Martian Moons Exploration

Martian Moons Exploration. The Martian Moons Exploration is a planned robotic space probe mission, developed by the Japan Aerospace Exploration Agency, with significant contributions from international partners including NASA, the Centre National d'Études Spatiales, and the German Aerospace Center. Its primary goal is to conduct detailed scientific investigations of the two moons of Mars, Phobos and Deimos, and to return the first-ever samples from the Martian moon Phobos to Earth. The mission aims to resolve fundamental questions about the origin of the Martian moons and, by extension, the processes that shaped the early Solar System.

Mission Overview

The mission is a cornerstone of JAXA's planetary exploration program, following the successes of Hayabusa and Hayabusa2. It is scheduled for launch in 2026 aboard an H3 rocket from the Tanegashima Space Center. Upon arrival at Mars, the spacecraft will enter orbit around the planet and commence a detailed reconnaissance phase of both Phobos and Deimos. The mission plan includes deploying small rovers, such as the DLR-developed IDEFIX, to the surface of Phobos. After extensive remote sensing and surface operations, the spacecraft will collect a regolith sample from Phobos before departing the Martian system for its return cruise to Earth.

Scientific Objectives

The core scientific objectives are designed to determine whether the moons are captured asteroids or coalesced from debris ejected from Mars after a giant impact, similar to the leading theory for the formation of Earth's Moon. Instruments will perform detailed spectroscopic mapping to compare the moons' composition with that of Mars and various asteroid types, such as those from the outer asteroid belt or D-type asteroids. A key payload, the NASA-provided MEGANE gamma-ray and neutron spectrometer, will measure elemental abundances. By analyzing returned samples with advanced laboratories like those at JAXA's Extraterrestrial Sample Curation Center, scientists hope to find clues about the delivery of water and organic materials to the inner Solar System and the early history of Mars.

Spacecraft Design

The spacecraft bus inherits design heritage from the Hayabusa2 mission, adapted for the challenges of operating in the weak gravity fields of the Martian moons. It features large solar arrays for power and a robust propulsion system for orbital maneuvers around Mars, Phobos, and Deimos. The payload suite includes a wide array of instruments: telescopic cameras like the TENGOO for terrain mapping, the OROCHI wide-angle camera, and the LIDAR for precise altitude measurement. The sample acquisition system is a critical component, designed to collect at least 10 grams of surface material using a pneumatic sampler. The spacecraft also carries the CNES-built Close-up Imager to document the sampling site in high resolution.

Launch and Trajectory

Launch is planned for September 2026 aboard Japan's flagship H3 launch vehicle from the Yoshinobu Launch Complex at Tanegashima Space Center. The interplanetary trajectory will utilize a combination of planetary gravity assists and onboard propulsion to reach Mars, with arrival anticipated in 2027. The mission profile includes a Mars gravity assist maneuver to adjust its approach. Following arrival, the spacecraft will spend several months in Areocentric orbit to characterize both moons before transitioning to a quasi-satellite orbit around Phobos for close-range operations. The departure window from the Martian system is planned for 2028, with the sample return capsule scheduled for re-entry and recovery in Australia in 2031.

Sample Return Strategy

The sample return strategy is a multi-stage process culminating in a high-speed atmospheric re-entry over Earth. After collection, the Phobos regolith sample will be sealed inside a dedicated return capsule, akin to those used on Hayabusa2 and the OSIRIS-REx mission. During the final Earth-approach phase, the main spacecraft will release the capsule on a precise trajectory. The capsule, protected by a heat shield, will decelerate through the Earth's atmosphere and deploy a parachute for a soft landing, likely at the Woomera Test Range in South Australia. The pristine samples will then be transported to curation facilities, such as those at JAXA and potentially NASA's Johnson Space Center, for initial analysis and long-term preservation for the global scientific community.

Category:JAXA space probes Category:Mars spacecraft Category:Sample return missions Category:Planned space probes