Short mission of the first Almaz


ops1

The OPS-1 (Almaz) space station is being integrated with its UR-500K rocket in preparation for launch in the Spring of 1973.


Almaz OPS-1 mission at a glance:

Spacecraft designation OPS-1, Almaz 11F71 No. 0101-1
Launch date and time 1973 April 3, 12:00 Moscow Time
Launch vehicle UR-500K (Proton) No. 283-01
Launch site Tyuratam, Site 81, Pad No. 23 (Left)
Deorbit date and time (uncontrolled) 1973 May 28, 14:51 Moscow Time

Preparations for launch

The general assembly of the first flight-worthy Almaz space station, OPS-1, was conducted at the Khrunichev plant, ZIKh, in Moscow from the Fall of 1971 until Oct. 1, 1972. During the night from Oct. 2 to Oct. 3, 1972, it was transferred from ZIKh in Moscow's northwest suburb of Fili to the TsKBM design bureau in Reutov, on the southeastern edge of Moscow. Here, the lab went through final integrated tests at the newly formed KITs checkout facility (from the Russian Kontrolno-Ispytatelny Tsentr). All the tests were completed on Dec. 12, 1972 and the station left for Tyuratam launch site on Dec. 25, 1972. The train carrying the lab reached the Kazakh launch site during the New Year's eve of 1973, or almost two years after the first Salyut civilian space station, developed at TsKBEM. The station was unloaded at Site 92 and prepared for launch at Building 92-2. In the meantime, the UR-500K rocket was being assembled at Building 92-1. (1050)

Mikhail Grigoriev, deputy commander of the Soviet Strategic Missile Forces, led the State Commission, which was formed on Dec. 27, 1972, to oversee the launch campaign. (100)

The launch site met the lab with a harsh winter conditions, putting considerable pressure on nearly 500 military testers and civilian specialists, who were preparing the spacecraft in the next 90 days.

OPS-1 space station was cleared for fueling and other irreversible operations on March 20, 1973, and on March 24, the fully assembled UR-500K rocket with the station was rolled out to Pad 23 at Site 81 in preparation for lift off before the end of the month.

A crew, including the commander Pavel Popovich and flight engineer Yuri Artyukhin, prepared to fly to OPS-1 onboard Soyuz 7K-T No. 61 spacecraft (INSIDER CONTENT), which was originally scheduled for launch 10 days after the station had reached orbit. However, when the station was already on the launch pad, technical problems with the parachute system of the Soyuz spacecraft forced the postponement of the crew launch. At the time, the processing personnel in Baikonur had already completed irreversible operations with the OPS-1 and its rocket booster, so on April 1, 1973, the State Commission made a decision to proceed with the launch on April 3, 1973, at 11:50 Moscow Time.

Shortly before the scheduled liftoff, a small amount of propellant was spilled from the rocket into the flame trench below the pad. The incident did not affect the vehicle, but there was some risk that the flammable fluid could get onto cable of ground equipment which could trigger an explosion. Alternatively, the delay of the launch would require a risky propellant drainage process. Instead, Vladimir Chelomei, Designer General at TsKBM, took a last-minute ride to the pad and, after a short inspection of the facility, issued his personal permission to proceed with the launch. (1050)

First Almaz enters orbit

The OPS-1 finally lifted off into orbit on April 3, 1973, at 12:00 Moscow Time. Six engines of the first stage fired until 125 seconds into the ascent, when they began throttling down the thrust. At the same time, the second stage ignited its four engines, firing through the lattice structure connecting the boosters and a second later, the first and second stages parted ways. At L+335 seconds, four vernier thrusters of the third stage began firing via special openings in the adapter connecting the second and third stage, followed by the separation of the second stage at L+339 and the ignition of the third-stage engine. Safely above the dense atmosphere, the payload fairing, protecting the station from the aerodynamic loads, was jettisoned at L+348 seconds. The propulsion system of the third stage was cut off by L+575 seconds and the station successfully separated from the third stage into a 221-kilometer orbit 592 seconds into the flight.

Next, the station's onboard sequencer commanded the station to deploy its antennas, to jettison window covers and to deploy solar panels. Also, the station fired two main engines to climb to a 275-kilometer operational orbit. According to available telemetry, all these operations had gone as planned. (1050)

Because the Soviet authorities did not want to disclose the existence of two space station projects in the USSR, and particularly, to reveal the development of the military Almaz, OPS-1 was announced as Salyut-2 upon reaching orbit.

The initial flight of OPS-1 was going smoothly — the station successfully established three-axis attitude control, aligning itself with the direction of the flight, the inertial orientation was also tested. Mission control also successfully oriented the station using small thrusters and gyroscopic system. The successful orbit corrections were performed on April 4 and April 8, 1973.

The flight continued uneventfully until April 14, 1973, when OPS-1 entered a routine phase of the flight out of range of communications. When the station emerged from the blackout on its 13th day of the flight, on April 15, ground control detected loss of main telemetry line, while the secondary channel showed a drop of pressure onboard to 425 millimeters of mercury or about twice lower than the normal level.

The official investigation concluded that as a result of a faulty welding, one of the lines in the station's propulsion system had burst during the engine firing and the plume of the engine burned through its pressurized hull.

However, future findings were to essentially disprove this theory. A careful analysis of fragments detected in orbit, showed that three days after the launch of the OPS-1, the upper stage of the Proton rocket, which had delivered the station into orbit, apparently exploded, as a result of pressure changes in its tanks caused by overheating. The stage carried about one ton of unspent propellant onboard and the explosion created a cloud of debris flying in the proximity of the station. The speed of some debris differed from that of the OPS-1 by as much as 300 meters per second. Eight days later, a piece of this orbital junkyard apparently hit the station. (41)

Soon after the accident, official Soviet sources announced that the Salyut-2 had completed its operations "after a series of tests." For years, official Soviet sources continued to claim that "during entire flight (of Salyut-2) reliable radio-contact with the station had been maintained ... and all onboard systems and science equipment of the station had functioned normally." (152) However, a Soviet book published in 1985, disclosed that the station was never piloted "due to a deviation in the work of the attitude control system." (2)

However, despite all this secrecy and "name game," western observers not only saw plenty of evidence of a failed mission, but almost instantly managed to discern the military nature of the new spacecraft. Unlike its civilian counterparts -- Salyut-1 and Kosmos-557 -- Salyut-2 transmitted signals at 19.944 MHz, the frequency common for Soviet reconnaissance satellites. (34) With their real name secret, the Almaz stations had become known in the West as "military Salyuts."

 

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UR-500K rocket with the Almaz space station shortly after its installation on the launch pad on March 24, 1973.


pad

Service tower is being retracted from the UR-500K rocket with the Almaz OPS-1 space station ahead of its launch on April 3, 1973.


Artist rendering of the OPS-1 station in orbit. Copyright © 2002 Anatoly Zak