Nozomi was a Mars orbiter that failed to reach Mars due to electrical failures. The mission was terminated on December 31, 2003.
A Molniya orbit is a type of satellite orbit designed to provide communications and remote sensing coverage over high latitudes. It is a highly elliptical orbit with an inclination of 63.4 degrees, an argument of perigee of 270 degrees, and an orbital period of approximately half a sidereal day. The name comes from the Molniya satellites, a series of Soviet/Russian civilian and military communications satellites which have used this type of orbit since the mid-1960s.
The Japan Aerospace Exploration Agency (JAXA) is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into orbit, and is involved in many more advanced missions such as asteroid exploration and possible human exploration of the Moon. Its motto is One JAXA and its corporate slogan is Explore to Realize.
An erg is a unit of energy.
The INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) is a space telescope for observing gamma rays of energies up to 8 MeV. It was launched by the European Space Agency (ESA) into Earth orbit in 2002, and is designed to provide imaging and spectroscopy of cosmic sources. In the MeV energy range, it is the most sensitive gamma ray observatory in space. It is sensitive to higher energy photons than X-ray instruments such as NuSTAR, the Neil Gehrels SWIFT Observatory, XMM-Newton, and lower than other gamma-ray instruments such Fermi and HESS.
Explorer 32, also known as Atmosphere Explorer-B (AE-B), was a NASA satellite launched by the United States to study the Earth's upper atmosphere. It was launched from Cape Canaveral on a Delta C1 launch vehicle, on 25 May 1966. It was the second of five "Atmosphere Explorer", the first being Explorer 17. Though it was placed in a higher-than-expected orbit by a malfunctioning second stage on its launch vehicle, Explorer 32 returned data for ten months before failing due to a sudden depressurization. The satellite reentered the Earth's atmosphere on 22 February 1985.
The Pegasus Project was a NASA initiative to study the frequency of micrometeorite impacts on spacecraft by means of a constellation of three satellites launched in 1965. All three Pegasus satellites were launched by Saturn I rockets, and remained connected with their upper stages.
The Tropical Rainfall Measuring Mission (TRMM) was a joint space mission between NASA and the Japan Aerospace Exploration Agency JAXA designed to monitor and study tropical rainfall. The term refers to both the mission itself and the satellite that the mission used to collect data. TRMM was part of NASA's Mission to Planet Earth, a long-term, coordinated research effort to study the Earth as a global system. The satellite was launched on 27 November 1997 from the Tanegashima Space Center in Tanegashima, Japan. TRMM operated for 17 years, including several mission extensions, before being decommissioned on 15 April 2015. TRMM re-entered Earth's atmosphere on 16 June 2015.
Explorer 8 was a NASA research satellite launched on 3 November 1960. It was intended to study the temporal and spatial distribution of the electron density, the electron temperature, the ion concentration, the ion mass, the micrometeorite distribution, and the micrometeorite mass in the ionosphere at altitudes between 400 km (250 mi) and 1,600 km (990 mi) and their variation from full sunlit conditions to full shadow, or nighttime, conditions.
Geotail is a satellite observing the Earth's magnetosphere. It was developed by Japan's ISAS in association with the United States' NASA, and was launched by a Delta II rocket on 24 July 1992 from Cape Canaveral Air Force Station.
The Global Geospace Science (GGS) Polar satellite was a NASA science spacecraft designed to study the polar magnetosphere and aurorae. It was launched into orbit in February 1996, and continued operations until the program was terminated in April 2008. The spacecraft remains in orbit, though it is now inactive. Polar is the sister ship to GGS Wind.
The Small Astronomy Satellite 2, also known also as SAS-2, SAS B or Explorer 48, was a NASA gamma ray telescope. It was launched on 15 November 1972 into the low Earth orbit with a periapsis of 443 km and an apoapsis of 632 km. It completed its observations on 8 June 1973.
An X-ray astronomy satellite studies X-ray emissions from celestial objects, as part of a branch of space science known as X-ray astronomy. Satellites are needed because X-radiation is absorbed by the Earth's atmosphere, so instruments to detect X-rays must be taken to high altitude by balloons, sounding rockets, and satellites.
The Epsilon Launch Vehicle, or Epsilon rocket, is a Japanese solid-fuel rocket designed to launch scientific satellites. It is a follow-on project to the larger and more expensive M-V rocket which was retired in 2006. The Japan Aerospace Exploration Agency (JAXA) began developing the Epsilon in 2007. It is capable of placing a 590 kg payload into Sun-synchronous orbit.
Hisaki, also known as the Spectroscopic Planet Observatory for Recognition of Interaction of Atmosphere (SPRINT-A) is a Japanese ultraviolet astronomy satellite operated by the Japan Aerospace Exploration Agency (JAXA). The first mission of the Small Scientific Satellite program, it was launched in September 2013 on the maiden flight of the Epsilon rocket.
OKEANOS was a proposed mission concept to Trojan asteroids, which share Jupiter's orbit, using a hybrid solar sail for propulsion; the sail was planned to be covered with thin solar panels to power an ion engine. In situ analysis of the collected samples would have been performed by either direct contact or using a lander carrying a high-resolution mass spectrometer. A sample-return to Earth was an option under study.
Explorer 12, also called EPE-A or Energetic Particles Explorer-A and as S3), was a NASA satellite built to measure the solar wind, cosmic rays, and the Earth's magnetic field. It was the first of the S-3 series of spacecraft, which also included Explorer 12, 14, 15, and 26. It was launched on 16 August 1961, aboard a Thor-Delta launch vehicle. It ceased transmitting on 6 December 1961 due to power failure.
Elektron ('electron'), in American sources sometimes called Electron, was the first Soviet multiple satellite program, comprising two identical pairs of particle physics satellites launched by the Soviet Union in 1964. The four spacecraft simultaneously monitored the lower and upper Van Allen radiation belts and returned a considerable volume of data regarding radiation in space and atmospheric conditions to an altitude of more than 58,000 kilometres (36,000 mi) above the Earth. Two of the four launched satellites are still in orbit as of 2020, the other two having reentered.
ASTERISC is a nanosatellite developed by the Planetary Exploration Research Center (PERC) at the Chiba Institute of Technology that will observe cosmic dust in low Earth orbit. It is built as 3U-sized CubeSat and will deploy a large membrane structure in space. ASTERISC was launched on 9 November 2021 by an Epsilon launch vehicle.
The Environmental Research Satellite program was a series of small satellites initially operated by the United States Air Force Office of Aerospace Research. Designed to be launched "piggyback" to other satellites during launch, detaching once in orbit, they were the smallest satellites launched to date—what would today be classified as microsatellites. 33 ERS satellites in six different series were launched between 1962 and 1971, conducting scientific research and serving as test beds to investigate the reliability of new spacecraft components.
