StarTalk Radio: "The New Space Race with Jeff Thornburg"

Host: Neil deGrasse Tyson
Guest: Jeff Thornburg, CEO of Portal Space Systems
Air Date: September 30, 2025

Episode Overview

In this insightful and comedic installment of StarTalk Radio, Neil deGrasse Tyson and co-host Chuck Nice sit down with aerospace engineer Jeff Thornburg, currently CEO of Portal Space Systems and a veteran of SpaceX, NASA, the Air Force, and Aerojet. Together, they explore the evolution and future of the space industry—delving into propulsion technology, government and private sector dynamics, the realities of rapid spacecraft maneuverability, and the risks and rewards of innovation in the new space race. Thornburg brings both technical expertise and candid perspective, framed with a blend of science, humor, and strategic urgency.

Major Discussion Themes and Insights

1. Jeff Thornburg’s Background and Portal Space Systems

• Introduction to Thornburg:
  Formerly with NASA, SpaceX (architect of the Raptor engine), Aerojet, and the U.S. Air Force, Thornburg is now leading Portal Space Systems, which aims to revolutionize spacecraft maneuverability.

  "Portal is building the most rapidly maneuverable spacecraft that's ever been built... we can accomplish a lot of missions for defense and commercial customers. We can do it with speed." — Jeff Thornburg [05:42]

• Problem Statement:
  Current spacecraft and satellites move too slowly for rapidly changing demands, especially for defense purposes. Thornburg’s vision is speedy, flexible payload delivery—transforming space transit into something as routine as trucking.

  "Our customers don't care about how cool the tech is...they just want speed. They want it now." — Thornburg [08:03]

2. Engineering Boldness and Persistence

• Motivation:
  Thornburg’s drive springs from impatience with stagnation in aerospace programs.

  "I'd go work at these places and be like, not moving fast enough. Not moving fast enough. Not moving fast enough." — Thornburg [05:00]

• The Importance of Engineering:
  Tyson repeatedly commends the overlooked role of engineers in making scientific ambition a reality.

  "There are engineers who you never come interview who enabled the James Webb Space Telescope... I just want to on record give a shout out to nameless engineers who...make the scientists look good." — Tyson [25:11]

3. Propulsion Technology—Past, Present, and Future

• Full Flow Stage Combustion:
  Thornburg’s early work on high-performing rocket engines at the Air Force Research Lab seeded later innovations, including SpaceX’s Raptor engine.

  "I got to develop a brand new type of rocket engine called a full flow stage combustion engine... the highest performing rocket engine ever made." — Thornburg [08:58]

• American vs. Russian Rocket Design:
  The U.S. pursuit of “performance and perfection” contrasts with the Russian focus on “reliability and manufacturability”—as exemplified by the enduring, workhorse Soyuz capsule.

  "Von Braun and his team...focused on performance and perfection. The Russians...focused on reliability and manufacturability." — Thornburg [18:28]

• Reusable Rockets and Market Choice:
  SpaceX’s two pricing models—reusable or expendable first stages—let the market choose. The shift to reusability prevailed due to strong financial incentives.

  "Let the buyer and the market choose that configuration because it makes the most financial sense." — Thornburg [23:30]

• New Era Needs: Speed in Orbit
  Chemical rockets excel for leaving Earth, but electric or thermal propulsion offers superior efficiency for on-orbit maneuvers—yet the industry is only starting to address these new imperatives.

  "To get out of Earth’s gravity well, you want a lot of thrust...but where technology has evolved is, once you're in orbit...liquid rocket engines aren’t the best way to get you around." — Thornburg [49:46]

4. The Value (and Necessity) of Failure

• Startups vs. Government Risk Culture:
  Startups embrace failure as the fastest path to learning, whereas legacy NASA programs are boxed in by a “failure is not an option” mentality—resulting in slower, more expensive progress.

  "To have infinitely low risk requires infinitely high cost. That’s not how a lot of commercial startups…have formed in the last decade." — Thornburg [27:22]
  "If your company or organizational culture accepts failure, then you will actually get to the end product much faster." — Thornburg [28:38]

• Public Perception and Accountability:
  NASA is scrutinized for failure, while private companies like SpaceX are perceived as innovative despite public missteps.

  "If NASA blew up 100 rockets, there'd be no more tax dollars going to NASA. Whereas Elon Musk can blow up as many rockets as he wants." — Chuck Nice [29:56]

5. Government vs. Private Sector in Space Innovation

• Role of FFRDCs:
  Federally Funded Research and Development Centers (FFRDCs) fill critical gaps, funding “necessary technology” with no immediate business case—and must continue to do so in the face of shrinking budgets.

  "FFRDCs should definitely be seeding new technologies...because no one else is going to do it." — Thornburg [12:07]

• Dangers of Budget Cuts:
  Loss of funding forces U.S. scientists abroad and drains decades of institutional wisdom, imperiling America’s future in technology leadership.

  "We’re watching our scientists walk over to other countries because there’s no funding for them here...current events will have ramifications for America as a leader in science and technology for decades to come." — Thornburg [39:20]

6. Ethics, Integrity, and Vaporware in the Space Industry

• Why Integrity Matters:
  Some companies overstate their technical readiness to secure VC funding—with risky consequences for the industry’s reputation.

  "They lie their asses off to get to the next step...and that’s where I see it the most." — Thornburg on "vaporware" [45:39]

• IP vs. Openness:
  Companies protect innovations as proprietary IP—sometimes at odds with science’s ethos of openness, but Thornburg emphasizes using technology “for the benefit of humanity” when possible.

  “If we had something so great and so beneficial to humanity, I wouldn't want to hide that.” — Thornburg [44:28]

7. The New Space Race and U.S.-China Competition

• China’s Strategic Approach:
  China leverages massive, state-backed investments in both heavy-duty brute force solutions and alternative (often non-space) critical infrastructure, presenting a growing threat to U.S. orbital assets.

  "China did not [tie financial and critical infrastructure to GPS]...they have other ways for timing for their banking and financial assets." — Thornburg [57:38]

• Space as the New Global Battleground:
  The risk isn’t alien weapons, but loss or disruption of the satellite constellation underlying finance, comms, defense, and daily life. Planned harassment—such as parking adversary satellites alongside American ones—poses escalating threat.

  "If you have a military, it’s...defend our assets. Our assets are bare ass in space." — Tyson [55:23]

8. Jeff Thornburg’s Current Work at Portal Space Systems

• Supernova Platform:
  Their “Supernova” propulsion system leverages concentrated solar energy in a thermal cycle—reducing parts, eliminating combusted propellant, doubling fuel capacity, and offering rapid, flexible deployment for diverse payloads.

  “With Supernova, it’s about that rapid movement...we've innovated around a heat exchanger so we don’t have to combust any liquid propellants.” — Thornburg [60:27]

• Living Off the Land in Space:
  Thornburg advocates for making spacecraft more adaptable and able to exploit local resources—a goal he brands “living off the land” (LotL) rather than NASA’s jargon-heavy “in situ resource utilization.”

  "If we're taking everything with us, we failed as engineers." — Thornburg [62:19]

9. Future-Oriented Questions and Cosmic Perspective

• What’s Next?
  Thornburg sees AI and machine learning as critical to accelerating exploration, with quantum physics holding keys for eventual “warp drive” breakthroughs.

  “There’s elements of the quantum world that are gonna unlock propulsion technologies that might look similar to a warp drive.” — Thornburg [66:36]

• Holy Grail of Commercial Space Flight
  For Tyson: suborbital point-to-point transit anywhere on Earth in under 45 minutes.
  For Thornburg: a future where travel anywhere between Earth and the Moon is no more remarkable than a business trip to Poughkeepsie.

  "I want to go suborbital between any two points on Earth so that I’m 45 minutes...away from lunch in Tokyo." — Tyson [68:51]
  "Humans can go to any orbit between here and the Moon, or the Moon, [so] it isn’t a significant emotional event. That’s just a standard." — Thornburg [69:31]

• Engineers and Society
  Tyson’s closing cosmic perspective frames engineers as the essential, unsung problem-solvers who convert ambition and uncertainty into functioning reality.

  "There is no future of civilization without happy engineers...and maybe it’s up to the rest of us to give them the kinds of problems we need solved." — Tyson [70:06]

Notable Quotes & Timestamp Highlights

• On Engineering Drive:
  "If no one’s going to do anything about it, I’m going to go do something about it." — Thornburg [06:11]
• On Failure’s Value:
  "To have infinitely low risk requires infinitely high cost...we want to actually break it because we want to see where the design fails and what we don’t know yet." — Thornburg [27:22]
• On U.S.–China Space Race:
  "Our adversaries are coming for us, and we are cutting R&D spending, we’re cutting engineering, we’re cutting science..." — Thornburg [54:49]
• On Civilizational Defenselessness:
  "Our assets that enable what we think of as modern life...are fundamentally pivoted on what we have orbiting this Earth." — Tyson [55:23]
• On Engineers’ Place in Civilization:
  "There is no civilization without...engineers that are given problems to solve." — Tyson [70:06]

Key Timestamps for Reference

| Segment | Topic | Timestamp | |--------------------------------------------|-----------------------------------------------------|------------| | Jeff Thornburg intro and background | Career trajectory, Portal Space Systems | 02:36–06:15| | Vision of rapid maneuverability | Portal's "trucking in space" analogy | 05:42–08:23| | Propulsion history and Raptor engine | SpaceX, Air Force, rocket engineering | 08:58–10:30| | U.S. vs. Russia (rocketry approaches) | "Performance vs. reliability" | 18:15–18:57| | Rise of private sector (SpaceX, NASA) | Reusability, market-driven shift | 20:02–23:45| | Failure in engineering | Value, necessity, legacy vs. commercial cultures | 27:11–28:55| | Budget cuts and brain drain risk | Future of U.S. science and technology | 39:20–40:39| | Intellectual property & integrity | Speed vs. vaporware, benefit to humanity | 43:27–45:48| | China’s brute force, space as battlefield | Global risk, military-industrial context | 52:39–55:54| | The Supernova platform | Solar thermal propulsion, living off the land | 60:18–62:19| | Moon and beyond as “new backyard” | Vision for routine space travel | 69:31–70:02| | Tyson’s closing cosmic perspective | Engineers as societal engines of progress | 70:06–72:50|

Memorable Moments

• “Dumbassitude” in Engineering:
  Chuck Nice and Thornburg riff on American units vs. metric and “pockets of dumbassery.” [38:39]
• Rick and Morty Origins:
  The company name “Portal Space Systems” stems from Thornburg’s love of Rick and Morty with his daughter. [59:54]
• Star-Themed Branding:
  Products at Portal are named with a cosmic motif: “Supernova,” star references, and more. [60:22]
• Pop Culture & Comedy Thread:
  “Not like Independence Day, right?” – Chuck Nice, on losing satellites to adversaries. [56:46]

Conclusion

This episode expertly blends technical expertise, strategic urgency, humor, and pop culture. Jeff Thornburg’s journey exemplifies the restless, visionary mind essential to space’s next frontier, revealing the interplay between government, private enterprise, engineering risk, and practical imagination. Tyson’s closing reflection is a rallying cry for valuing engineers as the core drivers of civilization’s future—and a reminder that without their boldness and skill, scientific dreams remain just that.

For further reference, listen to key segments at:

• Vision for rapid spacecraft ([05:42])
• Value of failure ([27:22])
• U.S.-China space power rivalry ([54:49])
• Portal’s Supernova propulsion ([60:22])
• Future hopes for "everyday" lunar travel ([69:31])
• Tyson’s cosmic perspective on engineers ([70:06])

Stay curious, and—per Neil’s signature sign-off—keep looking up!