100-510: USA-299 , also referred to as USSF-7 and Orbital Test Vehicle 6 ( OTV-6 ), is the third flight of the first Boeing X-37B , an American unmanned vertical-takeoff, horizontal-landing spaceplane . It was launched to low Earth orbit aboard an Atlas V launch vehicle from SLC-41 on 17 May 2020. Its mission designation is part of the USA series . The spaceplane is operated by the Department of
200-589: A spaceplane . The X-37 is operated by the Department of the Air Force Rapid Capabilities Office , in collaboration with United States Space Force , for orbital spaceflight missions intended to demonstrate reusable space technologies . It is a 120-percent-scaled derivative of the earlier Boeing X-40 . The X-37 began as a NASA project in 1999, before being transferred to the United States Department of Defense in 2004. Until 2019,
300-459: A 1.3-inch-thick (33 mm) optical pane, and an external thermal pane. The windows were tinted with the same ink used to make American banknotes . The Space Shuttle orbiter had three sets of landing gear which emerged downwards through doors in the heat shield. As a weight-saving measure, the gear could not be retracted once deployed. Since any premature extension of the landing gear would very likely have been catastrophic (as it opened through
400-671: A modified Boeing 747 airliner called the Shuttle Carrier Aircraft and released for a series of atmospheric test flights and landings. Enterprise was partially disassembled and retired after completion of critical testing. The remaining orbiters were fully operational spacecraft, and were launched vertically as part of the Space Shuttle stack. Columbia was the first space-worthy orbiter; it made its inaugural flight in 1981. Challenger , Discovery , and Atlantis followed in 1983, 1984, and 1985 respectively. In 1986, Challenger
500-472: A modified marking scheme for the shuttle fleet that would be matched by Discovery , Atlantis and Endeavour . The letters "USA" in black above an American flag were displayed on the left wing, with the NASA "worm" logotype in gray centered above the name of the orbiter in black on the right wing. Also, the name of the orbiter was inscribed not on the payload bay doors, but on the forward fuselage just below and behind
600-846: A scaled-up variant of the X-37B, referring to it as the X-37C. This spacecraft was planned to be between 165% and 180% of the size of the X-37B, allowing it to transport up to six astronauts inside a pressurized compartment housed in the cargo bay. The Atlas V was this variant's proposed launch vehicle. In this role, Boeing's X-37C could potentially compete with the corporation's CST-100 Starliner commercial space capsule. As of 2024, with NASA selecting Starliner and SpaceX Crew Dragon , there has been no further announcement to develop X-37C. Data from USAF, Boeing, Air & Space Magazine , and Phys.org General characteristics Performance Space Shuttle orbiter The Space Shuttle orbiter
700-705: A secondary site. In 2010, manufacturing work began on the second X-37B which conducted its maiden mission in March 2011. On 8 October 2014, NASA confirmed that X-37B vehicles would be housed at Kennedy Space Center in Orbiter Processing Facilities (OPF) 1 and 2, hangars previously occupied by the Space Shuttle. Boeing had said the space planes would use OPF-1 in January 2014, and the Air Force had previously said it
800-569: A shuttle flight would be uneconomical. The X-37 was transferred from NASA to the Defense Advanced Research Projects Agency (DARPA) on 13 September 2004. Thereafter, the program became a classified project because of its military applications. DARPA promoted the X-37 as part of the independent space policy that the United States Department of Defense has pursued since the 1986 Challenger disaster . The X-37A vehicle that
900-488: A total of 908 days in orbit. The seventh mission launched on 28 December 2023 on a Falcon Heavy rocket, entering a highly elliptical high Earth orbit . In 1999, NASA selected Boeing Integrated Defense Systems to design and develop an orbital vehicle, built by the California branch of Boeing's Phantom Works . Over a four-year period, a total of $ 192 million was spent on the project, with NASA contributing $ 109 million,
1000-540: Is 60 ft (18 m) by 15 ft (4.6 m), and could transport 24,400 kg (53,800 lb) to 204 km (127 mi), or 12,500 kg (27,600 lb) to the ISS at 407 km (253 mi). The most massive payload launched by the Space Shuttle was the Chandra X-ray Observatory in 1999 at 50,162 lb (22,753 kg), including its Inertial Upper Stage (IUS) and support equipment. The Shuttle
1100-470: Is a reusable robotic spaceplane . It is an approximately 120-percent-scale derivative of the Boeing X-40 , measuring over 29 feet (8.8 m) in length, and features two angled tail fins. The X-37 launches atop an Atlas V 501 or a SpaceX Falcon 9 or Falcon Heavy rocket. The spaceplane is designed to operate in a speed range of up to Mach 25 on its reentry. The technologies demonstrated in
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#17328546488831200-568: Is carried out inside Bays 1 and 2 of the Orbiter Processing Facility (OPF) at Kennedy Space Center in Florida, where the vehicle is loaded with its payload. The X-37 is then placed inside a fairing along with its stage adapter and transported to the launch site. Previous launch sites have included SLC-41 and Kennedy Space Center LC-39A . Landing is done at one of three sites across the US:
1300-474: Is testing a Hall-effect thruster system for Aerojet Rocketdyne . In July 2019, former United States Secretary of the Air Force Heather Wilson explained that when an X-37B was in an elliptic orbit it could, at perigee , use the thin atmosphere to make an orbit change preventing some observers from discovering the new orbit for a while, permitting secret activities. Processing for the X-37
1400-431: Is the spaceplane component of the Space Shuttle , a partially reusable orbital spacecraft system that was part of the discontinued Space Shuttle program . Operated from 1981 to 2011 by NASA , the U.S. space agency, this vehicle could carry astronauts and payloads into low Earth orbit , perform in-space operations, then re-enter the atmosphere and land as a glider , returning its crew and any on-board payload to
1500-538: Is the first time the space plane has been equipped with a service module to carry additional pieces for experiments. OTV-6 was deployed into an orbit with an inclination of approximately 44.60°. OTV-6 landed after a record-breaking 908 days at the Shuttle Landing Facility on November 12, 2022. A rideshare payload for the United States Air Force Academy , FalconSat-8, was deployed from
1600-421: Is the first time the spaceplane has carried a service module, a ring attached to the rear of the vehicle for hosting multiple experiments. The mission hosts more experiments than prior X-37B flights, including two NASA experiments. One is a sample plate evaluating the reaction of select materials to conditions in space. The second studies the effect of ambient space radiation on seeds. A third experiment designed by
1700-1019: The Adler Planetarium in Chicago, Illinois but was later transferred to the Stafford Air & Space Museum in Weatherford, Oklahoma . The Motion Base Simulator was transferred to the Texas A&;M Aerospace Engineering Department in College Station, Texas , and the Guidance and Navigation Simulator went to the Wings of Dreams Aviation Museum in Starke, Florida . NASA also made approximately 7,000 TPS tiles available to schools and universities. Data from General characteristics Performance The cargo bay
1800-554: The Air Force Research Laboratory (AFRL), the small satellite carries five experimental payloads. The spacecraft will test a novel electromagnetic propulsion system, low-weight antenna technology and a commercial reaction wheel to provide attitude control in orbit. According to the United States Air Force Academy, FalconSat-8's experiments include: The mission was completed with the vehicle landing at
1900-572: The Naval Research Laboratory (NRL) transforms solar power into radio frequency microwave energy, then studies transmitting that energy to Earth . The X-37B remains a Department of the Air Force asset, but the newly established U.S. Space Force is responsible for the launch, on-orbit operations, and landing. The X-37B released a small, 136 kg (300 lb) satellite named FalconSat-8 (USA-300) around 28 May 2020. Developed by United States Air Force Academy cadets in partnership with
2000-489: The Shuttle Landing Facility at Kennedy Space Center, Vandenberg Space Force Base , or Edwards Air Force Base . To return to Kennedy Space Center, the X-37 is placed into a payload canister and loaded into a Boeing C-17 cargo plane. Once at Kennedy, the X-37 is unloaded and towed to the OPF, where it is prepared for its next flight. Technicians must wear protective suits due to toxic hypergolic gases. The X-37 Orbital Test Vehicle
2100-458: The U.S. Air Force $ 16 million, and Boeing $ 67 million. In late 2002, a new $ 301 million contract was awarded to Boeing as part of NASA's Space Launch Initiative framework. The aerodynamic design of the X-37 was derived from the larger Space Shuttle orbiter , hence the X-37 has a similar lift-to-drag ratio, and a lower cross range at higher altitudes and Mach numbers compared to DARPA's Hypersonic Technology Vehicle . An early requirement for
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#17328546488832200-481: The Air Force Rapid Capabilities Office and United States Space Force , which considers the mission classified and as such has not revealed the objectives. However an unclassified secondary satellite, FalconSat-8 , was deployed from the X-37B soon after launch. OTV-6 is the third mission for the first X-37B built, and the sixth X-37B mission overall. It flew on an Atlas V in the 501 configuration, and launched from Cape Canaveral Space Launch Complex 41 . This flight
2300-649: The Air Force announced that one experiment flying is the Advanced Structurally Embedded Thermal Spreader II (ASETS-II), which measures the performance of an oscillating heat pipe. The mission was completed with the vehicle landing at the Shuttle Landing Facility on 27 October 2019 at 07:51 UTC. The sixth X-37B mission (OTV-6), U.S. Space Force 7 (formerly known as AFSPC 7), launched on an Atlas V 501 rocket from Cape Canaveral SLC-41 on 17 May 2020 at 13:14:00 UTC. This mission
2400-564: The American flag above the orbiter's name, left-justified rather than centered, on the right wing. The three surviving flight vehicles, Discovery , Atlantis and Endeavour , still bear these markings as museum displays. Enterprise became the property of the Smithsonian Institution in 1985 and was no longer under NASA's control when these changes were made, hence the prototype orbiter still has its 1983 markings and still has its name on
2500-558: The Earth. Six orbiters were built for flight: Enterprise , Columbia , Challenger , Discovery , Atlantis , and Endeavour . All were built in Palmdale, California , by the Pittsburgh , Pennsylvania -based Rockwell International company's North American Aircraft Operations branch. The first orbiter, Enterprise , made its maiden flight in 1977. An unpowered glider, it was carried by
2600-738: The Kennedy Space Center Shuttle Landing Facility , Florida, except STS-3 at the White Sands Space Harbor in New Mexico. Similar special clearances (no-fly zones) were also in effect at potential emergency landing sites, such as in Spain and in West Africa during all launches. When an orbiter landing was carried out at night, the runway was always strongly illuminated with light from floodlights and spotlights on
2700-439: The Shuttle Landing Facility on 12 November 2022 at 10:22 UTC. The fourth flight of second X-37B and seventh overall X-37B mission was planned to be launched on SpaceX's Falcon Heavy on 12 December 2023. This was rescheduled for 28 December 2023, when it was successfully launched at 8:07 pm EST (01:07:00 UTC on December 29). The orbit is higher than any spaceplane, in a highly elliptical HEO orbit. In October 2024, OTV-7
2800-874: The Smithsonian's Steven F. Udvar-Hazy Center , replacing Enterprise which was moved to the Intrepid Museum in New York City . Endeavour went to the California Science Center in Los Angeles arriving on October 14, 2012. Atlantis went to the Kennedy Space Center Visitor Complex in Merritt Island on November 2, 2012. Hundreds of other shuttle artifacts will be put on display at various other museums and educational institutions around
2900-735: The U.S. One of the Crew Compartment Trainer Flight and mid-deck training hardware is on display at the National Museum of the U.S. Air Force , while the other is on display at the JSC. The Full Fuselage Trainer, which includes the payload bay and aft section but no wings, is on display at the Museum of Flight in Seattle, Washington . The Mission Simulation and Training Facility's Shuttle Mission Simulator Fixed Base Simulator originally went to
3000-546: The U.S. Air Force announced that it would develop its own variant of NASA's X-37A. The Air Force version was designated the X-37B Orbital Test Vehicle (OTV). The OTV program was built on earlier industry and government efforts by DARPA, NASA, and the Air Force under the leadership of the Air Force Rapid Capabilities Office in partnership with NASA and the Air Force Research Laboratory . Boeing
3100-504: The U.S. space shuttle, which had automatic landing capability by the mid-1990s, but never tested it. The X-37 is the smallest and lightest orbital spaceplane flown to date; it has a launch mass of around 11,000 pounds (5,000 kg) and is approximately one quarter the size of the Space Shuttle orbiter . On 13 April 2015, the Space Foundation awarded the X-37 team with the 2015 Space Achievement Award "for significantly advancing
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3200-405: The X-37 include an improved thermal protection system , enhanced avionics , an autonomous guidance system and an advanced airframe . The spaceplane's thermal protection system is built upon previous generations of atmospheric reentry spacecraft, incorporating silica ceramic tiles. The X-37's avionics suite was used by Boeing to develop its CST-100 crewed spacecraft. The development of
3300-493: The X-37 was to "aid in the design and development of NASA's Orbital Space Plane , designed to provide a crew rescue and crew transport capability to and from the International Space Station ", according to a NASA fact sheet. The X-37 for NASA was to be powered by one Aerojet AR2-3 engine using storable propellants, providing thrust of 6,600 pounds-force (29.4 kN). The human-rated AR2-3 engine had been used on
3400-566: The X-37A completed a captive-carry flight underneath the White Knight from Mojave Spaceport in Mojave, California . Through the second half of 2005, the X-37A underwent structural upgrades, including the reinforcement of its nose wheel supports. The X-37A's public debut for its first free flight, scheduled for 10 March 2006, was canceled due to an Arctic storm. The next flight attempt, on 15 March 2006,
3500-469: The X-37B a few days into the mission. The satellite provides a platform for the academy's Cadet Space Operations Squadron to test various technologies. Onboard experiments include: Boeing X-37 The Boeing X-37 , also known as the Orbital Test Vehicle ( OTV ), is a reusable robotic spacecraft . It is boosted into space by a launch vehicle , then re-enters Earth's atmosphere and lands as
3600-422: The X-37B could be used as a spy satellite or to deliver weapons from space. The Pentagon subsequently denied claims that the X-37B's test missions supported the development of space-based weapons. In January 2012, allegations were made that the X-37B was being used to spy on China's Tiangong-1 space station module. Former U.S. Air Force orbital analyst Brian Weeden later rejected this claim, emphasizing that
3700-671: The air, and covered in silicon borides and borosilicate glass , with blacker tiles covering the lower surface, and whiter tiles covering the tail, parts of the upper wing and crew cabin surfaces, and the outsides of the payload bay doors. The nose cap, nose landing gear doors, and leading edges were made of reinforced carbon–carbon , which is rayon impregnated with graphite -filled resins and coated in silicon carbide . The upper, white materials that were not in tiles were mostly made of either Nomex felt coated in silicon -rich elastomer or beta cloth , woven silica fibers covered in Teflon . This
3800-403: The arrival of Hurricane Irma . The launch vehicle was a Falcon 9 rocket, and a number of small satellites also shared the ride. The spacecraft was inserted at a higher inclination orbit than previous missions, further expanding the X-37B's envelope. During the flight, the spacecraft modified its orbit using an on-board propulsion system. While the complete payload for OTV-5 is classified,
3900-545: The attitude of the orbiter during most of its re-entry into the Earth's atmosphere – until the air became dense enough that the rudder, elevons and body flap became effective. The orbiter's OMS and RCS fuel is monomethyl hydrazine (CH 3 NHNH 2 ), and the oxidizer is dinitrogen tetroxide (N 2 O 4 ). This particular propellant combination is extremely reactive and spontaneously ignites on contact (hypergolic) with each other. This chemical reaction (4CH 3 NHNH 2 + 5N 2 O 4 → 9N 2 + 4CO 2 + 12H 2 O) occurs within
4000-456: The cockpit windows. This would make the name visible when the orbiter was photographed in orbit with the doors open. Challenger also had black tiles on the tip of its vertical stabilizer much like Columbia , which the other orbiters lacked. In 1983, Enterprise had its wing markings changed to match Challenger , and the NASA "worm" logotype on the aft end of the payload bay doors was changed from gray to black. Some black markings were added to
4100-475: The different orbits of the two spacecraft precluded any practical surveillance flybys. In October 2014, The Guardian reported the claims of security experts that the X-37B was being used "to test reconnaissance and spy sensors, particularly how they hold up against radiation and other hazards of orbit". In November 2016, the International Business Times speculated that the U.S. government
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4200-413: The direction of their thrust. Hence, they steered the entire Space Shuttle, as well as providing rocket thrust towards orbit. The aft fuselage also housed three auxiliary power units (APU). The APUs chemically converted hydrazine fuel from a liquid state to a gas state , powering a hydraulic pump which supplied pressure for all of the hydraulic system, including the hydraulic sub-system that pointed
4300-469: The dual-power NF-104A astronaut training vehicle and was given a new flight certification for use on the X-37 with hydrogen peroxide/ JP-8 propellants. This was reportedly changed to a hypergolic nitrogen-tetroxide/hydrazine propulsion system. The X-37 lands automatically upon returning from orbit and is the third reusable spacecraft to have such a capability, after the Soviet Buran shuttle and
4400-417: The end of the mission. The hydrogen and oxygen for the fuel cells was kept in pairs of cryogenic storage tanks in the mid-fuselage underneath the payload bay liner, and a variable number of such tank sets could be installed (up to five pairs) depending on the requirements of the mission. The three fuel cells were capable of generating 21 kilowatts of power continuously (or a 15-minute peak of 36 kilowatts) with
4500-452: The engine's combustion chamber. The reaction products are then expanded and accelerated in the engine bell to provide thrust. Due to their hypergolic characteristics these two chemicals are easily started and restarted without an ignition source, which makes them ideal for spacecraft maneuvering systems. During the early design process of the orbiter, the forward RCS thrusters were to be hidden underneath retractable doors, which would open once
4600-503: The external tank. Two Orbital Maneuvering System (OMS) thrusters were mounted in two separate removable pods on the orbiter's aft fuselage, located between the SSMEs and the vertical stabilizer. The OMS engines provided significant thrust for course orbital maneuvers , including insertion, circularization, transfer, rendezvous, deorbit, abort to orbit, and to abort once around . At lift-off, two solid rocket boosters (SRBs) were used to take
4700-417: The federally owned Plant 42 complex. Each NASA Space Shuttle designation was composed of a prefix and suffix separated by a dash. The prefix for operational shuttles is OV, for Orbiter Vehicle . The suffix is composed of two parts: the series and the vehicle number; "0" was used for non-flight ready orbiters, and "1" was used for flight-ready orbiters. The vehicle number is sequentially assigned within
4800-527: The final Shuttle flight, STS-135 , on July 21, 2011. In addition to their crews and payloads, the reusable orbiter carried most of the Space Shuttle System 's liquid-propellant rocket system, but both the liquid hydrogen fuel and the liquid oxygen oxidizer for its three main rocket engines were fed from an external cryogenic propellant tank . Additionally, two reusable solid rocket boosters (SRBs) provided additional thrust for approximately
4900-515: The first US autonomous orbital landing onto a runway. This was the first such landing since the Soviet Buran shuttle in 1988. In all, OTV-1 spent 224 days and 9 hours in space. OTV-1 suffered a tire blowout during landing and sustained minor damage to its underside. The second X-37B launched on its inaugural mission, designated OTV-2/ USA-226 , aboard an Atlas V rocket from Cape Canaveral SLC-41 on 5 March 2011 at 22:46 UTC. The mission
5000-527: The first X-37B, OTV-3 was originally scheduled to launch on 25 October 2012, but was postponed because of an engine issue with the Atlas V launch vehicle. It was successfully launched from Cape Canaveral SLC-41 on 11 December 2012 at 18:03 UTC. Once in orbit, the spacecraft was designated USA-240 . Landing occurred at Vandenberg AFB on 17 October 2014 at 16:24 UTC, after a total time in orbit of 674 days and 22 hours. The fourth X-37B mission, OTV-4,
5100-524: The first two minutes of launch. The orbiters themselves did carry hypergolic propellants for their Reaction Control System (RCS) thrusters and Orbital Maneuvering System (OMS) engines. About the size of a McDonnell Douglas DC-9 , the Space Shuttle orbiter resembled an airplane in its design, with a standard-looking fuselage and two double delta wings, both swept wings at an angle of 81 degrees at their inner leading edges and 45 degrees at their outer leading edges. The vertical stabilizer of
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#17328546488835200-550: The flight phases of launching, orbiting , and re-entry. This system also executed any needed orbital maneuvers, including all changes in the orbit's altitude, orbital plane , and eccentricity . These were all operations that required more thrust and impulse than mere attitude control. The forward rockets of the Reaction Control System, located near the nose of the Space Shuttle orbiter, included 14 primary and two vernier RCS rockets. The aft RCS engines were located in
5300-470: The floor of the mid-deck and contained air and water tanks in addition to the carbon dioxide scrubbing system. Three Space Shuttle Main Engines (SSMEs) were mounted on the orbiter's aft fuselage in the pattern of an equilateral triangle . These three liquid-fueled engines could be swiveled 10.5 degrees vertically and 8.5 degrees horizontally during the rocket-powered ascent of the orbiter in order to change
5400-525: The ground, making landing lights on the orbiter unnecessary and also an unneeded spaceflight weight load. A total of 26 landings took place at night, the first being STS-8 in September 1983. The typeface used on the Space Shuttle orbiter was Helvetica . The prototype orbiter Enterprise originally had a flag of the United States on the upper surface of the left wing and the letters "USA" in black on
5500-508: The heat shield layers), the landing gear could only be lowered by manual controls, and not by any automatic system. Similarly, since the Shuttle landed at high speed and could not abort its landing attempt, the gear had to deploy reliably on the first try every time. The gear were unlocked and deployed by triple redundant hydraulics, with the gear doors actuated by mechanical linkages to the gear strut. If all three hydraulic systems failed to release
5600-472: The landing gear uplocks within one second of the release command, pyrotechnic charges automatically cut the lock hooks and a set of springs deployed the gear. During landing, the Shuttle nose wheel could be steered with the rudder pedals in the cockpit. During the construction of Space Shuttle Endeavour , an improved nose wheel steering system was developed which allowed easier and more effective nose wheel steering. After Endeavour 's roll-out,
5700-710: The main doors of OPF-1 were marked with the message "Home of the X-37B" by this point. Most of the activities of the X-37B project are secret. The official Air Force statement is that the project is "an experimental test program to demonstrate technologies for a reliable, reusable, uncrewed space test platform for the U.S. Air Force". The primary objectives of the X-37B are twofold: reusable spacecraft technology and operating experiments which can be returned to Earth. The Air Force states that this includes testing avionics , flight systems, guidance and navigation, thermal protection, insulation, propulsion, and re-entry systems. In May 2010, Tom Burghardt speculated on Space Daily that
5800-622: The navies of the world (though the test orbiter Enterprise , originally to be named " Constitution ", had its name changed after the Star Trek starship , itself named after a series of US Navy ships ), and they were also numbered using the NASA Orbiter Vehicle designation system. Three of the names had also been given to Apollo spacecraft between 1969 and 1972: Apollo 11 Command Module Columbia , Apollo 15 Command Module Endeavour , and Apollo 17 Lunar Module Challenger . While all of
5900-514: The nose, cockpit windows and vertical tail to more closely resemble the flight vehicles, but the name "Enterprise" remained on the payload bay doors as there was never any need to open them. Columbia had its name moved to the forward fuselage to match the other flight vehicles after STS-61-C , during the 1986–1988 hiatus when the shuttle fleet was grounded following the loss of Challenger , but retained its original wing markings until its last overhaul (after STS-93 ), and its unique black chines for
6000-567: The orbiter consuming an average of about 14 kilowatts of that power (leaving 7 kilowatts for the payload). Additionally, the fuel cells provided potable water for the crew during the mission. The orbiter's computer system consisted of five identical IBM AP-101 avionics computers, which redundantly controlled the vehicle's on-board systems. The specialized HAL/S programming language was used for orbiter systems. The orbiters were protected by Thermal Protection System (TPS) materials (developed by Rockwell Space Systems ) inside and out, from
6100-422: The orbiter had a leading edge that was swept back at a 45-degree angle. There were four elevons mounted at the trailing edges of the delta wings, and the combination rudder and speed brake was attached at the trailing edge of the vertical stabilizer . These, along with a movable body flap located underneath the main engines, controlled the orbiter during later stages of reentry . The prime contractor for
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#17328546488836200-525: The orbiter reached space. These were omitted in favor of flush-mounted thrusters for fear that the RCS doors would remain stuck open and endanger the crew and orbiter during re-entry. The orbiter's flight deck or cockpit originally had 2,214 controls and displays, about three times as many as the Apollo command module . The crew cabin consisted of the flight deck, the mid-deck, and the utility area. The uppermost of these
6300-525: The orbiter was Rockwell International, which built the pressurized cabin, thermal protection, forward attitude control system, and forward and aft fuselage in its Downey, California factory, the payload bay doors in its Tulsa, Oklahoma factory, and the body flap in its Columbus, Ohio factory. Subcontractors included Convair in San Diego for the midsection, Fairchild Aircraft in Farmingdale, New York for
6400-453: The orbiter were also located on the mid-deck, as well as the airlock . The airlock had an additional hatch into the payload bay. This airlock allowed two or three astronauts, wearing their Extravehicular Mobility Unit (EMU) space suits, to depressurize before a walk in space ( EVA ), and also to repressurize and re-enter the orbiter at the conclusion of the EVA. The utility area was located under
6500-406: The orbiter's outer surface to the payload bay. The TPS protected it from the cold soak of −121 °C (−186 °F) in space to the 1,649 °C (3,000 °F) heat of re-entry. The tile materials comprising much of the orbiter's outermost layer were mostly air held within near-pure silica fibers, which made it efficient at refractory insulation that absorbed and redirected heat back out into
6600-646: The orbiters were externally practically identical, they had minor differences in their interiors. New equipment for the Orbiters was installed in the same order that they underwent maintenance work, and the newer orbiters were constructed by Rockwell International, under NASA supervision, with some more advanced, lighter in weight, structural elements. Thus, the newer orbiters ( Discovery , Atlantis and Endeavour ) had slightly more cargo capacity than Columbia or Challenger . The Space Shuttle orbiters were assembled at Rockwell's assembly facility in Palmdale, California , at
6700-403: The payload bay doors. With the end of the Shuttle program, plans were made to place the three remaining Space Shuttle orbiters on permanent display. NASA Administrator Charles F. Bolden Jr. announced the disposition location of the orbiters on April 12, 2011, the 50th anniversary of the first human space flight and the 30th anniversary of the first flight of Columbia . Discovery went to
6800-567: The payload bay of the Space Shuttle, but after the Space Shuttle Columbia disaster , it was transferred to a Delta II 7920 . The X-37B was subsequently transferred to a shrouded configuration on the Atlas V rocket, due to concerns over the unshrouded spacecraft's aerodynamic properties during launch. Following their missions, X-37B spacecraft primarily land on a runway at Vandenberg Air Force Base , California, with Edwards Air Force Base as
6900-426: The performance of various materials in space for at least 200 days. The vehicle spent what was then a record-breaking 717 days and 20 hours in orbit before landing at Kennedy Space Center 's Shuttle Landing Facility on 7 May 2017 at 11:47 UTC. The fifth X-37B mission, designated USA-277 in orbit, was launched from Kennedy Space Center Launch Complex 39A on 7 September 2017 at 14:00 UTC, just before
7000-464: The program moved from Mojave to Air Force Plant 42 in Palmdale, California , for the remainder of the flight test program. White Knight continued to be based at Mojave, though it was ferried to Plant 42 when test flights were scheduled. Five additional flights were thought to have been performed, two of which resulted in X-37 releases with successful landings. These two free flights occurred on 18 August 2006 and 26 September 2006. On 17 November 2006,
7100-578: The program was managed by Air Force Space Command . An X-37 first flew during a drop test in 2006; its first orbital mission was launched in April 2010 on an Atlas V rocket, and returned to Earth in December 2010. Subsequent flights gradually extended the mission duration, reaching 780 days in orbit for the fifth mission, the first to launch on a Falcon 9 rocket. The sixth mission launched on an Atlas V on 17 May 2020 and concluded on 12 November 2022, reaching
7200-465: The remainder of its operational life. Beginning in STS-95 (1998), the flight vehicles' markings were modified to incorporate the NASA "meatball" insignia . The "worm" logotype, which the agency had phased out, was removed from the payload bay doors and the "meatball" insignia was added aft of the "United States" text on the lower aft fuselage. The "meatball" insignia was also displayed on the left wing, with
7300-509: The right wing. The name "Enterprise" in black was painted on the payload bay doors just above the forwardmost hinge and behind the crew module; on the aft end of the payload bay doors was the NASA "worm" logotype in gray. Underneath the rear of the payload bay doors on the side of the fuselage just above the wing was the text "United States" in black with a flag of the United States ahead of it. The first operational orbiter, Columbia , originally had
7400-523: The same given spot on Earth every four days, and operated at an altitude that is typical for military surveillance satellites. Such an orbit is also common among civilian LEO satellites, and the spaceplane's altitude was the same as that of the ISS and most other crewed spacecraft. The U.S. Air Force announced a 3–6 December landing on 30 November 2010. As scheduled, the X-37B was de-orbited, reentered Earth's atmosphere, and landed successfully at Vandenberg AFB on 3 December 2010, at 09:16 UTC, conducting
7500-431: The same markings as Enterprise , although the letters "USA" on the right wing were slightly larger and spaced farther apart. Columbia also had black tiles which Enterprise lacked on its forward RCS module, around the cockpit windows, and on its vertical stabilizer. Columbia also had distinctive black chines on the forward part of its upper wing surfaces, which none of the other orbiters had. Challenger established
7600-540: The series, beginning with 1. Therefore, there can never be an OV-100 as it would read "Orbiter Vehicle Series 1 Vehicle 0". Many proposals to build a second generation of orbiters, externally compatible with the current system but internally new, refer to them as "OV-200" or "OV-2xx" in order to differentiate them from the "first generation", the OV-100s. This terminology is informal, and it is unlikely that any Shuttle-derived vehicle built will be given such designation. Challenger
7700-413: The spacecraft called for a total mission delta-v of 7,000 miles per hour (3.1 km/s) for orbital maneuvers. An early goal for the program was for the X-37 to rendezvous with satellites and perform repairs. The X-37 was originally designed to be carried into orbit in the cargo bay of the Space Shuttle, but underwent redesign for launch on a Delta IV or comparable rocket after it was determined that
7800-508: The state of the art for reusable spacecraft and on-orbit operations, with the design, development, test and orbital operation of the X-37B space flight vehicle over three missions totaling 1,367 days in space". The two operational X-37Bs have completed six orbital missions; they have spent a combined 3,774.4 days (10.34 years) in space. The first X-37B launched on its first mission – OTV-1/ USA-212 – on an Atlas V rocket from Cape Canaveral SLC-41 on 22 April 2010 at 23:52 UTC. The spacecraft
7900-507: The system was installed on the other shuttles during their overhauls in the early 1990s. The Space Shuttle orbiter did not carry anti-collision lights , navigational lights , or landing lights , because the orbiter always landed in areas that had been specially cleared by both the Federal Aviation Administration (FAA) and the U.S. Air Force . The orbiter always landed at either Edwards Air Force Base , California or at
8000-430: The three main liquid-fueled rocket engines, under computerized flight control . The hydraulic pressure generated was also used to control all of the orbiter's flight control surfaces (the elevons, rudder, speed brake, etc.), to deploy the landing gear of the orbiter, and to retract the umbilical hose connection doors located near the rear landing gear, which supplied the orbiter's SSMEs with liquid hydrogen and oxygen from
8100-582: The two Orbital Maneuvering System (OMS) pods at the rear of the orbiter, and these included 12 primary (PRCS) and two vernier (VRCS) engines in each pod. The PRCS system provided the pointing control of the Orbiter, and the VRCS was used for fine maneuvering during the rendezvous, docking, and undocking maneuvers with the International Space Station , or formerly with the Russian Mir space station . The RCS also controlled
8200-466: The vehicle to an altitude of roughly 140,000 feet. Electric power for the orbiter's subsystems was provided by a set of three hydrogen-oxygen fuel cells which produced 28 volt DC power and was also converted into 115 volt 400 Hz AC three-phase electric power (for systems that used AC power ). These provided power to the entire Shuttle stack (including the SRBs and ET) from T-minus 3m30s up through
8300-612: The vertical stabilizer, Grumman in Bethpage, New York for the wings, Marquardt Corporation in Van Nuys, California for the attitude control propulsion, Aerojet in Rancho Cordova, California for the orbital insertion and deorbit propulsion, McDonnell Douglas for the surrounding pods, and Rocketdyne in Canoga Park, Los Angeles for the launch and ascent propulsion. Final assembly
8400-411: Was destroyed in a disaster shortly after its 10th launch, killing all seven crew members. Endeavour was built as Challenger ' s successor, and was first launched in 1992. In 2003, Columbia was destroyed during re-entry , leaving just three remaining orbiters. Discovery completed its final flight on March 9, 2011, and Endeavour completed its final flight on June 1, 2011. Atlantis completed
8500-407: Was below the flight deck, was normally equipped with up to three additional stowable seats, depending on the crew requirements of the mission. One mission carried four seats ( STS-61-A ) and NASA drew up plans that were never used to carry up to seven seats in the case of an emergency rescue ( STS-400 ). The galley, toilet, sleep locations, storage lockers, and the side hatch for entering and exiting
8600-404: Was canceled due to high winds. On 24 March 2006, the X-37A flew again but a datalink failure prevented a free flight and the vehicle returned to the ground still attached to its White Knight carrier aircraft. On 7 April 2006, the X-37A made its first free glide flight. During landing, the vehicle overran the runway and sustained minor damage. Following the vehicle's extended downtime for repairs,
8700-404: Was capable of returning approximately 16,000 kg (35,000 lb) of cargo to Earth. The orbiter's maximum glide ratio / lift-to-drag ratio varied considerably with speed, ranging from 1:1 at hypersonic speeds , 2:1 at supersonic speeds , and reaching 4.5:1 at subsonic speeds during approach and landing. Individual Space Shuttle orbiters were named in honor of antique sailing ships of
8800-427: Was carried out at United States Air Force Plant 42 near Palmdale, California . The Reaction Control System (RCS) was composed of 44 small liquid-fueled rocket thrusters and their very sophisticated fly-by-wire flight control system , which utilized computationally intensive digital Kalman filtering . This control system carried out the usual attitude control along the pitch, roll, and yaw axes during all of
8900-707: Was classified and described by the U.S. military as an effort to test new space technologies. On 29 November 2011, the U.S. Air Force announced that it would extend USA-226 beyond the 270-day baseline duration. In April 2012, General William L. Shelton of the Air Force Space Command declared the ongoing mission a "spectacular success". On 30 May 2012, the Air Force stated that the X-37B would land at Vandenberg AFB in June 2012. The spacecraft landed autonomously on 16 June 2012, having spent 468 days and 14 hours in space. The third mission and second flight of
9000-482: Was codenamed AFSPC-5 and designated as USA-261 in orbit. It was the second flight of the second X-37B vehicle. The X-37B launched on an Atlas V rocket from Cape Canaveral SLC-41 on 20 May 2015 at 15:05 UTC. Objectives included a test of Aerojet Rocketdyne's XR-5A Hall-effect thruster in support of the Advanced Extremely High Frequency communications satellite program, and a NASA investigation on
9100-415: Was considering consolidating X-37B operations, housed at Vandenberg Air Force Base in California, nearer to their launch site at Cape Canaveral. NASA also stated that the program had completed tests to determine whether the X-37B, one-fourth the size of the Space Shuttle, could land on the former Shuttle runways. NASA furthermore stated that renovations of the two hangars would be completed by the end of 2014;
9200-464: Was due to undertake aerobraking maneuvers to safely dispose of its service module. The X-37A Approach and Landing Test Vehicle (ALTV) was an initial NASA version of the spacecraft used in drop glide tests in 2005 and 2006. The X-37B is a modified version of the NASA X-37A, built for the U.S. Air Force. Two have been built and used for multiple orbital missions. In 2011, Boeing announced plans for
9300-472: Was especially true in the interior of the payload bay. The orbiter's structure was made primarily from aluminum alloy , although the engine thrust structure was made from titanium alloy . The later orbiters ( Discovery , Atlantis and Endeavour ) substituted graphite epoxy for aluminum in some structural elements in order to reduce weight. The windows were made of aluminum silicate glass and fused silica glass, and comprised an internal pressure pane,
9400-498: Was given to the set of structural components manufactured to replace those used in the construction of Endeavour ; however, the contract for these was canceled shortly afterwards, and they were never completed. The "096" and "097" designators were given to structural test articles that were canceled, but while they exist in some NASA records, the NASA History Office has no official record of STA-096 and STA-097. In addition to
9500-429: Was originally intended to be used as a Structural Test Article (STA), rather than a flight-capable orbiter; as such, the numbering was changed when it was rebuilt. Enterprise , on the other hand, was intended to be rebuilt into a flight-capable orbiter; it was found to be cheaper to rebuild STA-099 than OV-101, so it remained unflown. The designations were not altered, despite these changes in plans. An "OV-106" designation
9600-400: Was placed into low Earth orbit for testing. While the U.S. Air Force revealed few orbital details of the mission, a worldwide network of amateur astronomers claimed to have identified the spacecraft in orbit. On 22 May 2010, the spacecraft was in an inclination of 39.99°, circling the Earth once every 90 minutes on an orbit 249 by 262 miles (401 by 422 km). OTV-1 reputedly passed over
9700-506: Was testing a version of the EmDrive electromagnetic microwave thruster on the fourth flight of the X-37B. In 2009, an EmDrive technology transfer contract with Boeing was undertaken via a State Department TAA and a UK export license, approved by the UK Ministry of Defence . Boeing has since stated that it is no longer pursuing this area of research. The U.S. Air Force has stated that the X-37B
9800-399: Was the flight deck, in which sat the Space Shuttle's commander and pilot in permanently fixed seats with up to two mission specialists seated behind them in stowable seats. The mission specialist in seat four (located behind and between commander and pilot) served as the flight engineer during ascent and landing, tracking information from CAPCOM and calling out milestones. The mid-deck, which
9900-463: Was the prime contractor for the OTV program. The X-37B was designed to remain in orbit for up to 270 days at a time. The Secretary of the Air Force stated that the OTV program would focus on "risk reduction, experimentation, and operational concept development for reusable space vehicle technologies, in support of long-term developmental space objectives". The X-37B was originally scheduled for launch in
10000-509: Was used as an atmospheric drop test glider had no propulsion system. Instead of an operational vehicle's payload bay doors, it had an enclosed and reinforced upper fuselage structure to allow it to be mated with a mothership . In September 2004, DARPA announced that for its initial atmospheric drop tests the X-37A would be launched from the Scaled Composites White Knight , a high-altitude research aircraft. On 21 June 2005,
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