Cygnus cargo flight set for launch to space station
Update: Thursday's scheduled launch was postponed due to thick clouds and rain in the area.
An enhanced Cygnus cargo ship loaded with nearly 4,700 pounds of equipment and supplies bound for the International Space Station is "go" for launch Thursday atop an Atlas 5 rocket, one of two purchased by Orbital ATK to help make up for a spectacular launch failure last year.
The Atlas 5, built by United Launch Alliance, is scheduled for liftoff from complex 41 at the Cape Canaveral Air Force Station at 5:55:45 p.m. EST (GMT-5), roughly the moment Earth's rotation carries the pad into the plane of the space station's orbit. Forecasters predicted a 60 percent chance of favorable weather.
Assuming an on-time liftoff, the unpiloted Cygnus spacecraft will reach the lab complex early Sunday, pulling up to within about 30 feet and then standing by while astronaut Kjell Lindgren, operating the station's robot arm, locks onto a grapple fixture.
From there, ground controllers in Houston will remotely operate the arm to pull the cargo ship in for berthing at the Earth-facing port of the central Unity module.
Packed inside: nearly 2.5 tons of computer gear, science equipment, student experiments, spacesuit components, high pressure oxygen and nitrogen tanks, food, clothing, spare parts and Christmas gifts for the crew.
This will be Orbital's first space station resupply mission since a Cygnus spacecraft was destroyed Oct. 28, 2014, when its Orbital-designed Antares booster suffered a catastrophic main engine failure 15 seconds after liftoff from the Mid Atlantic Regional Spaceport at NASA's Wallops Island, Va., launch site.
In the wake of the failure, Orbital managers decided to discard the 1970s-era Russian engines used in the five Antares rockets launched to that point and to replace them with state-of-the-art RD-181 engines, also built in Russia. The first flight of a re-engined Antares is planned for late May.
In the meantime, Orbital purchased two Atlas 5s from ULA to to help make up for the Antares failure and fulfill the company's $1.9 billion contract with NASA to deliver some 44,000 pounds of supplies and equipment through 2016.
"It's been a challenge to get back to this point after our mishap at Wallops, but return to fight became the company's very, very sharp focus after that," said Frank Culbertson, a former shuttle commander and space station crew member who now serves as president of Orbital's Space Systems Group.
"Within a few days, actually, we had a plan," he said. "With the help of our friends at ULA who stepped forward and offered us a ride, in a very short period of time we've reached this point, and we're very excited about it."
Using the two, more powerful Atlas 5 rockets and an already planned "enhanced" version of the Cygnus, which can carry 30 percent more cargo, Orbital expects to fulfill its contract on schedule with just seven missions.
The Orbital launch failure was the first of three station resupply mishaps that included the loss of a Russian Progress supply ship in April and a SpaceX Dragon cargo ship in June. Since then, the Russians have successfully launched two Progress missions and Japan launched one of its large HTV cargo ships.
With the Cygnus arrival Sunday and another Progress mission later this month, station managers say they will be well on the way to restoring lost margin.
But Kirk Shireman, NASA's space station program manager, said it will still take many months to make up for the three failures. As it now stands, the station has enough food on board to last until April if no more cargo ships show up, he said.
NASA typically likes to maintain a six-month cushion in food and critical consumables.
"Food and science have been our number one priorities, and we've been consuming these spares," he said. "I expect ... a year from now and things go according to plan, we'll be in a very robust configuration."
