Podcast Summary: This Week in Space 176 – Beyond the Solar System
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Episode: This Week in Space 176: Beyond the Solar System
Date: September 5, 2025
Host: Rod Pyle
Co-Host: Dr. Rick Janet
Guest: Dr. Alan Stern – Principal Investigator, New Horizons Mission
Main Theme & Episode Purpose
This episode explores the science, challenges, and discoveries of the New Horizons mission to Pluto and the Kuiper Belt, featuring renowned planetary scientist Dr. Alan Stern. The hosts discuss Pluto’s place in the solar system, the ongoing hunt for new Kuiper Belt targets, planetary exploration’s future, and the tenuous challenges of sustaining deep space missions amidst budgetary threats.
Key Discussion Points & Insights
1. The Changing Landscape of Space Leadership
[03:10] – [08:20]
- U.S.–China Lunar Race:
- Concerns about the pace of NASA’s Artemis program compared to China's rapid progress.
- Chinese space program's centralized, consistent approach versus U.S. administrative “to and fro.”
- Debate over SLS vs. Starship as core architectures for Artemis.
- Host Rod Pyle draws a parallel with the original Space Race, noting global partners' alignment is in play again.
"We are just so confused about what it is we're going to do and what we should do… and the Chinese are just like, well this is what we're going to do and we're going to do it."
— Dr. Rick Janet [05:42]
2. Recent Scientific Discoveries: Interstellar Visitors
[08:20] – [11:57]
- Interstellar Comet Studies:
- Sphere X telescope detected a cloud of carbon dioxide around an interstellar comet, indicating similarities to solar system objects.
- Discussion on the novelty of tracking interstellar objects—three found in about a decade.
- Anticipation the Vera Rubin Observatory will allow discovery of many more such objects.
"It's really the beginning of a whole new field of astronomy and astrophysics."
— Dr. Rick Janet [11:57]
3. Welcome & Introduction of Dr. Alan Stern
[14:02] – [15:04]
- Overview of Dr. Stern’s credentials: New Horizons principal investigator, former NASA Science Mission Directorate head, suborbital astronaut, and Titanic explorer.
- Stern’s inspiration originated during the Apollo era—he was “swept off [his] feet” as a child fascinated by space.
"All I ever remember wanting to do was to grow up and be involved in space exploration."
— Dr. Alan Stern [15:04]
Deep Dive: New Horizons and Pluto
4. Why Go to Pluto?
[17:02] – [19:52]
- Scientific drive: Pluto was an "unchecked box" with immense potential, unexpectedly teeming with complexity.
- National pride and responsibility: U.S. had firsts at every other planet; missing Pluto was "unfinished business."
- Discovery of the Kuiper Belt reframed Pluto as the first of a new planetary class—dwarf planets.
"Pluto's an overachiever, really exceeded our expectations... [It was] unfinished business and a bit of a dare."
— Dr. Alan Stern [17:02]
5. First Data Downlink: Emotional Payoff
[20:30] – [22:38]
- Stern celebrates teamwork: 2,500 contributors make such missions possible.
- Describes seeing Pluto up close as “a whole mix of feelings...pride for this country...and a cherry on top” for doing something never done before.
"No single human being can do any space flight. It really comes down to teamwork and regular people working very hard and big teams can do things that are larger than life."
— Dr. Alan Stern [20:30]
6. Navigating to and Past Pluto
[24:04] – [26:24]
- Precision navigation used Deep Space Network, customized orbit tracking, and successive engine burns.
- Closest approach: 12,000 km from Pluto’s center (about 10,000 km above surface), calculated with careful trade-offs between resolution, science goals, and speed.
"You get really good people who know what they're doing. That's the answer."
— Dr. Alan Stern [24:04]
7. Surprises from Pluto
[26:34] – [28:19]
- Contrary to expectations, Pluto is "vastly geologically active" and "mind-bogglingly complicated" despite small size.
- Notable discoveries include likely subsurface ocean, complex geology, and ongoing tectonic activity.
"We were surprised to find that Pluto is vastly geologically active today, 4 billion years after formation, which pretty much rewrote the textbooks."
— Dr. Alan Stern [26:34]
Kuiper Belt: Arrokoth and Beyond
8. Flyby of Arrokoth (Formerly “Ultima Thule”)
[29:05] – [31:21]
- Chosen for best fuel preservation to allow potential for another flyby in the future.
- Revealed itself as a "contact binary," giving concrete evidence for low-speed accretion in planet formation.
"The way these things form is by low-speed accretion and we completely knocked off the other theory in one fell swoop. Fifty years after that debate began, probably the biggest discovery we made in Arrokoth."
— Dr. Alan Stern [36:25]
9. The Hunt for a Third Flyby Target
[31:28] – [34:40]
- Search uses Subaru telescope, shifting soon to Vera Rubin Observatory and—eventually—the Nancy Grace Roman Telescope.
- Diminishing options as spacecraft moves further from Sun; objects become “16 times fainter” at twice the distance.
"It's going to be a long shot...but if it's there, we will find it and go to it if I have to go have a bake sale to raise the money."
— Dr. Alan Stern [33:21]
Mission Operations, Budget Threats, and the Future
10. The Budgetary Cliff
[47:28] – [55:01]
- Recent threat to shut down New Horizons, among 50+ working U.S. space missions, due to proposed federal budget cuts.
- Stern lauds advocacy from the National Space Society: “played an enormous role in rescuing New Horizons.”
- Running costs are “about what it costs to run the staff of a McDonald's every year,” a fraction of the sunk costs.
- Risks U.S. “voluntarily abdicating leadership in space” if active missions are lost for modest budget savings.
"Now we spend about what it costs to run the staff of a McDonald's every year to operate it...The cost to keep doing it and to milk it now for the taxpayer and for, you know, American prestige and leadership is virtually almost free."
— Dr. Alan Stern [52:36]
11. New Horizons’ Scientific Legacy and Next Hopes
[55:25] – [57:09]
- Essential, unique science in the heliosphere and interstellar medium, superior to Voyager due to better instrumentation.
- Main dream: a final Kuiper Belt flyby, studying an object so far from the Sun it unlocks new planetary science.
"The spacecraft can do that, and it's the only one out there. Nothing is even being sent to come after New Horizons."
— Dr. Alan Stern [55:25]
12. Long-Term Vision for Exploration
[57:09] – [59:17]
- Dr. Stern compares himself to Ed Stone, expects to be active in the outer solar system as long as possible, but increasingly drawn to shorter-term missions closer to home as his career matures.
- Upcoming plans: Second flight with Virgin Galactic as a NASA researcher, and optimistic for humanity’s future in space—hoping life extension research lets him see even more.
"I am so excited the way the 21st century is shaping up for space...I only wish that the biologists hurry up with life extension because it's going to be a hell of a ride in the next few decades."
— Dr. Alan Stern [58:24]
Notable Quotes
- "Pluto’s an overachiever, really exceeded our expectations… a harbinger, a whole new class of planet." – Dr. Alan Stern [17:02]
- "Teamwork and regular people working very hard... that’s what is so magical to me about being in space flight." – Dr. Alan Stern [20:30]
- "Pluto just blew the doors off paradigm and has caused us to rethink a lot of what we thought we knew..." – Dr. Alan Stern [26:34]
- "The cost to keep doing it and to milk it now for the taxpayer and for American prestige and leadership is virtually almost free." – Dr. Alan Stern [52:36]
- "The way these things form is by low-speed accretion and we completely knocked off the other theory in one fell swoop." – Dr. Alan Stern [36:25]
- "I only wish that the biologists hurry up with life extension because it’s going to be a hell of a ride in the next few decades." – Dr. Alan Stern [58:24]
Timestamps for Key Segments
- 03:10 – U.S.–China lunar “space race” comparison
- 08:20 – Discovery and implications of interstellar objects
- 14:02 – Introducing Dr. Alan Stern
- 17:02 – Motivations for Pluto mission
- 20:30 – New Horizons’ first data return: emotion and teamwork
- 24:04 – Navigating to Pluto
- 26:34 – Surprising geology of Pluto
- 29:05 – Arrokoth flyby and what it taught us
- 31:28 – The race to identify a third target
- 47:28 – The fight to save New Horizons amid budget threats
- 55:25 – Scientific legacy and future dreams
- 58:24 – Stern’s personal vision for the future
Closing & Where to Learn More
- Follow New Horizons: NASA’s Pluto New Horizons Mission website
- Dr. Alan Stern: @AlanStern on X/Twitter, Facebook, Instagram
- Dr. Rick Janet: Expanding Frontiers, International Committee at nss.org
- Rod Pyle: pylebooks.com, astromagazine.com
Episode Tone & Final Notes
The tone is lively, enthusiastic, at times wry, and constantly fueled by genuine curiosity and commitment to exploration. There’s palpable urgency as Dr. Stern pleads for public support to keep New Horizons running—a true “national treasure chest” for science and inspiration, done on a shoestring budget.
Summary prepared for listeners seeking a deep, structured look at New Horizons’ past, present, and possible futures, in the words and spirit of those who steer its journey.