thumb|upright=1.0|right|KH7-13 launch on [[Atlas-Agena]]BYEMAN codenamed GAMBIT, the KH-7 (Air Force Program 206) was a reconnaissance satellite used by the United States from July 1963 to June 1967. Like the older CORONA system, it acquired imagery intelligence by taking photographs and returning the undeveloped film to earth. It achieved a typical ground-resolution of to . In 2002, all KH-7 satellite imagery, with the exception of some facilities in Israel, was declassified. Other details of the satellite program and construction remained classified until 2011.
In its summary report following the conclusion of the program, the National Reconnaissance Office concluded that the GAMBIT program was considered highly successful in that it produced the first high-resolution satellite photography, 69.4% of the images having a resolution under ; its record of successful launches, orbits, and recoveries far surpassed the records of earlier systems; and it advanced the state of the art to the point where follow-on larger systems could be developed and flown successfully. The report also stated that Gambit had provided the intelligence community with the first high-resolution satellite photography of denied areas, the intelligence value of which was considered "extremely high".
A feasibility study for the Geodetic Orbital Photographic Satellite System reveals three subsystems for U.S. optical reconnaissance satellites in the 1960s: the Orbital (or Orbiting) Control Vehicle (OCV), the Data Collection Module (DCM), and the Recovery Section (RS). For the KH-7, the DCM is also called the Camera Optics Module (COM), and is integrated in the OCV, which has a length of and a diameter of .
Camera Optics Module
The Camera Optics Module of KH-7 consists of three cameras: a single strip camera, a stellar camera, and an index camera.
In the strip camera the ground image is reflected by a steerable flat mirror to a diameter stationary concave primary mirror. The primary mirror reflects the light through an opening in the flat mirror and through a Ross corrector. It took images of a 6.3° wide ground swath by exposing a wide moving portion of film through a small slit aperture. The initial ground resolution of the satellite was , but improved to by 1966. Each satellite weighed about , and returned a single film bucket per mission. The camera and film transport system were manufactured by Eastman Kodak Company.
Mission
All KH-7 satellites were launched from Point Arguello, which became part of Vandenberg Air Force Base in July 1964. KH-7 satellites flew 38 missions, numbered 4001-4038, of which 34 returned film, and of these, 30 returned usable imagery. Mission duration was 1 to 8 days. KH-7 satellites logged a total of almost 170 operational days in orbit. Most of the imagery from this camera, amounting to 19,000 images, was declassified in 2002 as a result of Executive order 12951, the same order which declassified CORONA, and copies of the films were transferred to the U.S. Geological Survey's Earth Resources Observation Systems office. Approximately 100 frames covering the state of Israel remain classified.
In early 1964, the CIA toyed with the idea of using GAMBIT to photograph military installations in Cuba, but this was dismissed as unworkable as the satellites were primarily designed with higher-latitude Soviet territory in mind and because it would mean wasting an entire satellite on the Latin America-Caribbean area which had little else of interest to U.S. intelligence services. It was decided that U-2 spyplane flights were adequate to provide coverage of Cuban activity.
ELINT subsatellite
Mission 4009 included an ELINT P-11 subsatellite for radar monitoring, which was launched into a higher orbit.
List of launches
thumb|upright=1.0|right|A KH-7 GAMBIT optical reconnaissance satellite.
{| class="wikitable"
|-
! Name
! Mission No.
! Launch Date
! Alt. Name
! NSSDC ID No.
! Launch Vehicle
! Perigee (km)
! Apogee (km)
! Inclination (deg)
|-
| KH7-1
| 4001
| 1963-07-12
| OPS-1467
| 1963-028A
| Atlas-Agena D
| 164
| 164
| 95.4
|-
| KH7-2
| 4002
| 1963-09-06
| OPS-1947
| 1963-036A
| Atlas Agena D
| 168
| 263
| 94.4
|-
| KH7-3
| 4003
| 1963-10-25
| OPS-2196
| 1963-041A
| Atlas Agena D
| 144
| 332
| 99.1
|-
| KH7-4
| 4004
| 1963-12-18
| OPS-2372
| 1963-051A
| Atlas Agena D
| 122
| 266
| 97.9
|-
| KH7-5
| 4005
| 1964-02-25
| OPS-2423
| 1964-009A
| Atlas Agena D
| 173
| 190
| 95.7
|-
| KH7-6
| 4006
| 1964-03-11
| OPS-3435
| 1964-012A
| Atlas Agena D
| 163
| 203
| 95.8
|-
| KH7-7
| 4007
| 1964-04-23
| OPS-3743
| 1964-020A
| Atlas Agena D
| 150
| 366
| 103.6
|-
| KH7-8
| 4008
| 1964-05-19
| OPS-3592
| 1964-024A
| Atlas Agena D
| 141
| 380
| 101.1
|-
| KH7-9
| 4009
| 1964-07-06
| OPS-3684
| 1964-036A
| Atlas Agena D
| 121
| 346
| 92.9
|-
| KH7-10
| 4010
| 1964-08-14
| OPS-3802
| 1964-045A
| SLV-3 Agena D
| 149
| 307
| 95.5
|-
| KH7-11
| 4011
| 1964-09-23
| OPS-4262
| 1964-058A
| SLV-3 Agena D
| 145
| 303
| 92.9
|-
| KH7-12
| 4012
| 1964-10-08
| OPS-4036
| 1964-F11
| SLV-3 Agena D
| ---
| ---
| ---
|-
| KH7-13
| 4013
| 1964-10-23
| OPS-4384
| 1964-068A
| Atlas Agena D
| 139
| 271
| 88.6
|-
| KH7-14
| 4014
| 1964-12-04
| OPS-4439
| 1964-079A
| SLV-3 Agena D
| 158
| 357
| 97
|-
| KH7-15
| 4015
| 1965-01-23
| OPS-4703
| 1965-005A
| SLV-3 Agena D
| 146
| 291
| 102.5
|-
| KH7-16
| 4016
| 1965-03-12
| OPS-4920
| 1965-019A
| SLV-3 Agena D
| 93
| 155
|
|-
| KH7-17
| 4017
| 1965-04-28
| OPS-4983
| 1965-031A
| SLV-3 Agena D
| 180
| 259
| 95.7
|-
| KH7-18
| 4018
| 1965-05-27
| OPS-5236
| 1965-041A
| SLV-3 Agena D
| 149
| 267
| 95.8
|-
| KH7-19
| 4019
| 1965-06-25
| OPS-5501
| 1965-050B
| SLV-3 Agena D
| 151
| 283
| 107.6
|-
| KH7-20
| 4020
| 1965-07-12
| OPS-5810
| 1965-F07
| SLV-3 Agena D
| ---
| ---
| ---
|-
| KH7-21
| 4021
| 1965-08-03
| OPS-5698
| 1965-062A
| SLV-3 Agena D
| 149
| 307
| 107.5
|-
| KH7-22
| 4022
| 1965-09-30
| OPS-7208
| 1965-076A
| SLV-3 Agena D
| 98
| 164
| 95.6
|-
| KH7-23
| 4023
| 1965-11-08
| OPS-6232
| 1965-090B
| SLV-3 Agena D
| 145
| 277
| 93.9
|-
| KH7-24
| 4024
| 1966-01-19
| OPS-7253
| 1966-002A
| SLV-3 Agena D
| 150
| 269
| 93.9
|-
| KH7-25
| 4025
| 1966-02-15
| OPS-1184
| 1966-012A
| SLV-3 Agena D
| 148
| 293
| 96.5
|-
| KH7-26
| 4026
| 1966-03-18
| OPS-0879
| 1966-022A
| SLV-3 Agena D
| 162
| 208
| 101
|-
| KH7-27
| 4027
| 1966-04-19
| OPS-0910
| 1966-032A
| SLV-3 Agena D
| 139
| 312
| 116.9
|-
| KH7-28
| 4028
| 1966-05-14
| OPS-1950
| 1966-039A
| SLV-3 Agena D
| 133
| 358
| 110.5
|-
| KH7-29
| 4029
| 1966-06-03
| OPS-1577
| 1966-048A
| SLV-3 Agena D
| 143
| 288
| 86.9
|-
| KH7-30
| 4030
| 1966-07-12
| OPS-1850
| 1966-062A
| SLV-3 Agena D
| 137
| 236
| 95.5
|-
| KH7-31
| 4031
| 1966-08-16
| OPS-1832
| 1966-074A
| SLV-3 Agena D
| 146
| 358
| 93.3
|-
| KH7-32
| 4032
| 1966-09-16
| OPS-1686
| 1966-083A
| SLV-3 Agena D
| 148
| 333
| 93.9
|-
| KH7-33
| 4033
| 1966-10-12
| OPS-2055
| 1966-090A
| SLV-3 Agena D
| 155
| 287
| 91
|-
| KH7-34
| 4034
| 1966-11-02
| OPS-2070
| 1966-098A
| SLV-3 Agena D
| 159
| 305
| 91
|-
| KH7-35
| 4035
| 1966-12-05
| OPS-1890
| 1966-109A
| SLV-3 Agena D
| 137
| 388
| 104.6
|-
| KH7-36
| 4036
| 1967-02-02
| OPS-4399
| 1967-007A
| SLV-3 Agena D
| 136
| 357
| 102.4
|-
| KH7-37
| 4037
| 1967-05-22
| OPS-4321
| 1967-050A
| SLV-3 Agena D
| 135
| 293
| 91.5
|-
| KH7-38
| 4038
| 1967-06-04
| OPS-4360
| 1967-055A
| SLV-3 Agena D
| 149
| 456
| 104.8
|-
|}
<small>(NSSDC ID Numbers: See COSPAR)</small>
History
thumb|upright=1.0|right|An enlargement of a photograph of the [[U.S. Capitol taken by KH-7 mission 4025 on 19 February 1966.]]
thumb|upright=1.0|right|A KH-7 GAMBIT optical reconnaissance satellite.
:Section source: Space Review The developed results was sent to US Air Force imagery research analysts in Washington, DC.
GAMBIT mission 4003, was launched on 25 October 1963. The film canister was again ejected successfully after the photographic phase and the capsule recovered by an aircraft. Other tests were carried out with the OCV.
GAMBIT mission 4004 was launched and its film canister recovered on 18 December 1963. Missions 4005 through 4007 were also successful.
In May 1964, mission 4008 suffered major problems when the Agena did an unexplained roll during the boost phase. Even with OCV system problems, the film canister was able to return some imagery.
A variety of problems occurred with many of the remaining missions including poor or no imagery. Many of these difficulties were caused by the unreliable wire recording system carried by the GAMBITs (tape recorders were not yet in widespread use in the mid-1960s). Two satellites ended up in the Pacific Ocean. The first of them was 4012, launched on October 8, 1964. The Agena engine shut down after 1.5 seconds of operation and the GAMBIT did not attain orbit. An investigation of the failure found that an electrical short occurred in an engine relay box, resulting in a cutoff signal being issued 0.4 seconds after ignition. As soon as the engine arming command was stopped at 1.5 seconds, the Agena propulsion system shut down. Examination of factory records for the Agena found that a pair of metal screws from a little-used terminal connector had broken off and disappeared to parts unknown; it was speculated that they landed somewhere as to cause a short. Telemetry data indicated otherwise entirely normal performance of all Agena systems. The other failure was 4020, launched on 12 July 1965 when the Atlas programmer accidentally issued simultaneous SECO and BECO commands, the resultant propulsion system shutdown sending the launch vehicle into the Pacific Ocean some downrange. The latter was the first flight witnessed by newly arrived Brig. Gen John L. Martin who replaced Maj. Gen Robert Greer as head of the KH-7 program. Martin cracked down and began demanding higher workmanship and quality standards. He is credited with having significantly improved the success rate of the program.
It was noted that the GAMBIT flights through the first half of 1964 had been mostly successful, but a string of malfunctions occurred starting in the second half of the year and continuing through the first half of 1965. These included the two above-mentioned launch failures plus GAMBIT 4013 which did not return any imagery and GAMBIT 4014 which suffered a battery explosion. GAMBIT 4019 did not return any imagery either. Eventually, it was determined that the culprit was an extra structure added to the SLC-4W umbilical tower that sent resonant vibration through the Atlas-Agena stack at liftoff, jarring random components in the booster and/or spacecraft loose.
The KH-7 GAMBIT was an overall success, even with some failures; thus providing National Reconnaissance Office and the President with quality intelligence collection. Following KH-7 projects had greatly improved major upgrades in the spacecraft and its camera systems.
Cost
The total cost of the 38 flight KH-7 program from FY1963 to FY1967, without non-recurring costs, and excluding five GAMBIT cameras sold to NASA, was US$651.4 million in 1963 dollars (inflation adjusted US$ billion present day). Non-recurring costs for industrial facilities, development, and one-time support amounted to 24.3% of the total program cost, or US$209.1 million. The resulting total program costs were US$860.5 million in 1963 dollars (inflation adjusted US$ billion present day).