The first class of space shuttle astronauts were inducted into the U.S. Astronaut Hall of Fame on Saturday at Kennedy Space Center as veteran commanders Robert Crippen, Joe Engle, Richard Truly and Rick Hauck took their place along side Mercury, Gemini, Apollo, Skylab and Apollo-Soyuz fliers.

Marking the largest contingent of former astronauts ever to assemble on Florida's Space Coast, more than 30 space travelers were in attendance to pay tribute to the inductees.

The stage is filled with the members of the U.S. Hall of Fame at Kennedy Space Center on Saturday. Photo: Spaceflight Now/NASA TV

Given the large number of shuttle astronauts, it was decided to narrow the list of candidates for the Hall of Fame's first selection to pioneers of the space shuttle program who flew in 1981 through 1983.

Twenty-one were eligible, and their names were submitted to a committee of former NASA flight directors and officials, space journalists, a space historian and the director of the Smithsonian's National Air & Space Museum. The committee was appointed by the Astronaut Scholarship Foundation.

They voted their preferences on a 10-9-8-7-6-5-4-3-2-1 basis and submitted their ballots to the foundation, which decided to select the four top vote-getters -- Crippen, Engle, Truly and Hauck -- who came out on top well above the others, the foundation said.

The shuttle inductees join the 44 astronauts already in the Hall of Fame.

Robert Crippen was selected as an astronaut for the Air Force's Manned Orbiting Laboratory program in October 1966. When that space station effort was cancelled, Crippen became a NASA astronaut in September 1969. His first space flight was as pilot of the maiden space shuttle mission in April 1981 aboard Columbia.

Crippen became a frequent space traveler over the following three years by serving as commander on three shuttle flights all aboard the orbiter Challenger -- STS-7 in June 1983 with a crew that included the first woman astronaut; STS-41C in April 1984 that featured the first in-space repair of an orbiting satellite; and STS-41G in October 1984 that launched an Earth research satellite.

A fifth flight was scheduled for Crippen but it was cancelled. He was slated to command the first shuttle mission from Vandenberg Air Force Base in California in the summer of 1986. However, the site was abandoned after the Challenger accident. Crippen moved into NASA management through the early 1990s before leaving the space agency for the private sector.

Joe Engle made 16 flights in the X-15 rocket plane before becoming a NASA astronaut in April 1966. He was commander of one of two crews that flew the space shuttle Approach and Landing Test flights from June to October 1977 using Enterprise.

Engle was commander of the second shuttle mission in November 1981 aboard Columbia. He served as Deputy Associate Administrator for manned space flight for eight months in 1982, then returned to flight status. His second and final shuttle mission was as commander of Discovery's STS-51I flight in August/September 1985 that deployed three communications satellites and retrieved, repaired and redeployed a wayward military communications spacecraft.

Richard Truly was picked in 1965 as an astronaut for the Manned Orbiting Laboratory. Like Crippen, Truly moved over to the NASA astronaut corps. in 1969. Truly served as pilot to Engle during the Approach and Landing Tests on Enterprise and on STS-2 in 1981.

Truly returned to space in 1983 as commander of Challenger on the STS-8 mission, which featured the first night launch and landing for the shuttle program.

After leaving NASA to become the first commander of the Naval Space Command, he returned to the space agency after the Challenger accident 1986 to oversee the rebuilding of the shuttle program. In 1989, President George Bush selected Truly to be the NASA Administrator, a post he held for nearly three years.

Frederick "Rick" Hauck was selected by NASA to be an astronaut in January 1978. His first flight was as pilot on Challenger's STS-7 mission along with Crippen.

Hauck served as commander on Discovery's STS-51A mission in November 1984 that deployed two commercial communications satellites and retrieved two others stranded in worthless orbits and returned them to Earth. His final flight was as commander of America's return to space following the Challenger accident on STS-26 in September 1988.

The Astronaut Hall of Fame is located just outside the Titusville gate to the Kennedy Space Center.

You can watch the induction ceremony and hear from the astronauts via our Spaceflight Now Plus service. If you aren't a subscriber yet, click here.