Main Engine Cut Off

T+119: Dr. John Charles

Dr. John Charles spent nearly 33 years at NASA—most recently as Chief Scientist of the Human Research Program—working on human spaceflight through Shuttle, Mir, ISS, and beyond. He lead missions such as STS-95 (John Glenn’s Shuttle flight), STS-107, and the Twins Study with Scott and Mark Kelly. He retired from NASA in February 2018 and is now the Scientist in Resident at Space Center Houston. We talk about his career, the human spaceflight issues he worked and solved in his time at NASA, and the things that need to be solved for the exploration of the Moon, Mars, and beyond.

This episode of Main Engine Cut Off is brought to you by 39 executive producers—Kris, Pat, Matt, Jorge, Brad, Ryan, Jamison, Nadim, Peter, Donald, Lee, Jasper, Chris, Warren, Bob, Russell, John, Moritz, Joel, Jan, David, Grant, Mike, David, Mints, Joonas, Robb, Tim Dodd the Everyday Astronaut, Frank, Rui, Julian, Lars, Heather, and six anonymous—and 238 other supporters on Patreon.

DARPA Launch Challenge Down to Three

Jeff Foust, for SpaceNews:

Three launch vehicle developers, one of which is still in stealth mode, have qualified to compete in a DARPA competition in early 2020 to demonstrate responsive launch capabilities.

In a briefing at the 35th Space Symposium here April 10, DARPA announced that Vector, Vox Space and a stealth-mode company have qualified to participate in the DARPA Launch Challenge. Vox Space is the U.S.-incorporated subsidiary of Virgin Orbit, which is developing the LauncherOne air-launch system.

The stealth company is rumored to be Astra, and that sounds right to me. I’m pretty confident they’re the other one in on RALI, as well.

I totally understand why Vector and Astra are interested in the DARPA Launch Challenge—they’re inexpensive rides for small payloads, they both seem to be targeting responsiveness, and they both need some launches on the books and under their belts to prove themselves.

But I can’t for the life of me figure out why Virgin Orbit is interested in participating. The prize money is substantially less than the price of one of their launches, and they have to fly two flights to win it all. They also have a substantial amount of launches signed and waiting, so I’m not sure they need this DARPA program to prove themselves out. What am I missing?

Rocket Lab Photon

There’s a lot of interesting flexibility here with Rocket Lab’s new kick stage-derived satellite bus. End-to-end services—meaning a contract with one provider for your satellite, handling, and launch—are really hot right now, and this seems like a really nice way to recoup some development costs of the kick stage.

I’m curious to know what the key differences are between the kick stage and Photon, and I’m even more curious to know if Photon can be a kick stage for others before putting itself in its final orbit.

Even if that were possible, I’m not sure that’s what they’re envisioning here, given that they say Photon can support up to 170 kilograms of payload mass.

SpaceX Wins DART Launch, Drops Lucy Protest

The total cost for NASA to launch DART is approximately $69 million, which includes the launch service and other mission related costs.

The DART mission currently is targeted to launch in June 2021 on a Falcon 9 rocket from Space Launch Complex 4E at Vandenberg Air Force Base in California. By using solar electric propulsion, DART will intercept the asteroid Didymos’ small moon in October 2022, when the asteroid will be within 11 million kilometers of Earth.

A solid $30 million under their previous NASA science mission contracts, but DART is only 500 kilograms, so will likely be sharing its ride. It’ll be interesting to see who rides along, especially out of Vandenberg.

Didymos is a pretty easily accessible asteroid, and when you consider DART’s size and its electric propulsion, the mission has a lot of flexibility in its profile.

Speaking of SpaceX and NASA science missions, SpaceX has withdrawn its protest of the Lucy contract. I’ve yet to see a good scoop on what happened behind the scenes, but there was quite a bit of anxiety about the protest delaying the mission.

Maybe this was the best scenario all around—SpaceX makes a little noise, gets to talk with NASA about their concerns, and then backs off before the mission team becomes completely unhappy?

T+118: Rapid Agile Launch Initiative

Last week, the US Air Force announced and expounded on the Rapid Agile Launch Initiative. Along with the new initiative, the new era of small launch is finally here, so it’s worth discussing a bit.

This episode of Main Engine Cut Off is brought to you by 39 executive producers—Kris, Pat, Matt, Jorge, Brad, Ryan, Jamison, Nadim, Peter, Donald, Lee, Jasper, Chris, Warren, Bob, Russell, John, Moritz, Joel, Jan, David, Grant, Mike, David, Mints, Joonas, Robb, Tim Dodd the Everyday Astronaut, Frank, Rui, Julian, Lars, Heather, and six anonymous—and 239 other supporters on Patreon.

Thanks to March Patrons

Very special thanks to the 271 of you out there supporting Main Engine Cut Off on Patreon for the month of March. MECO is entirely listener- and reader-supported, and it’s your support keeps this blog and podcast going, growing, and improving, and most importantly, it keeps it independent.

And a huge thanks to the 39 executive producers of Main Engine Cut Off: Kris, Pat, Matt, Jorge, Brad, Ryan, Jamison, Nadim, Peter, Donald, Lee, Jasper, Chris, Warren, Bob, Russell, John, Moritz, Joel, Jan, David, Grant, Mike, David, Mints, Joonas, Robb, Tim Dodd, the Everyday Astronaut, Frank, Rui, Julian, Lars, Heather, and six anonymous executive producers.

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Rapid Agile Launch Initiative

On the heels of Rocket Lab’s DARPA flight, they’ve announced that their next mission is for the Space Test Program, and will carry a handful of Department of Defense satellites:

The US Space Test Program procured the mission in partnership with Defense Innovation Unit (DIU) as part of the Rapid Agile Launch Initiative. This initiative leveraged DIU’s knowledge of commercial technology companies, enabling the government to competitively and rapidly award launch service contracts with non-traditional, venture-class launch providers.

I was on a call earlier this week with US Air Force officials talking about the Rapid Agile Launch Initiative (RALI), which is the program handling the acquisition of new small launch vehicles.

Through the program, they’ve purchased 5 launches for 2019, spread over 3 launch providers and 21 satellites, all for a total of $25.6 million. The first of 5 is Rocket Lab’s next launch, and the only other provider they’ve announced is Virgin Orbit, for a launch at the end of 2019.


Let’s try and work the money side of things: the dedicated Rocket Lab flight comes in at just under $6 million, and a Virgin Orbit flight would be over $10 million if they bought the whole thing.

That really doesn’t leave much for the other 3 launches, so given the cost and the fact that they’re launching 21 satellites in 5 launches, my guess is the Virgin Orbit flight is a rideshare and they’ve only purchased some of the capacity.

If that guess is right, that’d leave $15 million for the last 3 launches, so I’ll throw my hat in the ring and bet on at least one other Rocket Lab flight, plus two flights from the third mystery launch provider (again because Virgin Orbit flights are too expensive to make this math work).


A few random things I picked up from the call. RALI handles everything from suborbital missions up to 8,000 pounds to orbit. That payload mass is the dividing line between small launch programs and the bigger National Security Space Launch program (think SpaceX, ULA, etc).

That means there is quite a bit of headroom for new providers, as most of the bigger small launch vehicles are in the range of 2,500 pounds (~1,000 kilograms) to orbit. Firefly Beta would be pretty close to, if not slightly over, that upper range of RALI.

Launch Sites

Per my obsession of late about the dwindling supply of polar-accessible launch sites, I asked the Air Force officials on the call about the number of remaining available launch sites at Vandenberg. Disappointingly, they were all pretty stumped on that. I’m waiting on an email back with the answer, but I’m not too hopeful I’ll get it.

They were also not particularly open to discussing any expansion plans at Vandenberg, or up in Alaska, or out at Wallops, or to any sites beyond those, but did mention that their investment in the new payload facilities out at Wallops has been progressing well.

Assured Access

There was some talk about how the small launch program would handle the concept of assured access. Right now, given the oversupply of new launch providers, the US Air Force is planning to roll with the ebbs and flows of industry, and sign deals with any provider that might come along with the necessary capabilities. I could see that mindset shifting if and when the inevitable consolidation of providers happens, but time will tell.


It’s good to see the US Air Force (somewhat) openly discussing their plans for acquiring launches from the newer, smaller launch providers. They’re clearly excited to be able to take advantage of so much new capability at such a low cost. The irony of announcing the acquisition of 5 small launches for $25.6 million total while Pegasus struggles to get its issues sorted out is not lost on me. Rocket Lab, Virgin Orbit, and others coming online in the next year or two will all but kill the usefulness of the old guard of small launch—Minotaur and Pegasus—and the Department of Defense is wasting no time hopping onboard.

Relativity Signs Telesat, Eyes Polar Launch Site

Jeff Foust, for SpaceNews:

The contract covers the launch of an unspecified number of Telesat LEO satellites on Relativity’s Terran 1 launch vehicle, starting no earlier than 2021. The companies declined to disclose the terms of the contract.

In an interview, Tim Ellis, chief executive of Relativity, said the contract is the first customer for the Terran 1 that the company has announced. He said Relativity previously signed a contract with another customer that has yet to be announced.

Good to hear them signing customers, but I’m ready for this era of extreme secrecy of space projects to be over.

Relativity says they’re aiming for the end of 2020 for their first launch, and of note to me was this nugget at the end:

The company, which announced in January an initial agreement with the U.S. Air Force to develop a launch facility at Launch Complex 16 at Cape Canaveral Air Force Station in Florida, is working through the environmental review process and building permits for that facility. Ellis added that Relativity is in “pretty close to final stages” of identifying a West Coast launch site that would allow Terran 1 to launch missions to polar orbits.

My bet is on SLC-3W. Nothing has happened there since Falcon 1 stood ready to launch back in 2005.

The dwindling supply of polar-accessible launch sites is something I’ve been thinking about a lot lately, and something that is going to be a real issue given the ratio of new launch providers to available pads.