SpaceX postpones its next ISS mission

The Falcon 9 rocket that will launch the next Dragon spacecraft is shown in its hangar in a photo released by SpaceX earlier this week. This is the first Falcon 9 to feature landing legs on its first stage. (credit: SpaceX)

The crew of the International Space Station (ISS) will have to wait a little longer for its next batch of supplies, and fans of reusable launch vehicles (RLVs) will have to wait a little longer for a key technology test.

SpaceX announced late Thursday that the launch of its next Falcon 9, on the third of twelve Commercial Resupply Services (CRS) missions to the ISS, had been postponed. The launch, previously planned for 4:41 am EDT (0841 GMT) Sunday, is now planned for the evening of March 30, with a backup launch date on April 2. The company was vague regarding the delay, saying only it needed to “allow additional time to resolve remaining open items.” However, CBS News reported the delay was triggered after engineers found contamination of some kind in the unpressurized trunk of the Dragon cargo spacecraft that could adversely affect two payloads contained in it: a laser communications experiment and high-definition cameras, both to be installed on the ISS.

(True to form, SpaceX was stingy with the information it provided, distributing the press release to a select group of media by email late Thursday afternoon, but not posting anything to its social media accounts, including Twitter and Facebook, for several hours. As of this writing, more than 12 hours after the announcement of the delay, there’s still no copy of the press release or other notice about the delay on the company’s website.)

The primary purpose of the launch is to deliver the Dragon spacecraft to the ISS. The spacecraft, flying a mission the company calls CRS-3 and what NASA designates at SpX-3 (to differentiate it from Orbital Sciences’ CRS missions), will carry nearly 2,100 kilograms of supplies to the station and return about 1,600 kilograms of cargo to Earth at the end of its mission, according to the mission press kit.

Many people, though, have been interested in this mission for reasons other than the Dragon spacecraft. Company officials have said they plan, after the first stage separates, to attempt what might be considered a “soft splashdown” of the stage, reigniting engines during descent to slow the stage down. SpaceX attempted something similar on the first Falcon 9 v1.1 launch in September, achieving some success, although the spinning of the stage pushed the remaining propellant to the walls of their tanks, shutting down the engines prematurely. This Falcon 9 is the first to be equipped with landing legs on the first stage that, eventually, will allow the stage to make a powered vertical landing on land; the legs clearly won’t be used for that on this mission, but will be tested during the descent.