When its mission was complete, the orbiter would reenter the Earth's atmosphere and land like a glider at either the Kennedy Space Center or Edwards Air Force Base.

The Shuttle was originally conceived of and presented to the public in 1972 as a 'Space Truck' which would, among other things, be used to build a United States space station in low Earth orbit during the 1980s and then be replaced by a new vehicle by the early 1990s.

The first experimental orbiter, Enterprise, was a high-altitude glider, launched from the back of a specially modified Boeing 747, only for initial atmospheric landing tests (ALT).

All of this was taking place in the midst of other NASA teams proposing a wide variety of post-Apollo missions, a number of which would cost as much as Apollo or more.

The weather criteria used for launch included, but were not limited to: precipitation, temperatures, cloud cover, lightning forecast, wind, and humidity.

In the course of 135 missions flown, two orbiters (Columbia and Challenger) suffered catastrophic accidents, with the loss of all crew members, totaling 14 astronauts.

For missions beyond low Earth orbit, NASA is building the Space Launch System and the Orion spacecraft, part of the Artemis program.

[15] In 2010, the incremental cost per flight of the Space Shuttle was $409 million, or $14,186 per kilogram ($6,435 per pound) to low Earth orbit (LEO).

[23][24][25] In the course of 135 missions flown, two orbiters were destroyed, with loss of crew totalling 14 astronauts: There was also one abort-to-orbit and some fatal accidents on the ground during launch preparations.

Close-up video footage of Challenger during its final launch on January 28, 1986, clearly shows that the problems began due to an O-ring failure on the right solid rocket booster (SRB).

The hot plume of gas leaking from the failed joint caused the collapse of the external tank, which then resulted in the orbiter's disintegration due to high aerodynamic stress.

Endeavour (OV-105) was built to replace Challenger (using structural spare parts originally intended for the other orbiters) and delivered in May 1991; it was first launched a year later.

The Shuttle program operated accident-free for seventeen years and 88 missions after the Challenger disaster, until Columbia broke up on reentry, killing all seven crew members, on February 1, 2003.

As Columbia reentered the atmosphere at the end of an otherwise normal mission, hot gas penetrated the wing and destroyed it from the inside out, causing the orbiter to lose control and disintegrate.

After the Columbia disaster, the International Space Station operated on a skeleton crew of two for more than two years and was serviced primarily by Russian spacecraft.

The Columbia Accident Investigation Board, in its report, noted the reduced risk to the crew when a Shuttle flew to the International Space Station (ISS), as the station could be used as a safe haven for the crew awaiting rescue in the event that damage to the orbiter on ascent made it unsafe for reentry.

Prior to STS-114, NASA Administrator Sean O'Keefe declared that all future flights of the Space Shuttle would go to the ISS, precluding the possibility of executing the final Hubble Space Telescope servicing mission which had been scheduled before the Columbia accident, despite the fact that millions of dollars worth of upgrade equipment for Hubble were ready and waiting in NASA warehouses.

On October 31, 2006, NASA announced approval of the launch of Atlantis for the fifth and final shuttle servicing mission to the Hubble Space Telescope, scheduled for August 28, 2008.

As Atlantis was prepared for the final launch-on-need mission, the decision was made in September 2010 that it would fly as STS-135 with a four-person crew that could remain at the ISS in the event of an emergency.

Enterprise was moved to New York City in April 2012 to be displayed at the Intrepid Museum, whose Space Shuttle Pavilion opened on July 19, 2012.

[32] On October 14, 2012, Endeavour completed an unprecedented 12 mi (19 km) drive on city streets from Los Angeles International Airport to the California Science Center, where it has been on display in a temporary hangar since late 2012.

Once moved, it will be permanently displayed in launch configuration, complete with genuine solid rocket boosters and external tank.

[37] The Rockwell passenger module had two decks, four seats across on top and two on the bottom, including a 25-inch (63.5 cm) wide aisle and extra storage space.

[37] Another proposal was based on the Spacelab habitation modules, which provided 32 seats in the payload bay in addition to those in the cockpit area.

Some passenger modules used hardware similar to existing equipment, such as the tunnel,[40] which was also needed for Spacehab and Spacelab During the three decades of operation, various follow-on and replacements for the STS Space Shuttle were partially developed but not finished.

[54] During the mission, an uncrewed Orion capsule spent 10 days in a 57,000-kilometer (31,000-nautical-mile) distant retrograde orbit around the Moon before returning to Earth.

[55] Artemis 2, the first crewed mission of the program, will launch four astronauts in 2024[56] on a free-return flyby of the Moon at a distance of 8,520 kilometers (4,600 nautical miles).

[59] Artemis 3 is planned to launch in 2025 aboard a SLS Block 1 rocket and will use the minimalist Gateway and expendable lander to achieve the first crewed lunar landing of the program.

[66][28]: III–489–490 The Space Shuttle was originally intended as a launch vehicle to deploy satellites, which it was primarily used for on the missions prior to the Challenger disaster.

NASA's pricing, which was below cost, was lower than expendable launch vehicles; the intention was that the high volume of Space Shuttle missions would compensate for early financial losses.