Teledesic
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Teledesic was a company founded in the 1990s to build a commercial broadband satellite constellation for Internet services. Using low-earth orbitting satellites small antennas could be used to provide uplinks of as much as 100 Mbit/second and downlinks of up to 720 Mbit/second. The original 1995 proposal was extremely ambitious, costing over US$9 billion originally planning 840 active satellites with in-orbit spares at an altitude of 700 km.[1] In 1997 the scheme was scaled back to 288 active satellites at 1400 km.[2] and was later scaled back further in complexity and number of satellites as the projected market demand continued to decrease.
The commercial failure of the similar Iridium and Globalstar ventures (composed of 66 and 48 operational satellites, respectively) and other systems, along with bankruptcy protection filings, were primary factors in halting the project, and Teledesic officially suspended its satellite construction work on October 1, 2002 [1].
Teledesic was notable for gaining early funding from Microsoft (investing US$30 million for an 8.5% stake), Craig McCaw, Bill Gates, Paul Allen and Saudi prince Alwaleed bin Talal, and for achieving allocation on the Ka-band frequency spectrum for non-geostationary services. Teledesic's merger with ICO Global Communications led to McCaw's companies taking control of ICO, which has successfully launched one test satellite.
[edit] Description
The satellites were 3-axis stabilized with a facetted antenna on the bottom and a large articulated solar panel on top. The spacecraft was designed to be compatible with over 20 different launch vehicles to permit launch option flexibility. The satellites were launched into a 700 km circular, near polar (98.2 deg) sun synchronous orbit. Initial rollout is slated to include 12 orbit planes with 24 spacecraft in each plane. The antenna footprint for each satellite is about 700 km. Large deployed phased array antenna.
[edit] References
- ^ http://www.fcc.gov/Bureaus/International/Orders/1997/da970527.txt
- ^ http://www.ee.surrey.ac.uk/Personal/L.Wood/constellations/fcc-teledesic.pdf
[edit] External links
- Lloyd's satellite constellations - Teledesic
- Teledesic home page
- Initial Teledesic FCC authorization
- Teledesic FCC Modification
- Article on Teledesic Shutdown
- 288 satellite visualization
- Technical Details on 288 satellite constellation
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