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146-409: In the post-war era, the division began to diversify and made major contributions to the development of synthetic aperture radar . In 1963 they became Goodyear Aerospace, with major product lines in radar, aircraft canopies, bulletproof glass, a number of spacecraft related products, and the unique Goodyear Inflatoplane . A 1986 hostile takeover attempt of the parent company by James Goldsmith led to

292-408: A 2D sinusoid at a given frequency without distortion while minimizing the variance of the noise of the resulting image. The purpose is to compute the spectral estimate efficiently. Spectral estimate is given as where R is the covariance matrix, and a ω 1 , ω 2 ∗ {\displaystyle a_{\omega _{1},\omega _{2}}^{*}}

438-492: 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. 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,

584-497: A crewed spaceflight engineer on both STS-51-C and STS-51-J to serve as a military representative for a National Reconnaissance Office payload. A Space Shuttle crew typically had seven astronauts, with STS-61-A flying with eight. The crew compartment comprised three decks and was the pressurized, habitable area on all Space Shuttle missions. The flight deck consisted of two seats for the commander and pilot, as well as an additional two to four seats for crew members. The mid-deck

730-413: A fixed antenna size and orientation, objects which are further away remain illuminated longer – therefore SAR has the property of creating larger synthetic apertures for more distant objects, which results in a consistent spatial resolution over a range of viewing distances. To create a SAR image, successive pulses of radio waves are transmitted to "illuminate" a target scene, and the echo of each pulse

876-467: A future reusable shuttle: Class I would have a reusable orbiter mounted on expendable boosters, Class II would use multiple expendable rocket engines and a single propellant tank (stage-and-a-half), and Class III would have both a reusable orbiter and a reusable booster. In September 1969, the Space Task Group, under the leadership of U.S. Vice President Spiro Agnew , issued a report calling for

1022-598: A glider. Its three-part fuselage provided support for the crew compartment, cargo bay, flight surfaces, and engines. The rear of the orbiter contained the Space Shuttle Main Engines (SSME), which provided thrust during launch, as well as the Orbital Maneuvering System (OMS), which allowed the orbiter to achieve, alter, and exit its orbit once in space. Its double- delta wings were 18 m (60 ft) long, and were swept 81° at

1168-588: A massive restructuring of Goodyear prompted by the hostile takeover attempt by James Goldsmith and the Hanson Trust . The Goodyear name disappeared and became the defense systems unit of Loral. The defense systems unit of Loral was acquired by Lockheed Martin in 1993, including intellectual property surrounding the now-retired Goodyear Blimp designs (GZ-20 and GZ-22). While owning the designs, Lockheed Martin does not manufacture airships. Synthetic aperture radar Synthetic-aperture radar ( SAR )

1314-471: A massive restructuring to build capital to buy Goldsmith out. Goodyear Aerospace was sold to Loral in 1987, which in turn sold their non-satellite operations with the defense products purchased by Lockheed Martin in 1993. Goodyear's aerospace operations began with the Goodyear Tire & Rubber Co.’s Aeronautics Department. As part of the settling of war reparations with Germany after World War I,

1460-482: A mobile platform for astronauts conducting an EVA. The RMS was built by the Canadian company Spar Aerospace and was controlled by an astronaut inside the orbiter's flight deck using their windows and closed-circuit television. The RMS allowed for six degrees of freedom and had six joints located at three points along the arm. The original RMS could deploy or retrieve payloads up to 29,000 kg (65,000 lb), which

1606-484: A pair of recoverable solid rocket boosters (SRBs), and the expendable external tank (ET) containing liquid hydrogen and liquid oxygen . The Space Shuttle was launched vertically , like a conventional rocket, with the two SRBs operating in parallel with the orbiter's three main engines , which were fueled from the ET. The SRBs were jettisoned before the vehicle reached orbit, while the main engines continued to operate, and

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1752-534: A partial-pressure version of the high-altitude pressure suits with a helmet. In 1994, the LES was replaced by the full-pressure Advanced Crew Escape Suit (ACES), which improved the safety of the astronauts in an emergency situation. Columbia originally had modified SR-71 zero-zero ejection seats installed for the ALT and first four missions, but these were disabled after STS-4 and removed after STS-9 . The flight deck

1898-530: 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 August 10, 1968. NASA issued a request for proposal (RFP) for designs of the Integral Launch and Reentry Vehicle (ILRV) on October 30, 1968. Rather than award a contract based upon initial proposals, NASA announced

2044-558: A phased approach for the Space Shuttle contracting and development; Phase A was a request for studies completed by competing aerospace companies, Phase B was a competition between two contractors for a specific contract, Phase C involved designing the details of the spacecraft components, and Phase D was the production of the spacecraft. In December 1968, NASA created the Space Shuttle Task Group to determine

2190-551: A point ( ω x , ω y {\displaystyle \omega _{x},\omega _{y}} ) is given by: where ϕ ^ E V {\displaystyle {\hat {\phi }}_{EV}} is the amplitude of the image at a point ( ω x , ω y ) {\displaystyle \left(\omega _{x},\omega _{y}\right)} , v i _ {\displaystyle {\underline {v_{i}}}}

2336-562: A point in the SAR image is in alignment to one of the signal subspace eigenvectors which is the peak in image estimate. Thus this method does not accurately represent the scattering intensity at each point, but show the particular points of the image. Backprojection Algorithm has two methods: Time-domain Backprojection and Frequency-domain Backprojection . The time-domain Backprojection has more advantages over frequency-domain and thus,

2482-481: A port-side hatch that the crew used for entry and exit while on Earth. The airlock is a structure installed to allow movement between two spaces with different gas components, conditions, or pressures. Continuing on the mid-deck structure, each orbiter was originally installed with an internal airlock in the mid-deck. The internal airlock was installed as an external airlock in the payload bay on Discovery , Atlantis , and Endeavour to improve docking with Mir and

2628-540: A range of defense products in later years, including jet aircraft canopies, bulletproof glass and vehicular armor products, military shelters and missile transporters. Darrell C. Romick, former Chief Engineer of Taylorcraft Airplane Company was a close associate of Wernher von Braun . Romick's worked for Goodyear Aircraft in the 1950s produced a rocket and spacecraft design called the Goodyear Meteor Junior concept. The 3-stage rocket had similarities to

2774-675: A result of an O-ring failing at low temperature, the SRBs were redesigned to provide a constant seal regardless of the ambient temperature. The Space Shuttle's operations were supported by vehicles and infrastructure that facilitated its transportation, construction, and crew access. The crawler-transporters carried the MLP and the Space Shuttle from the VAB to the launch site. The Shuttle Carrier Aircraft (SCA) were two modified Boeing 747s that could carry an orbiter on its back. The original SCA (N905NA)

2920-671: A second orbiter. Later that month, Rockwell began converting STA-099 to OV-099, later named Challenger . On January 29, 1979, NASA ordered two additional orbiters, OV-103 and OV-104, which were named Discovery and Atlantis . Construction of OV-105, later named Endeavour , began in February 1982, but NASA decided to limit the Space Shuttle fleet to four orbiters in 1983. After the loss of Challenger , NASA resumed production of Endeavour in September 1987. After it arrived at Edwards AFB, Enterprise underwent flight testing with

3066-670: A separate central processing unit (CPU) and input/output processor (IOP), 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 (PASS), which

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3212-410: A speech. After STS-4, NASA declared its Space Transportation System (STS) operational. 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,

3358-600: A system of reusable spacecraft where it was the only item funded for development. The first ( STS-1 ) of four orbital test flights occurred in 1981, leading to operational flights ( STS-5 ) 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 (KSC) in Florida . Operational missions launched numerous satellites , interplanetary probes , and

3504-515: 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 July 21, 2011. The U.S. relied on the Russian Soyuz spacecraft to transport astronauts to the ISS from the last Shuttle flight until the launch of

3650-428: A two-part drag parachute system to slow the orbiter after landing. The orbiter used retractable landing gear with a nose landing gear and two main landing gear, each containing two tires. The main landing gear contained two brake assemblies each, and the nose landing gear contained an electro-hydraulic steering mechanism. The Space Shuttle crew varied per mission. They underwent rigorous testing and training to meet

3796-465: Is a form of radar that is used to create two-dimensional images or three-dimensional reconstructions of objects, such as landscapes. SAR uses the motion of the radar antenna over a target region to provide finer spatial resolution than conventional stationary beam-scanning radars. SAR is typically mounted on a moving platform, such as an aircraft or spacecraft, and has its origins in an advanced form of side looking airborne radar (SLAR). The distance

3942-555: Is a nonparametric covariance-based method, which uses an adaptive matched-filterbank approach and follows two main steps: The adaptive Capon bandpass filter is designed to minimize the power of the filter output, as well as pass the frequencies ( ω 1 , ω 2 {\displaystyle \omega _{1},\omega _{2}} ) without any attenuation, i.e., to satisfy, for each ( ω 1 , ω 2 {\displaystyle \omega _{1},\omega _{2}} ), where R

4088-550: Is a parameter-free sparse signal reconstruction based algorithm. It achieves super-resolution and is robust to highly correlated signals. The name emphasizes its basis on the asymptotically minimum variance (AMV) criterion. It is a powerful tool for the recovery of both the amplitude and frequency characteristics of multiple highly correlated sources in challenging environment (e.g., limited number of snapshots, low signal-to-noise ratio . Applications include synthetic-aperture radar imaging and various source localization. SAMV method

4234-742: Is also a special case of the FIR filtering approaches. It is seen that although the APES algorithm gives slightly wider spectral peaks than the Capon method, the former yields more accurate overall spectral estimates than the latter and the FFT method. FFT method is fast and simple but have larger sidelobes. Capon has high resolution but high computational complexity. EV also has high resolution and high computational complexity. APES has higher resolution, faster than capon and EV but high computational complexity. MUSIC method

4380-459: Is capable of achieving resolution higher than some established parametric methods, e.g., MUSIC , especially with highly correlated signals. Computational complexity of the SAMV method is higher due to its iterative procedure. This subspace decomposition method separates the eigenvectors of the autocovariance matrix into those corresponding to signals and to clutter. The amplitude of the image at

4526-452: Is cooled by 1,080 interior lines carrying liquid hydrogen and is thermally protected by insulative and ablative material. The RS-25 engines had several improvements to enhance reliability and power. During the development program, Rocketdyne determined that the engine was capable of safe reliable operation at 104% of the originally specified thrust. To keep the engine thrust values consistent with previous documentation and software, NASA kept

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4672-456: Is critical to operation of the EV method. The eigenvalue of the R matrix decides whether its corresponding eigenvector corresponds to the clutter or to the signal subspace. The MUSIC method is considered to be a poor performer in SAR applications. This method uses a constant instead of the clutter subspace. In this method, the denominator is equated to zero when a sinusoidal signal corresponding to

4818-407: Is essentially a realization of the mapping of the mathematical framework through generation of the variants and executing matrix operations. The performance of this implementation may vary from machine to machine, and the objective is to identify on which machine it performs best. The Capon spectral method, also called the minimum-variance method, is a multidimensional array-processing technique. It

4964-465: Is given by Space Shuttle The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program . Its official program name was Space Transportation System (STS), taken from the 1969 plan led by U.S. Vice President Spiro Agnew for

5110-448: Is more preferred. The time-domain Backprojection forms images or spectrums by matching the data acquired from the radar and as per what it expects to receive. It can be considered as an ideal matched-filter for synthetic-aperture radar. There is no need of having a different motion compensation step due to its quality of handling non-ideal motion/sampling. It can also be used for various imaging geometries. In GEO-SAR, to focus specially on

5256-458: Is not advantageous to capture a waveform for each of both transmission directions for a given pair of antennas, because those waveforms will be identical. When multiple static antennas are used, the total number of unique echo waveforms that can be captured is where N is the number of unique antenna positions. The antenna stays in a fixed position. It may be orthogonal to the flight path, or it may be squinted slightly forward or backward. When

5402-671: Is not generally suitable for SAR imaging, as whitening the clutter eigenvalues destroys the spatial inhomogeneities associated with terrain clutter or other diffuse scattering in SAR imagery. But it offers higher frequency resolution in the resulting power spectral density (PSD) than the fast Fourier transform (FFT)-based methods. The backprojection algorithm is computationally expensive. It is specifically attractive for sensors that are wideband, wide-angle, and/or have long coherent apertures with substantial off-track motion. SAR requires that echo captures be taken at multiple antenna positions. The more captures taken (at different antenna locations)

5548-455: Is received and recorded. The pulses are transmitted and the echoes received using a single beam-forming antenna, with wavelengths of a meter down to several millimeters. As the SAR device on board the aircraft or spacecraft moves, the antenna location relative to the target changes with time. Signal processing of the successive recorded radar echoes allows the combining of the recordings from these multiple antenna positions. This process forms

5694-621: Is the coherency matrix and v i _ H {\displaystyle {\underline {v_{i}}}^{\mathsf {H}}} is the Hermitian of the coherency matrix, 1 λ i {\displaystyle {\frac {1}{\lambda _{i}}}} is the inverse of the eigenvalues of the clutter subspace, W ( ω x , ω y ) {\displaystyle W\left(\omega _{x},\omega _{y}\right)} are vectors defined as where ⊗ denotes

5840-392: Is the covariance matrix , h ω 1 , ω 2 ∗ {\displaystyle h_{\omega _{1},\omega _{2}}^{*}} is the complex conjugate transpose of the impulse response of the FIR filter, a ω 1 , ω 2 {\displaystyle a_{\omega _{1},\omega _{2}}}

5986-439: Is the 2D Fourier vector, defined as a ω 1 , ω 2 ≜ a ω 1 ⊗ a ω 2 {\displaystyle a_{\omega _{1},\omega _{2}}\triangleq a_{\omega _{1}}\otimes a_{\omega _{2}}} , ⊗ {\displaystyle \otimes } denotes Kronecker product. Therefore, it passes

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6132-457: Is the 2D complex-conjugate transpose of the Fourier vector. The computation of this equation over all frequencies is time-consuming. It is seen that the forward–backward Capon estimator yields better estimation than the forward-only classical capon approach. The main reason behind this is that while the forward–backward Capon uses both the forward and backward data vectors to obtain the estimate of

6278-513: Is used in majority of the spectral estimation algorithms, and there are many fast algorithms for computing the multidimensional discrete Fourier transform. Computational Kronecker-core array algebra is a popular algorithm used as new variant of FFT algorithms for the processing in multidimensional synthetic-aperture radar (SAR) systems. This algorithm uses a study of theoretical properties of input/output data indexing sets and groups of permutations. A branch of finite multi-dimensional linear algebra

6424-411: Is used to identify similarities and differences among various FFT algorithm variants and to create new variants. Each multidimensional DFT computation is expressed in matrix form. The multidimensional DFT matrix, in turn, is disintegrated into a set of factors, called functional primitives, which are individually identified with an underlying software/hardware computational design. The FFT implementation

6570-408: Is useful in environment monitoring such as oil spills, flooding, urban growth, military surveillance: including strategic policy and tactical assessment. SAR can be implemented as inverse SAR by observing a moving target over a substantial time with a stationary antenna. A synthetic-aperture radar is an imaging radar mounted on a moving platform. SAR is a Doppler technique. It is based on

6716-513: The Columbia disaster . Beginning with STS-114 , the orbiter vehicles were equipped with the wing leading edge impact detection system to alert the crew to any potential damage. The entire underside of the orbiter vehicle, as well as the other hottest surfaces, were protected with tiles of high-temperature reusable surface insulation, made of borosilicate glass -coated silica fibers that trapped heat in air pockets and redirected it out. Areas on

6862-780: The Crew Dragon Demo-2 mission in May 2020. In the late 1930s, the German government launched the " Amerikabomber " project, and Eugen Sanger 's idea, together with mathematician Irene Bredt , was a winged rocket called the Silbervogel (German for "silver bird"). During the 1950s, the United States Air Force proposed using a reusable piloted glider to perform military operations such as reconnaissance, satellite attack, and air-to-ground weapons employment. In

7008-685: The Hubble Space Telescope (HST), 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 (ISS). The Space Shuttle fleet's total mission time was 1,323 days. Space Shuttle components include the Orbiter Vehicle (OV) with three clustered Rocketdyne RS-25 main engines,

7154-571: The ISS , along with the Orbiter Docking System . The airlock module can be fitted in the mid-bay, or connected to it but in the payload bay. With an internal cylindrical volume of 1.60 metres (5 feet 3 inches) diameter and 2.11 metres (6 feet 11 inches) in length, it can hold two suited astronauts. It has two D-shaped hatchways 1.02 m (40 in) long (diameter), and 0.91 m (36 in) wide. The orbiter

7300-460: The Kronecker product of the two vectors. MUSIC detects frequencies in a signal by performing an eigen decomposition on the covariance matrix of a data vector of the samples obtained from the samples of the received signal. When all of the eigenvectors are included in the clutter subspace (model order = 0) the EV method becomes identical to the Capon method. Thus the determination of model order

7446-610: The Martin Marietta X-24B . The program tested aerodynamic characteristics that would later be incorporated in design of the Space Shuttle, including unpowered landing from a high altitude and speed. On September 24, 1966, as the Apollo space program neared its design completion, NASA and the Air Force released a joint study concluding that a new vehicle was required to satisfy their respective future demands and that

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7592-684: The Shuttle Carrier Aircraft , a Boeing 747 that had been modified to carry the orbiter. In February 1977, Enterprise began the Approach and Landing Tests (ALT) and underwent captive flights, where it remained attached to the Shuttle Carrier Aircraft for the duration of the flight. On August 12, 1977, Enterprise conducted its first glide test, where it detached from the Shuttle Carrier Aircraft and landed at Edwards AFB. After four additional flights, Enterprise

7738-853: The Shuttle Landing Facility at KSC, Florida, or to Rogers Dry Lake in Edwards Air Force Base , California. If the landing occurred at Edwards, the orbiter was flown back to the KSC atop the Shuttle Carrier Aircraft (SCA), a specially modified Boeing 747 designed to carry the shuttle above it. The first orbiter, Enterprise , was built in 1976 and used in Approach and Landing Tests (ALT), 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

7884-633: The Tracking and Data Relay Satellite System and the Spacecraft Tracking and Data Acquisition Network ground stations to communicate with the orbiter throughout its orbit. Additionally, the orbiter deployed a high-bandwidth K u  band radio out of the cargo bay, which could also be utilized as a rendezvous radar. The orbiter was also equipped with two UHF radios for communications with air traffic control and astronauts conducting EVA. The Space Shuttle's fly-by-wire control system

8030-540: The external tank (ET), and the two solid rocket boosters (SRBs). 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

8176-484: The qualification requirements for their roles. The crew was divided into three categories: Pilots, Mission Specialists, and Payload Specialists. Pilots were further divided into two roles: Space Shuttle Commanders and Space Shuttle Pilots. The test flights only had two members each, the commander and pilot, who were both qualified pilots that could fly and land the orbiter. The on-orbit operations, such as experiments, payload deployment, and EVAs, were conducted primarily by

8322-409: The synthetic antenna aperture and allows the creation of higher-resolution images than would otherwise be possible with a given physical antenna. SAR is capable of high-resolution remote sensing , independent of flight altitude, and independent of weather, as SAR can select frequencies to avoid weather-caused signal attenuation. SAR has day and night imaging capability as illumination is provided by

8468-448: The 2195 aluminum-lithium alloy, which was 40% stronger and 10% less dense than its predecessor, 2219 aluminum-lithium alloy. The SLWT weighed 3,400 kg (7,500 lb) less than the LWT, which allowed the Space Shuttle to deliver heavy elements to ISS's high inclination orbit. The Solid Rocket Boosters (SRB) provided 71.4% of the Space Shuttle's thrust during liftoff and ascent, and were

8614-452: 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. After they established the need for a reusable, heavy-lift spacecraft, NASA and the Air Force determined the design requirements of their respective services. The Air Force expected to use

8760-424: The Capon method, but more accurate spectral estimates for amplitude in SAR. In the Capon method, although the spectral peaks are narrower than the APES, the sidelobes are higher than that for the APES. As a result, the estimate for the amplitude is expected to be less accurate for the Capon method than for the APES method. The APES method requires about 1.5 times more computation than the Capon method. SAMV method

8906-404: The ET was jettisoned after main engine cutoff and just before orbit insertion , which used the orbiter's two Orbital Maneuvering System (OMS) engines. At the conclusion of the mission, the orbiter fired its OMS to deorbit and reenter the atmosphere . The orbiter was protected during reentry by its thermal protection system tiles, and it glided as a spaceplane to a runway landing, usually to

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9052-653: The German airship industry was reduced and Zeppelin operations forbidden. In 1924, Goodyear formed a joint interest company with the German Luftschiffbau Zeppelin company, of which Goodyear held 2/3 and the Zeppelin company 1/3 interest. This Goodyear Zeppelin Corporation was able to use Zeppelin's patents, and a number of German engineers and technical staff moved to the US. The chief engineer of

9198-680: The IMU, INS, and TACAN systems, which first flew on STS-118 in August 2007. While in orbit, the crew primarily communicated using one of four S band radios, which provided both voice and data communications. Two of the S ;band radios were phase modulation transceivers , and could transmit and receive information. The other two S band radios were frequency modulation transmitters and were used to transmit data to NASA. As S band radios can operate only within their line of sight , NASA used

9344-470: The IMUs while in orbit. The star trackers are deployed while in orbit, and can automatically or manually align on a star. In 1991, NASA began upgrading the inertial measurement units with an inertial navigation system (INS), which provided more accurate location information. In 1993, NASA flew a GPS receiver for the first time aboard STS-51 . In 1997, Honeywell began developing an integrated GPS/INS to replace

9490-485: The KSC. The Space Shuttle was prepared for launch primarily in the VAB at the KSC. The SRBs were assembled and attached to the external tank on the MLP. The orbiter vehicle was prepared at the Orbiter Processing Facility (OPF) and transferred to the VAB, where a crane was used to rotate it to the vertical orientation and mate it to the external tank. Once the entire stack was assembled, the MLP

9636-528: The RS-25 experienced multiple nozzle failures, as well as broken turbine blades. Despite the problems during testing, NASA ordered the nine RS-25 engines needed for its three orbiters under construction in May 1978. NASA experienced significant delays in the development of the Space Shuttle's thermal protection system . Previous NASA spacecraft had used ablative heat shields, but those could not be reused. NASA chose to use ceramic tiles for thermal protection, as

9782-443: The SAR device travels over a target during the period when the target scene is illuminated creates the large synthetic antenna aperture (the size of the antenna). Typically, the larger the aperture, the higher the image resolution will be, regardless of whether the aperture is physical (a large antenna) or synthetic (a moving antenna) – this allows SAR to create high-resolution images with comparatively small physical antennas. For

9928-423: The SAR image stack are a sampled version of the Fourier transform of reflectivity in elevation direction, but the Fourier transform is irregular. Thus the spectral estimation techniques are used to improve the resolution and reduce speckle compared to the results of conventional Fourier transform SAR imaging techniques. FFT (Fast Fourier Transform i.e., periodogram or matched filter ) is one such method, which

10074-582: The SAR. SAR images have wide applications in remote sensing and mapping of surfaces of the Earth and other planets. Applications of SAR are numerous. Examples include topography, oceanography, glaciology, geology (for example, terrain discrimination and subsurface imaging). SAR can also be used in forestry to determine forest height, biomass, and deforestation. Volcano and earthquake monitoring use differential interferometry . SAR can also be applied for monitoring civil infrastructure stability such as bridges. SAR

10220-505: The SRBs provided structural support for the orbiter vehicle and ET, as they were the only system that was connected to the mobile launcher platform (MLP). At the time of launch, the SRBs were armed at T−5 minutes, and could only be electrically ignited once the RS-25 engines had ignited and were without issue. They each provided 12,500 kN (2,800,000 lbf) of thrust, which was later improved to 13,300 kN (3,000,000 lbf) beginning on STS-8 . After expending their fuel,

10366-558: The SRBs were jettisoned approximately two minutes after launch at an altitude of approximately 46 km (150,000 ft). Following separation, they deployed drogue and main parachutes, landed in the ocean, and were recovered by the crews aboard the ships MV Freedom Star and MV Liberty Star . Once they were returned to Cape Canaveral, they were cleaned and disassembled. The rocket motor, igniter, and nozzle were then shipped to Thiokol to be refurbished and reused on subsequent flights. The SRBs underwent several redesigns throughout

10512-399: 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 (GNC) to systems management (SM) and payload (PL) to support

10658-526: The Space Shuttle to launch large satellites, and required it to be capable of lifting 29,000 kg (65,000 lb) to an eastward LEO or 18,000 kg (40,000 lb) into a polar orbit . The satellite designs also required that the Space Shuttle have a 4.6 by 18 m (15 by 60 ft) payload bay. NASA evaluated the F-1 and J-2 engines from the Saturn rockets , and determined that they were insufficient for

10804-583: The Spacelab module through a 2.7 or 5.8 m (8.72 or 18.88 ft) tunnel that connected to the airlock. The Spacelab equipment was primarily stored in pallets, which provided storage for both experiments as well as computer and power equipment. Spacelab hardware was flown on 28 missions through 1999 and studied subjects including astronomy, microgravity, radar, and life sciences. Spacelab hardware also supported missions such as Hubble Space Telescope (HST) servicing and space station resupply. The Spacelab module

10950-517: The Zeppelin company, Karl Arnstein , became the "Vice-President of Engineering" The company subsequently constructed rigid ( zeppelins ) and non-rigid ( blimps ) dirigibles for the US military. Goodyear's giant hangar was constructed where the huge rigid airships for the US Navy, including the USS Akron and USS Macon were constructed. Also due to the lack of business during the depression,

11096-585: The aft seating location, and also controlled the data on the HUD. In 1998, Atlantis was upgraded with the Multifunction Electronic Display System (MEDS), which was a glass cockpit upgrade to the flight instruments that replaced the eight MCDS display units with 11 multifunction colored digital screens. MEDS was flown for the first time in May 2000 on STS-101 , and the other orbiter vehicles were upgraded to it. The aft section of

11242-511: The antenna aperture travels along the flight path, a signal is transmitted at a rate equal to the pulse repetition frequency (PRF). The lower boundary of the PRF is determined by the Doppler bandwidth of the radar. The backscatter of each of these signals is commutatively added on a pixel-by-pixel basis to attain the fine azimuth resolution desired in radar imagery. The spotlight synthetic aperture

11388-490: The antenna — each object will have its own doppler shift. A precise frequency analysis of the radar reflections will thus allow the construction of a detailed image. In order to realise this concept, electromagnetic waves are transmitted sequentially, the echoes are collected and the system electronics digitizes and stores the data for subsequent processing. As transmission and reception occur at different times, they map to different small positions. The well ordered combination of

11534-411: The antenna's field of view. The 3D processing is done in two stages. The azimuth and range direction are focused for the generation of 2D (azimuth-range) high-resolution images, after which a digital elevation model (DEM) is used to measure the phase differences between complex images, which is determined from different look angles to recover the height information. This height information, along with

11680-401: The associated propellant tanks. The AJ10 engines used monomethylhydrazine (MMH) oxidized by dinitrogen tetroxide (N 2 O 4 ). The pods carried a maximum of 2,140 kg (4,718 lb) of MMH and 3,526 kg (7,773 lb) of N 2 O 4 . The OMS engines were used after main engine cut-off (MECO) for orbital insertion. Throughout the flight, they were used for orbit changes, as well as

11826-617: The azimuth-range coordinates provided by 2-D SAR focusing, gives the third dimension, which is the elevation. The first step requires only standard processing algorithms, for the second step, additional pre-processing such as image co-registration and phase calibration is used. In addition, multiple baselines can be used to extend 3D imaging to the time dimension . 4D and multi-D SAR imaging allows imaging of complex scenarios, such as urban areas, and has improved performance with respect to classical interferometric techniques such as persistent scatterer interferometry (PSI). SAR algorithms model

11972-562: The built-in hold at T−9 minutes, the countdown was automatically controlled by the Ground Launch Sequencer (GLS) at the LCC, which stopped the countdown if it sensed a critical problem with any of the Space Shuttle's onboard systems. At T−3 minutes 45 seconds, the engines began conducting gimbal tests, which were concluded at T−2 minutes 15 seconds. The ground Launch Processing System handed off

12118-461: The bulk of the ET, and was 29 m (96.7 ft) tall. The orbiter vehicle was attached to the ET at two umbilical plates, which contained five propellant and two electrical umbilicals, and forward and aft structural attachments. The exterior of the ET was covered in orange spray-on foam to allow it to survive the heat of ascent. The ET provided propellant to the Space Shuttle Main Engines from liftoff until main engine cutoff. The ET separated from

12264-1003: The company used its advanced aeronautical knowledge to design and build the high speed Comet streamlined train for the route between Boston and Providence . It became Goodyear Aircraft Corporation on December 5, 1939 in response to a contract from the Glenn L. Martin Company to design and build the empennage section for its new plane, the B-26 Marauder . The army had placed a large order and Goodyear had available manufacturing space at its huge Airship Dock , in Springfield Township, Ohio near Akron . Due to escalating problems in Europe and eventual war with Germany, Goodyear created Goodyear Aircraft Corporation to handle US military contracts in 1939. The German-US joint venture

12410-550: The contract to build the orbiter to North American Rockwell. In August 1973, the external tank contract to Martin Marietta , and in November the solid-rocket booster contract to Morton Thiokol . On June 4, 1974, Rockwell began construction on the first orbiter, OV-101, dubbed Constitution, later to be renamed Enterprise . Enterprise was designed as a test vehicle, and did not include engines or heat shielding. Construction

12556-477: The control to the orbiter vehicle's GPCs at T−31 seconds. At T−16 seconds, the GPCs armed the SRBs, the sound suppression system (SPS) began to drench the MLP and SRB trenches with 1,100,000 L (300,000 U.S. gal) of water to protect the orbiter vehicle from damage by acoustical energy and rocket exhaust reflected from the flame trench and MLP during lift-off. At T−10 seconds, hydrogen igniters were activated under each engine bell to quell

12702-413: The covariance matrix, the forward-only Capon uses only the forward data vectors to estimate the covariance matrix. The APES (amplitude and phase estimation) method is also a matched-filter-bank method, which assumes that the phase history data is a sum of 2D sinusoids in noise. APES spectral estimator has 2-step filtering interpretation: Empirically, the APES method results in wider spectral peaks than

12848-421: The deorbit burn prior to reentry. Each OMS engine produced 27,080 N (6,087 lbf) of thrust, and the entire system could provide 305 m/s (1,000 ft/s) of velocity change . The orbiter was protected from heat during reentry by the thermal protection system (TPS), a thermal soaking protective layer around the orbiter. In contrast with previous US spacecraft, which had used ablative heat shields,

12994-516: The development of a space shuttle to bring people and cargo to low Earth orbit (LEO), as well as a space tug for transfers between orbits and the Moon, and a reusable nuclear upper stage for deep space travel. After the release of the Space Shuttle Task Group report, many aerospace engineers favored the Class III, fully reusable design because of perceived savings in hardware costs. Max Faget ,

13140-674: The ease of refurbishing them for reuse after they landed in the ocean. In January 1972, President Richard Nixon approved the Shuttle, and NASA decided on its final design in March. The development of the Space Shuttle Main Engine (SSME) remained the responsibility of Rocketdyne, and the contract was issued in July 1971, and updated SSME specifications were submitted to Rocketdyne in that April. That August, NASA awarded

13286-492: The effects of aerodynamic and thermal stresses during launch and reentry. The beginning of the development of the RS-25 Space Shuttle Main Engine was delayed for nine months while Pratt & Whitney challenged the contract that had been issued to Rocketdyne. The first engine was completed in March 1975, after issues with developing the first throttleable, reusable engine. During engine testing,

13432-512: The engines during powered flight and fly the orbiter during unpowered flight. Both seats also had rudder controls, to allow rudder movement in flight and nose-wheel steering on the ground. The orbiter vehicles were originally installed with the Multifunction CRT Display System (MCDS) to display and control flight information. The MCDS displayed the flight information at the commander and pilot seats, as well as at

13578-465: The fact that "radar reflections from discrete objects in a passing radar beam field each [have] a minute Doppler, or speed, shift relative to the antenna". Carl Wiley, working at Goodyear, Arizona, (which later became Goodyear Aerospace, and eventually Lockheed Martin Corporation) in 1951, suggested the principle that — because each object in the radar beam has a slightly different speed relative to

13724-605: The feasibility of reusable boosters. This became the basis for the aerospaceplane , a fully reusable spacecraft that was never developed beyond the initial design phase in 1962–1963. Beginning in the early 1950s, NASA and the Air Force collaborated on developing lifting bodies to test aircraft that primarily generated lift from their fuselages instead of wings, and tested the NASA M2-F1 , Northrop M2-F2 , Northrop M2-F3 , Northrop HL-10 , Martin Marietta X-24A , and

13870-672: The final decision to scrub a launch was announced. In addition to the weather at the launch site, conditions had to be acceptable at one of the Transatlantic Abort Landing sites and the SRB recovery area. The mission crew and the Launch Control Center (LCC) personnel completed systems checks throughout the countdown. Two built-in holds at T−20 minutes and T−9 minutes provided scheduled breaks to address any issues and additional preparation. After

14016-532: The first four Shuttle missions, astronauts wore modified U.S. Air Force high-altitude full-pressure suits, which included a full-pressure helmet during ascent and descent. From the fifth flight, STS-5 , until the loss of Challenger , the crew wore one-piece light blue nomex flight suits and partial-pressure helmets. After the Challenger disaster, the crew members wore the Launch Entry Suit (LES),

14162-481: The first time NASA performed a crewed first-flight of a spacecraft. On April 12, 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

14308-635: The flight deck contained windows looking into the payload bay, as well as an RHC to control the Remote Manipulator System during cargo operations. Additionally, the aft flight deck had monitors for a closed-circuit television to view the cargo bay. The mid-deck contained the crew equipment storage, sleeping area, galley, medical equipment, and hygiene stations for the crew. The crew used modular lockers to store equipment that could be scaled depending on their needs, as well as permanently installed floor compartments. The mid-deck contained

14454-502: The forward separation motors and the parachute systems that were used during recovery. The rocket nozzles could gimbal up to 8° to allow for in-flight adjustments. The rocket motors were each filled with a total 500,000 kg (1,106,640 lb) of solid rocket propellant ( APCP + PBAN ), and joined in the Vehicle Assembly Building (VAB) at KSC. In addition to providing thrust during the first stage of launch,

14600-402: The inner leading edge and 45° at the outer leading edge. Each wing had an inboard and outboard elevon to provide flight control during reentry, along with a flap located between the wings, below the engines to control pitch . The orbiter's vertical stabilizer was swept backwards at 45° and contained a rudder that could split to act as a speed brake . The vertical stabilizer also contained

14746-504: The largest solid-propellant motors ever flown. Each SRB was 45 m (149.2 ft) tall and 3.7 m (12.2 ft) wide, weighed 68,000 kg (150,000 lb), and had a steel exterior approximately 13 mm (.5 in) thick. The SRB's subcomponents were the solid-propellant motor, nose cone, and rocket nozzle. The solid-propellant motor comprised the majority of the SRB's structure. Its casing consisted of 11 steel sections which made up its four main segments. The nose cone housed

14892-575: The late 1950s, the Air Force began developing the partially reusable X-20 Dyna-Soar . The Air Force collaborated with NASA on the Dyna-Soar and began training six pilots in June 1961. The rising costs of development and the prioritization of Project Gemini led to the cancellation of the Dyna-Soar program in December 1963. In addition to the Dyna-Soar, the Air Force had conducted a study in 1957 to test

15038-490: The launch pad, the Space Shuttle was used to verify the proper positioning of the launch complex hardware. Enterprise was taken back to California in August 1979, and later served in the development of the SLC-6 at Vandenberg AFB in 1984. On November 24, 1980, Columbia was mated with its external tank and solid-rocket boosters, and was moved to LC-39 on December 29. The first Space Shuttle mission, STS-1 , would be

15184-437: The mission specialists who were specifically trained for their intended missions and systems. Early in the Space Shuttle program, NASA flew with payload specialists, who were typically systems specialists who worked for the company paying for the payload's deployment or operations. The final payload specialist, Gregory B. Jarvis , flew on STS-51-L , and future non-pilots were designated as mission specialists. An astronaut flew as

15330-452: The more reliable the target characterization. Multiple captures can be obtained by moving a single antenna to different locations, by placing multiple stationary antennas at different locations, or combinations thereof. The advantage of a single moving antenna is that it can be easily placed in any number of positions to provide any number of monostatic waveforms. For example, an antenna mounted on an airplane takes many captures per second as

15476-427: The much later Space Shuttle in that it was crewed, had reusable stages, and its topmost stage was designed to ferry personnel and cargo to a large space station orbiting the Earth. The concept was designed in 1954 to 1958, with a launch date of 1962. The company became Goodyear Aerospace Corporation in 1963 to reflect the diverse range of products. In 1987 it was sold to Loral Corporation for $ 640 million following

15622-434: 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 (PGSC) that could integrate with

15768-424: The optimal design for a reusable spacecraft, and issued study contracts to General Dynamics , Lockheed , McDonnell Douglas , and North American Rockwell . In July 1969, the Space Shuttle Task Group issued a report that determined the Shuttle would support short-duration crewed missions and space station, as well as the capabilities to launch, service, and retrieve satellites. The report also created three classes of

15914-436: The orange foam itself was sufficiently protected, and the ET was no longer covered in latex paint beginning on STS-3. A light-weight tank (LWT) was first flown on STS-6, which reduced tank weight by 4,700 kg (10,300 lb). The LWT's weight was reduced by removing components from the hydrogen tank and reducing the thickness of some skin panels. In 1998, a super light-weight ET (SLWT) first flew on STS-91 . The SLWT used

16060-437: The orbiter vehicle 18 seconds after engine cutoff and could be triggered automatically or manually. At the time of separation, the orbiter vehicle retracted its umbilical plates, and the umbilical cords were sealed to prevent excess propellant from venting into the orbiter vehicle. After the bolts attached at the structural attachments were sheared, the ET separated from the orbiter vehicle. At the time of separation, gaseous oxygen

16206-467: The orbiter vehicle and would be removed and replaced in between flights. The RS-25 is a staged-combustion cycle cryogenic engine that used liquid oxygen and hydrogen and had a higher chamber pressure than any previous liquid-fueled rocket. The original main combustion chamber operated at a maximum pressure of 226.5 bar (3,285 psi). The engine nozzle is 287 cm (113 in) tall and has an interior diameter of 229 cm (90.3 in). The nozzle

16352-510: 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 payload bay comprised most of the orbiter vehicle's fuselage , and provided the cargo-carrying space for the Space Shuttle's payloads. It

16498-549: The orbiter vehicle's heat, and were opened upon reaching orbit for heat rejection. The orbiter could be used in conjunction with a variety of add-on components depending on the mission. This included orbital laboratories, boosters for launching payloads farther into space, the Remote Manipulator System (RMS), and optionally the EDO pallet to extend the mission duration. To limit the fuel consumption while

16644-528: The orbiter was docked at the ISS, the Station-to-Shuttle Power Transfer System (SSPTS) was developed to convert and transfer station power to the orbiter. The SSPTS was first used on STS-118, and was installed on Discovery and Endeavour . The Remote Manipulator System (RMS), also known as Canadarm, was a mechanical arm attached to the cargo bay. It could be used to grasp and manipulate payloads, as well as serve as

16790-549: The originally specified thrust at 100%, but had the RS-25 operate at higher thrust. RS-25 upgrade versions were denoted as Block I and Block II. 109% thrust level was achieved with the Block II engines in 2001, which reduced the chamber pressure to 207.5 bars (3,010 psi), as it had a larger throat area. The normal maximum throttle was 104 percent, with 106% or 109% used for mission aborts. The Orbital Maneuvering System (OMS) consisted of two aft-mounted AJ10-190 engines and

16936-558: The plane travels. The principal advantages of multiple static antennas are that a moving target can be characterized (assuming the capture electronics are fast enough), that no vehicle or motion machinery is necessary, and that antenna positions need not be derived from other, sometimes unreliable, information. (One problem with SAR aboard an airplane is knowing precise antenna positions as the plane travels). For multiple static antennas, all combinations of monostatic and multistatic radar waveform captures are possible. Note, however, that it

17082-405: The program's lifetime. STS-6 and STS-7 used SRBs 2,300 kg (5,000 lb) lighter due to walls that were 0.10 mm (.004 in) thinner, but were determined to be too thin to fly safely. Subsequent flights until STS-26 used cases that were 0.076 mm (.003 in) thinner than the standard-weight cases, which reduced 1,800 kg (4,000 lb). After the Challenger disaster as

17228-400: The propellant for the Space Shuttle Main Engines, and connected the orbiter vehicle with the solid rocket boosters. The ET was 47 m (153.8 ft) tall and 8.4 m (27.6 ft) in diameter, and contained separate tanks for liquid oxygen and liquid hydrogen. The liquid oxygen tank was housed in the nose of the ET, and was 15 m (49.3 ft) tall. The liquid hydrogen tank comprised

17374-429: The raw data was recorded on film and the postprocessing by matched filter was implemented optically using lenses of conical, cylindrical and spherical shape. The Range-Doppler algorithm is an example of a more recent approach. Synthetic-aperture radar determines the 3D reflectivity from measured SAR data. It is basically a spectrum estimation, because for a specific cell of an image, the complex-value SAR measurements of

17520-410: The received signals builds a virtual aperture that is much longer than the physical antenna width. That is the source of the term "synthetic aperture," giving it the property of an imaging radar. The range direction is perpendicular to the flight track and perpendicular to the azimuth direction, which is also known as the along-track direction because it is in line with the position of the object within

17666-433: The relative moving track, the backprojection algorithm works very well. It uses the concept of Azimuth Processing in the time domain. For the satellite-ground geometry, GEO-SAR plays a significant role. The procedure of this concept is elaborated as follows. Capon and APES can yield more accurate spectral estimates with much lower sidelobes and more narrow spectral peaks than the fast Fourier transform (FFT) method, which

17812-465: The requirements of the Space Shuttle; in July 1971, it issued a contract to Rocketdyne to begin development on the RS-25 engine. NASA reviewed 29 potential designs for the Space Shuttle and determined that a design with two side boosters should be used, and the boosters should be reusable to reduce costs. NASA and the Air Force elected to use solid-propellant boosters because of the lower costs and

17958-685: The reusability of the orbiter required a multi-use heat shield. During reentry, the TPS experienced temperatures up to 1,600 °C (3,000 °F), but had to keep the orbiter vehicle's aluminum skin temperature below 180 °C (350 °F). The TPS primarily consisted of four types of tiles. The nose cone and leading edges of the wings experienced temperatures above 1,300 °C (2,300 °F), and were protected by reinforced carbon-carbon tiles (RCC). Thicker RCC tiles were developed and installed in 1998 to prevent damage from micrometeoroid and orbital debris , and were further improved after RCC damage caused in

18104-456: The scene as a set of point targets that do not interact with each other (the Born approximation ). While the details of various SAR algorithms differ, SAR processing in each case is the application of a matched filter to the raw data, for each pixel in the output image, where the matched filter coefficients are the response from a single isolated point target. In the early days of SAR processing,

18250-529: The shuttle could then be constructed of lightweight aluminum , and the tiles could be individually replaced as needed. Construction began on Columbia on March 27, 1975, and it was delivered to the KSC on March 25, 1979. At the time of its arrival at the KSC, Columbia still had 6,000 of its 30,000 tiles remaining to be installed. However, many of the tiles that had been originally installed had to be replaced, requiring two years of installation before Columbia could fly. On January 5, 1979, NASA commissioned

18396-418: The underside of Columbia , and determined there was no damage. Columbia reentered the atmosphere and landed at Edwards AFB on April 14. NASA conducted three additional test flights with Columbia in 1981 and 1982. On July 4, 1982, STS-4 , flown by Ken Mattingly and Henry Hartsfield , landed on a concrete runway at Edwards AFB. President Ronald Reagan and his wife Nancy met the crew, and delivered

18542-467: The upper parts of the orbiter vehicle were coated in tiles of white low-temperature reusable surface insulation with similar composition, which provided protection for temperatures below 650 °C (1,200 °F). The payload bay doors and parts of the upper wing surfaces were coated in reusable Nomex felt surface insulation or in beta cloth , as the temperature there remained below 370 °C (700 °F). The Space Shuttle external tank (ET) carried

18688-462: Was 18 m (60 ft) long and 4.6 m (15 ft) wide, and could accommodate cylindrical payloads up to 4.6 m (15 ft) in diameter. Two payload bay doors hinged on either side of the bay, and provided a relatively airtight seal to protect payloads from heating during launch and reentry. Payloads were secured in the payload bay to the attachment points on the longerons . The payload bay doors served an additional function as radiators for

18834-499: 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

18980-641: Was a modified airport jet bridge that was used to assist astronauts to egress from the orbiter after landing, where they would undergo their post-mission medical checkups. The Astrovan transported astronauts from the crew quarters in the Operations and Checkout Building to the launch pad on launch day. The NASA Railroad comprised three locomotives that transported SRB segments from the Florida East Coast Railway in Titusville to

19126-466: Was carried for 5.6 km (3.5 mi) to Launch Complex 39 by one of the crawler-transporters . After the Space Shuttle arrived at one of the two launchpads, it would connect to the Fixed and Rotation Service Structures, which provided servicing capabilities, payload insertion, and crew transportation. The crew was transported to the launch pad at T−3 hours and entered the orbiter vehicle, which

19272-565: Was closed at T−2 hours. Liquid oxygen and hydrogen were loaded into the external tank via umbilicals that attached to the orbiter vehicle, which began at T−5 hours 35 minutes. At T−3 hours 45 minutes, the hydrogen fast-fill was complete, followed 15 minutes later by the oxygen tank fill. Both tanks were slowly filled up until the launch as the oxygen and hydrogen evaporated. The launch commit criteria considered precipitation, temperatures, cloud cover, lightning forecast, wind, and humidity. The Space Shuttle

19418-686: Was completed on September 17, 1976, and Enterprise was moved to the Edwards Air Force Base to begin testing. Rockwell constructed the Main Propulsion Test Article (MPTA)-098 , which was a structural truss mounted to the ET with three RS-25 engines attached. It was tested at the National Space Technology Laboratory (NSTL) to ensure that the engines could safely run through the launch profile. Rockwell conducted mechanical and thermal stress tests on Structural Test Article (STA)-099 to determine

19564-606: Was dissolved in 1941, and Goodyear's military and commercial airship operations were transferred to the Goodyear Aircraft Corporation. By 1941, manufacturing facilities were running at full capacity and ground was broken on July 15, 1941 at an additional location just west of Phoenix, Arizona. Goodyear was familiar with the area, and had been operating a large cotton ranch there for decades. Arizona produced more than three million pounds of airframes during World War II. The Akron plant where FG-1s were built

19710-551: Was entirely reliant on its main computer, the Data Processing System (DPS). The DPS 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 (GPC), two magnetic tape mass memory units (MMUs), and the associated sensors to monitor the Space Shuttle components. The original GPC used was the IBM AP-101B , which used

19856-657: Was equipped with an avionics system to provide information and control during atmospheric flight. Its avionics suite contained three microwave scanning beam landing systems , three gyroscopes , three TACANs , three accelerometers , two radar altimeters , two barometric altimeters , three attitude indicators , two Mach indicators , and two Mode C transponders . During reentry, the crew deployed two air data probes once they were traveling slower than Mach 5. The orbiter had three inertial measuring units (IMU) that it used for guidance and navigation during all phases of flight. The orbiter contains two star trackers to align

20002-653: Was first flown in 1975, and was used for the ALT and ferrying the orbiter from Edwards AFB to the KSC on all missions prior to 1991. A second SCA (N911NA) was acquired in 1988, and was first used to transport Endeavour from the factory to the KSC. Following the retirement of the Space Shuttle, N905NA was put on display at the JSC, and N911NA was put on display at the Joe Davies Heritage Airpark in Palmdale, California . The Crew Transport Vehicle (CTV)

20148-533: Was handed over to the U.S. Navy, which used it as the basis of Naval Air Station Akron in January 1948. Goodyear Aircraft Company employee Carl Wiley invented Synthetic Aperture Radar (SAR) in 1951. His invention resulted in the creation of the first SAR patent, first digital SAR processor, and development of several different high performance SAR systems used for applications such as surveillance , aerial warfare , and cartography . The Arizona plant produced

20294-403: Was later improved to 270,000 kg (586,000 lb). The Spacelab module was a European-funded pressurized laboratory that was carried within the payload bay and allowed for scientific research while in orbit. The Spacelab module contained two 2.7 m (9 ft) segments that were mounted in the aft end of the payload bay to maintain the center of gravity during flight. Astronauts entered

20440-406: Was located below the flight deck and was where the galley and crew bunks were set up, as well as three or four crew member seats. The mid-deck contained the airlock, which could support two astronauts on an extravehicular activity (EVA), as well as access to pressurized research modules. An equipment bay was below the mid-deck, which stored environmental control and waste management systems. On

20586-617: Was moved to the Marshall Space Flight Center (MSFC) on March 13, 1978. Enterprise underwent shake tests in the Mated Vertical Ground Vibration Test, where it was attached to an external tank and solid rocket boosters, and underwent vibrations to simulate the stresses of launch. In April 1979, Enterprise was taken to the KSC, where it was attached to an external tank and solid rocket boosters, and moved to LC-39 . Once installed at

20732-602: Was never used). The Johnson Space Center (JSC) 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 orbiter had design elements and capabilities of both a rocket and an aircraft to allow it to launch vertically and then land as

20878-422: Was not launched under conditions where it could have been struck by lightning , as its exhaust plume could have triggered lightning by providing a current path to ground after launch, which occurred on Apollo 12 . The NASA Anvil Rule for a Shuttle launch stated that an anvil cloud could not appear within a distance of 19  km (10 nmi). The Shuttle Launch Weather Officer monitored conditions until

21024-418: Was tested on STS-2 and STS-3, and the first full mission was on STS-9. Three RS-25 engines, also known as the Space Shuttle Main Engines (SSME), were mounted on the orbiter's aft fuselage in a triangular pattern. The engine nozzles could gimbal ±10.5° in pitch, and ±8.5° in yaw during ascent to change the direction of their thrust to steer the Shuttle. The titanium alloy reusable engines were independent of

21170-444: Was the top level of the crew compartment and contained the flight controls for the orbiter. The commander sat in the front left seat, and the pilot sat in the front right seat, with two to four additional seats set up for additional crew members. The instrument panels contained over 2,100 displays and controls, and the commander and pilot were both equipped with a heads-up display (HUD) and a Rotational Hand Controller (RHC) to gimbal

21316-551: Was vented from the nose to cause the ET to tumble, ensuring that it would break up upon reentry. The ET was the only major component of the Space Shuttle system that was not reused, and it would travel along a ballistic trajectory into the Indian or Pacific Ocean. For the first two missions, STS-1 and STS-2 , the ET was covered in 270 kg (595 lb) of white fire-retardant latex paint to provide protection against damage from ultraviolet radiation. Further research determined that

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