Deep Impact, a NASA spacecraft to be the first to probe beneath the surface of a comet and reveal the secrets of its interior, will be available for a press opportunity at 10:15 a.m. Thursday, Dec. 23, at the Astrotech Space Operations facility in Titusville.

Comets are time capsules that hold clues about the formation and evolution of the Solar System. They are composed of ice, gas and dust, primitive debris from the Solar System's distant and coldest regions that formed 4.5 billion years ago. Launch of NASA's Deep Impact spacecraft is scheduled for Jan. 12, 2005, at 1:08 p.m. EST. Liftoff will occur aboard a Boeing Delta II rocket from Pad 17-B at Cape Canaveral Air Force Station. On July 4, 2005, the Deep Impact spacecraft will arrive at Comet Tempel 1.

Deep Impact is comprised of two parts, a "fly-by" spacecraft and a smaller "impactor" to be released into the comet's path for a planned collision. On impact, the crater produced by the impactor is expected to range in size from that of a house to that of a football field and will be from two to fourteen stories deep. Ice and dust debris will be ejected from the crater, revealing the material beneath. The effects of the collision with the comet will be observed by the fly-by spacecraft, the Hubble, Spitzer and Chandra great observatories, and by telescopes on Earth. Results from the mission will lead to a better understanding of comets and the Solar System's formation.

For the media event, procedures for optically sensitive spacecraft must be followed by individuals entering the cleanroom where the spacecraft is being processed. Cleanroom attire will be furnished. Photographers will be requested to clean cameras, tripods and photo accessories using alcohol wipes which will be provided.

Long pants and closed-toe shoes must be worn -- no shorts or skirts. Non-essential equipment such as camera bags or other carrying cases must be left outside the cleanroom. No pencils or felt-tipped pens can be permitted inside the cleanroom; only ball-point pens may be used. Due to the sensitivity of the spacecraft's solar arrays, flash photography and flood lights will not be allowed. There is adequate metal halide lighting in the facility for photography (white with slight green cast; suggested exposure for ISO-ASA 400 is 1/30 sec. at f/5.6 ).

On Thursday, media may proceed directly to Astrotech located in the Spaceport Florida Industrial Park, 1515 Chaffee Drive, Titusville. Access at the gate will begin at 10:15 a.m.

Spokespersons available will be:

Rick Grammier, Deep Impact Project Manager
Jet Propulsion Laboratory

Mike A'Hearn, Deep Impact Principal Investigator
University of Maryland

Monte Henderson, Deputy Program Manager
Ball Aerospace & Technologies Corporation

The overall Deep Impact mission management for this Discovery class program is conducted by the University of Maryland. The spacecraft was built for NASA by Ball Aerospace and Technologies Corporation. Deep Impact project management is handled by the Jet Propulsion Laboratory in Pasadena, Calif.