* One-day delay due to thruster problem
* Carries food, equipment, science experiments
* Return to Earth slated for March 25
By Irene Klotz
CAPE CANAVERAL, Fla., March 3 A SpaceX Dragon
cargo capsule overcame a potentially mission-ending technical
problem to make a belated but welcome arrival at the
International Space Station on Sunday.
Astronauts aboard the outpost used the station's robotic arm
to pluck the capsule from orbit at 5:31 a.m. EST/1031 GMT as the
ships sailed 250 miles (400 km) over northern Ukraine.
Flight controllers at NASA's Mission Control in Houston then
stepped in to drive the capsule to its berthing port on the
station's Harmony connecting node. Docking occurred at 8:44 a.m.
The Dragon capsule, loaded with more than 2,300 pounds
(1,043 kg) of science equipment, spare parts, food and supplies,
blasted off from Cape Canaveral Air Force Station in Florida on
Friday aboard a SpaceX Falcon 9 rocket for the second of 12
planned supply runs for NASA.
SpaceX is the first private company to fly to the station, a
$100 billion project of 15 nations.
Dragon was to have arrived at the station on Saturday but a
problem with its thruster rocket pods developed soon after
reaching orbit. Engineers sent commands for Dragon to flip
valves and clear any blockage in a pressurization line in an
attempt to salvage the mission.
By Friday evening, Dragon had fired its thruster rockets to
raise its altitude and begin steering itself to rendezvous with
The orbital ballet ended when station commander Kevin Ford,
working from a robotics station inside the outpost, grabbed the
capsule with the station's robot arm.
"As they say, it's not where you start but where you finish
that counts. You guys really finished this one on the mark,"
Ford radioed to Dragon's flight control team in Hawthorne,
California, and NASA's Mission Control in Houston.
"What a fantastic day," Ford said.
Once Dragon's hatch is open, the station crew will spend the
next several days unpacking the food, clothing, supplies and
science experiments from the capsule. The research includes
studies on plant seedlings, mouse stem cells and combustion in
SpaceX also sent the crew a gift of fresh fruit from an
employee's father's orchard, company president Gwynne Shotwell
Ground controllers will use the station's robot arm again on
Wednesday to unpack equipment for a future spacewalk that is
stowed in Dragon's unpressurized trunk.
Once the capsule is unloaded, the crew will begin refilling
it with 3,000 pounds (1,361 kg) of unneeded and broken equipment
and science samples for analysis on Earth.
Dragon is the only station freighter that makes return
trips, a critical service that was lost after the U.S. shuttle
program ended in 2011. Cargo ships flown by Russia, Europe and
Japan incinerate in the atmosphere after leaving the station
Dragon's departure and parachute splashdown in the Pacific
Ocean is scheduled for March 25.
Dragon's flight is the second of 12 missions for privately
owned Space Exploration Technologies, known as SpaceX, under a
$1.6 billion NASA contract. Following a successful test flight
to the space station in May 2012, SpaceX conducted its first
supply run to the orbital outpost in October.
A second firm, Orbital Sciences Corp is due to debut
its freighter this year.
NASA turned to private companies for delivering supplies to
the station following the retirement of its shuttle fleet. The
agency hopes to buy rides commercially for its astronauts as
well beginning in 2017.