From Wikipedia, the free encyclopedia
American communications satellite
TDRS-9
, known before launch as
TDRS-I
, was an American
communications satellite
which was operated by
NASA
as part of the
Tracking and Data Relay Satellite System
. It was constructed by the
Boeing Satellite Development Center
, formerly
Hughes Space and Communications
, and was based on the
BSS-601
satellite bus
.
[4]
It was the second Advanced TDRS, or second-generation
Tracking and Data Relay Satellite
, to be launched.
History
[
edit
]
An
Atlas IIA
rocket was used to launch TDRS-I, under a contract with
International Launch Services
. The launch occurred at 22:59 GMT on 8 March 2002, and used
Space Launch Complex 36A
at the
Cape Canaveral Air Force Station
.
[5]
Deployment and problems
[
edit
]
TDRS-9 separated from its carrier rocket into a
geosynchronous transfer orbit
. At 06:00 on 6 October, following a series of apogee burns, it reached geostationary orbit.
[6]
The
orbit raising
maneuvers were originally scheduled to take ten days, but ended up lasting six months due to a problem with the system used to pressurize its number two fuel tank.
[7]
A valve used to release
helium
into the tank failed to open. This was later established to have been due to a wiring error prior to launch. Engineers developed a solution which involved pressurizing the tank using the pressurization system from the number one tank, which was still working, once the propellant in that tank had been used.
[7]
When orbit raising operations resumed on 19 March, it was estimated that it would take two months to raise the satellite's orbit. It was later discovered that only using fuel from the number one tank upset the satellite's center of mass, causing the satellite to tumble when its main engines were fired. Controllers were able to compensate for this, however it took longer to raise the orbit as a result.
[7]
Operations
[
edit
]
Upon reaching geostationary orbit, TDRS-I was initially placed at a longitude 151 degrees west of the
Greenwich Meridian
, and following on-orbit testing it received its operational designation, TDRS-9. In October 2003 it was moved from 151° West, and it arrived at 173.5° West in January 2004. It remained there until September, when it was moved to 64.5° West, arriving in March 2005.
[8]
Engineers believed that the problems with its fuel tank pressurization system would not affect its operational lifespan.
See also
[
edit
]
References
[
edit
]
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First generation
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Second generation
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Third generation
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- Italics
denotes launch failure.
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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
|
- TDRS-10
- Hot Bird 7
,
Stentor
,
MFD-A
,
MFD-B
- ADEOS II
,
Kanta Kun
,
FedSat
,
μ-LabSat 1
(
RITE 1
,
RITE 2
)
- NSS-6
- TrailBlazer-2001 STA
,
Saudisat 1C
,
LatinSat A
,
LatinSat B
,
UniSat 2
,
Rubin 2
- Kosmos 2393
- Kosmos 2394
,
Kosmos 2395
,
Kosmos 2396
- Shenzhou 4
- Nimiq 2
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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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