TAU (spacecraft)

TAU (Thousand Astronomical Units) was a proposed unmanned space probe to a distance of one thousand astronomical units (1000 AU) from the Earth and Sun by NASA/JPL in 1987 using tested technology. One scientific purpose would be to measure the distance to other stars via stellar parallax.

It was a proposed nuclear electric rocket spacecraft that used a 1 MW fission reactor and an ion drive with a burn time of about 10 years and reach a distance of 1000 AU in 50 years. The primary goal of the mission was to improve parallax measurements of the distances to stars inside and outside of our galaxy, with secondary goals being the study of the heliopause, measurements of conditions in the interstellar medium, and (via communications with Earth) tests of general relativity.

External links/ Further reading

• Tau (Thousand Astronomical Unit) Mission in The Encyclopedia of Astrobiology, Astronomy, and Spaceflight.
• Abstract of "TAU -- A MISSION TO A THOUSAND ASTRONOMICAL UNITS" by K. T. Neck of the Jet Propulsion Laboratory.
• Abstract of "Preliminary scientific rationale for a voyage to a thousand astronomical units" by M. I. Etchegaray of the Jet Propulsion Laboratory and the California Institute of Technology.

See also

• Innovative Interstellar Explorer (NASA 2003)
• Interstellar probe