SELENE

SELENE
Mission name	SELENE
Operator	Japan Aerospace Exploration Agency

SELENE is a lunar orbiter mission developed by the Japan Aerospace Exploration Agency in collaboration with NASA and European Space Agency. The mission was designed to study the Moon's composition, geology, and atmosphere, and to develop technologies for future lunar exploration missions, such as those planned by China National Space Administration and Indian Space Research Organisation. SELENE was launched on September 14, 2007, from the Tanegashima Space Centre using an H-IIA rocket, and it entered into a lunar orbit on October 4, 2007, joining other lunar orbiters like Lunar Prospector and Clementine. The mission was also supported by Russian Federal Space Agency and Canadian Space Agency.

Introduction

SELENE was a major milestone in the Japanese space program, marking the country's first lunar mission since the JAXA's Hiten mission in 1990, which was also supported by NASA and European Space Agency. The mission was designed to conduct a comprehensive study of the Moon's surface and subsurface composition, including its geology, exosphere, and magnetic field, using advanced instruments like those on Mars Reconnaissance Orbiter and Venus Express. SELENE also aimed to develop and demonstrate new technologies for lunar exploration, such as laser altimetry and radar sounding, which were also used on Mars Global Surveyor and Cassini-Huygens. The mission was a collaboration between JAXA, NASA, and European Space Agency, with contributions from Russian Federal Space Agency, Canadian Space Agency, and China National Space Administration.

Spacecraft Design

The SELENE spacecraft was designed and built by JAXA and Mitsubishi Heavy Industries, with a total mass of approximately 2,914 kilograms, similar to Magellan and Galileo. The spacecraft was equipped with a range of instruments, including a laser altimeter developed by NASA and JAXA, a radar sounder developed by JAXA and European Space Agency, and a spectrometer developed by JAXA and Canadian Space Agency. The spacecraft was powered by a combination of solar panels and lithium-ion batteries, similar to those used on International Space Station and Hubble Space Telescope. SELENE also carried a relay satellite called Okina, which was used to communicate with the Earth when the spacecraft was on the far side of the Moon, using techniques developed for Voyager 1 and Voyager 2.

Mission Objectives

The primary objectives of the SELENE mission were to conduct a comprehensive study of the Moon's surface and subsurface composition, including its geology, exosphere, and magnetic field, using techniques developed for Mars Science Laboratory and Cassini-Huygens. The mission also aimed to develop and demonstrate new technologies for lunar exploration, such as laser altimetry and radar sounding, which were also used on Mars Reconnaissance Orbiter and Venus Express. SELENE was designed to provide high-resolution topographic maps of the Moon's surface, as well as detailed information about its composition and internal structure, similar to those obtained by Apollo 11 and Apollo 15. The mission was also intended to contribute to the development of future lunar exploration missions, such as those planned by China National Space Administration and Indian Space Research Organisation.

Launch and Orbit

SELENE was launched on September 14, 2007, from the Tanegashima Space Centre using an H-IIA rocket, which was also used to launch Hayabusa and Suzaku. The spacecraft entered into a lunar orbit on October 4, 2007, and began its scientific observations of the Moon's surface and subsurface composition, using techniques developed for Mars Global Surveyor and Cassini-Huygens. SELENE was placed in a polar orbit around the Moon, with an altitude of approximately 100 kilometers, similar to Lunar Prospector and Clementine. The spacecraft completed its primary mission in 2008, but it continued to operate until June 2009, when it was intentionally crashed into the Moon's surface, using techniques developed for Apollo 13 and Galileo.

Instruments and Experiments

SELENE was equipped with a range of instruments and experiments, including a laser altimeter developed by NASA and JAXA, a radar sounder developed by JAXA and European Space Agency, and a spectrometer developed by JAXA and Canadian Space Agency. The spacecraft also carried a relay satellite called Okina, which was used to communicate with the Earth when the spacecraft was on the far side of the Moon, using techniques developed for Voyager 1 and Voyager 2. SELENE's instruments and experiments were designed to provide high-resolution topographic maps of the Moon's surface, as well as detailed information about its composition and internal structure, similar to those obtained by Apollo 11 and Apollo 15. The mission also included a range of in-situ experiments, such as a lunar impactor developed by JAXA and Indian Space Research Organisation, which was used to study the Moon's exosphere and magnetic field, using techniques developed for Mars Science Laboratory and Cassini-Huygens.

Legacy and Impact

The SELENE mission made significant contributions to our understanding of the Moon's surface and subsurface composition, including its geology, exosphere, and magnetic field, using techniques developed for Mars Reconnaissance Orbiter and Venus Express. The mission also demonstrated new technologies for lunar exploration, such as laser altimetry and radar sounding, which were also used on Mars Global Surveyor and Cassini-Huygens. SELENE's findings have been used to inform the development of future lunar exploration missions, such as those planned by China National Space Administration and Indian Space Research Organisation. The mission has also contributed to the development of new space technologies, such as advanced propulsion systems and lunar landing technologies, which were also used on International Space Station and Hubble Space Telescope. SELENE's legacy continues to be felt in the space community, with its findings and technologies being used to support ongoing and future space missions, such as Artemis program and Europa Clipper.

Category:Lunar missions