From Wikipedia, the free encyclopedia
Tracking and Data Relay Satellite System
Tianlian
(
Simplified Chinese
: 天?,
Traditional Chinese
: 天?, English:
Sky Link
) also known as
CTDRS
, is a Chinese
data relay communication satellite
constellation. The constellation serves to relay data from ground stations to spacecraft and rockets, most significantly
China's crewed spaceflight program
. The system currently consists of seven satellites in two generations, with the first satellite being launched in 2008.
Mission
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Tianlian is used to provide real-time communications between orbiting satellites and ground control stations. The Chinese tracking and data relay satellites were developed by the
China Academy of Space Technology
(CAST) and it is similar to the American
Tracking and Data Relay Satellite System
(TDRSS) in concept. The system is designed to support near-real-time communications between orbiting spacecraft and ground control, as well as complement the ground-based space tracking and telemetry stations and ships in tracking spacecraft.
[1]
This is necessary because ground stations can only maintain contact with a satellite while it is overhead. Positioning multiple satellites in
geostationary orbit
ensures that the ground station and satellite are both always in view of at least one relay satellite, allowing for constant communication between the ground station and target satellite. The system provides data relay services for crewed
Shenzhou
missions, from
Shenzhou 7
onwards, the
Tiangong space station
, and interplanetary missions.
[2]
[3]
[4]
All satellites were launched from the
Xichang Satellite Launch Center
and operate in geostationary orbit.
[5]
[6]
[7]
[8]
Tianlian I
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Tianlian I
consists of five satellites, all based on the
DFH-3
satellite bus
. The first satellite of the series,
Tianlian I-01
, was launched on the maiden flight of the
Long March 3C
launch vehicle
on 25 April 2008.
[9]
[10]
With the launch of Tianlian I-03, a spacecraft could be tracked for 70% of its orbit, compared to only 15% without the constellation.
[11]
Tianlian II
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Tianlian II
is the second generation of the constellation and currently consists of 3 satellites based on the
DFH-4
satellite bus
. The second generation system greatly improves data transmission rates and its multi-targeting ability. This in turn improves spacecraft operational safety and flexibility.
[12]
[13]
Satellites
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See also
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Wikinews has related news:
References
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Earth observation
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Communication and engineering
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Data relay satellite system
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Satellite navigation system
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Astronomical observation
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Lunar exploration
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Planetary exploration
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Microsatellites
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Future spacecraft in
italics
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Projects and missions
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Science
| Planetary science
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Astronomy and
cosmology
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Earth observation
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Human
spaceflight
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Navigation
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Telecommunications
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Technology
demonstrators
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Related
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- Future missions marked in
italics
. Failed missions marked with † sign
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Shenzhou missions
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Tianzhou missions
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Space stations
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Hardware
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Facility
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Related
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- Underline
indicates current missions
- Italics
indicates future missions
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January
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February
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March
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April
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May
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June
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July
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August
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September
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October
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November
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December
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Launches are separated by dots ( ? ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ).
Crewed flights
are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).
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