Lunar and Planetary Science XXVIII 1785.PDF

CHAMPOLLION: A LANDER AND SAMPLE RETURN DEMONSTRATION MISSION Paul R. Weissman, (Jet Propulsion Laboratory, Mail stop 183-601, 4800 Oak Grove Drive, Pasadena, CA 91109, [email protected]..gov)

The Champollion Mission, currently un- face are expected to last 3 1/2 days. Scientists on der study at JPL, is designed to perform the first the ground will update sequences based on landing of scientific instruments on the surface quick-look analyses of earlier measurements. of a cometary nucleus, and to demonstrate tech- The current Champollion payload includes pano- nologies for collecting and returning extra- ramic and near-field cameras, a combined infra- terrestrial samples to a mother , and red spectrometer/microscope for examining col- possibly to Earth. contain a cosmo- lected samples, a one-meter drill for obtaining chemical record of the conditions and composi- cometary samples at depth, a gas chroma- tion of the primordial solar nebula at the time of tograph/mass spectrometer for analyzing col- the formation of the planetary system. The in lected surface and sub-surface samples, and a situ study and return of cometary samples are physical properties experiment to measure the thus among the highest priority goals of the strength, density, temperature, conductivity and planetary exploration program. other properties of the nucleus surface.

The current Champollion mission plan is The 76 kg. Champollion lander will then to launch in April-May, 2003 on either a Delta collect a sub-surface sample, detach itself from 7925 or a Med-Lite 7425 launch vehicle, using a the anchor, take off, rendezvous with the carrier solar-electric powered carrier spacecraft to take spacecraft, and transfer the sample to the carrier Champollion to a rendezvous with periodic spacecraft. This will thus demonstrate the fea- Comet . Flight time with the SEP sibility of remote sample collection, automated stage is 2.7 years, considerably shorter than typi- orbital rendezvous, and transfer technologies, cal ballistic trajectories. Rendezvous occurs which could then be used on other sample return post-perihelion at about 2.5 AU from the Sun. missions, such as from Mars or from an outer After a series of slow flybys, the spacecraft will solar system satellite. Depending on the launch be placed in a low orbit around the nucleus of vehicle used and the resources which NASA can P/Tempel 1. Champollion would plan to spend allocate to the mission, the cometary sample may 3-5 months at the comet in order to map com- then either be analyzed onboard the carrier pletely the nucleus surface at high resolution, spacecraft or returned to Earth for analysis in prior to deploying the lander spacecraft. In ad- terrestrial laboratories. Flight time back to Earth dition, radio tracking data will be used to de- would be 4.2 years, delivering the sample in termine the nucleus mass and gravity harmonics, June, 2010. The sample would be enclosed in a and will be combined with imaging data to esti- direct entry capsule that would decelerate in the mate the bulk density of the cometary nucleus. Earth's atmosphere and then parachute safely to the surface. The 3-axis stabilized Champollion lander will slowly descend to the surface using Development of Champollion will be autonomous navigation, nulling out the lander accomplished in collaboration with other ad- velocity just before contact with the nucleus. At vanced technology development and demonstra- touchdown an explosive, deployable harpoon tion programs at JPL. will anchor the spacecraft to the surface to permit drilling operations and other relevant measurements. Operations on the nucleus sur-