To Phobos and Back

Episode Summary

Executive Summary: This Planetary Radio episode focuses on Russia’s planned Phobos sample-return mission, Phobos Grunt, and the Planetary Society’s proposed Life Experiment that would hitch a ride to test microbial survival in deep space. The show also covers updates on exoplanets, Mars rover instruments, spacecraft visibility, and a lively skywatch segment with comet Holmes and the current planet lineup.

Main Topics: Phobos Grunt sample-return mission: Russian scientists outline a complex 2009 mission to rendezvous with Phobos, collect regolith and rocks, and return samples to Earth, emphasizing Phobos’ low gravity and landing challenges. Planetary Society Life Experiment: Bruce Betts explains the proposed Living Interplanetary Flight Experiment, designed to expose microbes and soils to deep-space conditions for 34 months and assess survivability and mutation after return. International collaboration on Phobos observations: Tom Duxbury describes how Mars Express, MRO, and international partners are supporting landing-site selection and radar studies of Phobos, showcasing cooperation across agencies. Science news roundup: The episode briefly notes the discovery of a fifth planet around 55 Cancri and the restoration of instruments, including ChemCam, to the Mars Science Laboratory rover. Can telescopes see spacecraft?: Emily Lakdawalla answers why dead deep-space spacecraft are usually too small and distant to resolve optically, while nearby spacecraft can sometimes be tracked from Earth. Night sky and trivia segment: Bruce Betts discusses comet Holmes, visible planets, and the contest prize update, while also introducing the next trivia question about Phobos’ largest crater.

Key Arguments: Phobos Grunt is notable because it would be the first automated sample return from a planetary surface since the Soviet lunar missions. Phobos is so small that a lander must use jets to prevent bouncing off the surface during touchdown. Mars Express and other orbiters can provide critical high-resolution imaging and radar data to support the Russian landing site selection. The Life Experiment is intended as a rough simulation of interplanetary transfer, testing microbial survival outside Earth’s magnetosphere over nearly three years. The payload would prioritize non-pathogenic, well-characterized organisms and include controls on Earth to make the results scientifically meaningful. Most spacecraft in deep space cannot be seen optically from Earth because they are vastly smaller than the bodies they study and far beyond telescope resolution. Nearby spacecraft can sometimes be tracked from the ground and even misidentified as asteroids, but radio signals remain the best way to locate functioning craft.

Data Points: Phobos length: 27 kilometers - Described as the size of Phobos during the seminar introduction Phobos Grunt launch target: 2009 - Projected launch year discussed by Sasha Zakharov Sample return mass: 150 grams - Amount of Phobos material the mission aims to return Sample count: 15 to 20 samples - Number of sample acquisitions from around the spacecraft needed to meet return goals Life Experiment duration: 34 months - Exposure period for microbes in interplanetary flight Life Experiment payload mass limit: 100 grams - Mass constraint for the biological payload Sample holders: 30 individual tiny sample holders - Current design for the Life Experiment container Impact survival design: 4,000 Gs - Structural survivability requirement for return impact Mars Express Phobos flyby distance: 140 kilometers - Close flybys that yielded detailed Phobos data Current member count: nearly 100,000 - Planetary Society membership mentioned in the station break 55 Cancri distance: 41 light years - Discovery of a fifth planet around the star Contest deadline: November 19 at 2 p.m. Pacific time - Deadline for trivia and anniversary contest entries

Pivotal Quotes: "Phobos Grunt. No, no, Phobos soil. Okay." — Lou Friedman: He jokes about the Russian mission name while introducing the Phobos sample-return project "The basic concept here is to test the survivability of Microbes with two things that have not been done together before." — Bruce Betts: He explains the scientific premise of the Planetary Society’s Life Experiment "Dead spacecraft are mostly lost and gone forever." — Emily Lakdawalla: Her answer to whether Earth-based telescopes can spot spacecraft

Implications: The episode highlights how sample-return missions and biological hitchhikers can deepen understanding of Mars’ moons and life’s resilience, while also showing the growing importance of international cooperation in planetary exploration.