For the second day in a row, SpaceX scrubbed the launch of the SES-9 telecommunications satellite as well as the Falcon 9 rocket landing attempt that was due to follow.
The abort came with just 1 minute and 41 seconds left before the scheduled 3:47 p.m. PT (6:47 p.m. ET) liftoff from Cape Canaveral Air Force Station in Florida.
“Right now, preliminary [word] is that we were still evaluating the liquid oxygen propellant load, looking at how much time we had left in the count to finish loading the liquid oxygen, and at that time the launch team decided that we would need to hold the countdown,” SpaceX launch commentator John Insprucker said.
It was not clear when the next launch opportunity will come up.
The mission’s main objective is to put the SES-9 satellite into a geostationary transfer orbit. That’s the first step toward putting the satellite into position to provide high-speed data and TV services to millions of users in the Asia-Pacific region.
SpaceX’s secondary objective is to bring the Falcon 9’s first stage back down for a rocket-powered landing on an autonomous spaceport drone ship stationed in the Atlantic Ocean.
This launch has been delayed for months, due to scheduling complications in the wake of last June’s failure of a Falcon 9 space station resupply mission. For that reason, SES is anxious to get its satellite in the proper orbital position as quickly as possible.
SpaceX has stretched the Falcon 9’s capabilities to send the satellite to the desired orbit. It’s not certain whether there’ll be enough propellant left over after the ascent to get the booster to the drone ship. As a result, SpaceX has been lowering the expectations for the landing.
“A successful landing is not expected,” SpaceX said in its press kit for the mission.
SpaceX has been taking pains to make sure the Falcon 9 is at its best for this launch. The company called off Wednesday’s planned launch attempt with a half-hour left in the countdown, and used the extra day to make sure that the liquid oxygen propellant was as cold as possible. The oxygen becomes denser when it’s colder, which means more of it can be packed into the rocket’s tanks.
More oxidizer maximizes the chances of a successful launch, as well as a successful landing on the drone ship. The ship is known as “Of Course I Still Love You.” That weird moniker serves as a tribute to science-fiction author Iain M. Banks and the fanciful names he gave to his fictional sentient starships.
Of course SpaceX’s fans will still love the company and its billionaire founder, Elon Musk, even if the landing doesn’t work. SpaceX pulled off an onshore Falcon 9 first-stage landing in December, and came close to success in three offshore landing attempts dating back to the start of 2015.
An onshore landing is generally preferable, but SpaceX still wants to perfect the at-sea landing routine. That’s because there will be many occasions when a booster won’t have enough fuel left in its tanks to fly itself back to the mainland after an orbital launch. The SES-9 launch is a case in point.
Bringing back the boosters intact is a key part of SpaceX’s strategy for making rockets more reusable and driving down the cost of access to orbit.
Musk has said full reusability could lead to a 99 percent reduction in launch costs. That level of cost reduction is what’s needed if Musk is to succeed in his grand goal to send thousands of settlers to Mars. And even if today’s landing doesn’t succeed, the data gained during the attempt should take SpaceX one small step closer to that grand goal.
