Seven astronauts are scheduled to fly April 3 aboard the Space Shuttle Columbia, on the mission designated STS-83/MSL-1 -- the first Microgravity Science Laboratory. During the 16-day flight, microgravity sciences experiments will be conducted in a Spacelab module housed in Columbia's cargo bay.

The Marshall Center manages the mission for NASA.

MSL-1, which brings together many of the partners of the International Space Station, will use new and existing facilities to conduct science experiments that researchers say may someday enhance the quality of life on Earth.

The mission also will serve as a test-bed and means of validating new ways to conduct experiments in space. Using Spacelab as a transition vehicle, MSL-1 will test hardware, facilities and procedures to be used on the International Space Station.

Briefings on the mission will begin at 8:30 a.m. CST at Johnson Center. An overview of the mission will be provided by Lead Flight Director Rob Kelso of Johnson. At 9:30 a.m., briefings will switch to Marshall for an MSL-1 science overview. The briefings will conclude at 1 p.m. at Johnson with the crew news conference.

All briefings will be transmitted on NASA Television with two-way question-and-answer capability from participating NASA centers.

Following is the briefing schedule:

8:30 a.m. - 9:30 a.m. Mission Overview (originating from Johnson)

Rob Kelso, Lead Flight Director

9:30 a.m. - 11 a.m. MSL-1 Science Briefing (originating from Marshall)

Teresa B. Vanhooser, Marshall Center, MSL-1 Mission Manager;

Dr. Michael B. Robinson, Marshall Center, MSL-1 Mission Scientist;

Dr. Forman Williams, University of California, San Diego;

Dr. Ivan Egry, DLR (German Aerospace Research Establishment), Cologne, Germany;

Ms. Misako Uchida, Ishikawajima-Harima Heavy Industries, Tokyo, Japan.

11 a.m. NASA TV Video File

11:30 a.m. - Noon Cryogenic Flexible Diode heat pipe experiment briefing (originating from Johnson)

Marko Stoyanof, Goddard Space Flight Center

1 p.m. - 2:30 p.m. STS-83 Crew News Conference (originating from Johnson)

James D. Halsell Jr., Commander;

Susan Leigh Still, Pilot;

Janice E. Voss, Mission Specialist/Payload Commander;

Michael L. Gernhardt, Mission Specialist;

Donald A. Thomas, Mission Specialist;

Roger K. Crouch, Payload Specialist;

Gregory Linteris, Payload Specialist.

Effective March 15, NASA Television is carried on the GE-2 satellite, Transponder 9C, at 85 degrees West longitude, vertical polarization, with a frequency of 3880 Mhz, and audio of 6.8 Mhz.