In the first step of a potential two-step process, NASA has
selected two proposals for detailed mission feasibility studies as
candidates for a Pluto-Kuiper Belt (PKB) mission to explore the
only planet in our Solar System yet to be visited by a spacecraft
from Earth.

The President’s FY 2002 budget request does not contain development
funding for a Pluto mission. The Congress requested that NASA not
do anything precipitous which would preclude the ability to develop
a Pluto-Kuiper mission until the Congress could consider it in the
context of the FY 2002 budget. If funding is provided in the FY
2002 budget and either proposal is ultimately selected, the Agency
could down-select a proposal for development to ultimately fly a
spacecraft to Pluto and beyond. If a PKB mission is developed,
launch would be in the 2004-2006 time frame and the spacecraft
would arrive at Pluto before 2020.

“The PKB mission represents a possible opportunity to visit the
only planet not yet explored by spacecraft,” said Dr. Colleen
Hartman, Pluto Program Director in NASA’s Office of Space Science,
Washington, DC. “It’s really an opportunity to, in a sense, look
into a deep-freeze of history which could tell us how our Solar
System evolved to what it is today, including the precursor
ingredients of life.”

Each team will receive $450,000 to conduct a three-month concept
study. At the end of the three months, NASA will thoroughly
evaluate program content and technical, schedule and cost
feasibilities of both proposals to determine if either is

The two selected proposals were judged to have the best science
value among the five proposals submitted to NASA in April 2001 in
response to the Pluto-Kuiper Belt Mission Announcement of
Opportunity. Each selected investigation will work with the Office
of Space Science at NASA Headquarters to finalize the design of the
spacecraft and its accommodation of the instrument sets.

The selected investigations are:

Pluto and Outer Solar System Explorer (POSSE). Dr. Larry Esposito,
Principal Investigator, University of Colorado, Boulder, will lead
a team including the following major participants: NASA’s Jet
Propulsion Laboratory (JPL), Pasadena, CA; Lockheed Martin
Astronautics, Denver; Malin Space Science Systems, Inc., San Diego;
Ball Aerospace Corp., Boulder, CO; and University of California,

New Horizons: Shedding Light on Frontier Worlds. Dr. S. Alan Stern,
Principal Investigator, Southwest Research Institute, Boulder, CO,
will lead a team including the following major participants: Johns
Hopkins University Applied Physics Laboratory, Laurel, MD; Ball
Aerospace Corp.; Stanford University, Palo Alto, CA; NASA’s Goddard
Space Flight Center, Greenbelt, MD; and JPL.

Both proposals are for complete missions, including launch vehicle,
spacecraft and science instrument payload. Both address the major
science objectives defined in the original announcement. Each
proposal includes a remote sensing package that includes imaging
instruments, a radio science investigation, and other experiments
to characterize the global geology and morphology of Pluto and
Charon, map their surface composition, and characterize Pluto’s
neutral atmosphere and its escape rate.

Pluto is a different kind of planet. It is not a rocky planet like
Earth, Mars, Mercury or Venus, or a gas giant like Jupiter, Saturn,
Uranus or Neptune. It is a Kuiper Belt Object, a class of objects
composed of material left over after the formation of the other
planets, which has never been exposed to the higher temperatures
and solar radiation levels of the inner solar system.

It is known that Pluto has large quantities of ices of nitrogen,
and simple molecules containing combinations of carbon, hydrogen
and oxygen that are the necessary precursors of life. These ices
would be largely lost to space if Pluto had come close to the Sun.
Instead they remain on Pluto as a representative sample of the
primordial material that set the stage for the evolution of the
Solar System as it exists today, including life.

If a PKB mission is developed, it will be a Principal Investigator-
led investigation, bringing together teams from academia, industry,
NASA Centers and other communities, and will be developed following
the highly successful management philosophy of the Discovery

Related Links

° December 2000: NASA Reconsiders a Mission to Pluto, SpaceRef

° Pluto-Kuiper Express mission, NASA JPL

° Europa Orbiter mission, NASA JPL

° 21 December 2000: Public Wants NASA To Explore Europa, Pluto, Sky and Telescope Magazine

° 20 December 2000: Pluto Kuiper Mission AO Announcement, Commerce Business Daily

° 20 December 2000: NASA Seeks Proposals for Pluto Mission; Plans to Restructure Outer Planets Program, NASA PAO

° 20 December 2000: On to Pluto? – The Planetary Society Statement

° 27 November 2000: Letter from Michael J. Drake, Chair, Solar System Exploration Subcommittee (SSEC) to Jay Bergstralh, Office of Space Science, NASA HQ regarding the findings and recommendations of the SSEC’s recent meeting.

° 22 September 2000: Planetary Scientists Express Major Concern Over Work Stoppage On Pluto Mission, American Astronomical Society

° 22 September 2000: Earmarks, Rising Costs Threaten NASA Missions, Science, [summary – can be viewed for free once registered. A subscription fee is required for full access.]

° 22 September 2000: Planetary Society Urges Congress Not to Put Pluto on Ice, press release

° 4 August 2000: Dear Colleague Letter from NASA HQ regarding Pluto-Kuiper Express (PKE) mission

° 28 July 2000: Don’t Cancel Mission to Pluto: The Planetary Society Begins Public Campaign

° 30 December 1999: Pluto’s moon Charon is covered with crystalline water and ammonia Ice, SpaceRef

° 10 September 1999: Deep Space Systems Program Including Europa Orbitor Pluto-Kuiper Express And Solar Probe, NASA Announcements of Opportunity Soliciting Proposals for Basic Research, AO: 99-OSS-04 , Issued: September 10, 1999