Curt Brown, Jr. (Lieutenant Colonel, USAF)

STS-103 will be Commander Curt Brown's sixth Shuttle mission, and his third as commander. He led STS-95 in 1998 (which carried several GSFC payloads) and STS-85 in 1997, and he served as pilot aboard STS-77 in 1996, STS-66 in 1994, and STS-47 in 1992.

Jean-Francois Clervoy

SM3A is Jean-Francois Clervoy's (ESA) third trip to space: In 1994, he operated the robotic arm aboard STS-66 to deploy the CRISTA-SPAS atmospheric satellite, and in 1997, he visited the Russian Mir Space Station aboard STS-84.

C. Michael Foale (Ph.D.)

Five-time shuttle veteran Michael Foale flew aboard STS-45 in 1992, STS-56 in 1993, and the STS-63 rendezvous with MIR in 1995. STS-84 dropped him off at MIR in 1997 for a four-month stay and STS-86 returned him to Earth. Foale has spent over 160 days in space, including 10.5 hours of spacewalking.

John Grunsfeld (Ph.D.)

Fellow spacewalker John Grunsfeld served on two earlier missions, the 1995 Astro Observatory mission aboard STS-67 and the fifth mission to MIR on STS-81 in 1997.

Scott Kelly (Lieutenant Commander, USN)

Pilot -the identical twin of astronaut Mark Kelly-is a first-time space traveler. Scott Kelly is a Navy test and fighter pilot. He has logged over 2,000 flight hours in more than 30 different aircraft.

Claude Nicollier

Claude Nicollier (ESA) is another seasoned Hubble crewmember: He controlled the Shuttle's robotic arm aboard STS-61, the HST First Servicing Mission in 1993. He also served aboard STS-46 in 1992 and STS-75 in 1996.

Steven L. Smith

Payload Commander Steven L. Smith will be in charge of this servicing work. He is a veteran of two space flights, STS-68 in 1994 and STS-82 in 1997. On STS-82, the HST Second Servicing Mission, Smith performed three spacewalks.