A long-standing plan to launch the moon mission Orion on board the massive Space Launch System (SLS) is being rethought.

The news: NASA administrator Jim Bridenstine has just delivered some unexpected news. Before the US Senate Committee on Commerce, Science, and Transportation on Wednesday morning, he opened up the possibility of using commercial rockets to first launch the Orion Crew Capsule (without an actual crew on board, to begin with). That marks a big change from using the planned Space Launch System (SLS), the largest (and much-delayed) rocket that’s ever been built in US history.

What he said:

“SLS is struggling to meet its schedule. It was originally intended to launch in December in 2019 and no later than 2020. We are now understanding better how difficult this project is, and it’s going to take some additional time,” said Bridestine. “I want to be really clear. I think we as an agency need to stick to our commitments. If we tell you, and others, that we’re going to launch in June of 2020 around the moon, which is what EM-1 is, I think we should launch around the moon in June of 2020. And I think it can be done. We should consider, as an agency, all options to accomplish that objective. Some of those options would include launching the Orion Crew Capsule and European Service module on a commercial rocket.”

Pick your rocket: While he didn’t directly name any possible rockets, there are only two realistic possibilities: United Launch Alliance’s Delta IV Heavy and SpaceX’s Falcon Heavy. But there’s still a long way to go before they would be ready.

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