Japan's SLIM 'moon sniper' spacecraft leaves Earth orbit

A Japanese lunar lander is on its way to its final destination.

The Smart Lander for Investigating Moon (SLIM) spacecraft performed an engine burn to leave Earth orbit on Saturday (Sept. 30), the Japan Aerospace Exploration Agency (JAXA) announced today (Oct. 2).

SLIM fired its main engine for 39 seconds on Saturday, while it was flying about 410 miles (660 kilometers) above the South Atlantic Ocean, JAXA officials said via X (formerly Twitter). If all goes according to plan, the probe will have its first encounter with the moon on Wednesday (Oct. 4), they added.

Related: Japan's SLIM moon lander completes 1st critical phase in Earth orbit

SLIM launched to Earth orbit on Sept. 6, along with a powerful X-ray telescope called XRISM. SLIM team members spent the next few weeks checking their spacecraft out, making sure its various systems were functioning properly ahead of its journey to the moon. 

That work went well, so the team sent SLIM on its way with Saturday's engine burn. (XRISM, meanwhile, will stay in Earth orbit for the long haul.)

"After implementing any necessary corrective maneuvers, we plan to have the first meeting with the moon on the afternoon of October 4!" the SLIM team wrote in another X post today. 

SLIM's touchdown try is still a ways away; Wednesday's "meeting" will be a lunar swing-by, one more step on the probe's long, looping and fuel-efficient journey to the moon. JAXA officials have said that SLIM will likely arrive in lunar orbit three to four months after launch, with the landing attempt coming a month or two after that.

Success on that coming try would be historic; to date, only the Soviet Union, the United States, China and India have aced a soft landing on the moon to date.

SLIM's landing will be a milestone in another way as well. The mission aims to touch down within a mere 328 feet (100 meters) of its target point inside Shioli, a small crater on the moon's near side (which explains the probe's "moon sniper" nickname).

The ability to make such precise landings could allow future missions to access challenging but scientifically intriguing sites on the moon and other worlds beyond Earth, JAXA officials have said.