[Federal Register Volume 62, Number 68 (Wednesday, April 9, 1997)]
[Notices]
[Pages 17216-17217]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-9104]



[[Page 17216]]

=======================================================================
-----------------------------------------------------------------------

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

[Notice 97-040]


National Environmental Policy Act; Cassini Mission

AGENCY: National Aeronautics and Space Administration (NASA).

ACTION: Notice of availability of draft supplemental environmental 
impact statement (DSEIS) for the Cassini mission to Saturn and its 
moons.

-----------------------------------------------------------------------

SUMMARY: Pursuant to the National Environmental Policy Act of 1969 
(NEPA), as amended (42 U.S.C. 4321 et seq.), the Council on 
Environmental Quality Regulations for Implementing the Procedural 
Provisions of NEPA (40 CFR Parts 1500-1508), and NASA policy and 
procedures (14 CFR Part 1216, Subpart 1216.3), NASA has prepared and 
issued a DSEIS for the Cassini mission. The DSEIS focuses on updated 
information pertinent to the consequence and risk analyses of potential 
accidents during the launch and cruise phases of the mission. Such 
accidents could result in the release of plutonium dioxide from one or 
more of the three Radioisotope Thermoelectric Generators (RTG's) and 
the approximately 130 Radioisotope Heater Units (RHU's) onboard the 
Cassini spacecraft. The currently planned mission involves the launch 
of the Cassini spacecraft from Cape Canaveral Air Station (CCAS), 
Florida, during the primary launch opportunity that begins in early 
October 1997.

DATES: Comments on the DSEIS must be submitted in writing and received 
by NASA no later than May 27, 1997, or 45 days from the date of 
publication in the Federal Register of the U.S. Environmental 
Protection Agency's notice of availability of the Cassini mission 
DSEIS, whichever is later.

ADDRESSES: Written comments should be addressed to Mr. Mark R. Dahl, 
NASA Headquarters, Code SD, Washington, DC 20546-0001. The DSEIS may be 
reviewed at the following locations:
    (a) NASA Headquarters, Library, Room 1J20, 300 E Street, SW., 
Washington, DC 20546.
    (b) Spaceport U.S.A., Room 2001, John F. Kennedy Space Center, FL 
32899. Please call Lisa Fowler beforehand at 407-867-2497 so that 
arrangements can be made.
    (c) Jet Propulsion Laboratory, Visitors Lobby, Building 249, 4800 
Oak Grove Drive, Pasadena, CA 91109 (818-354-5179).
    In addition, the DSEIS may be examined at the following NASA 
locations by contacting the pertinent Freedom of Information Act 
Office:
    (d) NASA, Ames Research Center, Moffett Field, CA 94035 (415-604-
4190).
    (e) NASA, Dryden Flight Research Center, Edwards, CA 93523 (805-
258-3448).
    (f) NASA, Goddard Space Flight Center, Greenbelt, MD 20771 (301-
286-0730).
    (g) NASA, Johnson Space Center, Houston, TX 77058 (713-483-8612).
    (h) NASA, Langley Research Center, Hampton, VA 23665 (757-864-
2497).
    (i) NASA, Lewis Research Center, 21000 Brookpark Road, Cleveland, 
OH 44135 (216-433-2222).
    (j) NASA, Marshall Space Flight Center, AL 35812 (205-544-0031).
    (k) NASA, Stennis Space Center, MS 39529 (601-688-2164).
    Limited copies of the DSEIS are available, on a first request 
basis, by contacting Mark Dahl at the address or telephone number 
indicated herein.

FOR FURTHER INFORMATION CONTACT:
Mark Dahl, 202-358-1544.

SUPPLEMENTARY INFORMATION: The planned Cassini mission is an 
international cooperative effort of NASA, the European Space Agency, 
and the Italian Space Agency, to explore the planet Saturn and its 
environment. Saturn is the second-largest and second-most massive plant 
in the solar system and has the largest, most visible dynamic ring 
structure of all the planets. The planned mission is an important part 
of NASA's program for exploration of the solar system, the goal of 
which is to understand the system's birth and evolution. The Cassini 
mission would involve a 4-year scientific exploration of Saturn, it's 
atmosphere, moons, rings, and magnetosphere. The Cassini spacecraft 
consists of the Cassini Orbiter and the detachable Huygens Probe. The 
Huygens Probe would be released for a parachute descent into the 
atmosphere of Titan, Saturn's largest moon. The scientific information 
gathered by the Cassini mission could help provide clues to the 
evolution of the solar system and the origin of life on Earth.
    NASA issued the Final Environmental Impact Statement for the 
Cassini Mission in July 1995 (hereinafter the ``EIS'') followed by the 
associated Record of Decision (ROD) to complete preparation of the 
Cassini mission for launch in the October 1997 opportunity, or either 
the secondary or backup opportunities, and to implement the mission.
    The Cassini spacecraft would carry three RTG's that use the heat of 
decay of plutonium dioxide to generate electric power for the 
spacecraft and its instruments. The spacecraft would also use 
approximately 130 RHU's, each containing a small amount of plutonium 
dioxide, to generate heat for controlling the thermal environment of 
the spacecraft and several of its instruments.
    The action selected and documented in the ROD consists of 
completing preparations for and implementing the Cassini mission to 
Saturn and its moons, with a launch of the Cassini spacecraft onboard a 
Titan IV (SRMU)/Centaur. The launch would take place at CCAS during the 
primary launch opportunity that begins in early October 1997 and 
continues into mid-November 1997. A secondary launch opportunity 
extends from the end of November 1997 to early January 1998, with a 
backup opportunity from mid-March to early April 1999, both using the 
Titan IV (SRMU)/Centaur. The primary launch opportunity would employ a 
Venus-Venus-Earth-Jupiter-Gravity-Assist trajectory to Saturn; the 
secondary and backup opportunities would both employ a Venus-Earth-
Earth-Gravity-Assist (VEEGA) trajectory. The above primary launch 
opportunity remains NASA's preferred alternative and Proposed Action 
and would allow the Cassini spacecraft to gather the full science 
return desired to accomplish mission objectives.
    Along with the No-Action alternative (ceasing preparations and not 
implementing the Cassini mission), the EIS evaluated in detail two 
other mission alternatives. The March 1999 alternative would have used 
two Shuttle flights with on-orbit integration of the spacecraft and 
upper stage, followed by injection of the spacecraft into a VEEGA 
trajectory to Saturn. Due to the long lead-time in developing and 
certifying the new upper stage that would be needed to implement it, 
this alternative is no longer considered reasonable. The other mission 
alternative considered in the EIS was the 2001 alternative which would 
use a Titan IV (SRMU)/Centaur to launch the spacecraft from CCAS in 
March 2001 on a Venus-Venus-Venus-Gravity-Assist trajectory. A backup 
opportunity in May 2002 would use a VEEGA trajectory. The 2001 
alternative would require completing development and testing of a new 
high-performance rhenium engine for the spacecraft, as well as adding 
about 20 percent more propellant to the spacecraft. Science returns 
from this alternative would meet the minimum acceptable level for the 
mission.
    The EIS analyses demonstrated that completing preparations for and

[[Page 17217]]

implementing a normal Cassini mission would not significantly impact 
the human environment. The principal concern associated with all 
mission alternatives (except No-Action) was with accidents during 
launch and operation of the mission that have the potential to result 
in a release of plutonium dioxide from the RTG's and/or RHU's onboard 
the spacecraft. In response, NASA and the U.S. Department of Energy 
(DOE), using the best information available at that time, developed an 
array of representative accident scenarios that could potentially 
result in a release of plutonium dioxide from the RTG's. NASA and DOE 
analyzed the representative accident scenarios with respect to the 
consequences and risks. The results of those analyses were presented in 
the Cassini EIS.
    Updated results from the continuing tests and analyses have 
recently become available for NASA review. This updated data indicates 
that there is new information relevant to the environmental impacts of 
the Proposed Action.
    The DSEIS compares the updated data from the ongoing analyses with 
those in the EIS and focuses on the areas where the largest differences 
are estimated. The DSEIS addresses the Proposed Action, the No-Action 
alternative, and the 2001 mission alternative that is still available 
to NASA.
Jeffrey E. Sutton,
Acting Associate Administrator for Management Systems and Facilities.
[FR Doc. 97-9104 Filed 4-8-97; 8:45 am]
BILLING CODE 7510-01-M