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22-Feb-01 | NEAR performs first-ever landing on an asteroid!

On Monday, 12 February 2001, two days shy of a full year in orbit, NEAR Shoemaker became the first spacecraft in history to land on the surface of an asteroid.

In an unprecedented and incredible feat of tele-navigation, controllers at the JHU Applied Physics Lab (in consultation with navigators at JPL) directed NEAR to perform a series of four braking burns that altered its orbit to intersect 433 Eros in its “Saddle” region. At a distance of 316 million kilometers from Earth and a one-way transmission delay of over 17 minutes, real-time control of the landing was impossible. NASA estimated the likelihood of receiving a signal after landing (or more accurately, impact) at one chance in 100.

As it approached, NEAR continued to transmit pictures of the surface of Eros, one every 30 seconds or so, with ever increasing detail. The last image, only partially transmitted before impact, showed an area just 20 feet across. Against all odds, at 15:02:10 EST the signal reached Earth: NEAR had survived! (Actual landing time at the asteroid was 19:44:35 UTC, according to JSR 447, 19-Feb-01.)

The event must have been quite similar to the laughably gentle landing depicted in a NASA animation, for the impact at around 3.5 miles per hour did not damage any of the systems necessary for broadcast, and NEAR continued to send a low-bandwidth carrier signal. APL is still receiving telemetry as well, and a brief extended mission has been approved in order to attempt measurements with the gamma-ray spectrometer. Video images will not be taken, however, as NEAR’s camera was designed to be far-sighted and would only show blurs for close-up objects (such as an adjacent asteroid).

NEAR was launched aboard a Delta II rocket on 17 February 1996, the first mission in NASA’s Discovery Program. Other Discovery missions include Mars Pathfinder, Stardust, and the future Genesis, CONTOUR, Deep Impact, and MESSENGER missions, all of which will fly aboard Delta vehicles.


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