NASA May Not Use SLS for First Orion Lunar Mission

In an abrupt change of plans, NASA's administrator said that NASA is considering using commercial heavy-lift launchers for the Orion capsule's first circumlunar mission. The original plan was to launch on the new (and untested) SLS (Space Launch System, but it's behind schedule, way over budget, and likely won't be ready for the target 2020 launch date of the Orion mission.

Both Spaceflight Now and Ars Technica have articles with details on how the new mission would work, requiring two launches of either the Delta IV Heavy or the SpaceX Falcon Heavy launchers. From Spaceflight Now:

There are no rockets currently in service capable of sending an Orion spacecraft and its service module around the moon, but Bridenstine said a pair of commercial launches could be substituted for one SLS flight. A fully-fueled Orion spacecraft is estimated to weigh around 57,000 pounds (25,848 kilograms), near the maximum lift capability of an SLS Block 1 rocket — the heavy-lift launcher’s initial configuration — on a lunar trajectory.

Bridenstine announced NASA’s new look at commercial launch alternatives to the Space Launch System after committee chairman Sen. Roger Wicker, R-Mississippi, raised concerns about new SLS delays.

“Here’s what we can do, potentially — again, we’re starting the process now — we could use two heavy-lift rockets to put the Orion crew capsule and the European service module in orbit around the Earth, launch a second heavy-lift rocket to put an upper stage in orbit around the Earth, and then dock those two together to throw around the moon the Orion crew capsule with the European service module,” Bridenstine said. “I want to be clear. We do not have, right now, an ability to dock the Orion crew capsule with anything in orbit. So between now and June of 2020, we would have to make that a reality.”

This is good news. The SLS is horribly expensive. Estimates of the cost range from 1.5 billion to 2.5 billion dollars per launch. By contrast, SpaceX charges 163 million dollars for a Falcon Heavy launch, while a Detta IV Heavy launch is just over 350 million dollars. So either option would be between one-eighth to one-half of the cost of an SLS launch. And the SLS has yet to fly.

NASA expects to make a decision on this relatively quickly, possibly within the next couple of weeks. I think they will go with the Delta IV Heavy option, because it's a known quantity and has a successful launch record, while the Falcon Heavy has only flow once.