This Week in Space (Audio)

In this episode of This Week in Space, Rod Pyle and Tariq Malik host Dr. Robert O'Brien, Director of the Universities Space Research Association's Center for Space Nuclear Research, for a fascinating deep dive into nuclear propulsion technology for space exploration. They discuss the history, current developments, and future potential of nuclear electric and nuclear thermal propulsion systems, which could revolutionize our ability to explore Mars and beyond—both robotically and with human crews.

Headlines

• Crew-10 Launch Update: SpaceX's Dragon Endurance prepared to launch relief crew for ISS, addressing delays and setting stage for Williams and Wilmore's return.
• NASA Layoffs: NASA shuttering several offices including Technology Policy and Strategy, Chief Scientist, and diversity initiatives to comply with Trump administration executive orders.
• Saturn's Moon Count: 128 additional moons discovered orbiting Saturn, bringing total to 274 (surpassing Jupiter's 95), raising questions about moon classification criteria.
• Lunar Eclipse: First total lunar eclipse of 2025 visible across western hemisphere, with another eclipse in September for viewers in Asia and Australia.
• New Space Billionaire: Eric Schmidt, former Google CEO, takes over as CEO of Relativity Space (a 3D printing rocket company), joining Bezos, Musk, and Branson in the space industry.

Main Topic: Nuclear Propulsion with Dr. Robert O'Brien

• Propulsion Types: Dr. O'Brien explained two main types: nuclear electric propulsion generates electricity for electric thrusters, while nuclear thermal propulsion heats propellant directly through a fission reactor for thrust.
• Efficiency Advantages: Nuclear systems offer greater efficiency than chemical rockets, potentially reducing Mars mission mass to one-third or less while enabling "maneuver without regret" capability.
• Historical Context: US launched SNAP-10A reactor in mid-1960s; Rover-NERVA program demonstrated nuclear thermal rocket technology before cancellation after Apollo.
• Current Development: Working to regain 1960s capabilities while implementing modern safety protocols, testing procedures, and materials science improvements.
• Safety Considerations: Modern development includes full exhaust containment and comprehensive safety measures, with waste containment as the primary focus.
• AI Applications: AI could accelerate development through materials optimization, autonomous operation for deep space, and enhanced reactor control safety.
• Fusion Propulsion: Remains promising future technology potentially enabling interstellar travel, with growing international investment.
• Project Orion: Historical nuclear pulse propulsion concept using small nuclear explosions for thrust - impractical for Earth launches but potential for interstellar applications.
• Public Education: Addressing concerns requires transparent communication, moving away from the "veil of mystery" of earlier nuclear programs.
• Educational Outreach: The Universities Space Research Association is developing a talent pipeline for "unicorn capabilities" in space nuclear expertise.

Hosts: Rod Pyle and Tariq Malik

Guest: Dr. Robert O'Brien

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In this episode of This Week in Space, Rod Pyle and Tariq Malik talk with Dr. Jim Green, former NASA Chief Scientist. He discusses how we can search for technosignatures that might indicate advanced civilizations in other star systems, new ideas on Mars sample return, and his fascinating experience consulting on the movie, The Martian! Also: this week's robotic landings on the Moon - one successful, one partly so; what's up with the USAF X-37B mini-shuttle; and recent news on those Energizer Bunnies of space, Voyagers 1&2. Their wings have been clipped a bit, but they just keep going... join us!

News

• Lunar Landing Week: Firefly Aerospace's Blue Ghost lander achieved a flawless touchdown in Mare Chrisium, the Intuitive Machines Athena lander reached the Moon's south polar region but experienced issues with its navigation radar (and tipped over), and SpaceX's Starship test flight 8 successfully caught its booster for the third time but lost control of the upper stage, resulting in the breakup of the upper stage and debris over the Bahamas and Caribbean.
• NASA powered down additional instruments on both Voyager 1 and Voyager 2 to extend their remaining power supply, including Voyager 1's cosmic ray system that helped confirm its entry into interstellar space in 2012.
• The secretive US Space Force X-37B space plane landed at Vandenberg Space Force Base after 434 days in orbit, completing its seventh mission, which tested new orbital capabilities, including aerobraking techniques.
• A newly released list showcases the world's top ten locations for dark skies and stargazing, with the US only having only one location—in Hawaii—to make the list.

Dr. Jim Green

• His Career: Dr. Green goes over his former role as NASA's Chief Scientist and highlights key aspects of his career, including running the National Space Science Data Center (NSSDC) and leading NASA's Planetary Science Division, and how his interest in space first began.
• The Martian: Dr. Green also explains how he got involved as a consultant for Ridley Scott's movie, "The Martian," and how NASA got really involved with the film. He also shares his favorite scene from the movie.
• NASA's Search for Alien Civilizations: Dr. Green shares how he helped shift NASA's focus from traditional SETI to searching for technosignatures like Dyson Spheres and O'Neill structures in other star systems, securing $10 million in funding for research that could detect megastructures in our astronomical data while noting that humanity may need similar space habitats in 800 million years when the sun makes Earth uninhabitable.
• Mars Sample Return Strategy: Dr. Green explains how NASA's evolving plan to return samples fropm Mars includes developing Mars Ascent Vehicles that could eventually support human missions while revealing that Perseverance was deliberately designed to place sample tubes on the surface so any nation could retrieve them, making the mission more politically viable with budget offices and Congress.
• Humanity's Cosmic Future: Dr. Green reveals that he helped create NASA's Commercial Lunar Payload Services (CLPS) program to support new companies for lunar missions. Despite early failures, he emphasized that humanity must utilize space resources and capabilities to

These show notes have been truncated due to length. For the full show notes, visit https://twit.tv/shows/this-week-in-space/episodes/151

Hosts: Rod Pyle and Tariq Malik

Guest: Dr. Jim Green

We all think we know what NASA's up to, but there's nothing like hearing their plans directly from the top. This week, NASA Deputy Administrator Pam Melroy, who is also a former astronaut, commander of the space shuttle, and US Air Force test pilot, joins us for a very special episode. We discussed the recently announced delays to the Artemis lunar landing program, NASA's long-term goals on the Moon, the overall trajectory of human spaceflight, Pam's favorite memories of her time in space, and — perhaps our favorite moment — her "gentle" rejoinder to a male pilot who hadn't had much experience flying with "ladies"! Be sure to join us for this exclusive interview.

Headlines:

• Members of Congress made the claim that Russia is developing a new anti-satellite weapon with a possible nuclear component. Could possibly be used to knock out satellites and crucial infrastructure like GPS and communications. Raises concerns and questions about the future of the peaceful exploration of space.
• Private lunar lander Intuitive Machines 1 launched successfully, carrying NASA payloads to the Moon's south pole. Marks ongoing progress in partnerships between NASA and commercial companies for robotic Moon exploration.
• NASA's Voyager 1 spacecraft may be nearing the end of its operational life after 45+ years in space. Experiencing technical issues communicating with Earth due to its outdated systems. A remarkable achievement and inspiration nonetheless.

Main Topic: Interview with NASA Deputy Administrator Pam Melroy

• Melroy provides an overview of her role as Deputy Administrator, overseeing operations and execution of the Administrator's priorities.
• Discusses being inspired by Apollo and space exploration from a young age. Combined backgrounds in planetary science, test piloting, and astronaut experience inform her work.
• Emphasizes NASA's long-term vision for sustained human presence and exploration throughout the solar system, using the Moon as a proving ground.
• Explains how NASA is currently defining infrastructure requirements for Moon bases, pressurized rovers, communications, and more. International partnerships are expanding.
• Highlights the importance of Artemis missions for testing and maturing capabilities needed for Mars and beyond. Balancing technical challenges and schedule.
• Notes the convergence of robotic and human exploration seen with new commercial lunar landers supporting future astronaut missions.
• Reflects on personal highlights of seeing all aspects of space technology come together during spaceflights, and about the culture enabling teams to solve problems.
• Discusses the increase in opportunities for women now and in the future. Focusing on your goals and being part of the team.

Hosts: Rod Pyle and Tariq Malik

Guest: Pam Melroy

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This week, we're diving deep into some really clever and cutting-edge tech for Martian habitats... made from fungus! Dr. Lynn Rothschild of the NASA Ames Research Center has been working for years on how mushroom mycelia might be utilized as a habitat-building resource. It's quite fascinating--the organic material can be used to make bricks, to create shaped structures, and even to create an "astropharmacy" to supply certain compounds needed by the crew of a Mars excursion! And it is sufficiently enticing that NASA's NIAC innovation program has given her no less than five grants (which are not easy to get!) to study the possibilities. Join us for this really engaging and blue-sky conversation!

Headlines:
• ISS has been experiencing a slow air leak, increasing from 0.2 pounds per day to 3.7 pounds per day, causing concern for NASA's Office of the Inspector General
• Jupiter's Great Red Spot has been shrinking and "pulsing" over time, as observed by the Hubble Space Telescope, with scientists predicting it will eventually stabilize as a smaller, circular storm
• A rare G4-class solar storm triggered widespread auroras visible at much lower latitudes than usual, with NOAA issuing warnings to protect power grids and communication systems

Main Topic - Living in Martian Mushrooms:
• Dr. Rothschild explains synthetic biology as creating something new with biology, either by altering existing organisms or creating new ones from scratch
• The concept of using fungal mycelium for off-world habitats originated from a student project to create a biodegradable drone body
• Mycotecture involves growing habitats and structures using mycelium, which can bind various materials like sand, regolith simulant, and wood chips
• The properties of mycelium-based materials can be tuned by adjusting the substrate and post-processing, ranging from styrofoam-like to hardwood-like consistencies
• Dr. Rothschild's vision for a stable off-world habitat includes using cyanobacteria to process atmospheric gases and minerals, which would then feed the fungi used in construction
• Cross-contamination concerns on Mars are addressed, with the lack of liquid water on the surface making it unlikely for introduced organisms to thrive
• Additional applications of mycelium-based technology include biomining, water filtration, and even food production
• Dr. Rothschild also discusses the Astro Pharmacy project, which aims to develop an on-demand drug production system for astronauts
• While these technologies have significant potential for Earth-based applications, developing them for space allows for more freedom to explore revolutionary ideas without existing infrastructure constraints

Hosts: Rod Pyle and Tariq Malik

Guest: Dr. Lynn Rothschild

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Happy holidays! Rod and Tariq are taking the next two weeks off but will be back with our regularly scheduled programming on January 5th.

Host: Rod Pyle

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