2.5 Space programme  (Page 2/3)

[LO 3.1; 3.2]

Satellites

• A satellite is an object that revolves around a planet. The moon is the earth’s natural satellite.
• Man-made satellites are structures built by man and are usually launched by means of a rocket. This technology makes a wide variety of information possible - something that would not have been possible previously. Telecommunication satellites in particular have had a huge impact on our lives. Just think of how Telkom and your DSTV decoder work.
• The Hubble Telescope has given us unprecedented images of the universe, e.g. the impact of the Shoemaker-Levy comet that collided with Jupiter.
• Here in South Africa our own satellite, SUNSAT, was built by engineering students and academics of the University of Stellenbosch. It was launched on 23 February 1999 with the Delta 2 rocket, which also carried an American Air Force satellite and a Danish satellite. SUNSAT carries distance sensors and sends very high-resolution images back to us. Thousands of learners have been inspired by this project. ( www.sunstep.sun.ac.za )

space stations

MIR

• The Russians launched the space station Mir in 1986. (Mir means peace and world.) It consisted of a nucleus of about 17 m in length. Sections such as Kvant 1 were gradually added and many people worked and lived there over the years.
• Many problems, such as wear and tear damage and power failures, were experienced with Mir and on 23 March 2001 it fell into the atmosphere and broke up into several pieces. People between Chile and New Zealand were warned about the danger and it made news headlines all over the world.
• Do visit www.cnn.com/SPECIALS/2001/mir/

The ISS

• The ISS or International Space Station is a giant earth satellite that orbits around the earth at a height of 355 km and at a speed of 27 000 km/h. At this stage many of the planned missions has been delayed due to unforeseen problems.
• A number of countries are assisting in extending the ISS bit by bit. It is a perfect example of international cooperation between different countries. The idea is to complete it by 2006 at a proposed cost of 370 billion dollars.
• Laboratories inside the ISS will enable scientists to use the environment in which there is no gravity, for research on:

• chemical reactions;
• agricultural products;
• cultivating cells;
• medicine against AIDS and other diseases;
• new metal alloys;
• warning systems against giant asteroids, and
• a halfway-station between the earth and the rest of our solar system.

SPACE PROBES

• Space probes are launched to investigate other planets and areas of the solar system.
• The Viking series probed planets such as Mars and landed on Mars in 1976. A smaller spacecraft, the Pathfinder, landed on Mars in 1997 and carried out investigations with a robot vehicle, the Sojourner.
• Pioneer 10 and 11 were launched further into space and are already more than 11 billion kilometres from the earth.
• Voyager 2 has passed Saturn, Uranus and Neptune.
• The Cassini-Huygens research craft reached Saturn in July 2004. The Cassini orbiter is orbiting Saturn, while the Huygen craft landed on Saturn’s moon, Titan.
• In April 2003 the British launched the Beagle II with a Mars Express unit that arrived on Mars by Christmas 2003.