National Environmental Policy Act; Cassini Mission

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

[Notice 97-090]

National Environmental Policy Act; Cassini Mission

AGENCY: National Aeronautics and Space Administration (NASA).

ACTION: Notice of availability of final supplemental environmental

impact statement (FSEIS) for the Cassini Mission to Saturn and its

moons.

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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 an FSEIS for the Cassini Mission. The FSEIS focuses on the most

recently available information pertinent to the risk analyses of

potential accidents during the launch and cruise phases of the mission.

Certain accidents could potentially result in some release of plutonium

dioxide from one or more of the three Radioisotope Thermoelectric

Generators (RTG's) and the 129 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: NASA will take no final action on the proposed launch of the

Cassini Mission before August 4, 1997, or 30 days form the date of

publication in the Federal Register of the U.S. Environmental

Protection Agency's notice of availability of the Cassini Mission

FSEIS, whichever is later.

ADDRESSES: The FSEIS 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 FSEIS 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).

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(h) NASA, Langley Research Center, Hampton, VA 23655 (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 (202-544-0031).

(k) NASA, Stennis Space Center, MS 39529 (601-688-2164).

Limited copies of the FSEIS are available, on a first request

basis, by contacting Mark R. Dahl at the address or telephone number

indicated below.

FOR FURTHER INFORMATION CONTACT:

Mr. Mark R. Dahl, NASA Headquarters, Code SD, Washington, DC 20546-

0001; telephone 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

planet 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, its

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 129

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 associated with the

EIS 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 1997, 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 rehenium engine for, 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 results from the safety risk analyses have recently become

available. The FSEIS compares this recent best available information

with that presented in the EIS. The FSEIS addresses the Proposed

Action, the No-Action alternative, and the 2001 mission alternative

(which is still available to NASA).

Comments on the draft supplemental environmental impact statement

were solicited from Federal, State and local agencies, organizations,

and members of the general public through: (a) notices published in the

Federal Register--NASA notice on April 9, 1997, (62 FR 17216) and U.S.

Environmental Protection Agency notice on April 11, 1997, (62 FR

17810); and (b) direct mailings to interested parties. Comments

received have been addressed in the FSEIS.

Benita A. Cooper,

Associate Administrator for Management Systems and Facilities.

[FR Doc. 97-17404 Filed 7-2-97; 8:45 am]

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