Free to follow every thread. No paywall, no dead ends.
Space Shuttle: the story on HearLore | HearLore
Space Shuttle
In the late 1930s, the German government launched a project called the Amerikabomber, which included a winged rocket design known as the Silbervogel, or silver bird, conceived by Eugen Sänger and mathematician Irene Bredt. This early vision of a reusable spaceplane set the stage for decades of military and civilian development that would eventually culminate in the Space Shuttle. By the 1950s, the United States Air Force had proposed using a reusable piloted glider for reconnaissance and satellite attack missions, leading to the X-20 Dyna-Soar program. Although the Dyna-Soar was canceled in December 1963 due to rising costs and the prioritization of Project Gemini, the research into lifting bodies and aerodynamic characteristics laid the groundwork for future reusable spacecraft. NASA and the Air Force collaborated on testing various lifting bodies, including the M2-F1, M2-F2, M2-F3, HL-10, X-24A, and X-24B, which demonstrated the feasibility of unpowered landings from high altitudes and speeds. These tests proved that a vehicle could generate lift from its fuselage rather than relying solely on wings, a concept that would become central to the Space Shuttle's design. The historical context of the Space Shuttle is rooted in a long lineage of military and scientific experimentation, where the dream of a reusable spaceplane evolved from a theoretical German concept into a tangible American reality.
The Compromise That Shaped A Fleet
On the 24th of September 1966, NASA and the Air Force released a joint study concluding that a new vehicle was required to satisfy their respective future demands, and that a partially reusable system would be the most cost-effective solution. The head of the NASA Office of Manned Space Flight, George Mueller, announced the plan for a reusable shuttle on the 10th of August 1968, and NASA issued a request for proposal for designs of the Integral Launch and Reentry Vehicle on the 30th of October 1968. The Space Shuttle Task Group, under the leadership of U.S. vice president Spiro Agnew, issued a report in September 1969 calling for the development of a space shuttle to bring people and cargo to low Earth orbit, as well as a space tug for transfers between orbits and the Moon, and a reusable nuclear upper stage for deep space travel. Max Faget, a NASA engineer who had worked to design the Mercury capsule, patented a design for a two-stage fully recoverable system with a straight-winged orbiter mounted on a larger straight-winged booster. However, the Air Force Flight Dynamics Laboratory argued that a straight-wing design would not be able to withstand the high thermal and aerodynamic stresses during reentry, and would not provide the required cross-range capability. Additionally, the Air Force required a larger payload capacity than Faget's design allowed. In January 1971, NASA and Air Force leadership decided that a reusable delta-wing orbiter mounted on an expendable propellant tank would be the optimal design for the Space Shuttle. This compromise between the Air Force's need for cross-range capability and NASA's desire for reusability resulted in the unique configuration of the Space Shuttle, which combined the features of a rocket and an aircraft. The development of the Space Shuttle Main Engine remained the responsibility of Rocketdyne, and the contract was issued in July 1971, and updated SSME specifications were submitted to Rocketdyne that April. The following August, NASA awarded the contract to build the orbiter to North American Rockwell, which had by then constructed a full-scale mock-up, later named Inspiration. In August 1973, NASA awarded the external tank contract to Martin Marietta, and in November the solid-rocket booster contract to Morton Thiokol.
The Space Shuttle was a partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration as part of the Space Shuttle program. Its official program name was the Space Transportation System, taken from the 1969 plan led by U.S. vice president Spiro Agnew for a system of reusable spacecraft where it was the only item funded for development. The Space Shuttle was the first operational orbital spacecraft designed for reuse.
When did the Space Shuttle first launch?
The Space Shuttle launched for the first time on the 12th of April 1981, and was piloted by John Young and Robert Crippen. The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982. The Space Shuttle program ran from 1981 to 2011 with a total of 135 missions.
How many Space Shuttle orbiters were built and what happened to them?
Five complete Space Shuttle orbiter vehicles were built and flown on a total of 135 missions from 1981 to 2011. Two were lost in mission accidents: Challenger in 1986 and Columbia in 2003, with a total of 14 astronauts killed. A fifth operational orbiter, Endeavour, was built in 1991 to replace Challenger, and the three surviving operational vehicles were retired from service following Atlantis's final flight on the 21st of July 2011.
Where are the Space Shuttle orbiters currently displayed?
Atlantis is on display at the Kennedy Space Center Visitor Complex in Florida, Discovery is on display at the Steven F. Udvar-Hazy Center in Virginia, Endeavour is on display at the California Science Center in Los Angeles, and Enterprise is displayed at the Intrepid Museum in New York. Components from the orbiters were transferred to the US Air Force, ISS program, and Russian and Canadian governments.
What was the total cost of the Space Shuttle program?
The overall NASA budget of the Space Shuttle program has been estimated to be $221 billion in 2012 dollars. Accounting for the entire Space Shuttle program budget, the per-launch cost was $1.642 billion in 2012. The Space Shuttle fleet's total mission time was 1,323 days.
On the 12th of April 1981, the Space Shuttle launched for the first time, and was piloted by John Young and Robert Crippen. During the two-day mission, Young and Crippen tested equipment on board the shuttle, and found several of the ceramic tiles had fallen off the top side of the Columbia. NASA coordinated with the Air Force to use satellites to image the underside of Columbia, and determined there was no damage. Columbia reentered the atmosphere and landed at Edwards AFB on April 14. The first orbiter, Enterprise, was built in 1976 and used in Approach and Landing Tests, but had no orbital capability. Four fully operational orbiters were initially built: Columbia, Challenger, Discovery, and Atlantis. Of these, two were lost in mission accidents: Challenger in 1986 and Columbia in 2003, with a total of 14 astronauts killed. A fifth operational (and sixth in total) orbiter, Endeavour, was built in 1991 to replace Challenger. The three surviving operational vehicles were retired from service following Atlantis's final flight on the 21st of July 2011. The Space Shuttle was the first operational orbital spacecraft designed for reuse. Each Space Shuttle orbiter was designed for a projected lifespan of 100 launches or ten years of operational life, although this was later extended. At launch, it consisted of the orbiter, which contained the crew and payload, the external tank, and the two solid rocket boosters. Responsibility for the Space Shuttle components was spread among multiple NASA field centers. The KSC was responsible for launch, landing, and turnaround operations for equatorial orbits, the only orbit profile actually used in the program. The U.S. Air Force at the Vandenberg Air Force Base was responsible for launch, landing, and turnaround operations for polar orbits, though this was never used. The Johnson Space Center served as the central point for all Shuttle operations, and the MSFC was responsible for the main engines, external tank, and solid rocket boosters. The John C. Stennis Space Center handled main engine testing, and the Goddard Space Flight Center managed the global tracking network.
The Heart Of The Machine
The Space Shuttle's fly-by-wire control system was entirely reliant on its main computer, the Data Processing System, which controlled the flight controls and thrusters on the orbiter, as well as the ET and SRBs during launch. The DPS consisted of five general-purpose computers, two magnetic tape mass memory units, and the associated sensors to monitor the Space Shuttle components. The original GPC used was the IBM AP-101B, which used a separate central processing unit and input/output processor, and non-volatile solid-state memory. From 1991 to 1993, the orbiter vehicles were upgraded to the AP-101S, which improved the memory and processing capabilities, and reduced the volume and weight of the computers by combining the CPU and IOP into a single unit. Four of the GPCs were loaded with the Primary Avionics Software System, which was Space Shuttle-specific software that provided control through all phases of flight. During ascent, maneuvering, reentry, and landing, the four PASS GPCs functioned identically to produce quadruple redundancy and would error check their results. In case of a software error that would cause erroneous reports from the four PASS GPCs, a fifth GPC ran the Backup Flight System, which used a different program and could control the Space Shuttle through ascent, orbit, and reentry, but could not support an entire mission. The five GPCs were separated in three separate bays within the mid-deck to provide redundancy in the event of a cooling fan failure. After achieving orbit, the crew would switch some of the GPCs functions from guidance, navigation, and control to systems management and payload to support the operational mission. The Space Shuttle was not launched if its flight would run from December to January, as its flight software would have required the orbiter vehicle's computers to be reset at the year change. In 2007, NASA engineers devised a solution so Space Shuttle flights could cross the year-end boundary. Space Shuttle missions typically brought a portable general support computer that could integrate with the orbiter vehicle's computers and communication suite, as well as monitor scientific and payload data. Early missions brought the Grid Compass, one of the first laptop computers, as the PGSC, but later missions brought Apple and Intel laptops.
The Cost Of Reusability
The overall NASA budget of the Space Shuttle program has been estimated to be $221 billion in 2012 dollars. The developers of the Space Shuttle advocated for reusability as a cost-saving measure, which resulted in higher development costs for presumed lower costs-per-launch. During the design of the Space Shuttle, the Phase B proposals were not as cheap as the initial Phase A estimates indicated; Space Shuttle program manager Robert Thompson acknowledged that reducing cost-per-pound was not the primary objective of the further design phases, as other technical requirements could not be met with the reduced costs. Development estimates made in 1972 projected a per-pound cost of payload as low as $1,109 in 2012, but the actual payload costs, not to include the costs for the research and development of the Space Shuttle, were $37,207 in 2012 per pound. Per-launch costs varied throughout the program and were dependent on the rate of flights as well as research, development, and investigation proceedings throughout the Space Shuttle program. In 1982, NASA published an estimate of $260 million in 2012 per flight, which was based on the prediction of 24 flights per year for a decade. The per-launch cost from 1995 to 2002, when the orbiters and ISS were not being constructed and there was no recovery work following a loss of crew, was $806 million. NASA published a study in 1999 that concluded that costs were $576 million in 2012 if there were seven launches per year. In 2009, NASA determined that the cost of adding a single launch per year was $252 million in 2012, which indicated that much of the Space Shuttle program costs are for year-round personnel and operations that continued regardless of the launch rate. Accounting for the entire Space Shuttle program budget, the per-launch cost was $1.642 billion in 2012. The partial reusability of the Space Shuttle was one of the primary design requirements during its initial development. The technical decisions that dictated the orbiter's return and re-use reduced the per-launch payload capabilities. The original intention was to compensate for this lower payload by lowering the per-launch costs and a high launch frequency. However, the actual costs of a Space Shuttle launch were higher than initially predicted, and the Space Shuttle did not fly the intended 24 missions per year as initially predicted by NASA. The improvement of expendable launch vehicles and the transition away from commercial payloads on the Space Shuttle resulted in expendable launch vehicles becoming the primary deployment option for satellites. A key customer for the Space Shuttle was the National Reconnaissance Office responsible for spy satellites. The existence of NRO's connection was classified through 1993, and secret considerations of NRO payload requirements led to lack of transparency in the program. The proposed Shuttle-Centaur program, cancelled in the wake of the Challenger disaster, would have pushed the spacecraft beyond its operational capacity. The fatal Challenger and Columbia disasters demonstrated the safety risks of the Space Shuttle that could result in the loss of the crew. The spaceplane design of the orbiter limited the abort options, as the abort scenarios required the controlled flight of the orbiter to a runway or to allow the crew to egress individually, rather than the abort escape options on the Apollo and Soyuz space capsules. Early safety analyses advertised by NASA engineers and management predicted the chance of a catastrophic failure resulting in the death of the crew as ranging from 1 in 100 launches to as rare as 1 in 100,000. Following the loss of two Space Shuttle missions, the risks for the initial missions were reevaluated, and the chance of a catastrophic loss of the vehicle and crew was found to be as high as 1 in 9. NASA management was criticized afterwards for accepting increased risk to the crew in exchange for higher mission rates. Both the Challenger and Columbia reports explained that NASA culture had failed to keep the crew safe by not objectively evaluating the potential risks of the missions.
The Final Descent And The Last Flight
On the 8th of July 2011, STS-135 launched, and landed at the KSC on the 21st of July 2011, at 5:57 a.m. EDT. From then until the launch of Crew Dragon Demo-2 on the 30th of May 2020, the US launched its astronauts aboard Russian Soyuz spacecraft. Following each orbiter's final flight, it was processed to make it safe for display. The OMS and RCS systems used presented the primary dangers due to their toxic hypergolic propellant, and most of their components were permanently removed to prevent any dangerous outgassing. Atlantis is on display at the Kennedy Space Center Visitor Complex in Florida, Discovery is on display at the Steven F. Udvar-Hazy Center in Virginia, Endeavour is on display at the California Science Center in Los Angeles, and Enterprise is displayed at the Intrepid Museum in New York. Components from the orbiters were transferred to the US Air Force, ISS program, and Russian and Canadian governments. The engines were removed to be used on the Space Launch System. The Space Shuttle fleet's total mission time was 1,323 days. The Space Shuttle was a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration as part of the Space Shuttle program. Its official program name was the Space Transportation System, taken from the 1969 plan led by U.S. vice president Spiro Agnew for a system of reusable spacecraft where it was the only item funded for development. The first of four orbital test flights occurred in 1981, leading to operational flights beginning in 1982. Five complete Space Shuttle orbiter vehicles were built and flown on a total of 135 missions from 1981 to 2011. They launched from the Kennedy Space Center in Florida. Operational missions launched numerous satellites, interplanetary probes, and the Hubble Space Telescope, conducted science experiments in orbit, participated in the Shuttle-Mir program with Russia, and participated in the construction and servicing of the International Space Station. The Space Shuttle was the first operational orbital spacecraft designed for reuse. Each Space Shuttle orbiter was designed for a projected lifespan of 100 launches or ten years of operational life, although this was later extended. At launch, it consisted of the orbiter, which contained the crew and payload, the external tank, and the two solid rocket boosters. Responsibility for the Space Shuttle components was spread among multiple NASA field centers. The KSC was responsible for launch, landing, and turnaround operations for equatorial orbits, the only orbit profile actually used in the program. The U.S. Air Force at the Vandenberg Air Force Base was responsible for launch, landing, and turnaround operations for polar orbits, though this was never used. The Johnson Space Center served as the central point for all Shuttle operations, and the MSFC was responsible for the main engines, external tank, and solid rocket boosters. The John C. Stennis Space Center handled main engine testing, and the Goddard Space Flight Center managed the global tracking network.