A wayward boat and a load of liquid oxygen that got too warm forced SpaceX to abort what might have been a successful launch of the SES-9 telecommunication satellite today, just as the engines were firing up.
The snags mean SpaceX will have to wait until at least Tuesday for the next opportunity to launch its Falcon 9 rocket from Cape Canaveral Air Force Station in Florida, and to try landing the first-stage booster on an oceangoing platform in the Atlantic.
Today marked the third scrub for the launch, which is aimed at putting Luxembourg-based SES’ satellite into orbit to provide TV and data services to customers in the Asia-Pacific region. The first two delays were due to concerns over chilling down the rocket’s liquid oxygen propellant to the optimal temperature. Liquid oxygen played a role in today’s postponement as well, but there were a couple of additional twists.
The countdown was held up for more than a half-hour because an unauthorized vessel was in the “keep-out zone,” which is meant to keep boat traffic out of harm’s way as the rocket passes overhead. After a helicopter went out to shoo the ship out of the zone, SpaceX got clearance to launch at 7:21 p.m. ET (4:21 p.m. PT).
When the countdown clock reached zero, the engines flared up – and then immediately shut themselves down.
SpaceX’s billionaire founder, Elon Musk, said in a tweet that the shutdown was triggered by a low-thrust alarm about the engines. He said rising temperatures in the liquid oxygen tanks contributed to the weak thrust, and suggested that the launch might have gone ahead if it weren’t for the earlier countdown hold.