Hiten / Hagoromo
Type
Launch
Target
Objective
The mission of orbiter Hiten and the small satellite it carried, Hagoromo, featured Japan's first-ever lunar flyby, lunar orbiter, and lunar surface impact, making Japan only the third nation to achieve each of these goals.
What Was Hiten?
Hiten was Japan’s Earth orbiting satellite designed primarily to test and verify technologies for future lunar and planetary missions. The spacecraft carried a small satellite named Hagoromo that was released in the vicinity of the Moon. Hiten was put into a highly elliptical Earth orbit, and passed by the Moon 10 times before being intentionally crashed on its surface on April 10, 1993.
Nation | Institute of Space and Aeronautical Science (ISAS), Japan |
Objective(s) | Lunar Flyby and Lunar Orbit |
Spacecraft | Hiten and Hagoromo |
Spacecraft Mass | 434 pounds (197 kilograms) |
Mission Design and Management | ISAS |
Launch Vehicle | M-3SII-5 |
Launch Date and Time | Jan. 24, 1990 |
Launch Site | Kagoshima Space Center (Uchinoura) |
Scientific Instruments | Hiten: Cosmic dust detector |
In Depth: Hiten and Hagoromo
This two-module Japanese spacecraft was designed to fly past the Moon and release an orbiter. It was the first Japanese lunar mission, and also the first robotic lunar probe since the flight of the Soviet Luna 24 in 1976.
Muses-A (for Mu-launched Space Engineering Satellite) was launched into a highly elliptical Earth orbit that intersected the Moon's orbit. After launch, the spacecraft, which was renamed Hiten, returned technical data on trajectory and optical navigation from an onboard computer. The cosmic dust experiment was jointly designed with Germany.
On March 18, 1990, the spacecraft approached the Moon to a range of 10,240 miles (16,472 kilometers) and then released a small 27-pound (12-kilogram) satellite named Hagoromo into lunar orbit. Initial orbital parameters were 14,000 x 5,600 miles (22,000 x 9,000 kilometers). Although the maneuver successfully demonstrated the use of the swingby technique to enter lunar orbit, communication with Hagoromo was lost shortly after release.
It is not known whether Hagoromo impacted the Moon or escaped into a heliocentric orbit.
Hiten, on the other hand, continued on its trajectory, simulating the orbital path of the proposed Geotail spacecraft that was to study Earth's magnetic tail. On March 19, 1991, Hiten flew by Earth at a range of about 78 miles (26 kilometers) and conducted the first aerobraking maneuver by a deep-space probe, which slowed it by about 6 feet (1.7 meters) per second. On Oct. 2, 1991, Hiten was temporarily captured by the Moon and then put into a looping orbit which passed through the L4 and L5 stable libration points to look for trapped dust particles. No obvious increase was found.
During its 11th flyby of the Moon on Feb. 15, 1992, Hiten swung into lunar orbit. On April 10, 1993, it was deliberately crashed into the lunar surface.
Hiten was named after a flying, music-playing Buddhist angel. Hagoromo was named for the veil worn by Hiten.
Key Source
Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.
