The Boeing 601 (sometimes referred to as the BSS-601, and previously as the HS-601) is a
communications satellite
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. C ...
bus
A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for cha ...
designed in 1985 and introduced in 1987 by
Hughes Space and Communications Company
Hughes may refer to:
People
* Hughes (surname)
* Hughes (given name)
Places Antarctica
* Hughes Range (Antarctica), Ross Dependency
* Mount Hughes, Oates Land
* Hughes Basin, Oates Land
* Hughes Bay, Graham Land
* Hughes Bluff, Victoria La ...
. The series was extremely popular in the 1990s, with more than 84 purchased by customers globally. The more advanced 601HP derivative (for "high power") was introduced in 1995.
Hughes, and the 601 platforms, were acquired by
Boeing
The Boeing Company () is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, telecommunications equipment, and missiles worldwide. The company also provides leasing and product ...
in 2000.
The last commercial 601 satellite was ordered in 2001 and launched in 2004. The NASA Space Communications and Navigation (SCaN) Program Office in December 2007 selected the BSS-601HP for its third generation TDRS spacecraft, adding the two 15-foot (4.5m) diameter steerable antennas. The TDRS-M satellite, launched on August 18, 2017, became the last 601 satellite to reach orbit.
Background
The Boeing-601 model was Hughes’ first major design and development for a communications satellite with three-axis, or body stabilization. All previous Hughes satellite models (
HS-376
The Boeing 376 (sometimes referred to as the BSS-376, and previously as the HS-376) is a communications satellite bus introduced in 1978 by Hughes Space and Communications Company. It was a spin-stabilized bus that the manufacturer claims was th ...
) had been cylindrical spacecraft that were spin-stabilized at 50 revolutions per minute.
Design of the Boeing-601 began in 1985, with full-scale development following two years later. The new satellite's first official public presentation took place at the Telecom 87 conference in Geneva, Switzerland.
Variants
; Boeing-601HP: A high-power version of the standard model Boeing-601, it supports up to 60 transponders and 10,000 watts, making it twice as powerful as the standard 601. Innovations in
gallium arsenide
Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a Zincblende (crystal structure), zinc blende crystal structure.
Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits, monoli ...
solar cells, battery technology, and
xenon ion propulsion system
An ion thruster, ion drive, or ion engine is a form of electric propulsion used for spacecraft propulsion. It creates thrust by accelerating ions using electricity.
An ion thruster ionizes a neutral gas by extracting some electrons out of ...
s (XIPS) facilitated this upgrade. The 601HP made its debut in 1995, with upgrades in 2000 to address design and component failures.
; Ultra High Frequency Follow On (UFO): The U.S. Navy began replacing and upgrading its ultra-high frequency (UHF) satellite communications network during the 1990s with a constellation of customized HS-601 satellites known as the UFO (Ultra High Frequency Follow On) series. Eleven UFO satellites were launched between 1993 and 2003. The UHF Follow-On constellation replaced the Fleet Satellite Communications (FLTSATCOM) and the Hughes-built Leasat spacecraft.
; Third generation GOES satellites: The Geostationary Operational Environmental Satellite system (GOES), operated by
NOAA
The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditio ...
, selected the standard Boeing 601 bus for its third generation weather satellites,
GOES-13,
GOES-14, and
GOES-15
GOES-15, previously known as GOES-P, is an American weather satellite, which forms part of the Geostationary Operational Environmental Satellite (GOES) system operated by the U.S. National Oceanic and Atmospheric Administration. The spacecraft was ...
. This series featured a sun-pointed extreme ultraviolet sensor, a Solar X-Ray Imager (SXI), and space environment monitoring (SEM) instruments for their
space weather
Space weather is a branch of space physics and aeronomy, or heliophysics, concerned with the time varying conditions within the Solar System, including the solar wind, emphasizing the space surrounding the Earth, including conditions in the ma ...
role.
; Tracking and Data Relay Satellite (TDRS): The second generation satellites (3) used the standard 601 bus, while the follow-on third generation satellites (3) use the 601HP bus, after design changes addressing satellite failures in 1990s. The TDRS version features two 15-foot-diameter steerable graphite composite mesh antennas. These antennas are partially curled-up like a taco shell to fit within the Atlas/Centaur payload fairing.
Design
Structure
The 601 bus is divided into two modules. The first module houses the propulsion system, batteries, and electronics for the bus, and bears
launch vehicle
A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pad, launch pads, supported by a missile launch contro ...
loads. The second module contains shelves carrying the communications equipment, payload electronics, and
heat pipes
A heat pipe is a heat-transfer device that employs phase transition to transfer heat between two solid interfaces.
At the hot interface of a heat pipe, a volatile liquid in contact with a thermally conductive solid surface turns into a vapor ...
.
Solar array
A photovoltaic system, also PV system or solar power system, is an electric power system designed to supply usable solar power by means of photovoltaics. It consists of an arrangement of several components, including solar panels to absorb and co ...
s,
reflector
Reflector may refer to:
Science
* Reflector, a device that causes reflection (for example, a mirror or a retroreflector)
* Reflector (photography), used to control lighting contrast
* Reflecting telescope
* Reflector (antenna), the part of an ant ...
s, and
antenna feed
A radio transmitter or receiver is connected to an antenna which emits or receives the radio waves. The antenna feed system or antenna feed is the cable or conductor, and other associated equipment, which connects the transmitter or receiver w ...
s are mounted to the payload module.
Payload
The standard 601 platform supports up to 48
transponder
In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend word, blend of ''transmitter'' and ''responder''.
In air navigation or radio frequency identification, a T ...
s and provides up to 4,800 watts of power. The 601HP supports up to 60 transponders and provides up to 10,000 watts.
Failures
A significant number of Boeing 601s have experienced failures in orbit, some resulting in complete failure of the satellite.
Spacecraft Control Processor (SCP)
An unconfirmed number of 601s launched prior to August 1997 have a design flaw in their SCPs, where a tin-plated relay forms
crystalline "whiskers" under certain specific conditions. These whiskers eventually caused an electrical short. Each satellite contains two SCPs and the backup unit will take control in the event of a failure of the primary unit. In some cases, both SCPs have failed, rendering the spacecraft unusable. A notable example was the
Galaxy IV
Galaxy IV was a model HS-601 satellite built by Hughes Space and Communications Company (HSC). The satellite, which carried a payload of both C band and Ku band transponders, was launched on June 24, 1993 and operated by PanAmSat Corporation. It ...
satellite.
At least eight 601s have experienced SCP failures; four of which were double failures resulting in total loss of the satellite.
Hughes switched to nickel plating on later 601s to resolve this problem, at the expense of payload weight.
Batteries
Some 601HPs have experienced problems with their batteries, resulting in a reduction of eclipse protection. This would require some transponders to be shut down during eclipse periods.
Xenon Ion Propulsion System (XIPS)
Some Boeing-601 satellites featured the optional electronic propulsion system, called Xenon Ion Propulsion System or
XIPS
The gridded ion thruster is a common design for ion thrusters, a highly efficient low-thrust spacecraft propulsion method running on electrical power by using high-voltage grid electrodes to accelerate ions with electrostatic forces.
History
Th ...
, for station keeping. At least four satellites with XIPS propulsion have experienced partial or total failure of the XIPS system which significantly reduced the lifespan of the satellite.
Satellites based on the 601 and 601HP
See also
*
Boeing 702
Boeing 702 is a communication satellite bus family designed and manufactured by the Boeing Satellite Development Center, and flown from the late-1990s into the 2020s. It covers satellites massing from to with power outputs from 3 to 18 kW ...
*
Boeing Satellite Development Center
The Boeing Satellite Development Center is a major business unit of Boeing Defense, Space & Security. It brought together Boeing satellite operations with that of GM Hughes Electronics' Space and Communications division in El Segundo, Califo ...
References
{{Hughes satellites
Satellite buses
Military equipment introduced in the 1990s