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Sunday, October 18, 2026

The File

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Space · Sunday, October 18, 2026

Japan still plans a Mars-moons launch on Monday

The File desk · Oct 18, 2026, 11:30 AM UTC

Status

Confirmed as the scheduled launch time on NASA's Thursday article and on JAXA's mission page. The spacecraft has not launched.
  • Confirmed
    NASA says the MMX spacecraft is targeting launch at 3:41 p.m. Eastern on Monday, Oct. 19.
  • Confirmed
    JAXA's page lists lift-off as scheduled for 4:41:03 a.m. Japan time on Oct. 20, on an H3 rocket, flight number 10.
  • Confirmed
    As of Sunday morning, the launch is still marked scheduled. It has not happened.
A Japanese spacecraft bound for the moons of Mars is still set to launch Monday at 3:41 p.m. Eastern. It has not launched.1
NASA's article gives that clock: 3:41 p.m. EDT Monday, Oct. 19, from Tanegashima Space Center in Japan. In Japan that is 4:41 a.m. on Tuesday.2
Japan's space agency lists the same moment, 4:41:03 a.m. Japan time, on an H3 rocket, flight number 10. It says the return to Earth is targeted for 2031.3
The ship is still on the ground in Japan.

Notes

  1. 1.Friday's edition already noted the Monday plan. This is the Sunday check. The spacecraft had not launched when this edition locked.
  2. 2.NASA, “NASA to Help Unlock Mysteries of Mars’ Moons in Upcoming Mission,” the article opened for this desk: “The MMX spacecraft is targeting launch from JAXA’s Tanegashima Space Center in Japan at 3:41 p.m. EDT on Monday, Oct. 19 (4:41 a.m. JST on Tuesday, Oct. 20).” https://science.nasa.gov/directorates/smd/planetary-science-division/nasa-to-help-unlock-mysteries-of-mars-moons-in-upcoming-mission/
  3. 3.JAXA MMX mission page, opened for this edition. The launch block reads “LAUNCH [Scheduled],” date 2026.10.20, “Scheduled for 4:41:03 a.m. JST,” and the poster alt text says “MMX H3 Launch Vehicle Flight No. 10.” A separate line says launch is scheduled in autumn 2026, with the return to Earth targeted for 2031. https://www.mmx.jaxa.jp/en/

What is still unknown or disputed

Primary sources

Every claim in this story is drawn from the documents below. If a fetch failed, that is recorded on the card.

  1. Source 1

    NASA to Help Unlock Mysteries of Mars’ Moons in Upcoming Mission

    NASA · October 15, 2026

    The MMX spacecraft is targeting launch from JAXA’s Tanegashima Space Center in Japan at 3:41 p.m. EDT on Monday, Oct. 19 (4:41 a.m. JST on Tuesday, Oct. 20).

    https://science.nasa.gov/directorates/smd/planetary-science-division/nasa-to-help-unlock-mysteries-of-mars-moons-in-upcoming-mission/

  2. Source 2

    MMX — Martian Moons eXploration

    JAXA · October 18, 2026

    LAUNCH [Scheduled]. 2026.10.20. Scheduled for 4:41:03 a.m. JST. MMX H3 Launch Vehicle Flight No. 10. Return to Earth targeted for 2031.

    https://www.mmx.jaxa.jp/en/