1994 - Piloted Space Missions

The Mir space station program celebrated its eighth anniversary of orbital operations in 1994 amid growing international interest in exploiting the facility before construction of the International Space Station begins in late 1997.

In fact, Phase 1 of the ISS program revolves around seven missions during 1995-1997 when a US Space Shuttle will dock with the Mir space station. Meanwhile, ESA and French missions to Mir will continue under separate agreements. The Mir program is now set for termination in 1998 but may be extended.

The Mir core module has been in Earth orbit since February, 1986, and by the end of 1994 had exceeded its original design life. The vehicle is 13.1 m long with a maximum diameter of 4.2 m and an initial mass of 20.4 metric tons. The habitable volume is approximately 90 m³, and the two main solar arrays were augmented in 1987 with a third, deployed array for a total power capacity of 10.1 kW, although environmental effects have reduced this value. The basic outward configuration of Mir was similar to that of Salyut 6 and Salyut 7, but the forward transfer compartment of Salyut was replaced with a 5-port docking module on Mir. Internally, many design changes and system improvements were incorporated.

Space station logistical and upgrade requirements have been met with three classes of spacecraft: crew ferries (Soyuz T and Soyuz TM), unmanned cargo ships (Progress and Progress M), and large specialized modules (Kvant and Kristall). By the end of 1994, Mir had received one Soyuz T, 20 Soyuz TM, 18 Progress, and 25 Progress M spacecraft as well as three large, permanent modules: Kvant 1, Kvant 2, and Kristall. Impressively, all 68 of these spacecraft, representing about 540 metric tons, were launched successfully and achieved their primary objectives of docking and crew, and cargo deliveries.

Designed and manufactured by RKK Energiya, the Soyuz TM is capable of carrying three cosmonauts and has a gross weight of just over seven metric tons, a length of seven meters, and a maximum diameter of 2.7 m. The spacecraft consists of three main sections: the orbital module, the command and reentry module, and the service module. Two solar arrays (10.6 m span) provide, electrical power for the typical 50-hour journey to Mir and can be interconnected with the space station's electrical system to furnish additional 1.3 kW. The nominal flight time for Soyuz TM spaceship is 5-6 months (References 86-90).

Since the cargo capacity of a manned Soyuz TM is limited to only a few hundred kilograms, a more efficient logistics vehicle was designed for support operations to Mir. Progress M (maiden flight in August, 1989) is a "modernized" version of the original Progress cargo freighter (1978-1990) which flew 43 times (including Kosmos 1669) without a docking failure. Derived from Soyuz TM, Progress M has a launch mass of approximately 7.3 metric tons and a length of 8.2 m. Whereas the service module is essentially the same as the one used by Soyuz TM, the central module is designed for carrying propellants, air, and water, while dry cargo is stored in the forward, nearly spherical compartment (Figure 3.11). Continual improvements to the spacecraft have increased the total payload cargo to 2.7 metric tons, although the use of the Soyuz-U launch vehicle instead of the Soyuz-U2 since mid-1993 has generally limited the cargo capacity to 2.5 metric tons. Progress M was originally rated for 30 days independent flight and up to 180 days attached to Mir. During 1993-1994 Progress M17 established new records with a 131-day stay at Mir and a total flight time of 337 days. Although Progress M spacecraft are destroyed during reentry, beginning in 1990 (Progress M5) a small Raduga recoverable capsule (payload capacity of 150 kg) has been used on about every other mission (References 87, 89-95).

With the advent of the Mir space station in 1986, a new requirement for permanent expansion of the orbital complex was set. In 1987 Kvant 1, a specialized module left over from the Salyut 7 program, was attached to Mir not only to provide a complex set of scientific equipment (the international Roentgen X-ray Observatory consisting of the HEXE, Pulsar X-1, Sirene-2, and TTM instruments; the Glasar UV telescope; and the Svetlana electrophoresis unit) but also to enhance space station support systems, in particular attitude control via six large gyrodynes. When attached to the aft docking port of Mir Kvant 1 measured 5.8 m in length and 4.2 m in diameter with an initial mass of 11 metric tons (References 87, 89-90, 96-97).

The four forward radial ports were reserved for full-size modules of about 19.6 metric tons each. The highly specialized modules were built at the Khrunichev Machine Building plant for the Energiya NPO, now RKK Energlya. Kvant 2, which was attached in 1989, was also known as the additional equipment module in accordance with its wide variety of new systems. Perhaps the most important feature of the new module was the unique air-lock chamber with an enlarged (1 m diameter) exit hatch. In addition, the 12.4 m long, 4.4 m diameter Kvant 2 housed the following major equipment:

• Six gyrodynes
• MKF-6MA multi-spectral camera system
• ITS-7D infrared spectrometer
• MKS-M2 optical spectrometer
• KAP-350 Topographic camera
• ARIS X-ray sensor
• Inkubator 2 hatchery
• Rodnik water system
• Elektron and Vika electrolysis units
• ASP-G-M exterior instrument platform.

Less exotic but equally important are Kvant 2's two solar arrays with a capacity of 6.7 kW at beginning of life (References 87, 89-90, 98-103).

Six months after the arrival of Kvant 2, the Kristall module became the newest component of the Mir complex. Kristall possessed the same mass and diameter as Kvant 2 but was a little shorter at 11.9 m. In place of the Kvant 2 airlock chamber, Kristall was equipped with a new multiple docking adapter employing two APAS89 androgynous ports for mating with the Buran space shuttle and a new model of Soyuz TM.

The primary scientific payload was devoted to microgravity research and is described in more detail in the section on materials science. Kristall also carried the Priroda 5 high resolution camera and the Svet greenhouse for botanical research. The two solar arrays on Kristall were of a new design with a total 8.4 kW capacity, variable deployment positioning, and the ability to be removed and relocated to another part of the space station (References 87, 89-90).

By the end of 1990 the Mir space station's normal configuration consisted of six linked spacecraft: Mir, Kvant 1, Kvant 2, Kristall, a Soyuz TM, and a Progress M. Together they boasted a total mass of about 90 metric tonsand a habitable volume of 270 m³. With further additions installed during EVAs, the complex at the end of 1992 appeared as shown in Figure 3.12. Detailed interior drawings of the four main modules are presented in Figures 3.13 and 3.14 (Reference 108).