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

(November 1995), WIRE(March 1999), SIRTF(December
2001), IRIS (2003), NGSS (2003–2004), PRIME
(2006), FIRST (2007), FAIR (2007+), SPIRIT (2007+),
NGST (2010), and IRSI (2014).
infrared radiometer
An instrument that measures the intensity of infrared
energy coming from a source.
ingress
The act of, or the mechanism for, entrance to an enclosure.
In spacecraft this can relate to the act of a crew
member entering the space vehicle, or it can describe the
entrance chamber, pressure lock, and hatchways.
inhibitor
A substance bonded, taped, or dip-dried onto a solid propellant
to restrict the burning surface and give direction
to the burning.
initiator
A unit that receives electrical or detonation energy and
produces a chemical deflagration reaction.
injection
(1) The process of putting an artificial satellite into orbit.
(2) The time of such action. Injection altitude is the height
at which a space vehicle is turned from its launch trajectory
into an orbital trajectory. Injection massis the mass of
a space vehicle at the termination of one phase of a mission
that continues into the next phase.
injector
In a liquid-propellant rocket engine, the device that
injects fuel and oxidizer into the combustion chamber.
The injector also mixes and atomizes the propellants for
efficient combustion. Injection pressure is the pressure at
which the fuel is injected into the combustion chamber.
Inmarsat
A network of satellites operated by the International
Maritime Satellite Organization (IMSO) to support
global mobile transmissions at sea, in the air, and on
land.
INPE (Instituto Nacional de Pesquisas Espacias)
Brazil’s National Institute for Space Research, a government
body that manages and coordinates the country’s
involvement in space-related activities.
Insat
India’s multipurpose satellites for telecommunications,
meteorological imaging and data relay, radio and televi-
Intelsat (International Telecommunications Satellite Organization) 195
sion program distribution, and direct television broadcasting
for community reception. The most recent, Insat-
3C, was launched on January 31, 2002.
Inspector
A spacecraft intended to serve as a remote inspection
device for the Mir space station. Built by Daimler-Benz
Aerospace, it was delivered to Mir by a Progress-M supply
vessel and deployed on December 17, 1997. However,
Inspector failed, possibly due to a faulty gyro, and was
abandoned by cosmonauts. Mir was boosted out of the
way, and the inspection craft became an unintended
microsatellite before its orbit decayed on November 2,
1998.
Launch
Date: October 5, 1997
Vehicle: Soyuz-U
Site: Baikonur
Orbit: 377 × 387 km × 51.7°
Mass: 72 kg
INTA (Instituto Nacional de Técnica Aeroespacial)
The Spanish space agency. INTA implements and develops
Spain’s contributions to international space projects,
especially those of ESA (European Space Agency).
INTEGRAL (International Gamma-Ray
Astrophysics Laboratory)
An ESA (European Space Agency) satellite that will provide
the sharpest cosmic gamma-ray pictures to date and
identify many new gamma-ray sources. It is designed to
carry out fine spectroscopy and imaging of cosmic
gamma-ray sources in the 15 keV to 10 MeV energy
range, with concurrent source monitoring in the X-ray
(3–35 keV) and optical (V-band, around 550 nm) energy
ranges. Scheduled to be placed in a highly elliptical orbit
in October 2002 by a Proton rocket from Baikonur,
INTEGRAL has a nominal lifetime of two years with a
possible extension of up to five years.
Intelsat (International Telecommunications
Satellite Organization)
An organization formed in 1964 that designs, builds, and
operates a global system of communications satellites.
For most of its life, Intelsat was run by a consortium of
government telecommunications authorities with shares
in the organization in proportion to their use of it. However,
in 2000, the nearly 150 member nations agreed to
turn the enterprise from a treaty-based organization into
a privately held company. The following year, Bermudabased
Intelsat was formed.