Soyuz TMA Spacecraft Basic Modifications

The Soyuz TMA manned transport spacecraft is a modification of Soyuz TM spacecraft distinguished for a high reliability and safety of flight for the crew which is proven by all the launches of the spacecraft implemented in the period of years 1986 -2002 for the purposes of servicing orbital stations.
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 30mm 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.

Long chairs New reduced panel Cavities stamped in the primary structure in the area of side chair footrests

Instrument re-arrangement for chair accommodation Arrangement of new oxygen bottle and cooling-drying assembly New arrangement of control handles and their extension and adjustment mechanisms

Soyuz TMA descent module layout
with indication of modified elements

Soyuz TMA descent module layout with indication of modified elements

Anthropometric parameters of Soyuz TM and Soyuz TMA spacecraft


1. Cosmonaut (astronaut) height, cm

  • maximum, in the standing position
  • minimum, in the standing position
  • maximum, in the sitting position





2. Cosmonaut (astronaut) chest circumference, cm

  • maximum
  • minimum




not limited
not limited

3. Cosmonaut (astronaut) mass, kg

  • maximum
  • minimum





4. Maximum foot length, cm


ISS Crew