will grapple the spacecraft and berth it to the Earth-facing port on the Node 1, or Unity, module, the first time that docking port has been used by a cargo spacecraft. Cygnus’ cargo includes a mix of supplies and equipment, research materials and personal goods.

Orbital ATK has three CRS missions scheduled in 2016 to support ISS cargo needs.

Cygnus would stay attached to the station for more than a month, when it will act as a giant space dumpster.

Orbital ATK’s OA-4 Cygnus mission patch.

Supplies at the station have been running low following several failed supplied runs. Toilet supplies run out in February, said station program manager Kirk Shireman.

The ISS is also supplied by deliveries from Russia, Japan and Europe.

“It’s our first time launching the enhanced Cygnus which allows us to carry a lot more cargo to the ISS”.

The Cygnus spacecraft will launch into space atop the United Launch Alliance Atlas V rocket.