Commercial resupply of space station blasts off Sunday
BY STEPHEN CLARK
Posted: October 5, 2012
SpaceX is poised to start work on a $1.6 billion contract with NASA on Sunday, when a Falcon 9 rocket is set to blast off with 882 pounds of supplies on the first operational commercial cargo flight to the International Space Station.
Launch officials gave the green light for final countdown preparations during a Launch Readiness Review on Friday.
Hydraulic pistons will lift the 157-foot-tall booster vertical on the launch pad, and the automated countdown will begin at 1:05 p.m. EDT (1705 GMT).
Fuel tanks in the two-stage rocket will be filled with kerosene and liquid oxygen propellants, and liftoff is targeted for 8:35 p.m. EDT (0035 GMT Monday).
The mission is the first of 12 launches SpaceX plans under a $1.6 billion Commercial Resupply Services, or CRS, contract with NASA. The space agency reached agreements with SpaceX and Orbital Sciences Corp. in December 2008 to provide commercial cargo deliveries to the space station following the retirement of the space shuttle.
SpaceX completed three test flights of its Falcon 9 rocket and two Dragon flights before NASA approved the start of regular service.
The company's successful Dragon flight in May reached the space station and returned equipment to Earth, fulfilling the final demonstration objectives spelled out in an agreement with NASA.
The space agency in August announced SpaceX would be allowed to begin its dozen resupply missions with the next Falcon 9 launch.
Measuring 14.4 feet tall and 12 feet in diameter, the Dragon spacecraft is the newest member of a fleet of resupply freighters servicing the space station. Russia's Progress vehicle, Europe's Automated Transfer Vehicle, and Japan's H-2 Transfer Vehicle also fly to the outpost.
During the last space shuttle mission in July 2011, NASA stocked the space station with enough supplies to comfortably last until some time in 2013, giving commercial operators time to finish developing spacecraft and rockets.
SpaceX plans about three missions per year to the space station through 2016.
Orbital Sciences expects to begin service next year on its contract for nine resupply flights worth $1.9 billion.
Orbital has scheduled two test flights before then, the first of which should occur before the end of this year from a commercial launch pad at NASA's Wallops Flight Facility in Virginia, according to the company.
About 882 pounds of supplies are stowed inside the uncrewed capsule's pressurized cabin. The cargo includes 260 pounds of food and clothing, a refrigerator to store experiment samples, a rack for fluids investigations in microgravity, and payloads for Japan and European labs.
If all goes according to plan, the spacecraft will reach the complex Wednesday after a series of rocket burns designed to fine-tune the capsule's orbit to match the space station's trajectory.
Flying at a velocity of 5 miles per second, the Dragon will approach the space station from below and hold at a point about 30 feet below the outpost.
Japanese astronaut Aki Hoshide, operating the space station's robotic arm, will grapple the spacecraft around 7:32 a.m. EDT (1132 GMT) and move the ship into position on the Earth-facing port on the Harmony module.
The astronauts are scheduled to open the hatch to the Dragon on Thursday and begin unpacking the fresh supplies.
The spacecraft will stay at the complex for 18 days before departing Oct. 28 and returning to Earth with a parachuted-assisted splashdown in the Pacific Ocean west of Mexico.
It will come back to Earth with 1,673 pounds of equipment.
Since the shuttle's retirement, the Dragon is the only vehicle capable of returning significant cargo from the space station to Earth.