MISSION PLAN - PDS Small Bodies Node

8.0 Planetary Protection
The objective of planetary protection is to minimize the uncontrolled exchange of organic
or biological material between Earth and solar system bodies on which abiotic chemical
evolution could have taken place or life could exist. NASA follows established policy
for the protection of planetary environments from contamination by spacecraft, and has
obtained international acceptance of this policy through the Committee on Space
Research (COSPAR) of the International Council of Scientific Unions. NASA
implements this policy by establishing planetary protection requirements for each
applicable mission.
For the proposed STARDUST mission of a comet flyby and sample return, the planetary
protection restrictions apply to the transport of organic materials from Earth, which could
contaminate the comet nucleus in the case of an inadvertent impact. In addition, it
addresses the issue of evolved chemical material returned to Earth.
The outbound mission phase covers the mission up to and through the encounter with
Wild-2 and flythrough of its coma, during which samples of the ambient dust and
molecules will be obtained. For this part of the mission the spacecraft has been classified
as a Planetary Protection Category II mission, with a Planet Priority of “B”. The object
to be protected on the out-bound phase of the mission is the comet Wild-2. A Planet
Priority of “B” defines the planetary body as being “of significant interest relative to the
process of chemical evolution but only a remote chance that contamination by spacecraft
could jeopardize future exploration.” There are no specific requirements for clean room
assembly for planetary protection. The likelihood of an accidental impact with the comet
would result in mission failure and as such would be avoided.
The inbound mission phase covers the mission subsequent to sample acquisition and
continues through entry, descent, and landing at Earth. The STARDUST project has
requested and received certification as a Planetary Protection Category V mission,
“Unrestricted Earth Return,” for this mission phase. No further planetary requirements
beyond those levied on the outbound phase of the mission would be levied.
The STARDUST Project will comply with all planetary protection policies and
requirements specified by NASA and will document compliance in the STARDUST
Planetary Protection Plan.
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