A United Launch Alliance Atlas V rocket carrying an Orbital ATK Cygnus spacecraft on the OA-4 mission launches from the Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida at 4:44 p.m. EST on Sunday, Dec. 6, 2015.
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With two hours remaining in the countdown, forecasters announced that the wind that had spoiled previous launch attempts finally had eased, and the sky was clear save for a few wispy clouds. High wind on Saturday forced a third delay for the first US shipment of space station supplies since spring.
The Atlas V rocket left Cape Canaveral Air Force Station on Sunday. Each operator has had one failed launch.
With more than a century of combined heritage, United Launch Alliance is the nation’s most experienced and reliable launch service Provider. Once they arrive, the station’s astronauts will try them out as wearable aids for in-space operations.
A new microsatellite deployment system and a microsatellite will be sent to the ISS for the first time and will have to be floated through the station for deployment out of an airlock. The twin failures, both ending in spectacular fireballs that caused millions of dollars of loss, made some question NASA’s decision to contract out such important and hard missions to the private sector. Orbital’s Antares rocket is still grounded following a 2014 launch explosion that damaged a Virginia launch pad.
The California-based space transport company SpaceX now has an agreement with the American space agency, which is valued at $1.6 billion, to launch around 12 unmanned ISS missions using its Falcon 9 spacecraft and Dragon capsule. But it picked up the slack and has another resupply mission scheduled just before Christmas; Japan has chipped in as well. At the station, astronauts will unload 3,349.0 kilograms (7,383.3 pounds) of cargo before reloading the spacecraft with garbage for a destructive reentry in January.
Cygnus would stay attached to the station for more than a month, when it will act as a giant space dumpster. Toilet supplies run out in February, said station program manager Kirk Shireman.
After a 21 minute ascent, the Deke Slayton II was released into orbit from the Atlas V’s Centaur second stage to begin its rendezvous with the space station. Normally used for hefty satellite launches, it is the mighty successor to the Atlas used to put John Glenn into orbit in 1962.
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Orbital ATK arranged to use United Launch Alliance’s Atlas V rocket while it upgrades its Antares rocket, which failed due to a problem with its reconditioned Ukrainian engine. All cargo was lost, leaving the station to manage with smaller loads of supplies brought by other craft.
