Japan launches mission to bring home a piece of the Martian moon Phobos

Japan sends a mission to Phobos

On Monday, Japan launched a robotic spacecraft named MMX from Tanegashima Space Center in southern Japan. It rode into space on a large H3 rocket. The spacecraft will travel for about 10 months to reach Mars. Then it will land on Phobos, the largest moon of Mars, and collect samples to send back to Earth. The launch was a success, and the spacecraft quickly made contact with ground controllers and opened its solar panels.

Key facts

• The mission costs $578 million.
• The H3 rocket is 207 feet (63 meters) tall.
• The spacecraft weighs nearly 9,900 pounds (4.5 metric tons). About two-thirds of that is fuel.
• The rocket sped the spacecraft to more than 24,000 mph.
• The spacecraft separated from the rocket about 71 minutes after liftoff.

Japan's earlier sample missions

Japan has already brought samples back from space rocks. Its Hayabusa and Hayabusa 2 missions were the first two spacecraft to return clean samples from asteroids. Scientists think Phobos may be an asteroid that Mars captured into orbit billions of years ago. MMX will test this idea.

Why it matters

If MMX brings back samples, it would be the first sample return from the Martian moons. Scientists hope the samples can show how the Solar System formed. The mission also shows that Japan is building skills in space science and exploration.

What to watch

• The spacecraft's 10-month trip to Mars.
• Its landing on Phobos and sample collection.
• Whether the samples support the idea that Phobos is a captured asteroid.
• The safe return of samples to Earth.