# 【10月21日】火星衛星探査機MMX打ち上げ成功。5年後のサンプルリターン目指す - Show: News Connect あなたと経済をつなぐ5分間 #ニュースコネクト - Published: 2026-10-21 - Canonical: https://podc.club/en/episode/1608666340_dc98c9c8dfc5.html - Audio: https://anchor.fm/s/81fb5eec/podcast/play/127775183/https%3A%2F%2Fd3ctxlq1ktw2nl.cloudfront.net%2Fstaging%2F2026-9-20%2Fed6ddcc1-c85b-0124-7dde-8cb785989a23.mp3 - Source: Edited from a machine transcript of the first 30 minutes of the episode. Not an official summary. On October 20, 2026, JAXA successfully launched MMX (Martian Moons eXploration), the world's first spacecraft designed to return samples from the Martian system, aboard an H3 rocket. The probe will spend about ten months traveling to Mars, land twice on the moon Phobos to collect at least 10 grams of surface material, and deliver a sample capsule to an Australian desert in 2031. Also in the news, a Reuters–Ipsos poll recorded President Trump's approval rating at 31%, the lowest of his first and second terms combined. ## What this episode answers ### What kind of spacecraft is MMX and what is its primary mission? MMX is the world's first Mars-system sample-return spacecraft, designed to land on Phobos—Mars's inner moon—and bring back at least 10 grams of surface material; its primary goals are to resolve the mystery of Phobos's origin and to collect Martian-derived material believed to be mixed into the moon's regolith. ### What is the mission schedule for MMX? After roughly ten months of interplanetary travel MMX is scheduled to arrive in the Martian system in August 2027, spend about three years around Phobos conducting observations and two landings, depart in 2030, and have its sample capsule land in an Australian desert in 2031. ### Why is a sample from Phobos considered scientifically valuable? Japanese planetary scientists' simulations suggest that rocks ejected from Mars by meteorite impacts have been accumulating on Phobos for 500 million years, accounting for about 0.1% of its regolith; unlike Martian meteorites found on Earth, these particles experienced relatively low shock, raising hopes they preserve ancient Martian environments or even traces of life. ### Which countries and agencies are participating in this mission, and what roles do they play? NASA is providing the MEGANE instrument, which remotely analyzes elemental composition via gamma rays and neutrons; CNES and DLR jointly developed the small rover Idefix, which will be deployed onto Phobos before MMX itself lands; ESA is supporting the mission with communications hardware and tracking stations. ### What is the current state of President Trump's approval rating? A Reuters–Ipsos poll puts Trump's approval rating at 31%, the lowest across both his first and second terms, driven by surging gasoline prices since the February military strike on Iran; a hypothetical ballot question shows Democrats leading at 47% against Republicans' 35%. ## Article ## Trump's Approval Rating Hits Record Low A new Reuters–Ipsos poll puts President Trump's approval rating at 31%, the lowest figure recorded across both his first and second terms. Gasoline prices have surged since the U.S. military strike on Iran in February, and 68% of Americans say they do not support his handling of the economy. A hypothetical ballot question—"If an election were held today, whom would you vote for?"—shows Democrats leading at 47% against Republicans' 35%, widening the gap as the November 3 midterm elections draw intense global attention. ## JAXA Successfully Launches Mars Moon Explorer MMX On October 20, 2026, JAXA (Japan Aerospace Exploration Agency) successfully launched MMX (Martian Moons eXploration), the world's first spacecraft designed to return samples from the Martian system. Riding an H3 rocket developed by JAXA and Mitsubishi Heavy Industries, the probe separated from its launch vehicle one hour and eleven minutes after liftoff and was successfully placed on a trajectory toward Mars. The spacecraft weighs 4.5 tons including propellant. International media gave the mission prominent coverage. The BBC called it "incredibly ambitious," space.com described it as "Japan's groundbreaking mission," and NASA used the phrase "paradigm-shifting" in its own assessment. ## Mission Schedule and Objectives MMX will spend roughly ten months crossing interplanetary space before arriving in the Martian system in August 2027. It will then spend approximately three years in the vicinity of Phobos, using advanced instruments to map the moon's terrain and the distribution of surface materials in detail. The spacecraft will land on Phobos twice and use a dedicated sampling device to collect at least 10 grams of regolith. If all goes to plan, MMX will leave the Martian system in 2030, and a sample capsule will touch down in an Australian desert in 2031. ## The Scientific Value of Phobos Samples MMX's primary mission is to land on Phobos—the inner of Mars's two moons—and return surface sand and rock to Earth. The origin of the Martian moons has been debated for years through two competing hypotheses: the capture theory, which holds that Phobos was once an asteroid pulled in by Martian gravity, and the giant-impact theory, which proposes that debris from a massive collision with Mars coalesced into the moon. Resolving that long-standing question is one of the mission's central goals. Equally compelling is the small fraction of Martian material that simulations by Japanese planetary scientists suggest is mixed into Phobos's regolith. According to their models, rocks ejected from Mars's surface by meteorite impacts have been raining down on Phobos for the past 500 million years. Based on these estimates, about 0.1% of the surface material is of Martian origin, meaning a 10-gram sample returned by MMX would contain roughly 30 particles that originated on Mars itself. Unlike Martian meteorites found on Earth—which experience severe shock during their journey through space—rocks of Martian origin sitting on Phobos are thought to have undergone relatively mild shock, raising the possibility that they preserve records of Mars's ancient environment or even traces of life. ## International Collaboration and Japan's Sample-Return Heritage NASA, the French National Centre for Space Studies (CNES), the German Aerospace Center (DLR), and ESA are all participating in the mission. NASA is providing an instrument that remotely analyzes the elemental composition of surface materials by detecting gamma rays and neutrons; it was named "MEGANE" (メガネ) from the initials of "Mars Moon Exploration with Gamma Rays and Neutrons." CNES and DLR jointly developed a small rover called Idefix, which is mounted aboard MMX and will be released onto Phobos before the main spacecraft lands to conduct surface observations in the moon's extremely low-gravity environment. ESA is contributing communications hardware and support from its tracking stations. Underpinning the entire MMX project is Japan's established track record in sample-return technology. Hayabusa retrieved microparticles from asteroid Itokawa, and Hayabusa2 brought back precious samples—including organic matter and water-bearing minerals—from asteroid Ryugu, earning Japan global recognition. The use of the domestically developed H3 rocket adds another dimension: in an era of intensifying competition in space development, maintaining autonomous access to space is regarded as critical not only for science and technology but also for national security. ## Takeaways - JAXA successfully launched MMX aboard an H3 rocket on October 20, 2026, targeting the world's first sample return from the Martian system, with the capsule set to land in Australia in 2031. - Phobos regolith is estimated to contain about 0.1% Martian-origin material accumulated over 500 million years, and those relatively low-shock particles may preserve records of ancient Mars or traces of life. - President Trump's approval rating has fallen to a record-low 31%, and Democrats lead 47%–35% in a hypothetical ballot as the November 3 midterm elections approach.