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29 August 1988 04:23 GMT. Landing Date: 1989-04-27 02:59:00 PM. Flight Time: 240.94 days. Alternate Name: Soyuz TM-6 (Polyakov). Flight Up: Soyuz TM-6. Flight Back: Soyuz TM-7. Call Sign: Proton (Proton ). Crew: Polyakov. Backup Crew: Arzamazov. Program: Mir. Physician-cosmonaut V V Polyakov was transported to the Mir orbital station with a Soviet-Afghan crew comprising the cosmonauts V A Lyakhov and A A Momand. Lyakhov and Mohmand returned to earth aboard Soyuz TM-5, but Polyakov remained aboard Mir to monitor the EO-3 crew to the end of their record year-long mission and the EO-4 crew for the first months of their mission. Narrative (adapted from D S F Portree's Mir Hardware Heritage, NASA RP-1357, 1995) Soyuz TM-6 arrived on August 31, 1988. Its crew had a unique makeup, with a commander (Vladimir Lyakhov) who had been trained to fly a Soyuz TM-solo in the event a rescue ship needed to be sent to recover two cosmonauts from Mir, no flight engineer, and two inexperienced cosmonaut-researchers. One was Dr. Valeri Polyakov, who would remain aboard Mir with Titov and Manarov to monitor their health during the final months of their planned year-long stay. The other was Intercosmos cosmonaut Abdul Ahad Mohmand, from Afghanistan. Mohmand’s experiment program was dominated by a series of observations of Afghanistan, called Shamshad. The Lyakhov and Mohmand left their fresh spacecraft docked to Mir as a lifeboat and returned aboard Soyuz TM-5. They undocked at 22:55 GMT 5 September and jettisoned the Soyuz TM Orbital Module at 23:35 GMT. However the planned landing at 02:15 September 6 1988 failed due to confusion of infrared horizon sensors. A repeat retrofire attempt one orbit later resulted in a partial burn only. The crew had to spend a tense 24 hours in the cramped Descent Module (the Orbital Module having already been jettisoned before the retrofire burn) before making last chance deorbit. Finally Lyakhov and Afghani cosmonaut Mohmand returned safely to Earth and landed September 7, 1988 00:50 GMT, 160 km SE Dzhezkazgan. Soyuz TM-6 was flown by the EO-3 crew from the aft to forward crew of Mir on September 8, 1988. Progress 38 then docked and remained at the aft port from September 12-November 23, 1988 On October 20 Titov and Manarov stepped outside Mir, leaving Polyakov in the Soyuz TM-6 descent module. The spacewalkers wore improved spacesuits which did not need an umbilical connection to the station. Using tools delivered by Progress 38, Titov and Manarov removed the old TTM shadow mask X-ray unit and successfully replaced it. They then installed equipment in anticipation of the upcoming Franco-Soviet EVA. The EVA lasted 4 hr, 12 min. Soyuz-TM 7 arrived at Mir on November 28, 1988 on the Franco-Soviet Aragatz mission with French cosmonaut Jean-Loup Chretien (on his second mission to a Soviet space station) and Soviet cosmonauts Alexander Volkov and Sergei Krikalyov. This increased Mir’s population to six. According to Krikalev, this was the 'worst-case scenario' as far as crowding on the station was concerned. Not only were there more cosmonauts than usual aboard Mir; the station was also full of equipment and life support supplies delivered by Progress freighters for the joint Franco-Soviet mission. The crowding was exacerbated because there was no docking port free for a Progress freighter. Therefore, the crew could not use a Progress as a 'pantry' or 'storage room' for the station. The large joint experiment manifest—mostly medical and technology experiments chosen to support the French-led European Space Agency Hermes shuttle project—strained Mir’s electricity supply. The total mass of the experiments was 580 kg. Preparations for the first EVA involving a non-Soviet/non-U.S. space traveller forced the cosmonauts to cut short a TV meeting with diplomats from 47 countries on December 8. On December 9 Chretien and Volkov depressurised the multiport docking adapter and clambered outside Mir. Chretien was first out. He installed handrails, then attached the 15.5 kg Enchantillons experiment rack to the handrails by springs and hooks. He also attached electrical wires leading from the rack to Mir’s power supply. Enchantillons carried five technological experiments with applications to the Hermes shuttle program. Volkov and Chretien then assembled the 240-kg ERA experiment. They attached a mount to handrails on the frustum linking the multiport docking unit to the small-diameter portion of the work compartment. After resolving problems with cables linking ERA to a control panel inside Mir, they attached the folded ERA structure to a support arm on the platform. The structure was designed to unfold to form a flat six-sided structure 1 m deep by 3.8 m across. From inside Mir, Krikalyov commanded the structure to unfold, but to no avail. Volkov then kicked ERA, causing it to unfold properly. According to Krikalyov, taking the ERA outside helped relieve the crowding problems. The EVA lasted 5 hr and 57 min. After the EVA, Titov and Manarov showed Krikalyov, and Volkov the peculiarities of living and working on Mir. On December 15, their 359th day in space, Titov and Manarov officially beat Romanenko’s 326-day single-flight endurance record by the required 10%. On December 19, Soyuz TM-6 was powered up to prepare it for for descent. Manarov, Titov, and Chretien boarded Soyuz TM-6 and undocked at 03:33 GMT 21 December 1989, but revised software installed as a result of the Soyuz TM-5 abort overloaded the spacecraft's computer. The landing planned for 06:48 was aborted. A backup software program was used and the Soyuz orbital module was retained through retrofire. The crew finally landed safely on December 21, 1988 09:57 GMT, under low clouds, in sub-freezing temperatures, 180 km SE Dzhezkazgan. The Progress 39 freighter arrived at the station and remained docked to the aft port from December 27, 1988-February 7, 1989. Progress 39 was used to boost Mir's orbit, necessary because of greater than normal atmospheric drag. This in turn was caused by atmospheric expansion produced by atmospheric heating, the result of solar activity during the solar maximum period. According to Krikalyov, it was not possible to visually detect any difference in the station’s altitude after the reboost was completed. Krikalyov, Volkov, and Polyakov then cleaned Mir and loaded Progress 39’s orbital module with waste and excess equipment used on the joint Franco- Soviet Aragatz mission. Following the completion of the successful first flight of the Buran shuttle, during February the Cosmos 1897 Altair/SR satellite was moved from 12° E to its original position at 95° E. Progress 40 arrived at the station and remainded docked from February 12-March 3, 1989. In mid-February the Soviets announced that launch of the D-module (also called the augmentation module, or Kvant 2) was the victim of delays in the production of the module to be added after it, the Tmodule (technology module, or Kristall). The D-module had been at Baikonur, awaiting launch, since July 1988, but the T-module would not be ready until December 1989, and the Soviets did not wish to let 3 months go by with Mir in an asymmetrical configuration (that is, with only one lateral port filled). Rather than handing over to another Principal Expedition crew, the EO-4 cosmonauts would mothball Mir and return to Earth at the end of their stint. Krikalyov and Volkov had been trained to perform a total of six EVAs during Mir Principal Expedition 4. Krikalyov was to have been the first cosmonaut to fly the Soviet equivalent of the NASA manned manoeuvring unit (MMU), the YMK. But delay of Kvant 2, which carried the YMK, pushed back the EVAs to the next Principal Expedition, the crew for which would consist of Krikalyov and Volkov’s backups. In February the cosmonauts extended a 10-m pole from the Mir base block’s small airlock. It carried sensors used as part of the Diagramma program to characterize the environment around Mir. On March 3, when Progress 40 backed away from Mir, it deployed an antenna consisting of two loops of wire, each 20 m across, from a pair of containers on either side of the Progress cargo module. The cosmonauts observed the deployment. During the two days before its destructive reentry, Progress 40 continued in free flight while characteristics of the antenna were assessed by the TsUP. Progress 41 arrived at the station and remained docked from March 18-April 21, 1989 On April 10 Soviet reports had the cosmonauts beginning the process of preparing Mir for unmanned operation. Also during this period the cosmonauts replaced power supply units which were nearing the end of their design lives. Heightened solar activity led to some concern over the cosmonauts’ safety, but Soviet sources stated that radiation levels were not hazardous. The engine on Soyuz TM-7 was used to boost the Mir complex to a new record mean altitude of 410 km in mid-April. Volkov, Krikalyov, and Polyakov then loaded Soyuz TM-7 with experiment results and film and returned to Earth. The landing was unusually rough because of high winds in the recovery zone. Krikalyov sustained a minor knee injury, though he downplayed its importance. From April 26-August 25, 1989, although unmanned, astronomers on Earth used Mir’s Kvant astrophysical instruments to study Supernova 1987a and conduct more than 70 other observations. Progress-M 1 docked to the forward port of Mir from August 25-September 6, 1989. This was the first flight of a modified Progress freighter. It became the first of its class to dock with the front port of a space station. While there, it topped off the station’s attitude control propellant tanks. Mir LD-2 Chronology
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