Q 3.9 Has an orbiting satellite ever fallen on the Earth? If so,  please give examples.

Instances of (uncontrolled and controlled) re-entry of man-made space objects into the Earth’s atmosphere are reported regularly. A vast majority meet a fiery end soon after re-entry. Those which have reached the Earth’s surface fell in oceans or scarcely populated areas. The number of natural objects from outer space entering the Earth’s atmosphere far exceeds those by man-made space objects. For example, in the annual Leonid meteor shower, which occurs each year throughout November, 10-15 tiny meteors are typically visible each hour; while at their peak every 33 years (next peak is due in 2031), the rate can escalate up to 1000 meteor per hour (Ref 3.9-1).  Whereas, on an average 200-400 man-made objects are estimated to re-enter the Earth’s atmosphere each year (Ref 3.9-2), out of which a miniscule fraction ever reaches the Earth’s surface. Here is a sample of man-made debris, which have reached the Earth’s surface.

  1. ROSAT German satellite: ROentgen SATellite (ROSAT) was launched on 1 June 1990 to perform an all-sky survey of X-ray sources with an imaging telescope.  At the end of the prolonged mission, the satellite re-entered the atmosphere over the Bay of Bengal; whether any parts of the satellite reached Earth’s surface could not be confirmed. The reentry is estimated to occur on 23 October 2011 at 03:50 CEST based on the evaluation of data provided by international partners. (Ref 3.9-3).
  2. US spy satellite USA-193 was intercepted by US Navy on February 8, 2008 and debris was reported by amateur astronomers to be scattered over north-west US and Canada (Ref 3.9-4).
  3. During the tragic accident of Spaceship Columbia In 2003 following re-entry the remnants of the space shuttle were scattered over 75560 square kilometres in Eastern Texas and western Louisiana (Ref 3.9-4).
  4. Light debris – a charred woven material of DVD size floating in wind – from Delta-2 rocket is reported to have struck a lady exercising in a Park but fortunately did not hurt her in Oklahama in January 22, 1997 (Ref 3.9-4).
  5. A tank used for storing water on Gemini 5 American manned space flight which re-entered the Earth’s atmosphere  on August 29 1965 was recovered in Austarlia. (Ref 3.9-4).
  6. Kosmos 954, a Russian surveillance satellite using a nuclear power generator crashed in Canada in January 1978, scattering radio-active material over thousands of kilometres – Only 0.1% of debris could be recovered. (Ref 3.9-4).
  7. Up to September 2011 nearly 6,000 tons of human-made space debris had survived the re-entry burnout according to the Aerospace Corporation, – which provides “independent technical and scientific research, development, and advisory services to national security space (NSS) programs since 1960”. (Ref: 3.9-4).
  8. A delta-2 launcher’s third stage re-entered over Middle-East on January 21, 2001. Large chunks of fallen debris were reported in Saudi Arabia (a titanium motor of 70 kgs) and in Texas (a titanium pressure tank) (Ref 3.9-4).
  9. Salyut-7 Russian space station weighing some 39,916-kilogram —one of the largest human-made objects to re-enter the atmosphere— made an uncontrolled entry (despite attempts by controllers to control the decent) showering metal fragments on a city in Argentina where residents observed glowing trails in the sky. No one was reported hurt, according to the Aerospace Corporation, a space research organisation of USA (Ref 3.9-5).
  10. Nose cone of an Ariane V rocket was discovered at a beach in Texas in the year 2000 (Ref 3.9-5) following a launch.
  11. NASA’s Upper Atmospheric Research Satellite (UARS) satellite on September 24 in Pacific Ocean. The satellite mission was to monitor the upper atmosphere of the Earth and particularly the Ozone layer. (Ref 3.9.5). 

The reader can obtain additional examples from: (Ref 3.9-4 and 3.9-5)

References

3.9-1 https://www.space.com/23296-leonid-meteor-shower.html, Retrieved 05/03/2018.

3.9-2 https://www.popsci.com/space-junk-debris-falls#page-3 Retrieved 05/03/2018.

3-9-3: DLR News, Oct 25 2011,  Available, http://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10081/151_read-1779/#/gallery/3578, retrieved 2 March 2018]

3.9-4 https://www.space.com/9708-worst-space-debris-events-time.html, retrieved 2/3/2018

Ref 1.22-5 Available: https://news.nationalgeographic.com/news/2011/09/110909-nasa-space-debris-uars-satellite-top-five-science/ Retrieved 2nd March 2018.