The DOS Space Stations
2015 Nov 27
Friday, Day 331
The next Salyut gets a new name
The Soviet space station design that came out of the Korolyov design bureau was called "Zarya". One problem with it was that the call sign of ground control was also "Zarya", something that had begun with the Vostok flights.
Whether or not this was the determining factor, a late-in-the-day (about five days before launch) decision was made to change the spacecraft name. The chosen alternative was "Salyut" and the Salyut programme was born.
The decision to change came too late in one way as Zarya's name was already painted on the station's hull and there was no way to change it. The name can be seen, but is not readable, just below the red panel in this view of Salyut's Proton launch vehicle.The photograph originates from RKK Energiya company (the modern-day name of the successor organisation to Korolov's design bureau).
DOS and Almaz
Salyut 1 was not the only one of these spacecraft to bear a different name from the one painted on the side. The first of Chelomei's Almaz station to reach orbit got there 1973 April 4 but seems to have been damaged by debris from the explosion of its launch behicle upper stage. The result was that it never got to host a crew. The Soviet Union called it "Salyut 2" even though it was not the same class of spacecraft as the first Salyut.
Meanwhile, on the ground was another DOS space station, similar in design to the original Salyut. Painted on the hull was "Salyut 2" and it was launched 1973 May 11 - just over a month after the other "Salyut 2". It immediately used up all of its manoeuvring fuel through a thruster malfunction. As a failure, it was given the name "Cosmos 557" with no immediate acknowledgement that it was a Salyut-class spacecraft. The give-away was the radio frequencies at which it was tracked by western observers.
It was not until 1998 and the first element of the International Space Station that a vehicle openly named "Zarya" actually made it to orbit.
Design of the DOS Station
In this image (right), a Soyuz spacecraft is depicted approaching Salyut 1. The Kamchatka peninsula can be seen on the Earth's surface below.
The Salyut hull is about 15 metres long and 4 metres diameter - a figure dictated by the diameter of its "Proton" launching rocket.
The round opening on top of the large section of the station contains sensors for astronomical studies. The operating controls are mounted inside Salyut's hull. In the event of Salyut 1's launch, the cover protecting the opening as it ascended to orbit on its Proton rocket, did not fall away. The crew was actually unable to undertake observations.
The engine compartment and the two solar panels at the rear, are 'borrowed' directly from the design of Soyuz. This results from Korolyov's design bureau taking a fast-track design route using one of Chelomei's "Almaz" spacecraft hulls and adapting it using tried and tested Soyuz components.
The photograph on the left shows the interior of Salyut 1 whilst being prepared for flight - there is a protective transparent cover over the instrument panel - labelled "REMOVE BEFORE LAUNCH". In the background can be seen the tunnel leading to the docking unit.
Salyut 1 was equipped to perform a range of scientific experiments, and the spacecraft actually performed well although events surrounding it might suggest otherwise.
Missions to Salyut 1
In 1971 April, the attempt to put a crew aboard using Soyuz 10 failed when the hatch of the space station refused to open. Soyuz 11 was more successful but when the crew headed back to Earth, they became the victims of a major space tragedy.
A valve in Soyuz 11's hatch was jolted open at the time the descent cabin separated from the Soyuz orbital module. Normally, the valve would have opened during descent through the lower levels of the atmosphere to equalise pressure inside and outside the cabin. In the vacuum of space - the result was fatal.
Salyut 1 continued to orbit from the end of June, and the events of Soyuz 11, but changes resulting from the investigation which followed took nearly two years to be incorporated into the Soyuz design. Salyut 1 could not last that long. Early in October 1971, mission controllers fired the manoeuvring engines for the final time and Salyut 1 "..... entered the dense layers of the atmosphere and ceased to exist .....".
Members of the Soyuz 11 crew were not wearing space suits. The Soyuz re-design, which followed the Soyuz 11 accident, introduced them for subsequent cosmonaut crews. The resulting weight penalty of the spacesuits and their associated life-support systems meant that Soyuz no longer had the capacity to hold three people. It was nine years before a Soyuz flew again with three cosmonauts aboard - with the mission of Soyuz-T 3 in 1980.
Salyut 1 Statistics:
Launch Vehicle: Three Stage Proton
Launching Technique: Direct ascent
Mass: 18,500 kilogrammes
Length: 14.4 Metres
Diameter: 4.15 metres (maximum)
Salyut 1 Diary
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