Main Engine Cut Off

Tom Mueller, founder and CEO of Impulse Space and veteran rocket engine engineer, discusses in-space mobility hardware. He recounts Mira’s flight history and Helios’ upcoming launch. He covers propulsion roadmaps from chemical to electric, new Colorado facilities, defense contracts, and plans to move large cargo to the Moon and beyond.

A sudden Artemis roadmap overhaul cancels major upgrades and refocuses on faster, simpler SLS flights. Plans shift Artemis 3 to an LEO test while making Artemis 4 the first lunar landing. The show digs into technical tradeoffs, program politics, contractor fallout, and whether an accelerated flight cadence can actually fix SLS problems.

Loren Grush, Bloomberg space reporter known for scoops on SpaceX, Blue Origin, and NASA. She breaks down SpaceX’s acquisition of xAI and how it ties to IPO plans. They discuss Blue Origin pausing New Shepard and what that means for its strategy. They also cover the Artemis II wet dress rehearsal and the resulting launch delay.

Artemis II is on the pad, and I can’t stop thinking about it. So I guess listen to me think in the open? Also, a ton of Blue Origin news—the next flight of New Glenn will feature a flown booster, they’ve announced constellation plans under the name TeraWave, and Tory Bruno has left ULA to join the team at Blue.This episode of Main Engine Cut Off is brought to you by 33 executive producers—Matt, Fred, Will and Lars from Agile, Kris, Lee, Jan, Frank, Miles O’Brien, Josh from Impulse, Theo and Violet, Ryan, Joakim, Stealth Julian, Heiko, Tim Dodd (the Everyday Astronaut!), Better Every Day Studios, Joel, Steve, Joonas, The Astrogators at SEE, Pat, Warren, Natasha Tsakos, Russell, David, Donald, and four anonymous—and hundreds of supporters.TopicsNASA’s Moonbound Artemis II Rocket Reaches Launch Pad - NASAFinal Steps Underway for NASA’s First Crewed Artemis Moon Mission - NASAIs Orion’s heat shield really safe? New NASA chief conducts final review on eve of flight. - Ars TechnicaBlue Origin makes impressive strides with reuse—next launch will refly booster - Ars TechnicaNew Glenn-3 to Launch AST SpaceMobile’s BlueBird Satellite | Blue OriginBlue Origin on X: “Our lunar lander is headed to the Lone Star State! ⭐ Blue Moon MK1 departed from Florida today, bound for @NASA_Johnson's Thermal Vacuum Chamber A, where it will undergo testing at the same facility as the Apollo spacecraft.”Another Jeff Bezos company has announced plans to develop a megaconstellation - Ars TechnicaFirst Take: What We Think Blue Origin’s TeraWave Actually Is (and Isn’t)In a surprise announcement, Tory Bruno is out as CEO of United Launch Alliance - Ars TechnicaBlue Origin on X: “We’re pleased to announce that @torybruno is joining Blue Origin as president, National Security, reporting to CEO Dave Limp. Tory will spearhead our newly formed National Security Group.”The ShowLike the show? Support the show on Patreon or Substack!Email your thoughts, comments, and questions to anthony@mainenginecutoff.comFollow @WeHaveMECOFollow @meco@spacey.space on MastodonListen to MECO HeadlinesListen to Off-NominalJoin the Off-Nominal DiscordSubscribe on Apple Podcasts, Overcast, Pocket Casts, Spotify, Google Play, Stitcher, TuneIn or elsewhereSubscribe to the Main Engine Cut Off NewsletterArtwork photo by Blue OriginWork with me and my design and development agency: Pine Works

Casey Dreier of The Planetary Society joins me to talk about the NASA FY2026 budget, the early days of the Administrator Isaacman era, and how we feel going into Artemis II.This episode of Main Engine Cut Off is brought to you by 33 executive producers—Matt, Fred, Will and Lars from Agile, Kris, Lee, Jan, Frank, Miles O’Brien, Josh from Impulse, Theo and Violet, Ryan, Joakim, Stealth Julian, Heiko, Tim Dodd (the Everyday Astronaut!), Better Every Day Studios, Joel, Steve, Joonas, The Astrogators at SEE, Pat, Warren, Natasha Tsakos, Russell, David, Donald, and four anonymous—and hundreds of supporters.TopicsCasey Dreier | The Planetary SocietyThe Planetary SocietyYou just saved NASA's budget | The Planetary Society2025 Impact Report | The Planetary SocietyThe ShowLike the show? Support the show on Patreon or Substack!Email your thoughts, comments, and questions to anthony@mainenginecutoff.comFollow @WeHaveMECOFollow @meco@spacey.space on MastodonListen to MECO HeadlinesListen to Off-NominalJoin the Off-Nominal DiscordSubscribe on Apple Podcasts, Overcast, Pocket Casts, Spotify, Google Play, Stitcher, TuneIn or elsewhereSubscribe to the Main Engine Cut Off NewsletterArtwork photo by Blue OriginWork with me and my design and development agency: Pine Works

Celebrate the holidays with intriguing space news! NASA has a new administrator, Jared Isaacman, who's bringing fresh energy. Trump pledges a Moon landing by 2028, followed by a lunar outpost. SpaceX gears up for an $800 billion IPO, aiming for a staggering $1.5 trillion valuation. There's surprising leadership change at ULA with Tory Bruno's exit. MAVEN's signal loss raises concerns, while Chinese astronauts tackle debris issues. Plus, launch highlights from around the globe make this a must-listen!

Yesterday, I had the chance to visit the Pentagon and sit down with General Chance Saltzman, Chief of Space Operations—the head of the United States Space Force. We talk about the service 6 years into its existence, the state of acquisitions, the threats and space environment today, and what the future may hold for the Space Force when it comes to human spaceflight.This episode of Main Engine Cut Off is brought to you by 32 executive producers—Russell, Natasha Tsakos, Will and Lars from Agile, Theo and Violet, David, Matt, Better Every Day Studios, Warren, The Astrogators at SEE, Josh from Impulse, Stealth Julian, Joakim, Frank, Pat, Joel, Donald, Ryan, Tim Dodd (the Everyday Astronaut!), Joonas, Jan, Steve, Fred, Lee, Kris, Heiko, and four anonymous—and hundreds of supporters.TopicsUnited States Space ForceB. Chance Saltzman > United States Space Force > DisplaySpace Force roadmap set to define what the service needs and why - SpaceNewsUS intel officials “concerned” China will soon master reusable launch - Ars TechnicaAsked why we need Golden Dome, the man in charge points to a Hollywood film - Ars TechnicaSpace Force rolls out new naming scheme for satellites and space weapons - SpaceNewsAndrew Jones on X: “Outrageous images of China's Shijian-26, an apparent new-gen Earth observation satellite, from Maxar. SSD of 1.9 cm.”Andrew Jones on X: “China's CGST has returned the favour, using its Jilin-1 sats to image a Maxar Worldview Legion 2 satellite.”Scott Tilley 🇺🇦 🇨🇦 (@coastal8049) / XThe ShowLike the show? Support the show on Patreon or Substack!Email your thoughts, comments, and questions to anthony@mainenginecutoff.comFollow @WeHaveMECOFollow @meco@spacey.space on MastodonListen to MECO HeadlinesListen to Off-NominalJoin the Off-Nominal DiscordSubscribe on Apple Podcasts, Overcast, Pocket Casts, Spotify, Google Play, Stitcher, TuneIn or elsewhereSubscribe to the Main Engine Cut Off NewsletterArtwork photo by Blue OriginWork with me and my design and development agency: Pine Works

Stephen Clark of Ars Technica joins me to talk about a ton of stories in the news—Jared Isaacman was back in front of Congress, a few Starliner flights have been cut from the ISS manifest, Starship received environmental approval to proceed at SLC-37, Zhuque-3 almost stuck its first landing attempt, the Soyuz launch pad fell apart at Baikonur, and the Space Force has a new mission naming scheme.This episode of Main Engine Cut Off is brought to you by 32 executive producers—Matt, Fred, Kris, Natasha Tsakos, Josh from Impulse, Better Every Day Studios, Joakim, Joel, Ryan, The Astrogators at SEE, Tim Dodd (the Everyday Astronaut!), Heiko, Jan, Theo and Violet, Donald, Pat, Will and Lars from Agile, Lee, Russell, Joonas, Warren, Steve, Frank, Stealth Julian, David, and four anonymous—and hundreds of supporters.TopicsAuthor: Stephen Clark - Ars TechnicaNASA nominee appears before Congress, defends plans to revamp space agency - Ars TechnicaCongress warned that NASA’s current plan for Artemis “cannot work” - Ars TechnicaNASA seeks a “warm backup” option as key decision on lunar rover nears - Ars TechnicaIt’s official: Boeing’s next flight of Starliner will be allowed to carry cargo only - Ars TechnicaA spectacular explosion shows China is close to obtaining reusable rockets - Ars TechnicaBefore a Soyuz launch Thursday someone forgot to secure a 20-ton service platform - Ars TechnicaRivals object to SpaceX’s Starship plans in Florida—who’s interfering with whom? - Ars TechnicaSpaceX on X: “We’ve received approval to develop Space Launch Complex-37 for Starship operations at Cape Canaveral Space Force Station. Construction has started. With three launch pads in Florida, Starship will be ready to support America’s national security and Artemis goals as the world’s…”Attack, defend, pursue—the Space Force’s new naming scheme foretells new era - Ars TechnicaThe ShowLike the show? Support the show on Patreon or Substack!Email your thoughts, comments, and questions to anthony@mainenginecutoff.comFollow @WeHaveMECOFollow @meco@spacey.space on MastodonListen to MECO HeadlinesListen to Off-NominalJoin the Off-Nominal DiscordSubscribe on Apple Podcasts, Overcast, Pocket Casts, Spotify, Google Play, Stitcher, TuneIn or elsewhereSubscribe to the Main Engine Cut Off NewsletterArtwork photo by Blue OriginWork with me and my design and development agency: Pine Works

Blue Origin is fresh off an incredible few weeks—a successful second launch and first landing of New Glenn, followed by an exciting unveil of upgrades to the vehicle, including an enormous new version, New Glenn 9x4.This episode of Main Engine Cut Off is brought to you by 32 executive producers—Lee, Natasha Tsakos, Fred, Will and Lars from Agile, Ryan, Stealth Julian, Pat, Heiko, Kris, Jan, Better Every Day Studios, Theo and Violet, Matt, Josh from Impulse, Russell, Joel, Warren, Joonas, Joakim, Tim Dodd (the Everyday Astronaut!), Donald, David, Frank, Steve, The Astrogators at SEE, and four anonymous—and hundreds of supporters.TopicsBlue Origin’s New Glenn rocket came back home after taking aim at Mars - Ars TechnicaJeff Bezos on X: “Good overview of the landing. We nominally target a few hundred feet away from Jacklyn to avoid a severe impact if engines fail to start or start slowly. We’ll incrementally reduce that conservatism over time. We are all excited and grateful for yesterday…”New Glenn Update | Blue OriginBooster 18 suffers anomaly during proof testing - NASASpaceFlight.comSenate Commerce Committee schedules hearing on Isaacman renomination - SpaceNewsLawmakers writing NASA’s budget want a cheaper upper stage for the SLS rocket - Ars TechnicaThe ShowLike the show? Support the show on Patreon or Substack!Email your thoughts, comments, and questions to anthony@mainenginecutoff.comFollow @WeHaveMECOFollow @meco@spacey.space on MastodonListen to MECO HeadlinesListen to Off-NominalJoin the Off-Nominal DiscordSubscribe on Apple Podcasts, Overcast, Pocket Casts, Spotify, Google Play, Stitcher, TuneIn or elsewhereSubscribe to the Main Engine Cut Off NewsletterArtwork photo by JAXAWork with me and my design and development agency: Pine Works

Simone D’Amico of Stanford and EraDrive, DJ Bush of NVIDIA, and Al Tadros of Redwire join me to talk about autonomy in space, to get into the specific details of what they’re working on and how it comes together, and what it may do for the industry in the next few years.This episode of Main Engine Cut Off is brought to you by 32 executive producers—Joonas, Russell, Donald, Stealth Julian, Pat, Fred, David, Lee, Frank, Josh from Impulse, Steve, Joel, Joakim, Matt, Natasha Tsakos, Tim Dodd (the Everyday Astronaut!), Kris, Theo and Violet, Heiko, Will and Lars from Agile, Jan, Warren, The Astrogators at SEE, Ryan, Better Every Day Studios, and four anonymous—and hundreds of supporters.TopicsEpisode T+315: Autonomy in Space (with Simone D’Amico, DJ Bush, and Al Tadros) - YouTubeSimone D'Amico | LinkedInCenter for AEroSpace Autonomy Research (CAESAR)Stanford spinoff EraDrive claims $1 million NASA contract - SpaceNewsDJ Bush | LinkedInHow Starcloud Is Bringing Data Centers to Outer Space | NVIDIA BlogAl Tadros | LinkedInRedwire Space | Heritage + InnovationNASA Starling - Autonomous Tip and Cue in OrbitNASA Starling - Distributed Optical NavigationNASA Starling - Autonomous Space Domain AwarenessVISORS - Precise Formation-FlyingAutonomous Spacecraft 3D Model ReconstructionThe ShowLike the show? Support the show on Patreon or Substack!Email your thoughts, comments, and questions to anthony@mainenginecutoff.comFollow @WeHaveMECOFollow @meco@spacey.space on MastodonListen to MECO HeadlinesListen to Off-NominalJoin the Off-Nominal DiscordSubscribe on Apple Podcasts, Overcast, Pocket Casts, Spotify, Google Play, Stitcher, TuneIn or elsewhereSubscribe to the Main Engine Cut Off NewsletterArtwork photo by JAXAWork with me and my design and development agency: Pine Works