Soyuz Apollo Test Project
2015 Jul 5
Sunday, Day 186
The Partnership: A History of the Apollo Soyuz Test Project
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The Soviet Union readied two spacecraft, two rocket boosters and four crews for the ASTP mission. Three of the crews were at Baikonur for the launch and the other was in Spaceflight Control Centre at Kaliningrad (now renamed Korolyov) near Moscow.
Apollo took into orbit with it the ASTP docking module - a compartment which could be used by both crews in transferring between the oxygen-nitrogen atmosphere in Soyuz 19 and the low pressure oxygen-only atmosphere in Apollo. The Module was carried into orbit sitting below the Apollo in the same way the Apollo LM had been launched for the lunar missions. Using another 'lunar' technique, Apollo turned round after launch, docked with the Docking Module and pulled it away from the rocket.
The moment of rendezvous is captured in this NASA painting by Robert McCall
Only one incident marred the mission. During Apollo's return to Earth, the crew missed an item on a checklist because of radio interference on the voice link. It meant that the command module's thrusters were still 'live' while it was descending under the parachute. They fired automatically to try and steady the craft as it swung around. This resulted in poisonous gases entering the spacecraft through atmospheric pressure relief valves. The three crew members suffered blistering to their lungs - they had to use oxygen masks to breathe at one point.
ASTP's was the final splashdown and the last expendable spacecraft to be launched by the US before the Shuttle era began. The next flight into orbit by an American astronaut came in 1981 when Columbia lifted off on its maiden voyage. Soyuz, however, is still flying today - considerably updated from the 1975 model which, in turn, was an evolution from the 1966 version but nevertheless still the same basic structural components.
Soyuz 19 Launch
The basic rocket used to launch Soyuz 19 was based on the same vehicle that launched Sputnik and Vostok and still launches Soyuz today. It stands 49.3 metres tall.
The rocket uses three stages - at lift off, a central core fires, together with the four cone-shaped boosters. After two and a half minutes, the boosters are depleted and fall away. Stage two is the central core firing alone. When this too has used all its fuel it falls away allowing the upper stage to fire and place Soyuz into orbit.
Soyuz itself is covered at launch by a protective aerodynamic shroud. On top of the shroud is a small rocket system which may be used to pull the spacecraft away from the rocket in case of an emergency during the ascent. The black objects attached to the shroud are airbrakes which would open out and slow the spacecraft down after an emergency separation.
Apollo was launched using a Saturn 1B rocket from Launch Complex 39B at the Kennedy Space Center, Florida. The rocket was built in the Vertical Assembly Building (now known as the Vehicle Assembly Building for the Space Shuttle) which was originally constructed for the Apollo Moon landing programme.
In order that the Saturn 1B fit the handling equipment built for the Saturn 5 launcher, a tall pedestal was constructed to place the top of the rocket at the same height as the Saturn 5 - 110 metres. This arrangement was also used to launch Saturn 1B for the Skylab 2, Skylab 3 and Skylab 4 missions.
The only other piloted mission to use the Saturn 1B was Apollo 7 which checked-out the Apollo command and service modules for the first time with a crew aboard. It left from Launch Complex 34 at the Cape Canaveral Air Force Station, which was specially built to handle the rocket. It was the same launch complex where the crew of Apollo 1 died in 1967.
The Soyuz 19 Spacecraft
This magnificent photograph of Soyuz 19 was taken by the crew of Apollo while the two craft orbited in formation after they had undocked. It was the clearest photograph ever taken of an orbiting Soyuz until that time. The white backdrop is the Earth's cloud cover.
At top is the orbital module, a near-spherical compartment which provides room for the crew to move about, to stow equipment and can act as an airlock. It is covered in a green multi-layered material which provides thermal insulation, keeping the inside at a comfortable temperature. The white discs are radio transmission aerials, and the two silver plates at the very top are the docking system.
Just below, also shrouded in green insulation, is the descent compartment which houses the crew at launch and is the only part of Soyuz to return to Earth.
At bottom, with two panels of solar cells attached, is the instrument unit which houses fuel tanks, batteries and other electrical equipment, and a rocket motor system - the nozzles of which can be seen in the base.
The complete vehicle is 7.5 metres in length and weighs just over 6.5 tonnes.
The Apollo Spacecraft
The crew of Soyuz 19 took this photograph as the two craft flew in formation after separation. In it can be seen the Apollo command module, and behind it the cylindrical service module with its bell-shaped rocket nozzle. The cylinder at the front with the box-like projections is the Docking Module. At the end facing is the three-petal arrangement of the docking unit developed specially for the mission. The idea behind it is that any two craft equipped with such a unit can dock with each other. Both American and Soviet docking units up to that time consisted effectively of a plug (probe) and socket (drogue). Soviet and American designs were not compatible either.
Apollo is 3.9 metres in diameter and the command and service modules together weigh 14.7 tonnes.
The Docking Module is 3.15 metres long and 1.4 metres in diameter. It weighs 2.0 tonnes. The box-shaped object on the side houses gas bottles for storing oxygen and nitrogen to replenish the atmosphere inside the Docking Module.
Copyright © Robert Christy, all rights reserved
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