The refurbished missions cost only about 15% of the price of brand new missions. Deep Impact initially cost $333 million and Stardust cost $212 million. The combined costs of the refurbished missions is about $55 million—about 10% over the original cost—with about 5% added to take care of higher expenses over time.

Alan Stern, NASA’s associate administrator for its Science Mission Directorate, says, “These new mission assignments for veteran spacecraft represent not only creative thinking and planning, but are also a prime example of getting more from the budget we have.”

DEEP IMPACT (at JPL and NASA)

Launched on January 12, 2005, for its original mission, Deep Impact flew by Comet Tempel 1 and sent a probe (on July 4, 2005) to impact the comet’s surface. The probe successfully impact the comet’s nucleus, showing that the comet was less icy and more dusty than astronomers had previously thought.

The spacecraft will fly by Earth on December 31, 2007, before beginning its travels to study extrasolar planets (exoplanets) and the Comet Boethin.

Under the name EPOXI (whose acronym is a combination of its two coordinated projects), Deep Impact is now being sent to another comet in 2008 and to observe stars known to have planets orbiting them (what are called exoplanets). EPOXI is a mission using two projects, one called Extrasolar Planet Observation and Characterization (EPOCh) and the other called Deep Impact Extended Investigation (DIXI).

EPOCh will also involve the investigation of bright stars where giant planets are already known to orbit. Additional information about possible moons, rings, and other features associated with these giant exoplanets is hoped to be collected. The space probe will watch and record the passing of these planets in front of their host star. This investigation will occur while Deep Impact is traveling to Comet Boethin.

DIXI involves a first-ever flyby of Comet Boethin, a comet never explored by humans. It was supposed to be explored in 2002 by the failed CONTOUR (Comet Nucleus Tour) mission. Deep Impact is expected to fly by Comet Boethin on December 5, 2008.

STARDUST (JPL and NASA)

In 2006, Stardust, after being launched in 1999, returned to the Earth on January 2006 and sent a sample capsule for a landing on the Earth. The capsule contained comet dust from Comet Wild 2 that is visited in January 2004, along with interstellar materials.

It was the first sample return mission by humans to collect cosmic dust and return the sample back to the Earth.

Under the name NExT (New Exploration of Tempel 1), Stardust is being sent to Comet Tempel 1, after Deep Impact visited it earlier, in order to compare changes to the comet’s nucleus after its recent encounter around the Sun. This is the first time that Earth probes have visited a comet more than once. Deep Impact visited Tempel 1 on July 4, 2005, and Stardust is expected to encounter the comet on February 14, 2011. It will also add to the mapping of the comet’s nucleus already performed by Deep Impact. With this new mapping, the comet will become the most mapped comet nucleus so far in our comet studies.

{moscomment}