Just days after arrival at the Mir space station, a fresh crew verified that two of the outpost's modules did not leak air as previously suspected.
This weekend, cosmonauts Sergei Zaletin and Alexander Kalery completed testing the Priroda module and the docking module for possible leaks. In the process, both modules were sealed off from the rest of the station for about two days, while ground controllers monitored carefully the pressure inside.
The Priroda carries remote-sensing equipment to study Earth and its atmosphere, while the docking module allows Mir to receive the U.S. space shuttle. Both are the latest additions to the station.
The previous crew, which left Mir last August, noticed a small leak but the cosmonauts never had a chance to investigate the problem.
In a few days, the new crew will have to move to a more difficult task: isolating the transfer compartment and working zone inside of the crowded core module to check other station modules for leaks. The cosmonauts will have to disconnect a multitude of cables in order to shut hatches between both individual compartments and entire modules.
As of Monday, the pressure inside Mir was around 622 millimeters mercury, decreasing at a rate of about 0.7 millimeters a day.
In another housekeeping chore, the crew is conducting an operation to get rid of air bubbles from the loop of the station's thermal control system. The air bubbles clog the pump in the system, preventing its normal function.
The cosmonauts noticed warmer-than-normal conditions on board soon after they entered the station. According to a Mission Control representative, the temperature inside the core module is around 79 to 82 degrees Fahrenheit (26 to 28 degrees Centigrade), but said the temperature occasionally shoots higher than 86 degrees Fahrenheit (30 degrees Centigrade).
The cosmonauts started working on the thermal control system on Monday and will continue on Tuesday.
The crew also activated the station's toilet and the system that removes toxic gases from the station's atmosphere.
The new work schedule
The repair work performed on Mir requires the close participation of ground controllers, who guide the cosmonauts through a maze of the station's systems.
Since a data relay satellite -- which could widen the communication windows between Mission Control and the station -- has been grounded by a lack of funds, the ground controllers can only talk to the crew when Mir is within a range of the control stations in Russia.
Currently, the communication windows between Mir and Mission Control fall during the evening hours in Russia.
As a result, mission managers made a decision to shift the cosmonauts' schedule to night hours, Moscow time. On Monday, the Mir crew went to bed earlier in order to get up around 1 a.m. Moscow time on Tuesday (Monday, 5 p.m. Eastern Daylight Time; 21:00 GMT). Normally, cosmonauts rest between 11 p.m. and 8 a.m. Moscow time.
Currently, the main computer on Mir maintains the station's orientation, sending commands to on-board gyrodines -- the complex mechanical wheels that allow highly accurate attitude control in orbit. Ten out of 12 available gyrodines are now online.
The Mission Control representative said that two gyrodines -- one each in the Kvant 1 and Kvant 2 modules -- were down due to technical problems before the current crew docked to the station on April 6. The two Kvant modules each carry six gyrodines.
The accuracy of Mir's orientation diminishes with the loss of each gyrodine. The working devices will be used to orient the orbital outpost for the orbit correction maneuver planned later this week.
The engine on board the Progress cargo ship docked to Mir will fire to boost the station's altitude. The Mission Control representative said remaining 10 gyrodines provide enough accuracy for the maneuver.
advertisement
