The SAMOS (misidentified as Satellite and Missile Observation System)https://nssdc.gsfc.nasa.gov/nmc/spacecraft/spacecraft/query - type SAMOS in the spacecraft box. or SAMOS-E program was a relatively short-lived series of reconnaissance satellites for the United States in the early 1960s, also used as a cover for the initial development of the KH-7 GAMBIT system. Reconnaissance was performed with film cameras and television surveillance from polar low Earth orbits with film canister returns and transmittals over the United States. SAMOS was first launched in 1960 from Vandenberg Air Force Base.
SAMOS was also known by the unclassified terms Program 101 and Program 201.
History Background
WS-117L and costs SAMOS started as part of the WS-117L satellite reconnaissance and protection program of the United States Air Force in 1956. In May 1958, the Department of Defense directed the transfer of the WS-117L program to ARPA. Significant parts of the SAMOS development program were SAMOS-E (optical reconnaissance), SAMOS-F (ELINT Ferret reconnaissance).
In FY1958, WS-117L was funded by the Air Force at a level of US$ 108.2 million (inflation adjusted US$ billion in ). For SAMOS, USAF, and ARPA spent a combined sum of US$82.9 million in FY1959 (inflation adjusted US$ billion in ) and US$163.9 million in FY1960 (inflation adjusted US$ billion in ).
CORONA and SAMOS
During this period, the rival CORONA program, which saw its first launch in February 1959, began operation. SAMOS emerged as a more advanced satellite with additional capabilities that due to its larger mass would be launched on the Atlas-Agena booster instead of the Thor-Agena. While CORONA took photographs and returned them to Earth in a film capsule, SAMOS would instead electronically scan its film and beam images down by radio link.
While CORONA began flying in 1959, the reliability of the program for its first three years was abysmal and a backup reconnaissance program was needed. Moreover, the fear of the "missile gap" with the Soviet Union was very great, with space successes and boasts by Soviet politicians seeming to hint that the USSR not only had a large arsenal of nuclear missiles on hand, but were quite willing to use them. The US ballistic missile arsenal in 1960 consisted of a handful of Atlas ICBMs that were exposed to Soviet attack, took a long time to prepare for launch, and whose test flight record did not inspire much confidence. The Thor and Jupiter IRBMs stationed in the UK, Italy, and Turkey were not much of an improvement, also their bases could be attacked by Soviet bombers. Intelligence on Soviet missile activities was considered vital, but the only viable option, U-2 reconnaissance flights, had been halted by the Gary Powers shootdown in May 1960. Unbeknownst to the Pentagon, Soviet missiles were deployed in far smaller numbers than generally believed and their reliability was no better than any US missile. The initial SAMOS satellites were known as Program 101 and were merely a test model designed to verify the operability of the photo-optical camera system.
Name and secrecy "Samos" was the name of a Greek island and the name was picked with the belief that nobody would associate it with reconnaissance. However, a mistaken rumor later emerged that the name was an acronym for "Satellite And Missile Observation System". President Eisenhower was adamant about cultivating the image that the US space program was only for peaceful purposes. The Air Force for a while managed to create the fiction that Discoverer was a series of scientific satellites, but SAMOS's real purpose was known from the beginning, and efforts to not link it to Discoverer were made. Although the existence and mission purpose of SAMOS was publicly acknowledged until the fall of 1961, the Air Force did not release detailed information about the satellites or exactly what they were doing during their missions.
SAMOS 1
SAMOS 1 launch took place from PALC 1-1 (Point Arguello Launch Complex - later absorbed into the main launch center at Vandenberg Air Force Base) at 20:34 GMT on 11 October 1960, using Atlas LV-3 Agena-A vehicle 57D and Agena 2101. The Atlas lifted smoothly and steered downrange, as the weather was clear and cloudless, visibility was excellent and the launch vehicle could be seen until after booster section separation. Initial jubilation at the successful launch turned to dismay when the real-time telemetry readouts showed that the nitrogen pressure gas for the Agena-A's attitude control jets was gone. Without this, the stage could not be stabilized for ignition so that after separation from the Atlas, the Agena-A was left with no attitude control. Telemetry indicated an erratic attitude rate and abnormal gimbaling of the Bell XLR-81 engine. The Agena-A burn lasted 123 seconds, slightly longer than nominal, but tracking stations in VAFB, Kodiak Island, and Hawaii found no indication that orbit had been achieved, and it was concluded that the vehicle had reentered and broken up over an unknown point in the Pacific Ocean. The postflight analysis also found that the Atlas guidance system had malfunctioned in flight, due to either a failure of the rate beacon or waveguide antenna, but the guidance system was not telemetered so an exact cause could not be determined. The guidance system was unable to generate any steering or programmed engine cutoff commands, however, backup signals from the missile programmer managed to ensure a proper flight path and on-time engine cutoff. The Agena-A malfunction was traced to a technician installing a pad umbilical release lanyard improperly, which resulted in the Agena-A nitrogen quick fill line being ripped out at liftoff. Film and photographs of the launch clearly showed the gas escaping. At Agena engine ignition, the performance was also below normal, suggesting damage to the pneumatic system as well."Flight Evaluation Report, Atlas 57D Convair October 25, 1960"
The major objective of the SAMOS 1 mission was to determine the engineering feasibility of obtaining ground observation capability from an orbiting satellite. It launched on 11 October 1960 at 20:34 GMT from the Pacific Missile Range in Point Arguello, California. The first stage separated at 249.9 seconds after liftoff. The Agena-A second stage ignited at 506.7 seconds and cutoff at 629.3 seconds, as planned, but a loss of nitrogen gas pressure had disrupted the guidance and control systems at 123 seconds, resulting in poor trajectory and failure to orbit the payload. Tracking telemetry was lost prior to the Agena-A ignition, so the exact trajectory was unknown. SAMOS 1 was the first satellite in the series SAMOS launched by the US Air Force from Vandenberg Air Force Base aboard an Atlas Agena-A rocket. It was a first-generation photo surveillance satellite intended to radio relay images back to Earth but loss of nitrogen gas pressure disrupted the guidance and control systems, causing a second stage failure. No data were returned. The payload comprised photographic and related test equipment, telemetry, radiation, tracking, and command instrumentation. The payload was housed in the Agena second stage. The entire stage was designed to go into orbit. The stage, including payload and casing, had a planned orbital mass of 1,845 kg. It was a 6.7 meter high, 1.5-meter diameter cylinder. The first stage was a modified Atlas ICBM. The full rocket was 30.2 m high with a base diameter of 3.05 m and a liftoff mass of approximately 124 000 kg.
SAMOS 2 SAMOS 2 was launched on 31 January 1961, on Atlas 70D and Agena 2102. Unlike with SAMOS 1, the weather was foggy and gray, and the pad was not even visible from the blockhouse. This time, everything worked perfectly and SAMOS 2 achieved orbit. The F-1 ferret system was tested first, followed by the E-1 electro-optical cameras, which transmitted images of approximately 30.5 m of resolution. On-orbit 21, ground controllers sent the command to jettison the F-1 antenna, which was partially obstructing the camera, in the hopes of even better images. However, something went disastrously wrong when all telemetry signals from SAMOS 2 ceased. It was believed that the separation mechanism for the F-1 antenna had caused the partial or complete disintegration of the satellite vehicle. SAMOS 2 remained in orbit until it decayed into the atmosphere on 21 October 1971.
SAMOS 2 was launched from the Pacific Missile Range at 20:24:00 GMT, into a near-circular polar orbit of 474 x 557 km, 94.97 min of revolution, and 97.4° of inclination, to determine the capability for making observations of space, the atmosphere, and the nature of the globe from satellites. The 1 860 kg spacecraft was a cylinder 6.7 m long and 1.5 m in diameter, and it comprised the entire Agena-A second stage. Included in the instrumentation were photographic and associated test equipment, acoustical (Microphone Density Gauge) micrometeorite detection apparatus, a plasma probe, and an electric field meter. The computer on board was digital-to-analog. Telemetry, tracking, and command equipment completed the payload. Details about the satellite's transmitter were not announced. A conical nose cap detached from the satellite casing and remained in orbit. The expected lifetime of the satellite was 15 years, and the expected lifetime of the nose cap was 12 years.
The next attempt did not take place for seven months, because of the switch to the larger Agena-B second stage that could be restarted in orbit and the operational Program 101A satellites, which had a more advanced camera system with better resolution and a wider field of view. SAMOS satellites after SAMOS 2 also sported a large "mushroom cap" nose cone, as early plans had envisioned flying a crewed capsule similar to Project Mercury.
SAMOS 3
The SAMOS 3 launch was a complete disaster. SAMOS 3 lifted from PALC 1-1 on 9 September 1961 at 00:00:00 GMT, was a US Air Force first-generation photo surveillance satellite with 7 instruments on board but the Atlas LV-3 Agena-B booster's engines shut down after the rocket had ascended about 29 cm and it fell back onto the pad in an enormous fireball. Postflight investigation found that an umbilical on PALC 1-1 had not detached on time, resulting in the booster being switched from internal to external power, but since the power umbilicals on the pad had already detached, the result was a complete loss of electrical power to all Atlas systems. The accident necessitated improved procedures to umbilical lanyard installation, and modifications to the launcher system to prevent the hold-down arms from releasing the launch vehicle until all umbilicals had detached.
After SAMOS 3, it was decided to abandon the Program 101/101A satellites entirely and switch to a more conventional film recovery capsule, since the one successful mission had not proven the viability of the electro-optical camera system. While the 101/101A satellites separated from the Agena-B in orbit, the 101B would remain attached and would use it for orbital maneuvers and also deorbiting the film capsule at the end of the mission.
Several more 101/101A satellites were either completed or in a state of partial completion when the program was called off, but the problem of how to dispose of them was never satisfactorily solved. Most were left mothballed in warehouses or scrapped. There was talk of giving the camera systems to NASA for the planetary probe program, but they were of doubtful value for taking photographs of the Moon. The Agena stages that could not be repurposed for other programs were scrapped.