AQT-D (Aqua Thruster-Demonstrator) was a nanosatellite project of the University of Tokyo (UT) Space Propulsion Laboratory with the purpose of testing water-fueled propulsion. The satellite was a CubeSat of 3U size; 1U was occupied by the propulsion system, while the remaining 2U was for the

spacecraft bus A satellite bus (or spacecraft bus) is the main body and structural component of a satellite or spacecraft, in which the payload and all scientific instruments are held. Bus-derived satellites are opposed to specially produced satellites. Bus-d ...

. AQT-D was carried to space inside the pressurized section of

Kounotori 8 , also known as HTV-8 was the 8th flight of the H-II Transfer Vehicle, a robotic cargo spacecraft to resupply the International Space Station. It was launched on 24 September 2019, 16:05:05 UTC. Spacecraft Major changes from previous Kounot ...

, a Japanese resupply vehicle for the

International Space Station The International Space Station (ISS) is the largest modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA ...

(ISS). Kounotori 8 was launched on 24 September 2019. After arriving at the ISS, AQT-D was deployed to space on 20 November 2019 using the JEMRMS robotic arm at the space station's Kibō laboratory module. The AQT-D project was led by Jun Asakawa of the University of Tokyo. AQT-D reentered the atmosphere on 20 April 2022.

Spacecraft

AQT-D's spacecraft bus was based on Tasuki (TRICOM-1R), a previous satellite developed by the University of Tokyo and launched in 2017. The satellite was equipped with antennas for store and forward

communication Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inquir ...

Propulsion

AQT-D's propulsion system, called ''AQUARIUS-1U'' (Aqua Resistojet Propulsion System-1U), consisted of five water thrusters. A single delta-v thruster produced 4.0 mN, and four reaction control thrusters 1.0 mN, for attitude control.AQT-D: Demonstration of the Water Resistojet Propulsion System by the ISS-Deployed CubeSat
(PDF). ''Small Satellite Conference''. University of Tokyo. 2019. The spacecraft carried less than 0.4 kg of water. The delta-v thruster produced a specific impulse (I_sp) of 70 seconds, and a maximum 4.0 mN of thrust, which was dependent on available power. AQUARIUS-1U's design was based on the planned deep space probe EQUULEUS's propulsion system. According to the University of Tokyo, AQT-D was the first ISS-deployed satellite to have water-based propulsion. While satellites deployed from the ISS typically have a short lifetime owing to the station's low altitude, satellites equipped with a propulsion system like AQT-D may potentially remain in orbit for an extended period of time.

References

External links

AQT-D: AQUA Thruster-Demonstrator
{{Japanese space program Satellites of Japan University of Tokyo CubeSats 2019 in Japan Spacecraft launched in 2019 Spacecraft which reentered in 2022 Satellites deployed from the International Space Station