Near Earth Asteroid Rendezvous (NEAR) Mission and Instrument Description

Mission Summary

The Near Earth Asteroid Rendezvous (NEAR) mission is the first launch in the Discovery Program, a NASA initiative for small planetary missions with a maximum 3-year development cycle and a cost capped at $150 million for construction, launch, and 30 days of operation. The NEAR mission is managed by the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

As the first spacecraft to orbit an asteroid, the NEAR mission promises to answer fundamental questions about the nature and origin of near-Earth objects, such as the numerous asteroids and comets in the vicinity of Earth's orbit.

These objects are of interest for several reasons. First, they are the primary source of large bodies that collide with Earth, greatly influencing the evolution of the atmosphere and life on Earth. An asteroid collision with Earth was likely responsible for the mass extinction at the end of the Cretaceous period, and another impact in 1908 destroyed thousands of square kilometers of forest near Tunguska, Siberia.

In addition, clues to the nature of early solar system processes and conditions are preserved in various forms on small bodies like asteroids, comets, and meteorites (so-called primitive bodies). These records have been altered or destroyed on large, planet-sized bodies by processes of planetary evolution.

The near-Earth population of asteroids, in particular, is believed to contain clues to the nature of the building blocks (planetesimals) from which the inner planets, including Earth, were formed.

The NEAR mission will provide our first comprehensive scientific survey of an important class of objects found close to Earth, the near-Earth asteroids, and promises to be an auspicious beginning for the NASA Discovery Program.

Mission Objectives

The NEAR mission will make the first quantitative and comprehensive measurements of an asteroid's composition and structure. The measurements have been identified by the National Academy of Sciences as the most important scientific objectives in the exploration of primitive bodies. Primary scientific goals of the NEAR mission are to measure the following:

• Bulk properties: Size, shape, volume, mass, gravity field, and spin state
• Surface properties: Elemental and mineral composition, geology, morphology, and texture
• Internal properties: Mass distribution and magnetic field

433 Eros

Mission Characteristics

Science Payload

*Part of engineering system

Spacecraft Characteristics

Mission Management

Science Team Leaders