Introduction

During the last four decades, hundreds of satellites , probes and space shuttles have been launched, which have explored near-Earth space, travelled to the Moon, the Sun, and to all the planets except Pluto. And, with entire laboratories already in orbit around Earth and telescopes exploring more and more of our universe, space research is still continuing. Talk of future developments includes building a base on Mars, searching for life in other galaxies, and other exciting programs.

Space Shuttles

Columbia

The Space Shuttle Columbia was named after a sloop captained by Robert Gray, an 18th century American explorer. Gray sailed the Columbia around what is today southwestern Canada and the Washington-Oregon border and explored the 1,600-km river known today as the Columbia River.

Apollo 11's command module was also named after this ship. The word Columbia, which is also another name for the USA, can be traced to the surname of Christopher Columbus, the 15th century explorer who sailed to America

The Space Shuttle Columbia was first launched into an orbit around Earth on 12 April 1981. Space Shuttle Columbia has the distinction not only of being the first shuttle to fly, but also of having been used for the first five shuttle missions between 1981 and 1982. By the end of 1999, Columbia completed 26 space flights. Highlights from its flight career included being the first and only shuttle to land at White Sands, New Mexico in 1982 and being the first shuttle used to deploy a commercial satellite in November 1982.

More recently, the STS-93 crew flew aboard Columbia in July 1999 to deploy the Chandra X-ray Observatory. In February 2003, seven onboard astronauts of the science research mission (STS-107) on Space Shuttle Columbia lost their lives when an accident occurred just before its landing.

Challenger

Challenger was the second Space Shuttle orbiter to be launched. It was named after an American navy research ship that crossed the Atlantic and the Pacific in 1870. The lunar module of Apollo 17, the last of its kind, was also called Challenger.

The Space Shuttle Challenger was first launched on 4 April 1983. On 30 August 1983, NASA successfully conducted the first Space Shuttle night-time launch with Challenger, and then achieved a successful night-time landing.

Challenger completed a total of nine missions, including a spacewalk in which astronauts used the Man Maneuvering Unit without a lifeline. However on 28 January 1986, shortly after lift-off, there was an explosion on board the Shuttle and Challenger was lost. Space Shuttle Challenger was the second orbiter at Kennedy Space Center, Fla., but it was not originally intended to ever fly to space. It began as a structural test article, STA-099.

STA-099 endured 11 months of intensive vibration testing to simulate the stresses of the launch, ascent, on-orbit, reentry and landing phases of a mission. It was also used for heating and thermal simulations.

Then in 1978, NASA decided not to convert the Enterprise, the first orbiter created and used for testing, to a functional orbiter. This left Columbia as the only operable space shuttle.
Challenger flew nine succes

sful flights before the tragic STS-51L mission. The orbiter's tenth flight ended in disaster just 73 seconds after launch on Jan. 28,
1986. Cold launch temperatures caused the failure of an O-ring on the Solid Rocket Motor. The orbiter was destroyed and the entire crew was killed.

Discovery

The Space Shuttle Discovery took its name from one of British explorer James Cook's two ships, the Discovery and the Endeavour, in which he crossed the South Pacific and arrived in the Hawaiian islands in the 1770s.

The Discovery was also used in the exploration of Alaska and northern Canada The Space Shuttle Discovery was first launched on 30 August 1984. It was also the first orbiter in the relaunch of NASA's Space Shuttle program two years and eight months after the Challenger accident.

On 24 April 1990, Discovery carried the Hubble space telescope into orbit and on October 6 of the same year, it successfully launched the Ulysses solar probe.

Shuttles were not flown for approximately two years after the Challenger accident that killed the crew and destroyed the spacecraft. During this time, all the other shuttle underwent a series of improvements including upgrades to the main engines, thermal protection system and propellant supply system, and installation of a new crew escape system.

Discovery underwent additional upgrades during a nine-month Orbiter Maintenance Down Period from 1995 to 1996 in Palmdale, Calif. Workers added a fifth set of cryogenic tanks and installed an external airlock to support International Space Station missions. Discovery completed 25 flights by the end of 1999.

Atlantis

The Space Shuttle Atlantis was the fourth orbiter and was named after the first US ship used for ocean research. The Space Shuttle Atlantis was first launched on 3 October 1985. On 4 May 1989, it successfully sent Magellan, a Venus probe, into space, and in October of the same year, it launched Galileo, a Jupiter probe. Then on 31 July 1992, Atlantis successfully launched the European Space Agency's retrievable satellite Eureca. Experience from building earlier shuttles helped make Atlantis lighter and assemble it faster than Space Shuttle Columbia. Atlantis made its maiden voyage on Oct. 3, 1985. From that time through the end of the twentieth century, it completed twenty space missions. Its missions have included deploying the Galileo spacecraft and the Magellan Venus probe in 1989 and the Arthur Holley Compton Gamma Ray Observatory in 1991.

It made seven consecutive trips to the Mir Space Station from June 1995 to September 1997. It also would have deployed the Hubble Space Telescope, but that mission was canceled after the Challenger disaster and later reassigned to another spacecraft.

Endeavour

Endeavour, the newest orbiter in the fleet.Endeavour is the fifth orbiter in the Space Shuttle program. Like Discovery, this orbiter also takes its name from one of the two ships in which British explorer James Cook reached the Hawaiian islands in the 1770s.

The Space Shuttle Endeavour was first launched on 7 May 1992.

The International Space Station

The International Space Station is the largest and most complex international scientific project in history. And when it is complete just after the turn of the century, the station will represent a move of unprecedented scale off the home planet. Led by the United States, the International Space Station draws upon the scientific and technological resources of 16 nations: Canada, Japan, Russia, 11 nations of the European Space Agency and Brazil.

More than four times as large as the Russian Mir space station, the completed International Space Station will have a mass of about 1,040,000 pounds. It will measure 356 feet across and 290 feet long, with almost an acre of solar panels to provide electrical power to six state-of-the-art laboratories.

The station will be in an orbit with an altitude of 250 statute miles with an inclination of 51.6 degrees. This orbit allows the station to be reached by the launch vehicles of all the international partners to provide a robust capability for the delivery of crews and supplies. The orbit also provides excellent Earth observations with coverage of 85 percent of the globe and over flight of 95 percent of the population. By the end of this year, about 500,000 pounds of station components will be have been built at factories around the world.

Research on the International Space Station

The International Space Station will establish an unprecedented state-of-the-art laboratory complex in orbit, more than four times the size and with almost 60 times the electrical power for experiments — critical for research capability — of Russia's Mir. Research in the station's six laboratories will lead to discoveries in medicine, materials and fundamental science that will benefit people all over the world. Through its research and technology, the station also will serve as an indispensable step in preparation for future human space exploration.

MIR Space Station: Its Rise and Fall

During its 15 years in orbit, Mir became a chapter in the history of space exploration. The Mir Space Station was officially built to conduct studies and experiments of interest to science and the Russian economy.

When the Mir program began, the station's lifetime was estimated to be five years. The last crew left the station in August 1999 - more than 13 years after the first component was launched. The station is still in orbit, and additional missions to the outpost being planned. The Mir Core, the base unit of the station, was launched on Feb. 20, 1986. It had a mass of 20,100 kilograms, a length of 13.13 meters and a maximum diameter of 4.15 meters. Its pressurized volume equals 90 cubic meters. The solar panels have a total area of 76 square meters. Several modules are attached to the core.

By the fall of 2000, all efforts to raise enough funds to keep Mir operational proved futile and no time remained to prepare more transport ships to resupply the station in 2001. By the beginning of October 2000, RKK Energia made a final decision to deorbit the outpost. Symbolically, the company timed Mir's fiery reentry to occur only after the station passes its 15th anniversary on February 20, 2001. The Progress M43 cargo ship, launched toward Mir in October, boosted the station's orbit, so it could fly safely until beginning of 2001.

In the first week of January 2001, ground controllers turned on a high-accuracy attitude control system onboard the Mir space station. The computer controlled system, using electrically driven reaction wheels, or gyrodines, would facilitate the upcoming docking with the last supply ship scheduled to go to Mir before the station's deorbiting.

After 86,331 Orbits, Mir Space Station's 15 Years In Space Ended .As planned, Mir's re-entry was successfully accomplished on March 23, 2001 at around 05:43 UTC 80 km above the local day-night (dusk) terminator line in the South Pacific at 175 West longitude and 25 South latitude. Brief statistics of the Russian MIR station.

· Mir had docked with 31 spacecraft
· Mir had docked with 64 cargo vessels
· Mir docked with the shuttle 9 times
· There were 17 space expeditions to Mir
· There were 28 long-term crews on board Mir
· 125 cosmonauts/astronauts from 12 different countries visited Mir

The Hubble Space Telescope

The Hubble Space Telescope (HST) is a world class astronomical observatory in orbit above the earth. It is a project of international cooperation between NASA and the European Space agency (ESA).

Launched on the shuttle Discovery on April 24, 1990, HST is on a 15-year mission to explore the universe in the optical range from ultraviolet (UV) through visible and into the infrared (IR). It is operated by NASA as a general observer facility, available to astronomers from all countries.

Hubble is the first observatory designed to be serviced in orbit by shuttle astronauts with servicing and maintenance missions scheduled for every three years. The first servicing occurred during an eleven day mission in December, 1993. The HST team developed a corrective optics package that restored Hubble to its intended imaging capabilities.

The NASA astronaut spacewalking team also replaced other parts of the observatory. As the telescope continues its science mission, scientists and engineers are working toward the next servicing mission. The second in a planned series of four servicing missions for HST is scheduled to launch aboard the Shuttle Discovery in February 1997.

The manifest will include two new scientific instruments: the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) and the Space Telescope Imaging Spectrograph (STIS). In addition, one of the tape recorders will be replaced with a state-of-the-art Solid State Recorder (SSR) and a gyro Rate Sensing Unit (RSU) will be replaced with a Hemispherical Resonator Gyro (HRG) unit. One of the Fine Guidance Sensors (FGS) is also manifest for changeout along with some electronics. Other servicing missions are planned for 1999, 2002 and 2005.