‘World’s first’ steam-propelled spacecraft heads to the moon and beyond

It will take 1.5 years to reach its final destination far beyond the moon.

Chris Young
‘World’s first’ steam-propelled spacecraft heads to the moon and beyond
An artist's impression of EQUULEUS.

JAXA / University of Tokyo 

In a world first, Japan’s space agency announced it successfully used steam to propel a spacecraft toward the Moon.

Japan Aerospace Exploration Agency’s (JAXA) water-powered CubeSat spacecraft, EQUilibriUm Lunar-Earth point 6U (EQUULEUS), was launched on its way by NASA’s Orion spacecraft, which recently broke a record for the farthest distance traveled by a human-rated spacecraft.

“This is the world’s first successful orbit control beyond low-Earth orbit using water propellant propulsion system,” JAXA said in a statement on Saturday.

Japan’s deep space CubeSat spacecraft

JAXA confirmed that the EQUULEUS spacecraft performed a maneuver that moved it toward its planned orbital path on the second Earth-Moon Lagrange point (EML2), located beyond the Moon.

Lagrangian points are locations in space where the gravity of large objects, such as planets, are balanced out by the centrifugal force of a spacecraft, allowing for a very stable orbit. NASA’s James Webb Space Telescope, for example, is located out in Lagrange Point 2 (LP2).

Much like NASA’s CAPSTONE mission, which is testing a lunar orbit for the U.S. space agency’s lunar Gateway orbital station project, the EQUULEUS spacecraft will allow scientists to test the stability of EML2 for a potential construction of a deep spaceport that will enable deep space exploration. The mission will carry out a number of investigations, including testing of the radiation environment to help determine what precautions future astronauts would have to take out in the deep space location.

“I am proud of the EQUULEUS operation team, who were able to immediately complete the orbital control necessary for the lunar fly-by, just one day after the checkout operation shortly after launch,” Professor Ryu Funasefrom the Jaxa Institute of Space and Astronautical Science said.

Investigating the second Earth-Moon Lagrange point

The EQUULEUS mission’s primary goal is to demonstrate low-energy trajectory control technologies for reaching deep space locations such as EML2 using less fuel.

When it does reach EML2, the CubeSat spacecraft will also study phenomena caused by electromagnetic disturbances in the solar wind, analyze plasma in the Earth-Moon system, and observe Near-Earth Objects (NEOs), including asteroids and comets.

The small spacecraft is equipped with an ultra-high-speed camera, a dust sensor, and an ultraviolet telescope.

“As a result of the orbit maneuver control and orbit corrections before and after the lunar fly-by, the lunar fly-by was completed as planned on November 22, JST,” JAXA explained in its statement on Saturday, adding that “spacecraft departing from EML2 can transfer to various orbits, such as Earth orbits, Moon orbits, and interplanetary orbits, with a tiny amount of orbital control.”