JAXA Testing Deep Space Microsat With Asteroid Flyby


With all the attention that JAXA’s recently launched Hayabusa2 soil sample return mission has received, a secondary spacecraft sent into space along with it on Dec. 3 has been largely overlooked despite its ambitious objectives.

PROCYON, which stands for PRoximate Object Close flYby with Optical Navigation, is a 65-kg (143 lb.) spacecraft designed to demonstrate that micro-satellites can be used for deep-space exploration. In addition to testing out micro-sat systems in deep space, the spacecraft is to conduct a close flyby of an asteroid.

Developed by the University of Tokyo and JAXA, PROCYON was launched as a secondary payload along with Hayabusa2 on Dec. 3. JAXA reports that controllers have received confirmation that PROCYON was inserted into its planned interplanetary orbit as scheduled two hours after launch.

The spacecraft, which measures only 630 x 550 x 550 mm (24.8 x 21.65 x 21.65 in), has a mission that is divided into nominal and advanced phases.

The nominal mission seeks to accomplish the following goals:

  • demonstration of a deep space exploration micro-satellite bus system
  • power generation, thermal control, attitude control, communication, orbit determination in deep space
  • orbit control by small electric propulsion system
PROCYON trajectory
PROCYON trajectory

The advanced goals include:

  • communication using high-efficiency GaNX-band power amplifier
  • Precise Delta Differential One-Way Range Determination (DDOR) navigation in deep space
  • optical navigation to encounter asteroid
  • asteroid close flyby observation.
PROCYON asteroid flyby (Credit: JAXA)

In addition to the University of Tokyo and JAXA, cooperating organizations include Tokyo University of Science, Hokkaido University, Meisei University and Rikkyo University.