This evening a durable NASA spacecraft will get one last close encounter to wrap up a successful, 12-year lifespan.
Stardust-NExT will fly-by within 200km of comet Tempel 1 (NExT stands for New Exploration of Tempel), following up a visit one year ago by the Deep Impact spacecraft.
Stardust was launched in 1999, spending its first three years mostly collecting interstellar dust around the Solar System. In 2004 it reached the comet Wild-2, collecting particles as it flew by, which were sent via a return capsule to Earth, landing in the Utah desert.
Image of Tempel 1 from the Deep Impact mission. Photo Credit: NASA/UM M. F. A'Hearn et al
Meanwhile, the Deep Impact spacecraft was headed towards Comet Tempel 1, reaching it in July 2005. The spacecraft ejected a 370kg mass to impact the comet -- the first comet mission to do so -- sending up ice and debris and revealing the comet's interior. Deep Impact was able to image about half the comet during its fly-by. (The space probe then went on to fly by Comet Hartley 2 in 2010)
Stardust will reach its closet approach of Tempel 1 tonight at 11:37 p.m. EST. The mission's goal is to image the other half of the comet's surface and reimage the impact area that Deep Impact left behind, much of which was obscured by a large cloud of dust during that fly-by.
This fly-by will be the last task for the Stardust probe, as it will expend just about all of its remaining fuel to reach the comet. NASA will have a press conference at 1 p.m. Tuesday to discuss the mission.