From Merlin to Mira, with Tom Mueller (Impulse Space)


Shying away from the limelight is an art Tom Mueller, has perfected. The SpaceX founding member and mastermind behind Impulse Space is not a frequent podcast flier, with only one previous episode in the wild (that we could find). However, Mueller recently agreed to jump into the hot seat on the Pathfinder pod.


Tom Mueller is best known for his instrumental role at SpaceX as propulsion CTO, but he’s now turned his sights to his new venture, Impulse Space. Founded in 2021, Impulse aims to provide reliable and economical in-space transportation services. The company services include GEO/GTO/LEO logistics, in-orbit servicing, spacecraft life extension, active debris removal, and situational awareness.

The company plans to operate within Earth’s orbit and beyond, including lunar and Mars missions, which Mueller believes will open the gateway to space resource transportation, asteroid mining, in-space manufacturing, and propellant depots.

Last summer, the company announced a partnership with Relativity to launch the first private mission to Mars and just last week Orbit Fab announced that it would use a vehicle developed by Impulse Space for an in-orbit refueling demonstration.

In addition to Impulse’s origin story, Mo and Tom discuss:

  • Building propulsion systems
  • Initial target markets
  • Engineering thrusters vs engines
  • Mira’s first mission this October
  • Lessons learned (and memorable stories) from SpaceX

And much more… 

This episode is brought to you by SpiderOak, a US-based software company that builds space cybersecurity products and solutions for civilian, military, and commercial space operations. Learn more at 

• Chapters • 

00:00 – Intro and Ad spot

01:41 – Why rockets and why propulsion?

03:25 -Early work at TRW

07:43 – Introducing Impulse

10:54 – The size of Impulse’s market

12:59 – First product: Mira

15:19 – Second product: Helios

17:00 – Small thruster performance

20:31 – Competition in orbital transfer vehicles

22:16 – Chemical propulsion vs electrical?

23:10 – What are some of the elements/process of innovation that you’re applying from SpaceX?

26:38 – Relativity mission

28:56 – Efficiency in getting propellant from the Moon vs the Earth

31:03 – Building and recruiting a team

33:22 – Spider Oak Ad break

34:29 – Why is launch so hard?

37:55 – How do you bounce back from failure?

38:52 – Future of rocket propulsion

40:42 – Starship and the future of engineering constraints

42:26 – What other companies excite you?

43:32 – What’s harder, designing a championship-winning F1 car or a new launch vehicle from scratch?

46:46 – Do you spend more time racing or tinkering?

48:19 – The future of racing electric vehicles?

49:41 – If you could race a lap in your favorite car, who would you take with you?

52:57 – Most memorable moment from your time at SpaceX

54:29 – When do you think we’ll be back on the Moon? Mars?