Orbiting Binary Black Hole Investigation Satellite

Orbiting Binary Black Hole Investigation Satellite (ORBIS) is a small space telescope still in development by Japan that will study binary black holes in the X-ray region.

Orbiting Binary Black Hole Investigation Satellite
(ORBIS)

Mission type	Astrophysics
Operator	Tokyo Metropolitan University
Website	www.comp.sd.tmu.ac.jp/ssl/orbis/Top.html
Mission duration	1.5 years (planned)[1]
Spacecraft properties
Spacecraft type	microsatellite
Launch mass	46 kg[2]
Dimensions	46 ×46 ×44 cm [2]
Power	78 W[3] (solar panels)
Start of mission
Launch date	2020
Orbital parameters
Regime	Low Earth orbit
Periapsis altitude	550 km [2]
Apoapsis altitude	550 km
Inclination	3° [2]
Period	96 min [2]
Epoch	planned
Main X-ray astronomy
Focal length	20 cm (7.9 in)[2]
Wavelengths	X-ray
Transponders
Band	S band[1]

The ORBIS concept won the first prize at the 18th Satellite Design Contest in 2010,[3] and of 2015 it was on preliminary design and undergoing thermal simulations by the Tokyo Metropolitan University[3][4] with support from Japan Aerospace Exploration Agency (JAXA) and the Institute of Space and Astronautical Science (ISAS).[3][1][2]

The spacecraft will have a mass of about 46 kg and it features a propulsion system using 60 wt% hydrogen peroxide.[1] Launch is aimed for 2020.[5][6][7]

Scientific objectives

Binary black holes (BBHs) are believed to be formed during the merger and growth of galaxies. Although several binary blackhole candidates have been identified, they have yet to be verified by long-term observations.[3][8] In order to ascertain that an object is a BBH, periodical luminosity change in X-ray wavelength must be detected. However, continuous observation of BBHs by large X-ray telescopes is difficult as such spacecraft are used by many groups and have numerous observation targets.[8] Since microsatellites have comparatively low-cost, flexibility, and can fly more often than large spacecrafts, they can conduct unique studies where risks are associated.[8][9] As ORBIS is dedicated to study BBHs, it can conduct continuous observation of such bodies. The scientific goals of the microsatellite is to uncover the growth process of black holes and galaxies, and to and contribute to gravitational-wave astronomy.[2]

Some simulations have concluded that after crossing a certain distance, the energy dissipation of two approaching black holes ceases, result in them not getting closer any further.[8] However, the merger of black holes is expected to occur during the collision of galaxies.[8] This unsolved problem is known as the final parsec problem. By finding and studying black holes less than 1 pc apart, ORBIS aims to resolve this issue.[8]

References

1. Report on the current state of "Japanese Micro/Nano/Pico-satellite Projects". (PDF). page 61; University Space Engineering Consortium (UNISEC). July 2011.
2. ORBIS - Orbiting Binary black-hole Investigation Satellite. (PDF). Japan Aerospace Exploration Agency and ISAS
3. Development of Binary Black Hole Observation Satellite "ORBIS". (PDF). Kentaro Nishi, Tokyo Metropolitan University. 20 November 2013.
4. Tokyo Metropolitan University - ORBIS. 2017
5. (in Japanese)
6. (in Japanese)
7. (in Japanese)
8. Hanada, Yukiya; Asanuma, Tasuku; Okano, Yoshinobu. "第18回衛星設計コンテスト 設計の部 バイナリブラックホール探査衛星 ORBIS 衛星設計解析書" (PDF) (in Japanese). The 18th Satellite Design Contest. Retrieved 2018-02-04.
9. Hanada, Yukiya; Asanuma, Tasuku; Okano, Yoshinobu. "巨大バイナリブラックホール探査小型衛星 ORBIS" (PDF) (in Japanese). ISAS Laboratory of Infrared Astrophysics. Retrieved 2018-02-04.