Arabsat-1B was a Saudi Arabian
communications satellite
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a Transponder (satellite communications), transponder; it creates a communication channel between a source transmitter and a Rad ...
which was operated by
Arabsat
The Arab Satellite Communications Organization (often abbreviated as Arabsat) is a communications satellite operator in the Arab World, headquartered in the city of Riyadh, Saudi Arabia. Arabsat was created to deliver satellite-based, public and ...
. It was used to provide communication services to the
Arab States
The Arab world ( '), formally the Arab homeland ( '), also known as the Arab nation ( '), the Arabsphere, or the Arab states, comprises a large group of countries, mainly located in West Asia and North Africa. While the majority of people in ...
. It was constructed by
Aérospatiale
Aérospatiale () was a major French state-owned aerospace manufacturer, aerospace and arms industry, defence corporation. It was founded in 1970 as () through the merger of three established state-owned companies: Sud Aviation, Nord Aviation ...
, based on the
Spacebus 100
Spacebus is a satellite bus produced at the Cannes Mandelieu Space Center in France by Thales Alenia Space. Spacebuses are typically used for geostationary orbit, geostationary communications satellites, and seventy-four have been launched since ...
satellite bus
A satellite bus (or spacecraft bus) is the main body and structural component of a satellite or spacecraft, in which the payload and all scientific instruments are held.
Bus-derived satellites are less customized than specially-produced satelli ...
, and carried two NATO E/F-band (IEEE S band) and twenty five NATO G/H-Band (IEEE C band)
transponder
In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend of ''transmitter'' and ''responder''.
In air navigation or radio frequency identification, a flight trans ...
s. At launch, it had a mass of , and an expected operational lifespan of seven years.
History
Arabsat-1B was launched aboard on mission
STS-51-G
STS-51-G was the 18th flight of NASA's Space Shuttle program, and the fifth flight of Space Shuttle ''Discovery''. The seven-day mission launched from Kennedy Space Center, Florida, on June 17, 1985, and landed at Edwards Air Force Base, Calif ...
. ''Discovery'' was launched from
LC-39A
Launch Complex 39A (LC-39A) is the first of Kennedy Space Center Launch Complex 39, Launch Complex 39's three launch pads, located at NASA's Kennedy Space Center in Merritt Island, Florida. The pad, along with Launch Complex 39B, was built in t ...
at the
Kennedy Space Center
The John F. Kennedy Space Center (KSC, originally known as the NASA Launch Operations Center), located on Merritt Island, Florida, is one of the NASA, National Aeronautics and Space Administration's (NASA) ten NASA facilities#List of field c ...
at 11:33:00 GMT on 17 June 1985.
It was deployed from ''Discovery'', and boosted to a
geosynchronous transfer orbit
In space mission design, a geostationary transfer orbit (GTO) or geosynchronous transfer orbit is a highly elliptical type of geocentric orbit, usually with a perigee as low as low Earth orbit (LEO) and an apogee as high as geostationary orbit ...
by means of a
PAM-D
The Payload Assist Module (PAM) is a modular upper stage designed and built by McDonnell Douglas (Boeing), using Thiokol Star-series solid propellant rocket motors. The PAM was used with the Space Shuttle, Delta, and Titan launchers and carrie ...
upper stage.
Sultan bin Salman bin Abdulaziz Al Saud
Sultan bin Salman Al Saud (; ''Sulṭān bin Salmān Āl Suʿūd''; born 27 June 1956) is a Saudi prince and former Royal Saudi Air Force pilot who flew aboard the American STS-51-G Space Shuttle mission as a payload specialist. He is the fi ...
flew aboard the Shuttle to supervise deployment, becoming the first Saudi citizen and first member of
royalty
Royalty may refer to:
* the mystique/prestige bestowed upon monarchs
** one or more monarchs, such as kings, queens, emperors, empresses, princes, princesses, etc.
*** royal family, the immediate family of a king or queen-regnant, and sometimes h ...
to fly in space.
Morelos 1
The ''Morelos'' satellites are a series of Mexican communications satellites. The first two operated between 1985 and 1998 and provided telephony, data, and television services over the territory of the Mexican Republic and adjacent areas. ...
and
Telstar 303
Telstar 303 is a U.S. communications satellite launched from during STS-51-G on 17 June 1985. Owned by AT&T and operated by Loral Skynet Hughes Communications, it was one of three Telstar 3 satellites, preceded by Telstar 301 in 1983 and Tel ...
were also deployed on the same mission.
Arabsat 1B was placed into a
geosynchronous orbit
A geosynchronous orbit (sometimes abbreviated GSO) is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds (one sidereal day). The synchronization of rotation and orbital ...
at a
longitude
Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek lett ...
of 26° East.
In October 1991, a problem developed with the spacecraft's
attitude control system
Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle or satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, ...
, causing it to drift eastward out of control.
The same fault had developed aboard its sister satellite,
Arabsat-1A
Arabsat-1A () was a Saudi Arabian communications satellite which was operated by Arab Satellite Communications Organization. It was used to provide communication services to the Arab States. It was constructed by Aérospatiale, based on the Spa ...
, a month earlier.
It failed completely in early 1992.
See also
*
1985 in spaceflight
The following is an outline of 1985 in spaceflight.
Overview First ''Atlantis'' flight
Orbital launches
, colspan=8 style="background:white;",
January
, -
, colspan=8 style="background:white;",
Feb ...
References
{{Orbital launches in 1985
1985 in spaceflight
Derelict satellites orbiting Earth
Spacecraft launched in 1985
Satellites using the Spacebus bus
Satellites of Saudi Arabia
1985 in Saudi Arabia