Corona (satellite)

The Corona[1] program was a series of American strategic reconnaissance satellites produced and operated by the Central Intelligence Agency Directorate of Science & Technology with substantial assistance from the U.S. Air Force. The Corona satellites were used for photographic surveillance of the Soviet Union (USSR), the People's Republic of China, and other areas beginning in June 1959 and ending in May 1972.

A KH-4B CORONA satellite.
The recovery of Discoverer 14 return capsule (typical for the CORONA series).

History and costs

Lockheed's covert "advanced projects" facility at Hiller Aircraft in Menlo Park, California.

CORONA started under the name "DISCOVERER" as part of the WS-117L satellite reconnaissance and protection program of the US Air Force in 1956. The WS-117L was based on recommendations and designs from the RAND Corporation.[2] The United States Air Force credits the Onizuka Air Force Station (then called Sunnyvale Air Force Station) as being the "birthplace of the CORONA program".[3] In May 1958, the Department of Defense directed the transfer of the WS-117L program to Advanced Research Projects Agency (ARPA). In FY1958, WS-117L was funded by the USAF at a level of US$108.2 million (inflation adjusted US$0.96 billion in 2020). For DISCOVERER, the Air Force and ARPA spent a combined sum of US$132.3 million in FY1959 (inflation adjusted US$1.16 billion in 2020) and US$101.2 million in FY1960 (inflation adjusted US$0.87 billion in 2020).[4] According to John N. McMahon, the total cost of the CORONA program amounted to $US 850 million.[5]

The CORONA project was pushed forward rapidly following the shooting down of a U-2 spy plane over the Soviet Union on 1 May 1960.[6]

Design staff

Minoru S. "Sam" Araki, Francis J. Madden, Edward A. Miller, James W. Plummer, and Don H. Schoessler are responsible for the design, development, and operation of CORONA, the first space-based Earth observation systems. As a result, they were awarded Charles Stark Draper Prize in 2005.

Technology

The CORONA Satellite Index Camera Lens.

The Corona satellites used special 70 millimeter film with a 24-inch (610 mm) focal length camera.[7] Manufactured by Eastman Kodak, the film was initially 0.0003 inches (7.6 μm) thick, with a resolution of 170 lines per 0.04 inches (1.0 mm) of film.[8][9] The contrast was 2-to-1.[8] (By comparison, the best aerial photography film produced in World War II could produce just 50 lines per mm (1250 per inch) of film.)[8] The acetate-based film was later replaced with a polyester-based film stock that was more durable in Earth orbit.[10] The amount of film carried by the satellites varied over time. Initially, each satellite carried 8,000 feet (2,400 m) of film for each camera, for a total of 16,000 feet (4,900 m) of film.[8] But a reduction in the thickness of the film stock allowed more film to be carried.[10] In the fifth generation, the amount of film carried was doubled to 16,000 feet (4,900 m) of film for each camera for a total of 32,000 feet (9,800 m) of film. This was accomplished by a reduction in film thickness and with additional film capsules.[11] Most of the film shot was black and white. Infrared film was used on mission 1104, and color film on missions 1105 and 1008. Color film proved to have lower resolution, and so was never used again.[12]

The cameras were manufactured by the Itek Corporation.[13] A 12-inch (30 cm), f/5 triplet lens was designed for the cameras.[14] Each lens was 7 inches (18 cm) in diameter.[8] They were quite similar to the Tessar lenses developed in Germany by Zeiss.[15] The cameras themselves were initially 5 feet (1.5 m) long, but later extended to 9 feet (2.7 m) in length.[16] Beginning with the KH-4 satellites, these lenses were replaced with Petzval f/3.5 lens.[12] The lenses were panoramic, and moved through a 70° arc perpendicular to the direction of the orbit.[8] A panoramic lens was chosen because it could obtain a wider image. Although the best resolution was only obtained in the center of the image, this could be overcome by having the camera sweep automatically ("reciprocate") back and forth across 70° of arc.[17] The lens on the camera was constantly rotating, to counteract the blurring effect of the satellite moving over the planet.[12]

A diagram of "J-1" type stereo/panoramic constantly rotating CORONA reconnaissance satellite camera system used on KH-4A missions from 1963 to 1969.

The first Corona satellites had a single camera, but a two-camera system was quickly implemented.[18] The front camera was tilted 15° aft, and the rear camera tilted 15° forward, so that a stereoscopic image could be obtained.[8] Later in the program, the satellite employed three cameras.[18] The third camera was employed to take "index" photographs of the objects being stereographically filmed.[19] The J-3 camera system, first deployed in 1967, placed the camera in a drum. This "rotator camera" (or drum) moved back and forth, eliminating the need to move the camera itself on a reciprocating mechanism.[20] The drum permitted the use of up to two filters and as many as four different exposure slits, greatly improving the variability of images that Corona could take.[21] The first cameras could resolve images on the ground down to 40 feet (12 m) in diameter. Improvements in the imaging system were rapid, and the KH-3 missions could see objects 10 feet (3.0 m) in diameter. Later missions would be able to resolve objects just 5 feet (1.5 m) in diameter.[22] A single mission was completed with a 1 foot (0.30 m) resolution but the limited field of view was determined to be detrimental to the mission. 3 feet (0.91 m) resolution was found to be the optimum resolution for quality of image and field of view.

The initial Corona missions suffered from mysterious border fogging and bright streaks which appeared irregularly on the returned film. Eventually, a team of scientists and engineers from the project and from academia (among them Luis Alvarez, Sidney Beldner, Malvin Ruderman, Arthur Glines,[23] and Sidney Drell) determined that electrostatic discharges (called corona discharges) caused by some of the components of the cameras were exposing the film.[24][25] Corrective measures included better grounding of the components, improved film rollers that did not generate static electricity, improved temperature controls, and a cleaner internal environment.[25] Although improvements were made to reduce the corona, the final solution was to load the film canisters with a full load of film and then feed the unexposed film through the camera onto the take-up reel with no exposure. This unexposed film was then processed and inspected for corona. If none was found or the corona observed was within acceptable levels, the canisters were certified for use and loaded with fresh film for a launch mission.

The first satellites in the program orbited at altitudes 100 miles (160 km) above the surface of the Earth, although later missions orbited even lower at 75 miles (121 km).[12] Originally, CORONA satellites were designed to spin along their main axis so that the satellite would remain stable. Cameras would take photographs only when pointed at the Earth. The Itek camera company, however, proposed to stabilize the satellite along all three axes—keeping the cameras permanently pointed at the earth.[15] Beginning with the KH-3 version of the satellite, a horizon camera took images of several key stars.[19] A sensor used the satellite's side thruster rockets to align the rocket with these "index stars," so that it was correctly aligned with the Earth and the cameras pointed in the right direction.[26] Beginning in 1967, two horizon cameras were used. This system was known as the Dual Improved Stellar Index Camera (DISIC).[21]

Satellites were calibrated using the Corona Satellite Calibration Targets located outside of Casa Grande, Arizona. The targets consisted of concrete arrows located in and to the south of the city, and helped to calibrate the cameras of the satellites.[27][28][29]

Recovery

A CORONA film recovery maneuver.
A CORONA film bucket payload.

Film was retrieved from orbit via a reentry capsule (nicknamed "film bucket"), designed by General Electric, which separated from the satellite and fell to Earth.[30] After the fierce heat of reentry was over, the heat shield surrounding the vehicle was jettisoned at 60,000 feet (18 km) and parachutes deployed.[31] The capsule was intended to be caught in mid-air by a passing airplane[32] towing an airborne claw which would then winch it aboard, or it could land at sea.[33] A salt plug in the base would dissolve after two days, allowing the capsule to sink if it was not picked up by the United States Navy.[34] After Reuters reported on a reentry vehicle's accidental landing and discovery by Venezuelan farmers in mid-1964, capsules were no longer labeled "SECRET" but offered a reward in eight languages for their return to the United States.[35] Beginning with flight number 69, a two-capsule system was employed.[24] This also allowed the satellite to go into passive (or "zombie") mode, shutting down for as many as 21 days before taking images again.[11] Beginning in 1963, another improvement was "Lifeboat", a battery-powered system that allowed for ejection and recovery of the capsule in case power failed.[36][37] The film was processed at Eastman Kodak's Hawkeye facility in Rochester, New York.[38]

The CORONA film bucket was later adapted for the KH-7 GAMBIT satellites, which took higher resolution photos.

Launch

CORONA were launched by a Thor-Agena rocket, which used a Thor first stage and an Agena as the second stage of the rocket lifting the CORONA into orbit.

The first attempted launch in the program took place on January 21, 1959 at Vandenberg AFB's LC-75. As the Agena was being loaded with fuel (the Thor was still empty at this point), someone decided to conduct a test of the launch computer sequencer. The result was that the Agena accidentally received a signal that staging had taken place and to begin booster separation. As everyone in the blockhouse watched in dismay, the ullage rockets on the outside of the Agena began firing and the internal fuel pumps began spinning up for engine start. A quick-thinking member of the blockhouse crew then pressed a button on his control console to send a shutdown signal to the booster. Although potential disaster had been averted, the Agena now had nothing except gravity holding it onto the Thor and the risk of the stage falling to the ground, rupturing, and spilling its corrosive nitric acid/UDMH propellant load existed. In addition, the heat from the ullage rockets could potentially ignite the propellants in the stage. Pad crews had to wait several hours for the batteries in the Agena to run down before they could begin dismantling the launch vehicle. The Thor sustained minor damage and was sent back to Douglas for refurbishment, but the Agena had had nitric acid spilled down its exterior and was deemed unsafe to fly. In any case, it was one of the first Agena stages produced and lacked some technical refinements made to newer models. It ended up being used at Lockheed for training purposes.

A CORONA Target (Y4-7) is located on the southeast corner of South Montgomery Road and West Cornman Road in the City of Casa Grande, Arizona.

Discoverer 1 was a test of the performance capabilities of the propulsion and guidance system of the booster and satellite. It was launched on a Thor-Agena A rocket on 28 January 1959 at 21:49:16 GMT from Vandenberg Air Force Base in California. After first stage burnout at 28529 km/h, the rocket coasted to an orbital altitude where the second stage guidance system-oriented the spacecraft by means of pneumatic nitrogen jets. The second stage engine ignited when the correct attitude was achieved, putting the spacecraft into a polar orbit where it remained until re-entry on 17 March 1959. Discoverer 1 became the first man-made object ever put into a polar orbit. The difficulty was encountered receiving signals after launch, but the satellite broadcast intermittently later in the flight.[39]

Shortly after the launch of Discoverer 1, an East German radio station attacked the US for "launching a military satellite without giving prior warning to any nation whose territory it might pass over", while it was in fact just a test payload with no reconnaissance capability that had not actually made it into orbit.

Discoverer 2 (14 April 1959) carried a recovery capsule for the first time and was also the first satellite to be placed into polar orbit. The main bus performed well, but the capsule recovery failed. It apparently came down near Svalbard, Norway, but was never found. Rumors persist that the Soviets recovered the capsule themselves, but there is no evidence of this and in any case, there would have been little information they could have gained from the small test payload. At this early phase, program planners were not even sure if the Thor/Agena had enough lift capacity to orbit a camera package. It is more likely that Discoverer 2's capsule sank into the ocean.

Discoverer 3 was scheduled for launch on June 1. This satellite carried a biological payload with four black mice, the only one flown in the Corona program. The initial attempt miscarried when the mice poisoned themselves gnawing on Krylon paint inside the capsule, but a replacement batch was launched two days later. They never made it orbit however; the Agena suffered a guidance malfunction and sent the mice and spacecraft into the Pacific Ocean.

Discoverer 4 (June 25) failed to orbit when the Agena engine underperformed and the capsule could not attain orbital velocity.

Discoverer 5 (August 13) accidentally sent its capsule into a higher orbit where it remained until November 1961.

Discoverer 6 (August 19) suffered a retrorocket failure that prevented the deorbit of the capsule.

Discoverer 7 (November 7) experienced an attitude control malfunction in orbit, once again preventing capsule recovery.

Discoverer 8 (November 20) was put into an incorrect orbit by the launch vehicle, again preventing capsule recovery.

Discoverer 9 (February 4, 1960) ended up in the Pacific Ocean when the Thor cut off too early.

Discoverer 10 (February 19) failed when the Thor suffered a control malfunction and was destroyed by Range Safety Officer just under a minute into launch.

Discoverer 11 (April 15) suffered another attitude control malfunction in orbit.

Discoverer 12 (June 29) failed to orbit due to an attitude control problem with the Agena.

Discoverer 13 (August 10) managed a full successful capsule recovery for the first time. This was the first recovery of a man-made object from space, beating the Soviet Korabl Sputnik 2 by nine days. Discoverer XIII is now on display in the "Milestones of Flight" hall in the Smithsonian Air and Space Museum in Washington, D.C.

Discoverer 14 (August 18) carried a camera package for the first time. The cameras operated properly and the capsule was recovered from the Pacific Ocean 1-1/2 days after launch.

Discoverer 15 (September 13) managed to successfully deorbit its capsule, but it sank into the Pacific Ocean and was not recovered.

In 1963, the KH-4 system was introduced with dual cameras and the program now made completely secret. The Discoverer label was dropped and all launches became classified. Because of the increased satellite mass, the basic Thor-Agena vehicle was enhanced by the addition of three Castor solid-fueled strap-on motors. On February 28, 1963, the first Thrust Augmented Thor lifted from VAFB's LC-75 carrying the first KH-4 satellite. The launch of the new and unproven booster went awry as one SRB failed to ignite. Eventually the dead weight of the strap-on motor dragged the Thor off its flight path, leading to a Range Safety destruct. It was suspected that a technician had not attached an umbilical on the SRB properly. Although some failures continued to occur during the next few years, the reliability rate of the program significantly improved with KH-4.[36][40] Maneuvering rockets were also added to the satellite beginning in 1963. These were different from the attitude stabilizing thrusters which had been incorporated from the beginning of the program. Corona orbited in very low orbits to enhance resolution of its camera system. But at perigee (the lowest point in the orbit), Corona endured drag from the Earth's atmosphere. In time, this could cause its orbit to decay and force the satellite to re-enter the atmosphere prematurely. The new maneuvering rockets were designed to boost Corona into a higher orbit, and lengthen the mission time even if low perigees were used.[41] For use during unexpected crises, the National Reconnaissance Office (NRO) kept a Corona in "R-7" status, meaning ready for launch in seven days. By the summer of 1965, NRO was able to maintain Corona for launch within one day.[42]

The procurement and maintenance of the Corona satellites were managed by the Central Intelligence Agency, which used cover arrangements lasting from April 1958 to 1969 to get access to the Palo Alto plant of the Hiller Helicopter Corporation for the production.[43] At this facility, the rocket's second stage Agena, the cameras, film cassettes, and re-entry capsule were assembled and tested before shipment to Vandenberg Air Force Base.[44] In 1969, assembly duties were relocated to the Lockheed facilities in Sunnyvale, California.[45] (The NRO was worried that, as Corona was phased out, skilled technicians worried about their jobs would quit the program—leaving Corona without staff. The move to Sunnyvale ensured that enough skilled staff would be available.)

The decisions regarding what to photograph were made by the Corona Target Program. Corona satellites were placed into near-polar orbits.[22] This software, run by an on-board computer, was programmed to operate the cameras based on the intelligence targets to be imaged, the weather, the satellite's operational status, and what images the cameras had already captured.[46] Ground control for Corona satellites was initially conducted from Stanford Industrial Park, an industrial park on Page Mill Road in Palo Alto, California. It was later moved to Sunnyvale Air Force Base near Sunnyvale, California.[47]

Corona launches with system types

KH-1 Corona main features
KH-2 Corona main features
KH-3 Corona main features
KH-4 Corona M (Agena-B service module) main features
KH-4 Corona M (Agena-D service module) main features
KH-4A Corona J1 main features
KH-4B Corona J3 main features

The Corona satellites were designated KH-1, KH-2, KH-3, KH-4, KH-4A and KH-4B. KH stood for "Key Hole" or "Keyhole" (Code number 1010),[48] with the name being an analogy to the act of spying into a person's room by peering through their door's keyhole. The incrementing number indicated changes in the surveillance instrumentation, such as the change from single-panoramic to double-panoramic cameras. The "KH" naming system was first used in 1962 with KH-4 and the earlier numbers were retroactively applied. There were 144 Corona satellites launched, of which 102 returned usable photographs.

Corona image of The Pentagon, 25 Sep 1967

Below is a list of Corona launches, as compiled by the United States Geological Survey.[49] This table lists government's designation of each type of satellite (C, C-prime, J-1, etc.), the resolution of the camera, and a description of the camera system.

Time periodNo.NicknameResolutionNotesNumber
Jun 1959 – Sep 1960KH-1"Corona", C7.5 mFirst series of American imaging spy satellites. Each satellite carried a single panoramic camera and a single return vehicle.10 systems; 1 recovery.
Oct 1960 – Oct 1961KH-2Corona′, C′ (or "C-prime")*7.5 mSingle panoramic camera and a single return vehicle.7 systems; 4 recoveries.
Aug 1961 – Jan 1962KH-3Corona‴, C‴ (or "C-triple-prime")*7.5 mSingle panoramic camera and a single return vehicle.9 systems; 5 recoveries.
Feb 1962 – Dec 1963KH-4Corona-M, Mural7.5 mFilm return. Two panoramic cameras.26 systems; 20 recoveries.
Aug 1963 – Oct 1969KH-4ACorona J-12.75 mFilm return with two reentry vehicles and two panoramic cameras. Large volume of imagery.52 systems; 94 recoveries.
Sep 1967 – May 1972KH-4BCorona J-31.8 mFilm return with two reentry vehicles and two panoramic rotator cameras.17 systems; 32 recoveries.
Feb 1961 – Aug 1964KH-5Argon140 mLow-resolution mapping missions; single frame camera.12 systems; 5 recoveries.
Mar 1963 – July 1963KH-6Lanyard1.8 mExperimental camera in a short-lived program.3 systems; 1 recovery.

*(The stray "quote marks" are the original designations of the first three generations of cameras.)

Discoverer

The first dozen or more CORONA satellites and their launches were cloaked with disinformation as being part of a space technology development program called the DISCOVERER program. The first test launches for the CORONA / DISCOVERER were carried out early in 1959. The first CORONA launch containing a camera was carried out in June 1959 with the cover name Discoverer 4. This was a 750 kilogram satellite launched by a Thor-Agena rocket.

The return capsule of the Discoverer 13 mission, which launched 10 August 1960, was successfully recovered the next day.[50] This was the first time that any object had been recovered successfully from orbit. After the mission of Discoverer 14, launched on 18 August 1960, its film bucket was successfully retrieved two days later by a C-119 Flying Boxcar transport plane. This was the first successful return of photographic film from orbit. In comparison, Sputnik 5 was launched into orbit on 19 August 1960, one day after the launch of Discoverer 14. Sputnik 5 was a biosatellite that took into orbit the two Soviet space dogs, Belka and Strelka, and then safely returned them to the Earth.[51]

At least two launches of DISCOVERER were used to test satellites for the Missile Defense Alarm System (MIDAS), an early missile-launch-detection program that used infrared cameras to detect the heat signature of rockets launching to orbit.

The last launch under the DISCOVERER cover name was Discoverer 38 on 26 February 1962. Its bucket was successfully recovered in midair during the 65th orbit (the 13th recovery of a bucket; the ninth one in midair).[52] Following this last use of the DISCOVERER name, the remaining launches of CORONA satellites were entirely TOP SECRET. The last CORONA launch was on 25 May 1972. The project ended when CORONA was replaced by the KH-9 Hexagon program. The best sequence of CORONA missions was from 1966 to 1971, when there were 32 consecutive successful missions, including film recoveries.

An alternative program to the CORONA program was named SAMOS. This program included several types of satellite which used a different photographic method. This involved capturing an image on photographic film, developing the film aboard the satellite and then scanning the image electronically. The image was then transmitted via telemetry to ground stations. The SAMOS E-1 and SAMOS E-2 satellite programs used this system, but they were not able to take very many pictures and then relay them to the ground stations each day. Two later versions of the SAMOS program, such as the E-5 and the E-6, used the bucket-return approach, but neither of these programs carried out any successful missions.

ELINT subsatellites

Nine of the KH-4A and KH-4B missions included ELINT subsatellites, which were launched into a higher orbit.[53][54]

Declassification

The CORONA program was officially classified top secret until 1992. Then, on February 22, 1995, the photos taken by the CORONA satellites, and also by two contemporary programs (ARGON and KH-6 LANYARD) were declassified under an Executive Order signed by President Bill Clinton.[55] The further review by photo experts of the "obsolete broad-area film-return systems other than CORONA" mandated by President Clinton's order led to the declassification in 2002 of the photos from the KH-7 and the KH-9 low-resolution cameras.[56]

The declassified imagery has since been used by a team of scientists from the Australian National University to locate and explore ancient habitation sites, pottery factories, megalithic tombs, and Palaeolithic archaeological remains in northern Syria.[57][58] Similarly, scientists at Harvard have used the imagery to identify prehistoric traveling routes in Mesopotamia.[59][60]

The CORONA Digital Atlas of the Middle East Project hosts a large number of KH-4B imagery where users can view and download spatially corrected images.[61]

Launches

Mission No.Cover NameLaunch DateNSSDC ID No.Alt. NameCameraNotes
R&DDiscoverer Zero[62]21 Jan 19591959-F01noneAgena ullage/separation rockets ignited on the pad while the launch vehicle was being fueled prior to the intended flight.
R&DDiscoverer 128 Feb 19591959-002A1959 Beta 1noneDecay : 17 March 1959.[39]
R&DDiscoverer 213 Apr 19591959-003A1959 GAMnoneFirst three-axis stabilized satellite; capsule recovery failed
R&DDiscoverer 303 Jun 1959DISCOV31959-F02noneAgena guidance failure. Vehicle fell into the Pacific Ocean
9001Discoverer 425 Jun 1959DISC41959-U01KH-1Insufficient Agena engine thrust. Vehicle fell into the Pacific Ocean
9002Discoverer 513 Aug 19591959-005A1959 EPS 1KH-1Mission failed. Power supply failure. No recovery.
9003Discoverer 619 Aug 19591959-006A1959 ZETKH-1Mission failed. Retro rockets malfunctioned negating recovery.
9004Discoverer 707 Nov 19591959-010A1959 KAPKH-1Mission failed. Satellite tumbled in orbit.
9005Discoverer 820 Nov 19591959-011A1959 LAMKH-1Mission failed. Eccentric orbit negating recovery.
9006Discoverer 904 Feb 1960DiSC91960-F01KH-1Agena accidentally damaged during on-pad servicing. Premature cutoff and staging signal sent to Thor.
9007Discoverer 1019 Feb 1960DISC101960-F02KH-1Control failure followed by RSO destruct T+52 seconds after launch
9008Discoverer 1115 Apr 19601960-004A1960 DELKH-1Attitude control system malfunctioned. No film capsule recovery.
R&DDiscoverer 1229 Jun 1960DISC121960-F08noneAgena attitude control malfunction. No orbit.
R&DDiscoverer 1310 Aug 19601960-008A1960 THEnoneTested capsule recovery system; first successful capture.
9009Discoverer 1418 Aug 19601960-010A1960 KAPKH-1First successful recovery of IMINT from space. Cameras operated satisfactorily.
9010Discoverer 1513 Sep 19601960-012A1960 MUKH-1Mission failed. Attained orbit successfully. Capsule sank prior to retrieval.
9011Discoverer 1626 Oct 19601960-F151960-F15KH-2Agena failed to separate from Thor.
9012Discoverer 1712 Nov 19601960-015A1960 OMIKH-2Mission failed. Obtained orbit successfully. Film separated before any camera operation leaving only 1.7 ft (0.52 m) of film in capsule.
9013Discoverer 1807 Dec 19601960-018A1960 SIGKH-2First successful mission employing KH-2 camera system.
RM-1Discoverer 1920 Dec 19601960-019A1960 TAUnoneTest of Missile Defense Alarm System
9014A Discoverer 2017 Feb 19611961-005A1961 EPS 1KH-5See KH-5
RM-2Discoverer 2118 Feb 19611961-006A1961 ZETnoneTest of restartable rocket engine
9015Discoverer 2230 Mar 1961DISC221961-F02KH-2Agena control malfunction. No orbit.
9016A Discoverer 2308 Apr 19611961-011A1961 LAM 1KH-5See KH-5
9018A Discoverer 2408 Jun 1961DISC241961-F05KH-5See KH-5
9017Discoverer 2516 Jun 19611961-014A1961 XI 1KH-2Capsule recovered from water on orbit 32. Streaks throughout film.
9019Discoverer 2607 Jul 19611961-016A1961 PIKH-2Main camera malfunctioned on pass 22.
9020A Discoverer 2721 Jul 1961DISC271961-F07KH-5See KH-5
9021Discoverer 2804 Aug 1961DISC281961-F08KH-2Thor guidance failure. RSO destruct at T+60 seconds.
9022Discoverer 3012 Sep 19611961-024A1961 OME 1KH-3Best mission to date. Same out-of-focus condition as in 9023.
9023Discoverer 2930 Aug 19611961-023A1961 PSIKH-3First use of KH-3 camera system. All frames out of focus.
9024Discoverer 3117 Sep 19611961-026A1961 A BETKH-3Mission failed. Power failure and loss of control gas on orbit 33. Capsule was not recovered.
9025Discoverer 3213 Oct 19611961-027A1961 A GAM 1KH-3Capsule recovered on orbit 18. 96% of film out of focus.
9026Discoverer 3323 Oct 1961DISC331961-F10KH-3Mission failed. Satellite failed to separate from Thor booster. No orbit.
9027Discoverer 3405 Nov 19611961-029A1961 A EPS 1KH-3Mission failed. Improper launch angle resulted in extreme orbit. Gas valve failed
9028Discoverer 3515 Nov 19611961-030A1961 A ZET 1KH-3All cameras operated satisfactorily. Grainy emulsion noted.
9029Discoverer 3612 Dec 19611961-034A1961 A KAP 1KH-3Best mission to date. Launch carried OSCAR 1 to orbit.
9030Discoverer 3713 Jan 1962DISC371962-F01KH-3Mission failed. No orbit.
9031Discoverer 3827 Feb 19621962-005A1962 EPS 1KH-4First mission of the KH-4 series. Much of film slightly out of focus.
90321962 Lambda 118 Apr 19621962-011A1962 LAM 1KH-4Best mission to date.
9033FTV 112528 Apr 19621962-017A1962 RHO 1KH-4Mission failed. Parachute ejector squibs holding parachute container cover failed to fire. No recovery.
9034A FTV 112615 May 19621962-018A1962 SIG 1KH-5See KH-5
9035FTV 112830 May 19621962-021A1962 PHI 1KH-4Slight corona static on film.
9036FTV 112702 Jun 19621962-022A1962 CHI 1KH-4Mission failed. During air catch. Launch carried OSCAR 2 to orbit.
9037FTV 112923 Jun 19621962-026A1962 A BETKH-4Corona static occurs on some film.
9038FTV 115128 Jun 19621962-027A1962 A GAMKH-4Severe corona static.
9039FTV 113021 Jul 19621962-031A1962 A ETAKH-4Aborted after 6 photo passes. Heavy corona and radiation fog.
9040FTV 113128 Jul 19621962-032A1962 A THEKH-4No filters on slave horizon cameras. Heavy corona and radiation fog.
9041FTV 115202 Aug 19621962-034A1962 A KAP 1KH-4Severe corona and radiation fog.
9042A FTV 113201 Sep 19621962-044A1962 A UPSKH-5See KH-5
9043FTV 113317 Sep 19621962-046A1962 A CHIKH-4placed in highly eccentric orbit (207 km x 670 km), caspule called down after one day, film suffered severe radiation fog due to SAA crossing[63][64][65]
9044FTV 115329 Aug 19621962-042A1962 A SIGKH-4Erratic vehicle attitude. Radiation fog minimal.
9045FTV 115429 Sep 19621962-050A1962 B BETKH-4First use of stellar camera
9046A FTV 113409 Oct 19621962-053A1962 B EPSKH-5See KH-5
9047FTV 113605 Nov 19621962-063A1962 B OMIKH-4Camera door malfunctioned
9048FTV 113524 Nov 19621962-065A1962 B RHOKH-4Some film exposed through base.
9049FTV 115504 Dec 19621962-066A1962 B SIGKH-4Mission failed. During air catch chute tore
9050FTV 115614 Dec 19621962-069A1962 B PHIKH-4Best mission to date.
9051OPS 004807 Jan 19631963-002A1963-002AKH-4Erratic vehicle attitude. Frame ephemeris not created.
9052OPS 058328 Feb 19631963-F021963-F02KH-4Mission failed. Destroyed by range safety officer
9053OPS 072001 Apr 19631963-007A1963-007AKH-4Best imagery to date.
9054OPS 095412 Jun 19631963-019A1963-019AKH-4Some imagery seriously affected by corona.
9055A OPS 100826 Apr 19631963-F071963-F07KH-5See KH-5
9056OPS 099926 Jun 19631963-025A1963-025AKH-4Experimental camera carried. Film affected by light leaks.
9057OPS 126619 Jul 19631963-029A1963-029AKH-4Best mission to date.
9058A OPS 156129 Aug 19631963-035A1963-035AKH-5See KH-5
9059A OPS 243729 Oct 19631963-042A1963-042AKH-5See KH-5
9060OPS 226809 Nov 19631963-F141963-F14KH-4Mission failed. No orbit.
9061OPS 226027 Nov 19631963-048A1963-048AKH-4Mission failed. Return capsule separated from satellite but remained in orbit.
9062OPS 138821 Dec 19631963-055A1963-055AKH-4Corona static fogged much of film.
9065A OPS 273921 Aug 19641964-048A1964-048AKH-5See KH-5
9066A OPS 323613 Jun 19641964-030A1964-030AKH-5See KH-5
1001OPS 141924 Aug 19631963-034A1963-034AKH-4AFirst mission of KH-4A. Some film was fogged. Two buckets but 1001-2 was never recovered.
1002OPS 135323 Sep 19631963-037A1963-037AKH-4ASevere light leaks
1003OPS 346724 Mar 19641964-F041964-F04KH-4AMission failed. Guidance system failed. No orbit.
1004OPS 344415 Feb 19641964-008A1964-008AKH-4AMain cameras operated satisfactorily. Minor degradations due to static and light leaks.
1005OPS 292127 Apr 19641964-022A1964-022AKH-4AMission failed. Recovery vehicle impacted in Venezuela.
1006OPS 348304 Jun 19641964-027A1964-027AKH-4AHighest quality imagery attained to date from the KH-4 system.
1007OPS 375419 Jun 19641964-032A1964-032AKH-4AOut-of-focus area on some film.
1008OPS 349110 Jun 19641964-037A1964-037AKH-4ACameras operated satisfactorily
1009OPS 304205 Aug 19641964-043A1964-043AKH-4ACameras operated successfully.
1010OPS 349714 Sep 19641964-056A1964-056AKH-4ASmall out of focus areas on both cameras at random times throughout the mission.
1011OPS 333305 Oct 19641964-061A1964-061AKH-4APrimary mode of recovery failed on second portion of the mission (1011-2). Small out of focus areas present at random on both cameras.
1012OPS 355917 Oct 19641964-067A1964-067AKH-4AVehicle attitude became erratic on the second portion of the mission necessitating an early recovery.
1013OPS 543402 Nov 19641964-071A1964-071AKH-4AProgram anomaly occurred immediately after launch when both cameras operated for 417 frames. Main cameras ceased operation on rev 52D of first portion of mission negating second portion. About 65% of aft camera film is out of focus.
1014OPS 336018 Nov 19641964-075A1964-075AKH-4ACameras operated successfully.
1015OPS 335819 Dec 19641964-085A1964-085AKH-4ADiscrepancies in planned and actual coverage due to telemetry problems during the first 6 revolutions. Small out-of-focus areas on film from aft camera.
1016OPS 392815 Jan 19651965-002A1965-002AKH-4ASmearing of highly reflective images due to reflections within camera.
1017OPS 478225 Feb 19651965-013A1965-013AKH-4ACapping shutter malfunction occurred during last 5 passes of mission.
1018OPS 480325 Mar 19651965-026A1965-026AKH-4ACameras operated successfully. First KH-4A reconnaissance system to be launched into a retrograde orbit.
1019OPS 502329 Apr 19651965-033A1965-033AKH-4ACameras operated successfully. Malfunction in recovery mode on 1019-2 negated recovery.
1020OPS 842509 Jun 19651965-045A1965-045AKH-4AAll cameras operated satisfactorily. Erratic attitude caused an early recovery after the second day of 1020–2.
1021OPS 843118 May 19651965-037A1965-037AKH-4AAft camera ceased operation on pass 102.
1022OPS 554319 Jun 19651965-057A1965-057AKH-4AAll cameras operated satisfactorily.
1023OPS 720817 Aug 19651965-067A1965-067AKH-4AProgram anomaly caused the fore camera to cease operation during revolutions 103–132.
1024OPS 722122 Sep 19651965-074A1965-074AKH-4AAll cameras operated satisfactorily. Cameras not operated on passes 88D-93D.
1025OPS 532505 Oct 19651965-079A1965-079AKH-4AMain cameras operated satisfactorily.
1026OPS 215528 Oct 19651965-086A1965-086AKH-4AAll cameras operated satisfactorily.
1027OPS 724909 Dec 19651965-102A1965-102AKH-4AErratic attitude necessitated recovery after two days of operation. All cameras operated satisfactorily.
1028OPS 463924 Dec 19651965-110A1965-110AKH-4ACameras operated satisfactorily.
1029OPS 729102 Feb 19661966-007A1966-007AKH-4ABoth panoramic cameras were operational throughout.
1030OPS 348809 Mar 19661966-018A1966-018AKH-4AAll cameras operated satisfactorily.
1031OPS 161207 Apr 19661966-029A1966-029AKH-4AThe aft-looking camera malfunctioned after the recovery of bucket 1. No material was received in bucket 2 (1031-2).
1032OPS 15083 May 19661966-F05A1966-F05KH-4AMission failed. Vehicle failed to achieve orbit.
1033OPS 177824 May 19661966-042A1966-042AKH-4AThe stellar camera shutter of bucket 2 remained open for approximately 200 frames.
1034OPS 159921 Jun 19661966-055A1966-055AKH-4AFailure of velocity altitude programmer produced poor imagery after revolution 5.
1035OPS 170320 Sep 19661966-085A1966-085AKH-4AAll cameras operated satisfactorily. First mission flown with pan geometry modification.
1036OPS 154509 Aug 19661966-072A1966-072AKH-4AAll cameras operated satisfactorily.
1037OPS 186608 Nov 19661966-102A1966-102AKH-4ASecond pan geometry mission. Higher than normal base plus fog encountered on both main camera records.
1038OPS 166414 Jan 19671967-002A1967-002AKH-4AFair image quality.
1039OPS 475022 Feb 19671967-015A1967-015AKH-4ANormal KH-4 mission. Light from horizon camera on both main camera records during 1039–1.
1040OPS 477930 Mar 19671967-029A1967-029AKH-4ASatellite flown nose first.
1041OPS 46969 May 19671967-043A1967-043AKH-4ADue to the failure of the booster cut-off switch, the satellite went into a highly eccentric orbit. There was significant image degradation.
1042OPS 355916 Jun 19671967-062A1967-062AKH-4ASmall out-of-focus area in forward camera of 1042–1.
1043OPS 482707 Aug 19671967-076A1967-076AKH-4AForward camera film came out of the rails on pass 230D. Film degraded past this point.
1044OPS 056202 Nov 19671967-109A1967-109AKH-4AAll cameras operated fine.
1045OPS 224324 Jan 19681968-008A1968-008AKH-4AAll cameras operated satisfactorily.
1046OPS 484914 Mar 19681968-020A1968-020AKH-4AImage quality good for 1046-1 and fair for 1046–2.
1047OPS 534320 Jun 19681968-052A1968-052AKH-4AOut-of-focus imagery is present on both main camera records.
1048OPS 016518 Sep 19681968-078A1968-078AKH-4AFilm in the forward camera separated and camera failed on mission 1048-2
1049OPS 474012 Dec 19681968-112A1968-112AKH-4ADegraded film
1050OPS 372219 Mar 19691969-026A1969-026AKH-4ADue to abnormal rotational rates after revolution 22
1051OPS 11012 May 19691969-041A1969-041AKH-4AImagery of both pan camera records is soft and lacks crispness and edge sharpness.
1052OPS 353122 Sep 19691969-079A1969-079AKH-4ALast of the KH-4A missions
1101OPS 508915 Sep 19671967-087A1967-087AKH-4BFirst mission of the KH-4B series. Best film to date.
1102OPS 100109 Dec 19671967-122A1967-122AKH-4BNoticeable image smear for forward camera
1103OPS 14191 May 19681968-039A1968-039BKH-4BOut-of-focus imagery is present on both main camera records.
1104OPS 595507 Aug 19681968-065A1968-065AKH-4BBest imagery to date on any KH-4 systems. Bicolor and color infrared experiments were conducted on this mission, including SO-180 IR camouflage detection film.[66]
1105OPS 131503 Nov 19681968-098A1968-098AKH-4BImage quality is variable and displays areas of soft focus and image smear.
1106OPS 389005 Feb 19691969-010A1969-010AKH-4BThe best image quality to date.
1107OPS 365424 Jul 19691969-063A1969-063AKH-4BForward camera failed on pass 1 and remained inoperative throughout the rest of the mission.
1108OPS 661704 Dec 19691969-105A1969-105AKH-4BCameras operated satisfactorily and the mission carried 811 ft (247 m) of aerial color film added to the end of the film supply.
1109OPS 044004 Mar 19701970-016A1970-016AKH-4BCameras operated satisfactorily but the overall image quality of both the forward and aft records is variable.
1110OPS 472020 May 19701970-040A1970-040AKH-4BThe overall image quality is less than that provided by recent missions and 2
1111OPS 432423 Jun 19701970-054A1970-054AKH-4BThe overall image quality is good.
1112OPS 499218 Nov 19701970-098A1970-098AKH-4BThe forward camera failed on pass 104 and remained inoperative throughout the rest of the mission.
1113OPS 329717 Feb 19711971-F01A1971-F01KH-4BMission failed due to failure of Thor booster. Destroyed shortly after launch.
1114OPS 530024 Mar 19711971-022A1971-022AKH-4BThe overall image quality is good and comparable to the best of past missions. On-board program failed after pass 235
1115OPS 545410 Sep 19711971-076A1971-076AKH-4BOverall image quality is good.
1116OPS 564019 Apr 19721972-032A1972-032AKH-4BVery successful mission and image quality was good.
1117OPS 637125 May 19721972-039A1972-039AKH-4BLast KH-4B mission. Very successful mission, failure to deploy one solar panel and leak in Agena gas system shortened mission from 19 to 6 days[65]
gollark: ddg! IRS
gollark: IRS is Internal Revenue Service.
gollark: RSA is Rotating Stellar Avocados.
gollark: Technically, we *did* make a substantial fraction of pigeons sapient and networked them into a hive mind, slightly.
gollark: Some birds apparently grasp trade with humans, so it's fine.

See also

The 1963 thriller novel Ice Station Zebra and its 1968 film adaptation were inspired, in part, by news accounts from April 17, 1959, about a missing experimental Corona satellite capsule (Discoverer II) that inadvertently landed near Spitzbergen on April 13. While Soviet agents may have recovered the vehicle,[44][67] it is more likely that the capsule landed in water and sank.[35] The Corona program is also mentioned in the video-game Call of Duty: Black Ops 2.

References

Notes

  1. https://www.cia.gov/library/center-for-the-study-of-intelligence/csi-publications/books-and-monographs/corona.pdf
  2. Rich, Michael D. (1998). "RAND's Role in the CORONA Program". RAND Corporation. Retrieved 9 March 2014.
  3. "'Mission accomplished' for NRO at Onizuka AFS". USAF. 2007-04-23. Archived from the original on 2011-07-20.
  4. "Chronology of Air Force space activities" (PDF). National Reconnaissance Office. Archived from the original (PDF) on 2011-10-16. Retrieved 2011-07-13.
  5. "CIA Holds Landmark Symposium on CORONA". Federation of American Scientists. June 1995.
  6. United States; Central Intelligence Agency; Ruffner, Kevin Conley; Center for the Study of Intelligence (U.S.); History Staff (1995-01-01). Corona America's first satellite program. Washington, D.C.: History Staff, Center for the Study of Intelligence, Central Intelligence Agency. pp. xiii. OCLC 42006243.
  7. Yenne, p. 63; Jensen, p. 81.
  8. Drell, "Physics and U.S. National Security," p. S462.
  9. Brown, Stewart F. "America's First Eyes in Space." Popular Science. February 1996, p. 46.
  10. Brown, Stewart F. "America's First Eyes in Space." Popular Science. February 1996, p. 46-47.
  11. Peebles, p. 157.
  12. Olsen, p. 57.
  13. Yenne, p. 64.
  14. Smith, p. 111-114.
  15. Lewis, p. 93.
  16. Monmonier, p. 24.
  17. Day, Logsdon, and Latell, p. 192-196.
  18. Ruffner, p. 37.
  19. Kramer, p. 354.
  20. Ruffner, p. 34, 36.
  21. Ruffner, p. 36.
  22. Chun, p. 75.
  23. personal memoirs of Arthur R Glines, Corona program engineer, 1/1962 to 6/1967
  24. Ruffner, p. 31.
  25. Drell, "Reminiscences of Work on National Reconnaissance," p. 42.
  26. Brown, p. 44; Burrows, p. 231.
  27. Manaugh, Geoff (8 April 2014). "Zooming-In On Satellite Calibration Targets in the Arizona Desert". Atlas Obscura. Retrieved 14 April 2016.
  28. Hider, Anna (3 October 2014). "What the heck are these abandoned cement targets in the Arizona desert?". Roadtrippers. Retrieved 14 April 2016.
  29. "Corona Test Targets". borntourist.com. Retrieved 14 April 2016.
  30. Peebles, p. 48.
  31. Collins, p. 108.
  32. Hickam Kukini, page A-4, Vol 15, No 48, Friday, December 5, 2008, Base newspaper from Hickam AFB
  33. Monmonier, p. 22-23.
  34. Monmonier, p. 23.
  35. Day, Dwayne Allen (2008-02-18). "Spysat down!". The Space Review. Retrieved June 11, 2012.
  36. Ruffner, p. 32.
  37. Peebles, p. 159.
  38. National Reconnaissance Office. "National Reconnaissance Office Review and Redaction Guide for Automatic Declassification of 25-Year-Old Information. Version 1.0, 2006 edition, p. 58. Accessed 2012-06-06.
  39. https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1959-002A
  40. National Reconnaissance Office. "National Reconnaissance Office Review and Redaction Guide for Automatic Declassification of 25-Year-Old Information. Version 1.0, 2006 edition, p. 52. Accessed 2012-06-06.
  41. Ruffner, p. 32-33.
  42. Day, Dwayne Allen (2009-01-12). "Ike's gambit: The KH-8 reconnaissance satellite". The Space Review. Retrieved June 11, 2012.
  43. Peebles, p. 51.
  44. National Reconnaissance Office. "National Reconnaissance Office Review and Redaction Guide for Automatic Declassification of 25-Year-Old Information. Version 1.0, 2006 edition, p. 154. Accessed 2012-06-06.
  45. National Reconnaissance Office. The Corona Story. BYE 140001-98. December 1988, p. 32. Archived 2016-01-22 at the Wayback Machine Accessed 2012-06-06.
  46. National Reconnaissance Office. "National Reconnaissance Office Review and Redaction Guide for Automatic Declassification of 25-Year-Old Information. Version 1.0, 2006 edition, p. 118. Accessed 2012-06-06.
  47. Chien, Phillip. "High Spies." Popular Mechanics. February 1996, p. 49.
  48. Yenne, Bill (1985). The Encyclopedia of US Spacecraft. Exeter Books (A Bison Book), New York. ISBN 978-0-671-07580-4.p.82 Key Hole
  49. "Declassified intelligence satellite photographs fact sheet 090-96". United States Geological Survey. February 1998. Archived from the original on July 5, 2007.
  50. "Discoverer 13 - NSSDC ID: 1960-008A". NASA NSSDC.
  51. "Sputnik 5 - NSSDC ID: 1960-011A". NASA NSSDC.
  52. Yenne, Bill (1985). The Encyclopedia of US Spacecraft. Exeter Books (A Bison Book), New York. ISBN 978-0-671-07580-4.p.37 Discoverer
  53. "1967-043B". NASA National Space Science Data Center. 2010-10-08.
  54. "1970-098B". NASA National Space Science Data Center. 2010-10-08.
  55. Executive Order 12951
  56. Broad, William J. (12 September 1995). "Spy Satellites' Early Role As 'Floodlight' Coming Clear". The New York Times.
  57. "Satellite images spy ancient history in Syria". PhysOrg. August 3, 2006.
  58. Britt, Robert Roy (August 7, 2006). "Ancient Syrian Settlements Seen in Spy Satellite Images". LiveScience.
  59. Ur, Jason. "Ancient Communication Networks in Northern Mesopotamia". Harvard University. Archived from the original on February 5, 2013. Retrieved 20 March 2013.
  60. Ur, Jason. "Archaeological Applications of Declassified Satellite Photographs". Harvard University. Archived from the original on April 8, 2011. Retrieved 20 March 2013.
  61. "Corona".
  62. https://www.thespacereview.com/article/1333/1
  63. "MISSION 9043 SUCCESSFUL AIR RECOVERY" (PDF). National Reconnaissance Office. 21 September 1962. Archived from the original (PDF) on 16 March 2012. Retrieved 23 December 2010.
  64. "Photographic Evaluation Report: Mission 9043" (PDF). National Reconnaissance Office. 31 October 1962. Archived from the original (PDF) on 16 March 2012. Retrieved 23 December 2010.
  65. Robery Perry (October 1973). "A History of Satellite Reconnaissance: Volume I - Corona (page 215)" (PDF). Central Intelligence Agency. Archived from the original (PDF) on November 5, 2010.
  66. "MEMO: PHOTOGRAPHIC RECONNAISSANCE SYSTEMS, PROGRESS TOWARDS OBJECTIVES" (PDF). NRO. 1972-09-05. Archived from the original (PDF) on 2016-05-14. Retrieved 2011-07-15.
  67. Taubman, Secret Empire, p. 287.

Bibliography

  • Burrows, William E. This New Ocean: The Story of the First Space Age. New York: Random House, 1998.
  • Chun, Clayton K.S. Thunder Over the Horizon: From V-2 rockets to Ballistic Missiles. Westport: Praeger Security International, 2006.
  • Collins, Martin. After Sputnik: 50 Years of the Space Age. New York: Smithsonian Books/HarperCollins, 2007.
  • "Corona." Mission and Spacecraft Library. Jet Propulsion Laboratory. National Aeronautics and Space Administration. No date. Accessed 2012-60-06.
  • Day, Dwayen A.; Logsdon, John M.; and Latell, Brian, eds. Eye in the Sky: The Story of the Corona Spy Satellites. Washington, D.C.: Smithsonian Institution Press, 1998. ISBN 978-1560988304
  • "Discoverer/Corona: First U.S. Reconnaissance Satellite. National Air and Space Museum. Smithsonian Institution. 2002. Accessed 2012-06-06.
  • Drell, Sidney D. "Physics and U.S. National Security." Reviews of Modern Physics. 71:2 (1999), p. S460-S470.
  • Drell, Sidney D. "Reminiscences of Work on National Reconnaissance." in Nuclear Weapons, Scientists, and the Post-Cold War Challenge: Selected Papers on Arms Control. Sidney D. Drell, ed. Hackensack, N.J.: World Scientific, 2007.
  • Jensen, John R. Remote Sensing of the Environment: An Earth Resource Perspective. Upper Saddle River, N.J.: Pearson Prentice Hall, 2007.
  • Kramer, Herbert J. Observation of the Earth and Its Environment: Survey of Missions and Sensors. Berlin: Springer, 2002.
  • Lewis, Jonathan E. Spy Capitalism: Itek and the CIA. New Haven, Conn.: Yale University Press, 2002.
  • Monmonier, Mark S. Spying With Maps: Surveillance Technologies and the Future of Privacy. Chicago: University of Chicago Press, 2004.
  • National Aeronautics and Space Administration. Societal Impact of Spaceflight. Washington, D.C.: NASA, 2009.
  • Olsen, Richard C. Remote Sensing From Air and Space. Bellingham, Wash.: SPIE Press, 2007.
  • Peebles, Curtis. The Corona Project: America's First Spy Satellites. Annapolis, Md.: Naval Institute Press, 1997.
  • Ruffner, Kevin C., ed. Corona: America's First Satellite Program. New York : Morgan James, 1995.
  • Smith, F. Dow. "The Design and Engineering of Corona's Optics." in CORONA: Between the Sun & the Earth: The First NRO Reconnaissance Eye in Space. Robert McDonald, ed. Bethesda, Md.: ASPRS, 1997.
  • Taubman, Phil. Secret Empire: Eisenhower, the CIA, and the Hidden Story of America’s Space Espionage. New York: Simon & Schuster, 2003. ISBN 0-684-85699-9
  • Yenne, Bill. Secret Gadgets and Strange Gizmos: High-Tech (and Low-Tech) Innovations of the U.S. Military. Grand Rapids, Mich.: Publishers Group Worldwide, 2006.
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