The Complete Book of Spaceflight: From Apollo 1 to Zero Gravity

168 Gonets
Gonets
A Russian messaging constellation—“gonets” means
“messenger”—with dual military and commercial uses.
The current system comprises 18 satellites in two orbital
planes, and the system is planned to grow to 36 satellites
in six orbital planes once the market is established. One
set of 8 satellites entered the incorrect orbit, and its plane
will drift with respect to the others. The orbits are 1,400
km high inclined at 82.5°, with individual cell sizes 500
to 800 km in diameter. Only some of the satellites carry
digital store and forward payloads. The system is being
run by Smolsat, and the satellites will operate as medical
and civil data relays.
Gordon, Richard Francis, Jr. (1929–)
An American astronaut who walked in space during the
Gemini 11 mission and orbited the Moon on Apollo 12.
Gordon received a B.S. from the University of Washington
in 1951 before entering the U.S. Navy and serving as
a flight test pilot. In 1960, he joined Fighter Squadron
121 at the Miramar, California, Naval Air Station as a
flight instructor and won the Bendix Trophy Race (an
annual air race across America, sponsored by the Bendix
Aviation Corporation, held from 1931 to 1962) from Los
Angeles to New York in May 1961, setting a new speed
record of 1,399 km/hr and a transcontinental record of 2
hours 47 minutes. He was selected as an astronaut in
1963 and made his first spaceflight as pilot alongside
Charles Conrad on the three-day Gemini 11 mission in
1966. Gordon and Conrad served together again in 1969
aboard Apollo 12, with Gordon as Command Module
pilot. In 1971, Gordon became chief of advanced programs
for the Astronaut Office and worked on the design
and testing of the Space Shuttle and development equipment.
A year later he retired from NASA and the Navy to
become executive vice president of the New Orleans
Saints football team. He subsequently held management
positions with various energy and aerospace companies.
Gorizont
General-purpose Russian communications satellites
owned by Informcosmos and operated by several firms,
including Intersputnik; “gorizont” is Russian for “horizon.”
Thirty Gorizonts have been successfully deployed,
the last of them on June 5, 2000; three others were lost in
launch mishaps.
GPS (Global Positioning System)
Also known as Navstar-GPS (Navigation Satellite Time
and Ranging–GPS), a global system of 24 Department of
Defense navigation satellites (21 operational plus 3
spares), completed in 1993 and designed to provide time,
position, and velocity data for ships, planes, and land-
based vehicles, and for many other purposes. The satellites
are arranged in six planes, each in a 12-hour, 20,000km-high
orbit. GPS satellites transmit signals that allow
the determination, to great accuracy, of the locations of
GPS receivers. These receivers can be fixed on Earth, or
in moving vehicles, aircraft, or in satellites in low Earth
orbit. GPS is used in navigation, mapping, surveying,
and other applications where precise positioning is necessary.
Each satellite broadcasts two L-band (see frequency
bands) radio signals containing ranging codes,
ephemeris parameters, and Coordinated Universal Time
(UTC) synchronization information. Both military and
civilian users can use GPS receivers to receive, decode,
and process the signals to gain 3-D position, velocity,
and time information. Civilian GPS receivers are somewhat
less accurate than their military counterparts, owing
to their inability to read the coded portions of the satellite
transmissions.
GRAB
The first series of American ELINT (electronic intelligence)
satellites, operated by the U.S. Navy between July
1960 and August 1962. Documents declassified only in
1998 reveal that the project was originally called Tattletale,
then renamed GRAB (an acronym of the spurious
name “Galactic Radiation and Background”), which was
later revised to GREB (Galactic Radiation Experimental
Background). Each GRAB carried two payloads—the classified
ELINT satellite itself and an unclassified satellite
designed to measure solar radiation. The latter, known as
Solrad, was publicly disclosed by the Department of
Defense at the time and used as a cover for the intelligence
mission. However, the Solrad experiments were
not merely for show: by revealing the effect of solar radiation
on the ionosphere and hence on high-frequency
radio communications, they supplied data of military
value.
Work on GRAB began in 1958, around the time of the
first successful Vanguard launch. Reid Meyo of the Naval
Research Laboratory (NRL) Countermeasures Branch
had developed an electronic intelligence antenna for submarine
periscopes. NRL was seeking quick military
exploitation of the Vanguard satellite it had developed,
and it occurred to Reid that the NRL could simply put
his periscope antenna into orbit aboard a Vanguard. The
original calculations behind this idea were done, in the
best tradition of aerospace engineering, on a restaurant
placemat.
From 800 km above the Earth, a GRAB satellite’s circular
orbit passed it through the beams from Soviet radar,
whose pulses traveled beyond the horizon into space.
GRAB’s task was to receive each radar pulse in a certain
bandwidth and to transpond a corresponding signal to