The first of two Mars Exploration Rovers, MER-A, is targeted for
launch no earlier than Sunday, June 8 at 2:05:55 p.m. EDT. Liftoff will
occur aboard a Boeing Delta II launch vehicle from Pad A at Space Launch
Complex 17 on Cape Canaveral Air Force Station. A second launch opportunity
exists at 2:44:07 p.m. EDT, if necessary.

Should launch be delayed by 24 hours, the two launch times
available are 2:02:23 p.m. and 2:40:30 p.m. EDT. The planetary launch period
window extends through June 19. The second of the two rovers, MER-B, is
scheduled to launch June 25.

MER-A will reach Mars on Jan. 4, 2004, and MER-B on Jan. 25. The
two MER missions seek to determine the history of climate and water at two
sites on Mars where conditions may once have been favorable to life. Both
rovers are identical. Each rover carries five scientific instruments
including a panoramic camera and microscope, plus a rock abrasion tool that
will grind away the outer surfaces of rocks to expose their interiors for
examination. The rovers each weigh approximately 400 pounds. They will
navigate themselves around obstacles as they drive across the Martian
surface, traveling up to about 130 feet each Martian day. Each rover’s
prime mission is planned to last three months on Mars.

MER SCIENCE BRIEFING AND MISSION BRIEFING

On Friday, June 6 at 2 p.m., a MER science briefing will be held at the KSC
News Center. Participating will be:

Dr. Ed Weiler, Associate Administrator for Space Science,
NASA Headquarters

Dr. Jim Garvin, Mars lead scientist
NASA Headquarters

Dr. Cathy Weitz, MER program scientist
NASA Headquarters

Dr. Joy Crisp, MER project scientist
Jet Propulsion Laboratory

Dr. Steve Squyres, MER principal investigator
Cornell University

Immediately following the science briefing, a mission briefing will be held.
Participating will be:

Dr. Firouz Naderi, Mars exploration program manager
Jet Propulsion Laboratory

David Lavery, MER program director
NASA Headquarters

Peter Theisinger, MER project manager
Jet Propulsion Laboratory

Rob Manning, MER entry, descent and landing development manager
Jet Propulsion Laboratory

ROVER NAMES TO BE ANNOUNCED IN SPECIAL PRESS BRIEFING

A special event will be held on Saturday, June 7 at 12:30 p.m. at
the KSC News Center to announce the names chosen by NASA for the two MER
rovers. The names were selected from more than 9,000 student entries, and
the winning student will be introduced.

PRELAUNCH PRESS CONFERENCE

The prelaunch press conference is scheduled for Saturday, June 7 at
1 p.m. EDT in the KSC News Center auditorium and will be carried live on
NASA Television. Participating in the briefing will be:

Orlando Figueroa, Mars exploration program director
NASA Headquarters

Omar Baez, NASA launch director
NASA John F. Kennedy Space Center

Kris Walsh, director of NASA programs
Boeing Expendable Launch Systems

Peter Theisinger, Mars Exploration Rover project manager
Jet Propulsion Laboratory

Joel Tumbiolo, Launch Weather Officer
45th Weather Squadron, Cape Canaveral Air Force Station

ACCREDITATION

Media who wish to cover the launch of MER-A including the science
briefing, mission briefing, prelaunch press conference and post-launch press
conference should send a letter of request to the NASA-KSC News Center on
news organization letterhead. It should include full legal name, Social
Security Number, birth date, birthplace and country of citizenship.
Accreditation requests must be received by the close of business on
Thursday, June 5. Letters may be faxed to 321-867-2692 or addressed to:

MER-A Launch Accreditation
NASA XA-E1
Kennedy Space Center, FL 32899

Badges may be obtained at Gate 3 on State Road 405, just east of
U.S. 1 south of Titusville Monday through Friday between 6 a.m. and 5 p.m.
On launch day, Sunday, June 8, badges to cover the MER-A launch from Press
Site 1 will be available starting at 12 noon and issued at the Pass and
Identification Building on SR 401 outside Gate 1 of Cape Canaveral Air Force
Station. Proof of identification and news media affiliation will be
required.

Departure on launch day from the Gate 1 Pass and Identification
Building for Press Site 1 will be at 12:30 p.m. After launch, media will be
escorted back to Gate 1 or to the post-launch press conference. An escort
is required for all areas of the Kennedy Space Center and Cape Canaveral Air
Force Station. For further information on MER-A launch accreditation,
contact Diana Boles, Bruce Buckingham or George Diller at the NASA-KSC News
Center at 321/867-2468.

L-1 DAY SET UP OF REMOTE CAMERAS

Media wishing to establish remote cameras at the launch pad should
meet at the Gate 1 Pass and Identification Building of Cape Canaveral Air
Force Station on State Road 401 on Saturday, June 7, at 2:30 p.m. to be
escorted to Launch Complex 17.

LAUNCH DAY PAD PHOTO OPPORTUNITY

A photo opportunity at Launch Complex 17 of the Delta II/MER-A
launch vehicle on the pad will be provided on the morning of launch day upon
rollback of the mobile service tower. Media wishing to attend should be at
the Gate 1 Pass and Identification Building of Cape Canaveral Air Force
Station on SR 401 at 5 a.m.

POST-LAUNCH PRESS CONFERENCE

A post-launch press conference will be held at the NASA News
Center and is targeted to begin at 3:45 p.m. if launch occurs on the first
opportunity or at 4:30 p.m. if launch occurs on the second opportunity. In
order to cover the post-launch press conference, media representatives must
already possess a permanent KSC picture badge, or have applied in advance
for their launch accreditation and been issued a picture badge. Once
issued, these badges will be valid for all planned press conferences at the
NASA News Center.

These badges can only be issued from the Gate 3 Pass and Identification
building on SR 405 south of Titusville, just east of U.S. 1 and obtained
between 8 a.m. and 5 p.m. on Friday, June 6. They will not be available from
Gate 1 on Cape Canaveral Air Force Station.

There will be a special caravan of news media vehicles that will
be escorted from Press Site 1 to the NASA News Center at KSC following
launch for those desiring to attend the post-launch press conference.

PRESS SITE OPERATING HOURS

On launch day, Sunday, June 8, the NASA News Center at KSC will be open from
8 a.m. to 6:30 p.m.

NASA TELEVISION COVERAGE, “V” CIRCUITS, AND LAUNCH STATUS

NASA Television will carry the mission briefings beginning at 2 p.m.
on Friday, June 6, and the prelaunch press conference beginning at 1 p.m. on
Saturday, June 7. The post-launch press conference will also be carried. A
two-way question-and-answer capability will be available from other NASA
field centers.

On launch day, Sunday, June 8, countdown coverage will begin at
12:15 p.m. Coverage will conclude after acquisition of the spacecraft by
the Deep Space Network approximately one hour after launch, at which time
the spacecraft’s initial state of health will be reported.

NASA Television is available on satellite GE-2, transponder 9C,
located at 85 degrees West longitude. Information about the MER missions is
available on-line at: http://mars.jpl.nasa.gov/mer/

Audio only of NASA Television coverage of the prelaunch news
conference and launch commentary will be available on the “V” circuits which
may be dialed directly at 321/867-1220, 867-1240, 867-1260, 867-7135.

The NASA-KSC News Center codaphone will carry recorded MER-A pre-launch
status reports beginning at L-3 days, Thursday, June 5, and may be dialed at
321-867-2525.

“NASA DIRECT!” WEB COVERAGE

The Kennedy Space Center web will celebrate the launch of MER-A with the
debut of its Expendable Launch Vehicle (ELV) mission coverage, including
special webcasts on NASA Direct!

For more information on the MER web activities, go to http://www.ksc.nasa.gov/elvnew/mera/index.htm

For a detailed NASA Direct! event calendar, go to: http://www.ksc.nasa.gov/nasadirect/index.htm