The Soyuz TMA crewed spacecraft has been developed as a modification
on the basis of a Soyuz TM spacecraft in accordance with
intergovernmental agreements between Russia and the USA and is an integral part of the
International Space Station (ISS) Complex. It is to provide rescue of the main crew of the
station in emergency and delivery of visiting crews.
During the flight the spacecraft fulfills the following tasks:
- delivery of a visiting crew consisting of up to three persons and small accompanying
cargoes
- constant availability of the spacecraft, attached to the station during its crewed
flight, in the standby mode to be ready for emergency descent of the main crew onto the
ground in case of hazardous situation on the station, cosmonaut illness or injury, etc.
(assured crew return vehicle function);
- planned descent of the visiting crew onto the ground;
- returning to the ground, together with the crew, payloads of relatively low mass and
volume
- disposal of wastes from the station in the living compartment to be burned down in the
atmosphere during descent.
The basic modifications of the Soyuz TM spacecraft are
connected with implementation of requirements for enlargement of crew anthropometric
parameter range up to the values acceptable for the American astronaut contingent, and
with increase of crew protection level from shock loads by decreasing landing speeds and
improving shock-absorption of its chairs.
To denote the modification of this spacecraft in design and general technical
documentation, the name "Soyuz TMA" (anthropometric) was adopted.
For implementation of the above requirements on the baseline Soyuz
TM spacecraft the following basic modifications in layout, design and onboard systems
of the descent module (DM) were made without increase of its dimensions:
- Three newly developed long Kazbek-UM amortization chairs with new four-mode dampers that
provide chair adjustment, depending on the astronaut mass.
- A re-arrangement of equipment was made in the areas above and below DM chairs which
allows one to accommodate longer chairs and astronauts with increased anthropometry and to
enlarge the passage area through the access hatch. In particular, a new control panel
decreased in height, a new cooling-drying assembly, data storage system and other new or
modified systems are installed.
- On the DM primary structure in the area of right and left chair footrests the cavities
were stamped about 30 mm deep that allowed big cosmonauts and their long chairs to be
accommodated. Correspondingly, the primary structure and the routing of pipes and cables
were changed.
- A minimum of modification was made to elements of DM primary structure, instrument frame
and brackets. The crew cabin was "cleared" as far as possible from projecting
elements - one moved them to more convenient places, remade a valves unit of the spacesuit
oxygen supply system.
- Modifications of a landing equipment set were made.
- two (of 6 single-mode) soft landing engines (SLE) were replaced with two new three-mode
engines (SLE-M);
- for reduction of measurement errors the Kaktus-1V gamma-altimeter was replaced with a
new Kaktus-2V instrument.
In addition to the above changes, separate systems and assemblies were modified on the
Soyuz TMA spacecraft. The modifications are mainly connected with transfer to new
components and introduction of design improvements.
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