EXECUTIVE SUMMARY

    The Pluto Express mission is designed to provide the first 
reconnaissance of the Solar System's most distant planet, Pluto, and its 
moon Charon. To be viable in the current environment of tight financial 
limitations, the mission will be the first to employ a new philosophy of 
integrated spacecraft, instrument and mission operations design 
("sciencecraft"), which necessitates a tight collaboration between 
selected instrument builders and spacecraft designers.

    Tremendous progress in understanding Pluto and Charon enabled a 
well-focused set of questions to be developed which can be addressed by 
a first spacecraft reconnaissance of the system. Fundamental questions 
regarding the physical and chemical processes in protoplanetary disks 
and their relationship with the surrounding nascent molecular cloud will 
be addressed through study of Pluto and Charon, as well as investigation 
of the environment of the outer Solar System during its early history 
from analysis of the cratering and tectonic records of these bodies. The 
physics of the unique evolution of Pluto's atmosphere as the planet moves
away from the sun will also be a focus of study on this mission.

    The baseline mission will involve two identical sciencecraft on 
flyby trajectories of the Pluto/Charon system. The spacecraft will carry 
an integrated array of scientific sensors which will conduct measurements
capable of satisfying at least the Category 1a science objectives 
regarding Pluto's atmosphere and surface, and Charon's surface, developed 
by the Outer Planets Science Working Group and detailed herein. Radio 
science provides an essential complement to fulfill these goals, and will
be incorporated as part of the sciencecraft subsystems. Science 
investigation teams will be competitively selected and expected to work 
closely with spacecraft designers to produce an integrated sciencecraft 
within the stringent cost, mass and power constraints of the mission.

    The recent discovery of dozens of objects, from comet-sized up to 
hundreds of kilometers, orbiting in the predicted Kuiper Belt region just
beyond the planets, has raised the exciting possibility of an extended 
mission to fly close to one or two such bodies. If implemented, this 
extended mission would allow comparison of the properties of Pluto and 
Charon with the smaller bodies from which they (and the larger outer 
planets) were likely assembled.

    As befits an exciting mission to the outer reaches of the Solar 
System, substantial interest exists from two international partners. The 
German space agency, DARA, has played a strong role in developing two 
possible collaborative scenarios: If the spacecraft are launched on 
trajectories which allow a Jupiter gravity assist, DARA could provide a 
detachable probe spacecraft to explore Jupiter's moon Io and its 
environment. A second possibility would be construction of a particles 
and fields experiment package to be used to investigate the interaction 
of Pluto and its atmosphere with the solar wind. The Russian space 
agency, RSA, is interested in possibly supplying a Drop Zond to 
investigate Pluto's atmosphere in situ prior to impacting on Pluto's 
surface.

Mission studies underway now could lead to a launch early in the next 
decade of the Pluto Express mission, allowing the primary targets to be 
reached roughly a decade after.

** directly copied from Pluto Express Science homepage.