[FPSPACE] Russians Blame Crew For Station Attitude Disturbance

[Jim Oberg]

JimO: OK, the Russian MCC seems to be blaming the loss of attitude control on the energetic movements of the spacewalkers and the weakness of the CMGs. They make NO mention of the actual cause of the attitude disturbance -- the thrust from the sublimators in the Orlan backpacks. Can anybody else contribute to the understanding of this 'expected surprise'?





2004-08-03 19:05     ISS CREW'S EVA ROCKS THE STATION 

    MISSION CONTROL CENTER (Korolev), August 3 (RIA Novosti) - The ISS crew composed of Gennadi Padalaka of Russia and Michael Fincke of the United States was so active in the extravehicular activities (EVA) that caused dynamic disturbance, which, in turn, led to short-term disorientation of the station on the orbit, said ISS Flight Director Vladimir Soloviev right after they completed the EVA. 

    According to him, the U.S. astronaut and the Russian cosmonaut worked so intensively that produced extra disturbance of the station's hull, which preliminary stopped the gyrodynes, ensuring the ISS orientation. "The U.S. and Russian Mission Control Center's experts are looking into the reasons why these disturbances were growing following an avalanche pattern, we have never experienced anything of the sort", said Mr. Soloviev. 

    He pointed out that all space systems on the ISS had rather simple design. "The systems consist of three elements - sensors, logic units and drives. As soon as the sensors detect accumulation of angular momentum, the logic unit commands the gyroscopes to counteract, they can do it until a certain moment, but then get saturated, which led to the short-term disorientation of the station on the orbit", explained the expert. 

    At the same time, according to Mr. Soloviev, the Mission Control Center is satisfied with the crew's work. "They experienced problems with communications and the gyroscopes, but despite all this, they accomplished all scheduled EVA ahead of time, having spent four and a half hours instead of planned six hours", Mr. Soloviev pointed out. "All this gives certain grounds for optimism, so for September 3 we plan to perform next EVA", concluded Vladimir Soloviev. 

    The crew managed to fit the Zvezda module with laser reflectors and a new radio link antenna for docking the new European cargo spacecraft Jules Verne, and replace some elements of the extravehicular scientific equipment and the cable of the malfunctioning camera to be installed by the Russian crew commander and U.S. onboard engineer Michael Fincke during the next EVA. 

    The next Russian cargo spacecraft Progress M-50 will be launched to the station on August 11 from Baikonur and docked on August 14. The spacecraft will carry parcels for the crew, foodstuffs, water, spare parts and some of the freights intended for the tenth main expedition, which will start for the ISS on October 9. 

    The expedition will be made up of the current crew's backup cosmonauts Salizhan Sharipov of Russia and Leroy Ciao of the United States. They may be accompanied for a week by either a tourist, whose candidacy is being determined by the Federal Space Agency, or the Russian Space Forces' cosmonaut No.1 Yuri Shargin. 

 

Russian Spokesman Details Loss of Contact with, Reorientation of ISS

Moscow Ekho Moskvy Radio in Russian 1300 GMT 03 Aug 04 

    [Presenter] There was a contingency in orbit today: contact with the crew of the International Space Station, who were out on a space walk, was lost for 20 minutes after they went on a space walk. The station itself suffered a brief loss of orientation. 

    The chief of the Mission Control Center press service Valeriy Lyndin explained the details to Ekho Moskvy:

    [Lyndin] It did not affect the work of the crew in any way. They continued to do their jobs. When contact was restored, it was necessary to turn on the station's jet engines in order to readjust its orientation so that it faced in the right direction. To do this, the cosmonauts first had to sent to a safe zone, to avoid the jet damaging their space suits. That is exactly what was done: they were told to move to within a safe distance of about 15 meters, and did just that, after which the station's orientation was restored and the cosmonauts continued their work.

    [Presenter] Specialists are now establishing why contact with the crew was lost. Some reports suggest it could have been caused by the overloading of the three devices ensuring the station's orientation in orbit. There is also a theory that the cosmonauts were working too hard, causing the station to rock.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: /pipermail/attachments/20040803/92814778/attachment.html