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The following list contains only selected spacecraft of interest to planetary science. It is far from complete (see below for more details). Much of the following was adapted from the sci.space FAQ.
(more info from NASA Spacelink)
(Apollo "home page"; Apollo Missions)
Pioneer 11's RTG power supply is dead. Its last communication with Earth was in November 1995. Pioneer 10 is still functioning (barely) but is no longer being tracked regularly due to budget cutbacks. The last data was received from it on 1997 March 31. They are heading off into interstellar space, the first craft ever to do so.
As the first two spacecraft to leave our solar system, Pioneer 10 & 11 carry a graphic message in the form of a 6- by 9-inch gold anodized plaque bolted to the spacecraft's main frame.
(Pioneer Project Home Page and more about Pioneer 10 and Pioneer 11 from NASA Spacelink; current status from NASA Ames)
(more info from NASA Spacelink; and NSSDC a tutorial from UCLA)
The last data from Viking (Lander 1) made its final transmission to Earth Nov. 11, 1982. Controllers at JPL tried unsuccessfully for another six and one-half months to regain contact with Viking Lander 1. The overall mission came to an end May 21, 1983.
An interesting side note: Viking 1's lander has been designated the Thomas A. Mutch Memorial Station in honor of the late leader of the lander imaging team. The National Air and Space Museum in Washington, DC is entrusted with the safekeeping of the Mutch Station Plaque until it can be attached to the lander by a manned expedition.
(more info and an web page from JPL)
Between the two probes, our knowledge of the 4 giant planets, their satellites, and their rings has become immense. Voyager 1&2 discovered that Jupiter has complicated atmospheric dynamics, lightning and aurorae. Three new satellites were discovered. Two of the major surprises were that Jupiter has rings and that Io has active sulfurous volcanoes, with major effects on the Jovian magnetosphere.
When the two probes reached Saturn, they discovered over 1000 ringlets and 7 satellites, including the predicted shepherd satellites that keep the rings stable. The weather was tame compared with Jupiter: massive jet streams with minimal variance (a 33-year great white spot/band cycle is known). Titan's atmosphere was smoggy. Mimas's appearance was startling: one massive impact crater gave it the Death Star appearance. The big surprise here was the stranger aspects of the rings. Braids, kinks, and spokes were both unexpected and difficult to explain.
In contrast to Uranus, Neptune was found to have rather active weather, including numerous cloud features. The ring arcs turned out to be bright patches on one ring. Two other rings, and 6 other satellites, were discovered. Neptune's magnetic axis was also skewed. Triton had a canteloupe appearance and geysers. (What's liquid at 38K?)
If no unforeseen failures occur, we will be able to maintain communications with both spacecraft until at least the year 2030. Both Voyagers have plenty of hydrazine fuel -- Voyager 1 is expected to have enough propellant until 2040 and Voyager 2 until 2034. The limiting factor is the RTGs (radio-isotope thermal generators). The power output from the RTGs is slowly dropping each year. By 2000, there won't be enough power for the UVS (ultraviolet spectrometer) instrument. By 2010, the power will have dropped low enough such that not all of the fields and particles instruments can be powered on at the same time. A power sharing plan will go into effect then, where some of the F&P instruments are powered on, and others off. The spacecraft can last in this mode for about another 10 years, and after that the power will probably be too low to maintain the spacecraft.
(the Voyager Project Home Page from JPL; another nice "home page" at NSSDC; fact sheets and a web page from JPL; General Info from NASA/ARC)
In April, 1990, Giotto was reactivated. 3 of the instruments proved fully operational, 4 partially damaged but usable, and the remainder, including the camera, were unusable. On July 2, 1990, Giotto made a close encounter with Earth and was retargeted to a successful flyby of comet Grigg-Skjellerup on July 10, 1992.
Ground controllers have regained control of the spacecraft, however. Its potential future mission is being considered.
(for more information see the Clementine Mission Home page from USGS and the Clementine page from NASA PDS or The Clementine Mission from LPI.)
(more info, a web page and another web page from JPL; fact sheet from NSSDC)
Both Voyagers are using their ultraviolet spectrometers to map the heliosphere and study the incoming interstellar wind. The cosmic ray detectors are seeing the energy spectra of interstellar cosmic rays in the outer heliosphere
Voyager 1 has passed the Pioneer 10 spacecraft and is now the most distant human-made object in space.
(more info from JPL)
Galileo has already returned the first resolved images of two asteroids, 951 Gaspra and 243 Ida, while in transit to Jupiter. It has also returned pictures of the impact of Comet SL9 onto Jupiter from its unique vantage point.
Efforts to unfurl the stuck High Gain
Antenna (HGA) have essentially been abandoned.
With its Low Gain Antenna
Galileo transmits data at about 10 bits per second.
JPL has developed a
backup plan using enhancements of the receiving antennas in the
Deep
Space Network and data compression (JPEG-like for images,
lossless
compression for data from the other instruments) on the
spacecraft. This
should allow Galileo to achieve approximately 70% of its
original
science objectives with the much lower speed Low Gain Antenna.
Long term
Jovian weather monitoring, which is imagery intensive, will
suffer the
most.
Galileo Schedule (times UTC) ---------------- 10/18/89 - Launch from Space Shuttle 02/09/90 - Venus Flyby 10/**/90 - Venus Data Playback 12/08/90 - 1st Earth Flyby 05/01/91 - High Gain Antenna (was to have) Unfurled 07/91 - 06/92 - 1st Asteroid Belt Passage 10/29/91 - Asteroid Gaspra Flyby 12/08/92 - 2nd Earth Flyby 05/93 - 11/93 - 2nd Asteroid Belt Passage 08/28/93 - Asteroid Ida Flyby 07/13/95 - Probe Separation 07/20/95 - Orbiter Deflection Maneuver 12/07/95 - Jupiter Encounter 06/27/96 06:30 - Ganymede-1 09/06/96 19:01 - Ganymede-2 11/04/96 13:30 - Callisto-3 11/06/96 18:42 - Europa-3A ("non-targeted" flyby @32,000 km on the same orbit as Callisto-3) 12/19/96 06:56 - Europa-4 01/20/97 01:13 - Europa-5A (flyby @27,400 km during solar conjunction - counts for gravity - not science) 02/20/97 17:03 - Europa-6 04/04/97 06:00 - Europa-7A ("non-targeted" @23,200 km on the Ganymede-7 orbit) 04/05/97 07:11 - Ganymede-7 05/06/97 12:12 - Callisto-8A ("non-targeted" @33,500 km on the Ganymede-8 orbit) 05/07/97 15:57 - Ganymede-8 06/25/97 13:48 - Callisto-9 06/26/97 17:20 - Ganymede-9A ("non-targeted" @80,000 km on the Callisto-9 orbit) 09/17/97 00:21 - Callisto-10 11/06/97 21:47 - Europa-11 (more details)Galileo's extended mission has been approved. If all goes well, it will spend another two years focusing primarily on Europa.
(Education and Public Outreach (images!); Galileo Home Page; Galileo Probe Home Page and more info from JPL; newsletter; web page; NSSDC page; preliminary Galileo Probe Results from JPL and ARC and LANL)
Named for the American astronomer Edwin Hubble.
Much, much more information about HST and HST pictures are available at the Space Telescope Science Institute. HST's latest images are posted regularly. (Here is a brief history of the HST project. There's also some more HST info at JPL.)
(Ulysses Home Pages from JPL and ESA; a Fact Sheet from JPL; yet more info from JPL)
The main scientific goal of the mission is to measure the mass, momentum and energy of the solar wind that somehow is transferred into the space environment around the Earth. Although much has been learned from previous space missions about the general nature of this huge transfer, it is necessary to gather a great deal of detailed information from several strategic regions of space around the Earth before scientists understand the ways in which the planet's atmosphere responds to changes in the solar wind.
The launch also marks the first time a Russian instrument will fly on an American spacecraft. The Konus Gamma-Ray Spectrometer instrument, provided by the Ioffe Institute, Russia, is one of two instruments on Wind which will study cosmic gamma-ray bursts, rather than the solar wind. A French instruments is also aboard.
At first, the satellite will have a figure-eight orbit around the Earth with the assistance of the Moon's gravitational field. Its furthest point from the Earth will be up to 990,000 miles (1,600,000 kilometers), and its closest point will be at least 18,000 miles (29,000 kilometers).
Later in the mission, the Wind spacecraft will be inserted into a special halo orbit in the solar wind upstream from the Earth, at the unique distance which allows Wind to always remain between the Earth and the Sun (about 930,000 to 1,050,000 miles, or 1,500,000 to 1,690,000 kilometers, from the Earth).
Launched on 1996 February 17 aboard a Delta 2 rocket, the NEAR spacecraft should arrive in orbit around asteroid 433 Eros in early January 1999. It will then survey the rocky body for a minimum of one year, at altitudes as close as 15 miles (24 kilometers). Eros is one of the largest and best-observed asteroids whose orbits cross Earth's path. These asteroids are closely related to the more numerous "Main Belt" asteroids that orbit the Sun in a vast doughnut-shaped ring between Mars and Jupiter.
(NEAR Home Page; more info from NSSDC; more from John Hopkins Univ.; Curriculum materials; more from JPL)
Mars Global Surveyor will be a polar-orbiting spacecraft at Mars designed to provide global maps of surface topography, distribution of minerals and monitoring of global weather.
Launched with a Delta II expendable vehicle from Cape Canaveral, Fla., on November 7 1996, the spacecraft in an eliptical orbit around Mars. During the year, thruster firings and aerobraking techniques will be used to reach the nearly circular mapping orbit over the Martian polar caps. Aerobraking, a technique pioneered by the Magellan mission, which uses the forces of atmospheric drag to slow the spacecraft into its final mapping orbit, will provide a means of minimizing the amount of fuel required to reach the low Mars orbit. Mapping operations are expected to begin in March 1999.
The spacecraft will circle Mars once every two hours, maintaining a "sun synchronous" orbit that will put the sun at a standard angle above the horizon in each image and allow the mid-afternoon lighting to cast shadows in such a way that surface features will stand out. The spacecraft will carry a portion of the Mars Observer instrument