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1.13 Soyuz-TM (1986-Present) Soyuz-TM (figure 1-30) is an upgraded version of Soyuz-T used with the Mir space station. The “TM” in Soyuz-TM is usually translated as “transport modified,” meaning that it is a further improvement of the Soyuz-T.

Figure 1-30. Soyuz-TM spacecraft. Compare the antennae on the orbital module to those on Soyuz-T. Differences reflect the change from the Igla rendezvous system used on Soyuz-T to the Kurs rendezvous system used on Soyuz-TM.

1.13.1 Soyuz-TM Specifications

Launch weight .......................................... 7070 kg

Length ..................................................... 6.98 m

Span across solar arrays .......................... 10.6 m

Diameter of habitable modules ................... 2.2 m

Maximum diameter ................................... 2.72 m

Habitable volume ...................................... 9.5-10 m³

Number of crew ........................................ 2-3

1.13.2 Soyuz-TM Notable Features The Kurs rendezvous system, which permitted automatic dockings with an unresponsive space station, replaced the Igla system. Kurs could operate at greater distances from a station than Igla, and could lock on even if its antennas were not aligned with those on the target station; that is, the antennas were omnidi-

rectional and did not have to be in line of sight. 10-kg launch and reentry pressure suits, which in an emergency can protect the wearer in open space. Lighter parachutes, which take up less room in the descent module and save up to 140 kg of weight. Launch payload increased by 200-250 kg to 51.6° orbit; return payload increased by 70-90 kg. Improved propellant tanks—these featured metal membranes for

dividing the oxidizer from the fuel. Past Soyuz propellant systems used organic (plastic?) membranes which could leak, degrading engine performance. Improved communications gear—separate voice channels for each cosmonaut and improved reception quality. Improved landing radar altimeter. Lighter escape system motors. Triple redundant electrical systems, and redundant hydraulic systems.