A capsule carrying cargo to the International Space Station ran into trouble shortly after its Friday morning launch from Cape Canaveral, Fla., but officials expressed confidence later in the day that the mission would go forward.
On its third commercial mission to the space station under contract with NASA, Hawthorne-based Space Exploration Technologies Corp., or SpaceX, ran into a thruster issue with its Dragon capsule as it orbited around the Earth.
The capsule is packed with more than 1,200 pounds of food, scientific experiments and other cargo for delivery to the six astronauts aboard the space station. But trouble struck when SpaceX engineers found that only one of the spacecraft's four thruster pods, which help maneuver the capsule in orbit, was working.
By late afternoon, both NASA and the company said all four pods were operational and the mission was back on track.
"The company will continue to check out Dragon, test its systems ... and perform some orbital maneuvers," NASA said in a statement. "The next opportunity for Dragon to rendezvous with the International Space Station is early Sunday, if SpaceX and NASA determine the spacecraft is in the proper configuration and ready to support an attempt."
In a conference call with reporters, SpaceX Chief Executive Elon Musk said the problem was initially "frightening" but was under control. "I think it was essentially a glitch of some kind and not a serious thing."
Musk speculated the problem could be traced back to a stuck valve or other blockage that caused a drop in pressure in the pods' oxidizer tanks. But he cautioned that it was too soon to determine the cause.
NASA requires at least three thrusters be functioning for the capsule to approach the space station. Now that the thrusters are online, the space agency will review the data before giving the go-ahead for docking.
William Gerstenmaier, NASA's associate administrator for Human Exploration and Operations, said during the conference call that the agency would "make sure it doesn't put the station in danger."
The initial mission plan was that Dragon would reach and attach to the space station Saturday and would return to Earth on March 25, splashing down in the Pacific Ocean about 300 miles off the coast of Baja California. Those plans are subject to change.
The mission began without a hitch on an overcast morning, when SpaceX's Falcon 9 rocket launched from Space Launch Complex 40 at Cape Canaveral Air Force Station and sped through the clouds on its way to the space station.
However, about 12 minutes into the mission, a problem arose after the spacecraft separated from the rocket's upper stage.
John Insprucker, Falcon 9 product director, told viewers during SpaceX's live webcast: "It appears that although it reached Earth orbit, Dragon is experiencing some type of problem right now. We'll have to learn the nature of what happened."
The live webcast was then shut down.
SpaceX, Musk and NASA posted updates throughout the day on their websites and Twitter feeds to keep the public informed.
On the teleconference, which was made before all four thruster pods were put back in operation, Musk said: "We're definitely not going to rush" docking with the space station.
The company has already performed successful NASA resupply missions to the orbiting outpost. There was one official mission in October, and a demonstration mission took place in May.
Both of those missions also had problems.
In May, a problem with the Dragon's onboard sensors pushed back its capture by the space station to about two hours later than planned.
In October, one of the nine engines on the massive Falcon 9 rocket experienced a problem and shut down shortly after launch. Because of the glitch, a satellite the rocket was carrying didn't reach proper orbit, but the NASA resupply mission went on as planned and the Dragon capsule connected with the space station.
SpaceX is the only commercial company so far to resupply the space station. The company has secured a $1.6-billion contract to carry out 12 cargo missions, and if the current mission is successful, it would be the second.
NASA wants to turn the job of carrying cargo and crews over to private industry. Meanwhile, the agency will focus on deep-space missions to land astronauts on asteroids and Mars.
SpaceX, founded in 2002, employs nearly 3,000 scientists, engineers and technicians, many of whom work at the company's sprawling production facility in Hawthorne where it builds rockets and capsules.
But SpaceX is not alone in the so-called private space race. Orbital Sciences Corp. of Dulles, Va., is nipping at the company's heels, with a test flight of its commercial rocket set for later this year. Orbital also has a $1.9-billion cargo-hauling contract with NASA.
The idea is that the cargo missions will one day lead to privately run manned missions. Critics, including some former astronauts, have voiced concerns about NASA's move toward private space missions. They have said private space companies are risky ventures with unproven technology.
But currently the United States government has no way for its astronauts to reach space other than doling out $63 million for a seat on a Russian Soyuz rocket.