Space Missions

We have a number of experiences in design, development and operation of satellites.

ISSL OSS Project

In the ISSL OSS (Open-Source Software) project, we published several software for spacecraft research and development to contribute progress of space development. Currently, the following software is published in the GitHub.

  • Embedded software C2A (Command Centric Architecture)
  • Numerical simulator S2E (Spacecraft Simulation Environment)
  • Ground station software WINGS (Web-based Interface Ground-station Software)

Please check the GitHub page to see the details of each software.

GEO-X

We are planning a 50kg-class spacecraft for technology demonstration of deep space escape from Earth-Moon orbit and observation of the Earth’s magnetosphere using small satellite technology. ISSL is conducting bus design and development, and plans to incorporate a small X-ray imaging spectrograph currently under development at Tokyo Metropolitan University.

Ref: Specially Promoted Research X-ray Imaging of the Earth’s Magnetosphere Revealing Global Behavior of the Magnetosphere

ISSL 6U

The main goal is to develop a versatile and high-performance bus system for 6U CubeSats, which can be used for a variety of space missions. Our knowledge and experiences of past CubeSats and 50 kg class satellites are integrated. This 6U bus system has been adopted in the following two missions.

We will not only design and develop satellites for these specific missions, but also for the future projects. Softwares, development-aid tools, operation-support tools and versatile unit/bus are developed, which will also make the future projects more sophisticated and efficient.

ONGLAISAT (launched in 2024)

ONGLAISAT is a 6U satellite co-developed with TASA (Taiwan Space Agency). It combines a telescope developed by TASA with a 6U bus system developed by ISSL, aiming for high signal-to-noise ratio image capture using Time Delay Integration (TDI) technology as its mission. It was transported to the ISS on November 5, 2024, and deployed into the orbit on December 9, 2024. The operation was terminated on February 24, 2025 due to the orbit altitude was decreased below the specified altitude.

SPHERE-1 EYE (launched in 2023)

SPHERE-1 EYE is a 6U satellite launched as part of the STAR SPHERE project, a joint project by Sony Group Corporation, JAXA, and the University of Tokyo. Sony developed the mission camera, while ISSL was responsible for the development of the bus system. It was launched on January 3, 2023, and the operation was terminated on February 19, 2025 due to the orbit altitude was decreased below the specified altitude.

EQUULEUS (launched in 2022)

The main mission of EQUULEUS is to demonstrate orbit control technology in the Sun-Earth-Moon system. By utilizing the gravity of the Sun and the Moon, it aims to efficiently navigate to the Lagrangian point of the Earth-Moon system (EML2, the L2 point on the far side of the Moon as seen from the Earth) with an orbit transfer capability that is feasible even for resource-constrained CubeSats. The satellite was launched on November 16, 2022, by NASA’s new Space Launch System (SLS) rocket.

EQUULEUS has three scientific missions. The first of which is PHOENIX (Plasmaspheric Helium ion Observation by Extreme Ultraviolet Light), to image the entire Earth’s magnetospheric plasma at a distance from the Earth. The second science mission is to observe the lunar impact flashes on the lunar surface. The second scientific mission is to observe the lunar impact flashes on the lunar backside. By using a high-speed camera to detect the fleeting flashes of light emitted by micrometeorites impacting the lunar surface at high speed, we can assess the size and frequency of the meteorites falling on the Moon, and assess the threats to future manned activities and infrastructure on the Moon. The third science mission is to assess the dust environment in cis-lunar space (the space between the Earth and the lunar orbit), using an integrated science and satellite bus instrument named CLOTH (Cis-Lunar Object detector within THermal insulation).

RWASAT-1 (launched in 2019)

RWASAT-1 is Rwanda’s first artificial satellite, developed as a nano-satellite by Rwandan engineers in collaboration with the University of Tokyo and ArkEdge Space. Built upon the achievements of TRICOM-1R, RWASAT-1 incorporates a satellite design suitable for deployment from the International Space Station (ISS). It is equipped with a weak signal reception mission (Store & Forward, S&F) and a multispectral camera. RWASAT-1 was launched on November 20, 2019, and reentered Earth’s atmosphere and concluded its operations in 2022.

MicroDragon (launched in 2019)

MicroDragon project is a capacity-building program aimed at helping young researchers at the Vietnam National Space Center (VNSC) acquire satellite design, manufacturing, and testing skills through the development, launch, and operation of a 50kg-class ultra-small Earth observation satellite. The project is a collaboration between VNSC and five Japanese universities: Hokkaido University, Tohoku University, University of Tokyo, Keio University, and Kyushu Institute of Technology. MicroDragon was launched on January 18, 2019, aboard the Epsilon-4 rocket.

In this project, the foundation technologies of the HODOYOSHI satellite series were leveraged to achieve the efficient manufacturing of the satellite bus in a short period.

MicroDragon reentered Earth’s atmosphere in 2024, and its operations concluded.

TRICOM-1R (launched in 2018)

The 3U-class satellite TRICOM-1R (“Tasuki”) was developed by the University of Tokyo and successfully launched into orbit in 2018, aboard the SS-520-5 sounding rocket from the Uchinoura Space Center. TRICOM-1R is a 3U-class satellite that shares the same design and capabilities as the previously launched TRICOM-1. In 2017, the same type of satellite, TRICOM-1, was launched using the SS-520-4 rocket, but the mission ended in failure due to a rocket malfunction. TRICOM-1R has the same performance as TRICOM-1, with Earth observation and data relay (S&F: Store and Forward) systems. Additionally, as an improvement over TRICOM-1, TRICOM-1R includes a new immediate observation mission. TRICOM-1R was launched on February 3, 2018 and reentered the Earth’s atmosphere and ended its operations on August 22, 2018.

TRICOM-1 (launched in 2017)

TRICOM-1 is a 3U-class satellite that utilizes the foundational technologies of the Hodoyoshi satellite series, incorporating advanced attitude control, Earth observation capabilities, and a Store and Forward (S&F) experiment. The satellite also marked a new attempt by using the SS-520 sounding rocket for the launch of an artificial satellite.

The S&F mission involves sending data from transmitters placed on stationary or moving objects on the ground or at sea to the satellite. The satellite, orbiting the Earth, receives and collects this data during its mission. The development of TRICOM-1 involved a collaboration between institutions such as the University of Tokyo, Tokyo University of Science, Tokyo University of Electric Engineering, Chubu University, the Institute of Space and Astronautical Science (ISAS), as well as companies and organizations participating in the Hodoyoshi program.

On January 15, 2017, due to a malfunction in the rocket during launch, TRICOM-1’s launch ended in failure.

PROCYON (launched in 2014)

PROCYON is a micro-deep space probe launched on December 3, 2014, together with the asteroid probe Hayabusa2. It was developed mainly by our laboratory at the University of Tokyo, in collaboration with ISAS and other universities in Japan.

The main mission of PROCYON is to demonstrate the bus technology of a 50 kg class ultra-small deep space probe (to demonstrate that the necessary technologies for a probe, such as power supply, communication, attitude and orbit control, can function even in ultra-small size in deep space far from the Earth). In addition, as an advanced mission, we will demonstrate the world’s most efficient X-band communication amplifier, conduct high-precision orbit determination experiments, observe the geocorona from deep space, and demonstrate ultra-close flyby imaging technology for asteroids.

HODOYOSHI-3 and HODOYOSHI-4 (launched in 2014)

HODOYOSHI-3 and HODOYOSHI-4 satellites were launched on June 20, 2014 using a “Dnepr” rocket as the first demonstration satellite based on “the HODOYOSHI reliability concept” for micro-satellites. They are still operational today.

The mission payloads of HODOYOSHI-3 include a medium-low resolution optical camera, Store and Forward, and a hosted payload space. Notably, the use of the Store and Forward system and the hosted payload for user equipment marked the world’s first attempt in the field of micro-satellites. These innovations have the potential to significantly expand the scope of small satellite applications in the future. The HODOYOSHI-3 satellite uses a common bus for the HODOYOSHI series and is equipped with radiation-resistant computers, reaction wheels, star sensors, fiber optic gyros, and GPS receivers, enabling advanced three-axis attitude control. Additionally, it also performs orbit control using a hydrogen peroxide thruster.

The mission of HODOYOSHI-4 includes medium resolution Earth observation, demonstration of several new technologies, and formation flying operation with HODOYOSHI-3. The mission payloads include a 6-meter resolution optical camera, and new technologies such as a high-speed (100Mbps) X-band transmitter and an ion engine for on-orbit demonstration. These technologies are designed to dramatically expand data communication and orbit control capabilities within the size and weight constraints of micro-satellites. Similar to HODOYOSHI-3, the HODOYOSHI-4 satellite also carries a Store and Forward system and hosted payload space for user equipment.

Link

Nano-JASMINE (canceled)

Nano-JASMINE is the first Japanese positional astronomical satellite, which aims to make a precise map of stars in our Galaxy. The satellite bus system is developed by the Nakasuka laboratory, and the telescope is developed by the JASMINE laboratory of NAOJ. Unfortunately, the launch was cancelled and the development was terminated.

PRISM (launched in 2009)

PRISM (nicknamed “Hitomi”) is a remote sensing satellite that deploys a soft-propagating boom in space to take images of the Earth with a resolution of 30 meters. It was launched on January 23, 2009 by H-2A rocket with other partner satellites, and successfully deployed the boom and took images with the main camera.

XI-V (launched in 2005)

XI-V is the second flight model of the XI series, and following the successful launch of XI-IV, XI-V, a spare model of XI-IV, was launched from Russia on October 27, 2005, with a new technology demonstration mission including a space demonstration of a new solar cell (CIGS). XI-V is still in operation as of March 2025.

XI-IV (launched in 2003)

The XI (X-factor Investigator) series is our first nano-satellite development project. XI-I and XI-II are BBM (Bread Board Model), XI-III is EM (Engineering Model), and XI-IV is the first FM (Flight Model). XI-IV was launched from Russia on June 30, 2003, and became the world’s first successful launch and operation of a CubeSat (10 cm cube, 1 kg). XI-IV is still in operation in space and continues to extend the world’s longest life span as a CubeSat (as of March 2025).