Encyclopedia Astronautica

American infrared astronomy satellite. One launch, 2001.06.30. NASA's Microwave Anisotropy Probe was placed at the L2 Earth-Moon Lagrangian point 1.

5 million km from Earth to observe the dark extragalactic sky with differential microwave radiometers using two 1.5-meter reflectors working at 22 to 90 GHz.

It measured fluctuations in the cosmic 3 Kelvin microwave background down to 35 microKelvin on scales down to 0.2 degrees. Ground-based experiments had provided convincing evidence that these background fluctuations were consistent with a model in which the total density of the universe was closely equal to the critical density; MAP was designed to refine and extend these observations. The spacecraft had a dry mass of 768 kg and carried 72 kg of propellant. It was built at NASA-Goddard, and the microwave instrument was built in collaboration with Princeton University. MAP was the second MIDEX mid-sized Explorer - the first was IMAGE, which studied the magnetosphere. The third MIDEX was to be SWIFT, for gamma ray burst studies, due for launch in 2003.

The 400 W MAP probe was to scan the sky in five wavelength bands at 13.6, 10.0, 7.5, 5.0, and 3.3 mm at an angular resolution of about 0.58 (+/- 0.035) deg, and at a sensitivity of 35 micro-Kelvin after "parking" itself over the second Lagrangian point (L-2) at 1.5 million km in the nightside. These parameters were invoked on the basis of the anisotropy in the 2.7 deg Kelvin cosmic radiation revealed by the earlier mission, COBE. It carried two Gregorian telescopes each with a primary reflector of about 1.5 m and a secondary of 1.0 m diameter. The two telescopes were to point to the sky a few degrees apart so that the difference in the temperature could be directly outputted. (One of the branches of cosmology invokes an early "inflationary" epoch of spurious super-expansion of the "Big Bang" fireball giving rise to a small anisotropy that eventually gave birth to the galactic structures in the otherwise mathematically homogenous and isotropic universe.) The spacecraft had an intrinsic spin of 0.464 rpm superposed on a precession (22.5 deg about the Sun-MAP line) of 1.0 rph. A full-sky map could be obtained every six months. MAP was to reach L-2 after three or more lunar encounters/phasings, and enter into a controlled Lissajous orbit around that point with a maximum deviation of the Sun-MAP line from the Sun-Earth line of 10 deg. About four thrust maneuvers/year were required to sustain the orbit configuration.

Gross mass: 840 kg (1,850 lb).
Unfuelled mass: 768 kg (1,693 lb).
First Launch: 2001.06.30.
Number: 1 .

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Associated Countries
See also
  • Delta The Delta launch vehicle was America's longest-lived, most reliable, and lowest-cost space launch vehicle. Development began in 1955 and it continued in service in the 21st Century despite numerous candidate replacements. More...

Associated Launch Vehicles
  • Delta American orbital launch vehicle. The Delta launch vehicle was America's longest-lived, most reliable, and lowest-cost space launch vehicle. Delta began as Thor, a crash December 1955 program to produce an intermediate range ballistic missile using existing components, which flew thirteen months after go-ahead. Fifteen months after that, a space launch version flew, using an existing upper stage. The addition of solid rocket boosters allowed the Thor core and Able/Delta upper stages to be stretched. Costs were kept down by using first and second-stage rocket engines surplus to the Apollo program in the 1970's. Continuous introduction of new 'existing' technology over the years resulted in an incredible evolution - the payload into a geosynchronous transfer orbit increasing from 68 kg in 1962 to 3810 kg by 2002. Delta survived innumerable attempts to kill the program and replace it with 'more rationale' alternatives. By 2008 nearly 1,000 boosters had flown over a fifty-year career, and cancellation was again announced. More...
  • Delta 2 7000 American orbital launch vehicle. The Delta 7000 series used GEM-40 strap-ons with the Extra Extended Long Tank core, further upgraded with the RS-27A engine. More...
  • Delta 7425-10 American orbital launch vehicle. Four stage vehicle consisting of 4 x GEM-40 + 1 x EELT Thor/RS-27A + 1 x Delta K + 1 x Star 48B with 3.05 m (10 foot) diameter fairing More...

Associated Manufacturers and Agencies
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • National Space Science Center Planetary Page, As of 19 February 1999.. Web Address when accessed: here.
  • NASA Report, MAP Fact Sheet, Web Address when accessed: here.
  • NASA Report, Goddard MAP Fact Sheet 2001, Web Address when accessed: here.

Associated Launch Sites
  • Cape Canaveral America's largest launch center, used for all manned launches. Today only six of the 40 launch complexes built here remain in use. Located at or near Cape Canaveral are the Kennedy Space Center on Merritt Island, used by NASA for Saturn V and Space Shuttle launches; Patrick AFB on Cape Canaveral itself, operated the US Department of Defense and handling most other launches; the commercial Spaceport Florida; the air-launched launch vehicle and missile Drop Zone off Mayport, Florida, located at 29.00 N 79.00 W, and an offshore submarine-launched ballistic missile launch area. All of these take advantage of the extensive down-range tracking facilities that once extended from the Cape, through the Caribbean, South Atlantic, and to South Africa and the Indian Ocean. More...
  • Cape Canaveral LC17B Delta launch complex. Part of a dual launch pad complex built for the Thor ballistic missile program in 1956. Upgraded over the decades for use with Thor, Delta, Delta II, and Delta III launch vehicles, it remained in use for over half a century. More...

MAP Chronology

2001 June 30 - . 19:46 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC17B. Launch Pad: SLC17B. LV Family: Delta. Launch Vehicle: Delta 7425-10. LV Configuration: Delta 7425-10 D286.
  • MAP - . Mass: 840 kg (1,850 lb). Nation: USA. Agency: NASA Greenbelt. Class: Astronomy. Type: Infrared astronomy satellite. Spacecraft: MAP. USAF Sat Cat: 26859 . COSPAR: 2001-027A. Apogee: 379,553 km (235,842 mi). Perigee: 4,704 km (2,922 mi). Inclination: 27.8000 deg. Period: 14,669.70 min. NASA's Microwave Anisotropy Probe (MAP) was placed in a 167 x 204 km x 28.8 deg parking orbit at 1958 GMT. At 2104 GMT the second stage ignited again for a 4 second burn, raising the orbit to around 181 x 308 km; the third stage spun up and ignited at 2108 GMT, accelerating MAP to a highly elliptical orbit of 182 x 292,492 km x 28.7 deg. MAP used on-board fuel to tweak the orbit and make a lunar flyby at fourth apogee on July 30, arriving at the L2 Earth-Moon Lagrangian point 1.5 million km from Earth three months later. From L2, MAP was to measure fluctuations in the cosmic 3 Kelvin microwave background with the degree of precision required to answer questions about the big bang and the total mass and fate of the universe. By July 22 the MAP probe was in a 4055 x 355,935 km x 28.0 deg orbit. It flew past the Moon on July 30 at 1639 GMT at an altitude of 5200 km above the lunar surface.

2001 July 30 - .
  • MAP, Moon Flyby - . Spacecraft: MAP.

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