The first flight of the Almaz manned military space station. In January 1973 the first Almaz OPS was delivered to Baikonur. Launch and initial orbital checkout went according to plan. But before a crew could be launched the station depressurized. It was concluded that a short in electrical equipment started a fire in pressure vessel, leading to rupture of hull and depressurization. An alternate theory was that debris from an explosion of the third stage of Proton penetrated the hull. Control was lost on April 25, 1973, and the OPS cased operations on 29 April. Decayed May 28, 1973. Initial crew was to have been Popovich and Artyukhin.
Officially: Testing of improved design, on-board systems and equipment; conduct of scientific and technical research and experiments. References: 1 , 2 , 5 , 6 , 67 , 274 .

Studies were conducted to determine the feasibility of conducting a controlled deorbit of the Orbital Workshop. Three methods were considered: (l) using the CSM service propulsion system; (2) using the CSM reaction control system; and (3) implementing an S-II (Saturn V second stage) deorbit. The service propulsion system deorbit was assessed as not feasible; the reaction control system deorbit was considered technically feasible but, like the service propulsion system, it had an inherent program and crew safety risk associated with it. Implementation of an S-II deorbit would have serious time and cost impacts on the program. A 1970 study, which indicated that the probability of damage from the deorbiting Skylab was so small that changes which caused major impact in cost and schedule were not worth pursuing, was confirmed.

Continued operation of the long-range telephone and telegraph radio-communication system within the Soviet Union and transmission of USSR central television programmes to stations in the Orbita and participating international networks (international coope ration scheme). References: 1 , 2 , 5 , 6 .

Jupiter flyby December 1974; Saturn flyby September 1979. Solar system escape trajectory. Pioneer 11 was the second mission to investigate Jupiter and the outer solar system and the first to explore the planet Saturn and its main rings. Pioneer 11, like Pioneer 10, used Jupiter's gravitational field to alter its trajectory radically. It passed close to Saturn and then it followed an escape trajectory from the solar system. During its closest approach, December 4, 1974, Pioneer 11 passed to within 34,000 km of Jupiter's cloud tops. It passed by Saturn on September 1, 1979, at a distance of 21,000 km from Saturn's cloud tops. The spacecraft has operated on a backup transmitter since launch. Instrument power sharing began in February 1985 due to declining RTG power output. Science operations and daily telemetry ceased on September 30, 1995 when the RTG power level was insufficient to operate any experiments. As of the end of 1995 the spacecraft was located at 44.7 AU from the Sun at a nearly asymptotic latitude of 17.4 degrees above the solar equatorial plane and was heading outward at 2.5 AU/year. Routine tracking and project data processing operations were terminated on March 31, 1997 for budget reasons. References: 1 , 2 , 5 , 6 , 278 , 296 .

Investigation of the upper atmosphere and outer space. References: 1 , 2 , 5 , 6 , 99 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable; exploded in orbit. References: 1 , 2 , 5 , 6 .

Solar radition monitor. Name is 'Intercosmos Copernicus 500'. Investigation of solar radio-frequency radiation and the characteristics of the earth's ionosphere. References: 1 , 2 , 5 , 6 , 99 , 116 .

Anik I and Anik II also registered as United States objects. .The satellites, act as space repeaters capable of receiving transmissions from earth stations and retransmitting them to other earth stations in Canada. The antenna coverage of the satellite pr ovides the capability of serving virtually all of Canada. Anik I and II had weights of 1240.59 lb and 1246.48 lb. Each satellite has 12 RF channels each capable of transmitting a color television signal or up to 900 one-way voice channels. References: 1 , 2 , 5 , 6 .

Area survey photo reconnaissance satellite; returned film capsule; separated science capsule. References: 1 , 2 , 6 .

Ocean surveillance; nuclear powered. American 'sniffer' aircraft flew over the Pacific after this failure looking for radioisotopes traces in order to characterise the reactor. References: 42 , 290 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

Salyut failure. Unsuccessful mission. Salyut out of control. Decayed May 22, 1973. Was to have been manned by initial crew of Leonov and Kubasov. Last chance to upstage Skylab, launched three days later. References: 1 , 2 , 5 , 6 , 67 , 274 .

First and only US space station to date. Project began life as Apollo Orbital Workshop - outfitting of an S-IVB stage with docking adapter with equipment launched by several subsequent S-1B launches. Curtailment of the Apollo moon landings meant that surplus Saturn V's were available, so the pre-equipped, five times heavier, and much more capable Skylab resulted.

An unexpected telemetry indication of meteoroid shield deployment and solar array wing 2 beam fairing separation was received 1 minute and 3 seconds after liftoff. However, all other systems of the OWS appeared normal, and the OWS was inserted into a near-circular Earth orbit of approximately 435 km altitude. The payload shroud was jettisoned, and the ATM with its solar array was deployed as planned during the first orbit. Deployment of the Workshop solar array and the meteoroid shield was not successful. In fact the xternal solar/meteoroid shield had ripped off 63 seconds into ascent, tearing away one solar panel wing and debris jamming the remaining panel. Without shield temperatures soared in station. Repairs by crews led to virtually all mission objectives being met.

Following the final manned phase of the Skylab mission, ground controllers performed some engineering tests of certain Skylab systems--tests that ground personnel were reluctant to do while men were aboard. Results from these tests helped to determine causes of failures during the mission and to obtain data on long term degradation of space systems.

Upon completion of the engineering tests, Skylab was positioned into a stable attitude and systems were shut down. It was expected that Skylab would remain in orbit eight to ten years. It was to have been visited by an early shuttle mission, reboosted into a higher orbit, and used by space shuttle crews. But delays in the first flight of the shuttle made this impossible.

On July 11, 1979, Skylab disintegrated when it re-entered the earth's atmosphere after a worldwide scare over its pending crash. The debris stretched from the south-east Indian Ocean into Western Australia. Additional Details: Skylab 1. References: 1 , 2 , 5 , 6 .

KH-8 type satellite. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A). References: 1 , 2 , 5 , 6 .

Investigation of the upper atmosphere and outer space. References: 1 , 2 , 5 , 6 , 99 .

First flight of Soyuz U launch vehicle. High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 5 , 6 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

Area survey photo reconnaissance satellite; returned film capsule; separated gamma ray telescope experiment capsule. References: 1 , 2 , 6 .

First and failed attempt to release jammed solar panel. References: 66 .

Epic repair mission which brought Skylab into working order. Included such great moments as Conrad being flung through space by the whiplash after heaving on the solar wing just as the debris constraining it gave way; deployment of a lightweight solar shield, developed in Houston in one week, which brought the temperatures down to tolerable levels. With this flight US again took manned spaceflight duration record.

Skylab 2 , consisting of a modified Apollo CSM payload and a Saturn IB launch vehicle, was inserted into Earth orbit approximately 10 minutes after liftoff. The orbit achieved was 357 by 156 km and, during a six-hour period following insertion, four maneuvers placed the CSM into a 424 by 415 km orbit for rendezvous with the Orbital Workshop. Normal rendezvous sequencing led to stationkeeping during the fifth revolution followed by a flyaround inspection of the damage to the OWS. The crew provided a verbal description of the damage in conjunction with 15 minutes of television coverage. The solar array system wing (beam) 2 was completely missing. The solar array system wing (beam) 1 was slightly deployed and was restrained by a fragment of the meteoroid shield. Large sections of the meteoroid shield were missing. Following the flyaround inspection, the CSM soft-docked with the OWS at 5:56 p.m. EDT to plan the next activities. At 6:45 p.m. EDT the CSM undocked and extravehicular activity was initiated to deploy the beam 1 solar array. The attempt failed. Frustration of the crew was compounded when eight attempts were required to achieve hard docking with the OWS. The hard dock was made at 11:50 p.m. EDT, terminating a Skylab 2 first-day crew work period of 22 hours. Additional Details: Skylab 2. References: 1 , 2 , 5 , 6 , 33 , 60 .

Acquisition of meteorological information needed for use by the weather service. References: 1 , 2 , 5 , 6 .

Meteorological Rocket. References: 98 .

Planned first mission to the Salyut DOS 3 space station (Cosmos 557). Cancelled after it failed in orbit. References: 344 .

Investigation of the upper atmosphere and outer space. References: 1 , 2 , 5 , 6 , 99 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

Succeeded in release of jammed solar panel. References: 66 .

Eight satellites launched by a single carrier rocket. References: 1 , 2 , 5 , 6 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

Radio Astronomy Explorer; measured galactic, stellar radio noise. Lunar Orbit (Selenocentric). Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B). References: 1 , 2 , 5 , 6 .

Soyuz test flight. Recovered June 17, 1973 6:01 GMT. Soyuz 7K-T redesign test. References: 1 , 2 , 6 .

Replacement of film cartridges for solar camera. References: 66 .

Military navigation satellite. References: 1 , 2 , 5 , 6 .

Area survey photo reconnaissance satellite; returned film capsule; separated capsule. References: 1 , 2 , 6 .

Military topography satellite; returned film capsule; separated science capsule. References: 1 , 2 , 6 .