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

256 MAP (Microwave Anisotropy Probe)
MAP (Microwave Anisotropy Probe)
A MIDEX (Medium-class Explorer) mission developed
by the Goddard Space Flight Center and Princeton University
to study conditions in the early universe. It can
detect anisotropy (directional variations) in the cosmic
microwave background—the afterglow of the Big Bang—
with a much higher resolution than that of the earlier
COBE (Cosmic Background Explorer). As the microwave
background ripples through the universe in waves
of slightly different temperatures, it preserves a record, in
expanded form, of the shape of the universe as it
appeared about 13 billion years ago. MAP’s advanced set
of microwave radiometers will record temperature patterns
across the full sky, providing the best indicator yet
of the size and shape of the entire universe. The spacecraft’s
two-year mission is carried out from a halo orbit
about the second Sun-Earth Lagrangian point 1.5 million
km from Earth.
Launch
Date: June 30, 2001
Vehicle: Delta 7425
Site: Cape Canaveral
Orbit: halo
Mass: 840 kg
MARECS
Two geostationary satellites—MARECS A (launched on
December 20, 1981) and MARECS-B2 (launched on
November 10, 1984)—that formed part of Inmarsat’s
global maritime communications satellite network. The
program began as the experimental Maritime Orbital Test
Satellite (MAROTS) in 1973, but subsequently evolved
into an operational system resulting in a name change, a
satellite redesign, and delayed development.
Mariner
See article, pages 257–259.
Mars
See article, pages 260–261.
Mars 96
An ambitious Russian Mars probe, launched on November
16, 1996, that fell back to Earth after a failed burn
that should have taken it out of Earth orbit. The probe
included an orbiter, two small autonomous landers, and
two surface penetrators. Having achieved an initial 160
km-high circular orbit, Mars 96 was to have been boosted
onto a Mars trajectory by the upper-stage engine still
attached to the probe. Instead, a misfiring of the upper
stage placed the probe on an orbit that caused it to reenter.
No advance warning of the probe’s imminent descent
was given by the Russians despite the fact that Mars 96
was carrying 270 grams of plutonium-238 as an energy
source. Its final whereabouts remain unknown, although
parts of it are presumed to have fallen into the South
Pacific and possibly regions of Bolivia and Chile.
Mars 1969 A and B
Two identical Soviet probes launched in the spring of
1969 and intended to orbit Mars. Both were lost following
launch failures and not officially announced. Each
spacecraft carried three television cameras designed to
image the Martian surface, a radiometer, a water vapor
detector, ultraviolet and infrared spectrometers, a radiation
detector, a gamma spectrometer, a hydrogen/helium
mass spectrometer, a solar plasma spectrometer, and a
low-energy ion spectrometer. See Mars, unmanned
spacecraft.
Mars 2005
See Mars Reconnaissance Orbiter.
Mars 2007
A long-range, long-duration NASA rover equipped to
perform a variety of surface studies of Mars and to
demonstrate the technology for accurate landing and
hazard avoidance in difficult-to-reach sites. In the same
year, CNES (the French space agency) plans to launch a
remote sensing orbiter and four small NetLanders, and
ASI (the Italian space agency) plans to launch a communications
orbiter to link to the NetLanders and future
missions. Also slated for possible launch in 2007 are one
or more small Scout missions.
Mars Climate Orbiter
One of the spacecraft in the Mars Surveyor ’98 program.
It was designed to study the weather, climate, and cycling
of water and carbon dioxide on Mars from orbit but was
lost following a navigational error. A failure review board
set up by NASA found that the problem lay in some
spacecraft commands having been issued in English units
instead of their metric equivalents. As a result, the probe
went into an orbit of less than half the intended altitude
and burned up in the Martian atmosphere. This loss,
together with that of the Mars Polar Lander, prompted
NASA to revise its plans for the robotic exploration of
Mars.
Launch
Date: December 11, 1998
Vehicle: Delta 7425
Site: Cape Canaveral
Mass at launch: 629 kg