Space Missions

University of California, San Diego
Center for Astrophysics & Space Sciences

  CASS Astronomy Tutorial

Space Telescopes

Because some wavelengths of light do not penetrate the Earth's atmosphere, observations at these wavelengths must be taken from space. Each different waveband provides different information about the object being observed, so it is useful to do as many types of observations as possible. Below are links to web pages about the many satellite missions being conducted by NASA, The European Space Agency (ESO), and the Japanese Space Agency (ISAS).

NASA's Great Observatories

The Electromagnetic Spectrum

Beyond the Solar System

Gamma Rays

Compton Gamma-Ray Observatory - launched by NASA in 1991. UCSD's High Energy Astrophysics group participated in the development and analysis of data from the BATSE instrument.

Gamma Rays in the Universe


ASCA - Japan's Advanced Satellite for Cosmology and Astrophysics, an x-ray satellite with NASA participation.

Here are ASCA results.

Chandra X-Ray Observatory (formerly known as AXAF) tentatively scheduled for launch in July 1999. It was renamed to honor Subrahmanyan Chandrasekhar, the Indian-American physicist who won the Nobel Prize in Physics in 1983 for his work on the structure and evolution of stars.

Chandra Interactive Games

ROSAT X-Ray Satellite (Rontgensatellit) was named in honor of Wilhelm Conrad Rontgen, the German physicist who discovered x-rays. It was originally scheduled to be launched from the Space Shuttle, but was delayed by the Challenger accident. The launch was rescheduled for June,1990 using a Delta-II rocket.
Roentgen took the first x-ray of a human hand

RXTE The Rossi X-RAY Timing Explorer, launched in 1996. High time-resolution satellite designed to study the x-ray variability of pulsars, black holes, and quasars.
UCSD's High Energy Astrophysics group, led by Dr. Rick Rothschild, constructed the HEXTE experiment.
RXTE images and Learning Center.
The satellite was named in honor of Bruno Rossi , a pioneer in the field of X-ray Astronomy.


The Extreme Ultraviolet Explorer

International Ultraviolet Explorer,(IUE) was launched in 1978, and was in continuous operation for 18 years, 9 months. (The expected lifetime of the satellite at launch was 5 years.) It was used to observed every type of object in the Universe, from Comet Halley to Supernova 1987a, in the wavelength range 1200 to 3350 angstroms.

IUE Image Gallery


Learn about Infrared Astronomy

COBE The Cosmic Background Explorer launched in 1989 to measure the infrared and microwave radiation left from the Big Bang.

Learn about the Big Bang

See the Earth from COBE The line separating day from night (called the terminator) is clearer if you zoom out.
Request a free COBE poster

Infrared Space Observatory (ISO) Launched in 1995, ISO observed in the wavelength range 2.5 to 240 microns. It was used to study stellar, planetary and galactic evolution. It operated until 1998, when the liquid helium used to cool its detectors was exhausted.

ISO images and movies

Launched in 1983, the Infrared Astronomical Satellite (IRAS) IRAS performed an all-sky survey at 12,25,60 and 100 micron wavelengths. It was the first satellite to observe the core of the Milky Way. IRAS was a joint project of The US, the United Kingdon and the Netherlands.

IRAS Image Gallery

IRAS view of the Milky Way

Space Infrared Telescope Facility (SIRTIF) is part of NASA's Origins program to study the formation of galaxies, stars, and planetary systems, and to investigate the origin of life on Earth and beyond.
Launch is planned for December 2001.

The Solar System

The Sun:

SOHO The Solar and Heliospheric Observatory SOHO is a joint project of NASA and the European Space Agency(ESA). It carries 12 instruments to study the Sun,the solar wind, and the heliosphere.
SOHO Movie Theatre
A virtual Tour of the Sun

Sunspots and the Solar Cycle

Request a free poster of the Sun

Check today's space weather

SOHO is monitored by NASA's Deep Space Network, a collaboration of large radio telescopes around the world.

Ulysses is another joint mission of NASA and ESA. It was designed to study the polar regions of the Sun. To get into a polar orbit required that the spacecraft fly by Jupiter, whose strong gravity provided a slingshot effect.

Ulysses Nutation Control Maneuver Game

3D Maneuver Simulator Game

The Planets:

Cassini - NASA/JPL Mission to Saturn to study the planet,its rings and moons.The spacecraft is composed of an orbiter and the Huygens probe that will be dropped through Titan's atmosphere.
Because Saturn is 7 x 108 kilometers from the Sun, solar power could not be used by Cassini. Instead, the satellite runs on Radioisotope Thermoelectric Generators which convert the heat produced by the radioactive decay of plutonium to electricity. This is the same power source used by both Pioneers, both Voyagers, the Galileo, and Ulysses missions.
Cassini Images and Videos
Cassini carries a DVD with over 600,000 signatures from Earth

Galileo - NASA/JPL Mission to Jupiter. The spacecraft was launched in 1989 and arrived at Jupiter on December 7,1995. After orbiting Jupiter for two years, Galileo conducted detailed observations of Europa for 14 months, then went on to Io.

Galileo Image Gallery

Learn about Galileo

You've seen Galileo's middle finger, but have you seen his fifth lumbar vertebra?

Kidsat is a program developed by UCSD professor and Space Shuttle astronaut Dr.Sally Ride. It allows students to design and run experiments that are carried aboard the Space Shuttles. The instruments are operated by the Shuttle crew at the direction of the students in Mission Control.If you are interested in participating in Kidsat, you can contact Mrs. T. McEntee

Mars Global Surveyor was launched in November 1996, and was placed in orbit around Mars in September 1997.

Mars Global Surveyor image of the Face on Mars

Visit NASA's Mars Exploration Program page.

Mars Pathfinder landed on the Martian surface on July 4, 1997.

Image Archive

Carl Sagan Memorial Station

The Sojourner Rover was voted Cool Robot of the Week in December 1996.

Mars Surveyor 98 The Surveyor program includes a pair of satellites, Mars Climate Orbiter, launched December 11, 1998 and Mars Polar Lander, launched January 3, 1999 to land near the South Polar Cap in December 1999.

Pioneer 10 & 11 the spectacularly successful satellites that were launched in 1972 and 1973 respectively to obtain the first close-up looks at Jupiter and Saturn. Pioneer 10 became the first man-made object to leave the solar system on June 13,1983.
Both Pioneers carry a gold plaque with a message from Earth for any civilization in the cosmos who might someday recover the satellite.

Image Gallery

Pioneer 10 Silver Anniversary page

TOMS Total Ozone Mapping Spectrometer The TOMS missions monitor the ozone content of the Earth's atmosphere. The ozone layer of the atmosphere protects the Earth's surface from dangerous ultraviolet radiation.It has been damaged by the worldwide use of chloro- and fluorhydrocarbons as propellants in spray products.

Check the current ozone value over any location.

The Viking Missions The first of the Mars missions, Viking I and II were launched in 1976 and 1975 respectively. Each consisted of an orbiter and a landing module. They were first pieces of human technology to reach the surface of another planet.

NASA's Planetary Photo Journal

The Voyager I & II Interstellar Missions extended space exploration to the outer planets of our solar system and on into interstellar space.

Interesting Voyager Facts

Latest distance information

Voyager Trajectories
The Voyagers each carried a 12-inch gold-plated copper disk containing images and sounds from Earth, for the benefit of any other civilization in the galaxy who might encounter the spacecraft in the future. Although the spacecraft left our solar system in 1990, it will take 40,000 Earth years before either will closely approach another planetary system. Voyager's Greetings From Planet Earth

Comets and Asteroids

NEAR - Near Earth Asteroid Rendezvous, originally scheduled to begin orbiting and studying the asteroid Eros, flew past the asteroid after an unsuccessful engine firing, but has been recovered and is now scheduled to catch up to Eros in February 2000.

A pictorial voyage with NEAR

Animations and Videos

Stardust was launched on February 9, 1999 to rendezvous with Comet Wild 2 in 2004 and return samples of cometary dust to earth.

Visit theStardust Cafe

See what's showing at the Stardust Theatre

Giotto The Giotto spacecraft was launched in 1986 to study comets Halley and Grigg-Skjellerup.

The nucleus of Comet Halley

More about Comet Halley


Susan Rappoport Last Modified August 25,1999