NASA Gives Go-ahead To Build 'Deep Impact' Spacecraft
May 24, 2001

Artist's concept of Deep Impact

     The Deep Impact mission, the first mission to ever attempt to impact a comet nucleus in order to answer basic questions about the nature of comets, has successfully completed its preliminary design phase and has been approved by NASA to begin full- scale development for a launch in January 2004.

     The Deep Impact team of scientists, engineers and mission designers, from the University of Maryland, NASA's Jet Propulsion Laboratory and Ball Aerospace & Technologies Corporation, Boulder, Colo., have been working for more than 18 months designing the mission, the dual spacecraft and three science instruments. The encounter with Comet Tempel 1 on July 4, 2005 will reveal clues to the origin of comets and the composition and structure of perhaps the most mysterious objects in our solar system.

     Now the Deep Impact team is completing the final design details and will begin building the mission's two spacecraft: a flyby spacecraft and a 350-kilogram (771-pound) impactor spacecraft. They will be launched together in early 2004 and travel to Comet Tempel 1's orbit where they will separate and operate independently. The flyby spacecraft will release the impactor into the comet's path, then watch from a safe distance as the impactor guides itself to collide with the comet, making a football field-sized crater in the comet's nucleus.

     "This is a major milestone for us," said Dr. Michael A'Hearn, the prinicipal investigator and director of the Deep Impact mission, from the University of Maryland, College Park, Md. "We have now shown NASA that we have a viable design for the spacecraft and the mission to carry out a truly rare, large-scale experiment on another body of the solar system."

     "The Deep Impact mission follows in the tradition of other Discovery missions like Mars Pathfinder and the Near-Earth Asteroid Rendezvous by doing first of a kind science on a low-cost, highly focused project," said Brian Muirhead, the manager of the Deep Impact mission, of NASA's Jet Propulsion Laboratory, Pasadena, California. "The project team is fully prepared to implement this technically challenging and scientifically unique mission."

     As the gases and ice inside the comet are exposed and expelled outward by the impact, the flyby spacecraft will take pictures and measure the composition of the outflowing gas. The images and data will be transmitted to Earth as quickly as possible. Many observatories on Earth should be able to see the comet dramatically brighten just after the impact on July 4, 2005.

     Scientists refer to comets as time capsules that hold clues about the formation and evolution of the solar system. Comets are composed of ice and dust, the primitive debris from the solar system's earliest and coldest formation period, 4.5 billion years ago. They would also like to learn much more about a comet's composition, structure and how its interior is different from its surface. The controlled cratering experiment of the Deep Impact mission will provide answers to these questions.

     Comet Tempel 1 was discovered in 1867. Orbiting the Sun every 5.5 years, it has made many passages through the inner solar system. This makes it a good target to study evolutionary change in the mantle, or outer crust, of a comet.

     "Ball Aerospace is pleased and proud to be involved with JPL and the University of Maryland in working on this first of a kind deep space mission," said Ball's John Marriott, deputy project manager.

     Principal investigator A'Hearn oversees Deep Impact's scientific investigations. Project manager Brian Muirhead, of NASA's Jet Propulsion Laboratory manages and will operate the Deep Impact mission for NASA's Office of Space Science, Washington D.C. JPL is managed by the California Institute of Technology, Pasadena, Calif., for NASA. John Marriott of Ball Aerospace & Technology Corporation manages the spacecraft development in Boulder, Colo.

     Images and more information about the mission are available on the Web at: http://deepimpact.jpl.nasa.gov. A mirror site is available at http://deepimpact.umd.edu .