SpaceX Dragon cargo craft ISS re-supply mission delayed

The SpaceX Dragon spacecraft is being prepared for launch inside the SpaceX hangar at Cape Canaveral. 

Photo credit: SpaceX 

The next supply run by SpaceX Dragon spacecraft to the International Space Station (ISS) has been delayed because of what sources described as apparent contamination that could pose problems for research hardware carried by the Dragon spacecraft.

SpaceX was scheduled to launch a cargo ship from Cape Canaveral, Fla., before dawn on Sunday when engineers noticed contamination of some sort on the Dragon's lower unpressurized trunk section..

On Thursday, the private company said it needed more time and postponed the launch for two weeks, until March 30.

Dragon, the unmanned capsule, holds about 2 tons of supplies and experiments.

It will also take up a pair of legs for the humanoid robot at the space station. Until now, Robonaut-2 has been stuck on a pedestal.

Two of six electrically powered payloads aboard the Dragon are mounted in the trunk section, a first for this mission, and engineers were concerned the contamination might "outgas" in orbit and cause problems for the station-bound hardware.

One of the payloads, the Optical Payload for Lasercomm Science (OPALS), "will test the use of laser optics to transfer information to Earth from space," according to the NASA-SpaceX press kit.

The other trunk payload includes four High-Definition Earth Viewing (HDEV), cameras that will be mounted on the station's hull.

Both payloads will be removed from the trunk by the station's robot arm.

By delaying the flight to the end of the month, engineers will have time to correct the problem while making way for the planned March 25 launch of a Russian Soyuz spacecraft carrying three crew members to the international outpost.

This will be the third operational commercial resupply mission carried out by SpaceX under a $1.6 billion contract with NASA that calls for at least 12 flight to deliver some 44,000 pounds of cargo to the space station.

In a brief statement, SpaceX acknowledged the launch delay for the CRS-3 mission, but did not provide any details as to what prompted it.

"To ensure the highest possible level of mission assurance and allow additional time to resolve remaining open items, SpaceX is now targeting March 30th for the CRS-3 mission launch, with April 2nd as a back-up," the company said in an email release.

"These represent the earliest available launch opportunities given existing schedules, and are currently pending approval with the (Air Force Eastern) Range.