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Building the NEAR Spacecraft: 1994 and 1995

NEAR was the first mission launched in NASA's Discovery Program of "faster, cheaper, better" missions, and it will be is now! the first spacecraft to orbit an asteroid.

NEAR's six science experiments contribute in different ways to understanding the surface, interior, and origin of Eros:

The NEAR spacecraft and science instruments.
For instrument descriptions, click in areas of the image, or on the links below.

• The magnetometer (MAG) will determine whether Eros has a magnetic field. A magnetic field would be strong evidence for abundant metallic iron like that in some meteorites.
• The X-ray/gamma-ray spectrometer (XGRS) will measure key elements like silicon, magnesium, iron, uranium, thorium, and potassium.
• The near-infrared spectrometer (NIS), measuring the spectrum of sunlight reflected by Eros, will map the mineral composition of the surface.
  
• The laser rangefinder (NLR), a "laser radar," will read the shape of the asteroid with accuracy down to a few meters.
• The multispectral imager (MSI) will map the shape, landforms, and color properties of the asteroid to determine the configuration of its different rock types and the processes that have shaped the surface.
  
• And finally, a radio science experiment (RS) will track tiny changes in NEAR's radio frequency caused by changes in the spacecraft velocity (the Doppler effect) as the spacecraft is pulled by Eros' gravity. This will determine the asteroid's mass. Mass, divided by the volume as derived from imaging, will tell us Eros's density - a critical clue to the structure and configuration of rock types comprising the asteroid's interior.

The NEAR spacecraft was designed, built, and managed for NASA by The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. During 1994 and early 1995 the components of the spacecraft were assembled and tested, and late in 1995 the pieces were mated and checked for proper function. The fully assembled spacecraft was transported to Cape Canaveral and mounted atop its launch vehicle for the journey to Eros.