New X-ray nanosatellite to study black holes, neutron stars

This satellite, dubbed NinjaSat X-ray, would spend two years in low-Earth orbit (LEO) studying bright X-ray sources in the Milky Way Galaxy.
Mrigakshi Dixit
Artists image of NinjaSat.
Artists image of NinjaSat.


A new nanosatellite dedicated to studying black holes and neutron stars from low Earth orbit is expected to launch this year.

This satellite, dubbed NinjaSat X-ray, would spend two years in low-Earth orbit (LEO) studying bright X-ray sources in the Milky Way Galaxy.

The satellite results from a collaboration between Japan's RIKEN research institution, Mitsui Bussan Aerospace, and mission integrator Kongsberg NanoAvionics (NanoAvionics). 

NanoAvionics recently delivered their multi-purpose nanosatellite bus, integrated with the RIKEN research payloads. The Lithuania-based start-up has also provided satellite testing services for this mission.

As per the official release, the SpaceX Transporter 9 mission will launch the satellite this year.

The observation of bright X-ray objects

Once in low Earth orbit, the satellite will search for X-ray photons generated by bright X-ray sources in the Galaxy. 

The mission team's primary goal is to tap into NinjaSat abilities to collect data on mysterious black holes and neutron stars. The latter is formed when a massive star runs out of fuel and collapses. 

Scientists can also conduct follow-up observations using ground-based optical telescopes upon confirmation of X-ray light emitted by two cosmic entities. The extensive investigation will reveal "how matter accretes to these compact objects."

Furthermore, the satellite has been designed to undertake on-demand follow-up studies of transient objects detected by the Monitor of All-sky X-ray Image (MAXI). It's an X-ray camera on the International Space Station's Japanese Experiment Module.

For example, it will carefully examine Scorpius X-1, a known bright X-ray source situated around 9,000 light-years away in the direction of the constellation Scorpius. 

It is a significant target for astronomers because it contains a fast-spinning neutron star in a binary star system. It is also an excellent target for studying gravitational waves. 

“Small but flexible CubeSats, such as NinjaSat, attempt to observe the X-ray sky in ways that are difficult to achieve with large observatories. RIKEN and collaborators are now operating the Monitor of All-sky X-ray Image (MAXI) instrument aboard the International Space Station (ISS) and have discovered many new black holes in our Galaxy that suddenly brighten in X-rays. NinjaSat allows high cadence monitoring and flexible operations for such transient sources, which are of great value in time-domain astronomy, covertly targeting critical scientific results as a ninja,” explained Toru Tamagawa, the chief scientist at RIKEN, in an official release. 

Satellite payloads

The statement elaborates on the NinjaSat X-ray observatory's structure, stating that it is a 6U-size CubeSat designed to make observations in X-ray wavelength light released by cosmic objects. 

The satellite is equipped with pair of deployable solar panels, two Radiation Belt Monitors (RBMs) for checking energetic background particles, and a star tracker for positioning.