The Japan Aerospace Exploration Agency (JAXA) announced in a press release on
November 26 that it successfully used a water propellent system to drive its
“EQUULEUS” CubeSat. The craft was launched by NASA’s Artemis I on November 16.
EQUULEUS has a water propellant engine named AQUARIUS (AQUA ResIstojet
propUlsion System) that uses heat from communications equipment to turn water
into steam, which can be jetted out to generate thrust.
Why Use Water as Fuel?
Water is a better choice than other fuels for use in small, cheap satellites
because it is easier to store and handle.
EQUULEUS Flight Path
Artemis I injected the spacecraft into a lunar flyby trajectory. Then EQUULEUS
fired its steam engines and started its journey to the second Moon Lagrange
point (EML2), and it should take a year and a half to reach EML2.
“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. This was a difficult
operation that had to be successful. I feel we were able to succeed in this
critical operation due to their careful preparation, including numerous
back-up plans, and the ability to respond flexibly through training. We are
now at the start line of the long voyage to the Lagrange point,”
said FUNASE Ryu, an associate professor at the Department of Aeronautics
and Astronautics, the University of Tokyo, Japan.
If you want to know more about EQUULEUS and how it works, read
Development of the Water Resistojet Propulsion System for Deep Space
Exploration by the CubeSat: EQUULEUS.