(163249) 2002 GT is an Apollo asteroid with an absolute magnitude of 18.26.^[1] It is a potentially hazardous asteroid as its orbit crosses that of Earth.^[3]

In 2011, NASA considered sending the unmanned spacecraft Deep Impact toward the asteroid with the aim of performing a flyby^[3] in 2020. It was uncertain whether Deep Impact carried sufficient fuel for this operation.^[3]

On 24 November 2011 and 4 October 2012, the space probe's thrusters were fired briefly for two trajectory correction maneuvers that targeted Deep Impact for an encounter with 2002 GT in 2020, possibly within a distance of no more than 400 kilometers. However, funding for the flyby mission was not guaranteed.^[4] In June 2013 the asteroid was observed in radar by the Arecibo Observatory.^[5]

However, on 8 August 2013 NASA lost communication with the spacecraft, and on 20 September 2013, NASA abandoned further attempts to contact the craft.^[6] According to A'Hearn,^[7] the most probable reason of software malfunction was a Y2K-like problem (at 11 August 2013 0:38:49 it was 2³² deciseconds from 1 January 2000^[8]).

• List of minor planets and comets visited by spacecraft