I’m Anthony Colangelo.

Boeing’s proposal won Phases 2 and 3 of DARPA’s XS-1 program, and I’m pretty bummed about it. And the Air Force announced that SpaceX will launch the fifth X-37B mission in August.

Dr. Thomas Lang, Professor of Radiology and Biomedical Imaging at the UCSF School of Medicine, joins the show to discuss human health and physiology in space.

Rand Simberg joins me to talk about his recent trip to the Space Tech Expo, the dawning of the age of in-space manufacturing, the future of SLS and Orion, the National Space Council, and a lot more.

Last week was rough for the Space Launch System. An issue with weld tooling was discovered, with some serious consequences, and then a LOX tank dome was dropped and damaged beyond repair. To top it off, NASA announced that EM-1 will fly without crew, and is delayed until 2019.

Eric Berger, Senior Space Editor at Ars Technica, joins me to talk SLS/Orion, New Space vs. Old Space, space policy in the Trump administration, and why the fight might not be settled until 2020.

As the award date approaches for the 2018 Air Force launch vehicle development contracts, we keep hearing from Congress about how they would like to see it go. And I discuss the future of Antares and the Next-Generation Launch Vehicle in light of the continuing flights of Cygnus on Atlas V.

SpaceX made history this week by launching SES-10 with a previously-flown first stage. I discuss implications of this achievement, the things we learned from Elon Musk in the post-flight press briefing, and the doubters, as always.

The last two weeks have been filled with a bunch of smaller stories—SpaceX’s GPS III bid win and upcoming SES-10 launch, ULA’s decision on Vulcan’s engines and Congress’ potential meddling, and the ISS beyond 2024.

This week, Blue Origin shed some more light on New Glenn—by way of an animation, launch agreements, and a talk by Jeff Bezos at Satellite 2017—and the first fully-assembled BE-4 shipped to their test site in Texas for a hot firing. I discuss the new details we learned and how New Glenn will fit into the industry in the 2020s.

This week is all about #hotdrama, with two surprise media briefings: one from NASA on a potential crewed EM-1, and one from SpaceX on a privately-crewed journey around the Moon—riding on a Dragon 2 and Falcon Heavy—at the end of 2018. I discuss the implications of both, and go on a rant about SpaceX and “focus.” This episode of Main Engine Cut Off is brought to you by 5 executive producers—Pat, Matt, Jorge, Brad, and one anonymous—and 34 other supporters on Patreon.