Service module due to launch July 12th, but the US warns they have other plans if it does not

Published: 2/16/2000

The council of chief designers of Russian spacecraft have set a new launch date of 12th July 2000 for the Zvezda service module (SM), the most important Russian-built ISS element. Reportedly, the SM, weighing in excess of 20 tons, is a heavy load for the Proton-K, so making it possible for the rocket technically to place the module into the assigned orbit only when facilitated by the Earth"s movement. Such a window is expected to be from 8th to 14th July. The meeting took place at the RKK Energia rocketry-space corporation in Korolyev, near Moscow. During the first day, various space projects were discussed in camera. On the second day, the council invited NASA representatives to join the discussion and advised them of the new launch date. Initially, the Zvezda was scheduled to fly in May 1998. It was then postponed until June 1999, then November 1999 and January 2000. The latest delay was partly caused by the two recent failure of Proton-K launch vehicles, in July and October last year, due to manufacturing defects in rocket engines, supplied by the Voronezh plant. Although the defects have been allocated and all the engines checked for proper functioning, the scientific supervisor of Russia"s ISS project, Academican Utkin, said he would not sign the permit for the ISS launch unless two successful launches of the modified Proton-Ks had been made. A modified Proton was successful launched on 12th February, when the rocket placed an Indonesian communications satellite in orbit. Two more Proton launches will be made before the SM flies, in May and June respectively, of a Gorizont and an Ekran-M satellite, as part of the Russian national space programme. Although the SM has historically suffered badly from federal underfunding, last year, budgetary funds were fully provided. This allowed the RAKA to pay for all the work done on the spacecraft, including payment to Khrunichev space centre for the launch vehicle. But delays with SM light have also been caused by troubles with SM"s ESA-built central computer. Although the computer was delivered to Russia last spring, its software is still not ready, according to some informed sources. Software, downloaded into the SM computer at the end of 1999, failed to function during a check at the Baikonur cosmoderome. Reportedly, this was an unexpected setback for the ESA and Russian specialists. Since then, the combined efforts of the European and Russian engineers have yielded some positive results, but the software still does not run satisfactorily. Sources suggest that the software problems have been the major reason for postponing the SM launch. They claim that, even if the Protons had flown without failures, the SM launch would have been postponed anyway. It is not yet known how much more time is needed to complete the work on software improvement. It is therefore by no means certain that a special meeting of RAKA and NASA heads, planned for end of February – early March will be able tp come to a final decision on the date of SM flight. Earlier, NASA warned Russia that, if the SM does not fly until August 2000, then the US will implement its contingency plans, by replacing the SM with the US-built Interim Control Module (ICM). This $210m module could be quickly created on the base of a US naval reconnaissance platform to fulfil the primary SM functions: namely to provide trajectory control for the whole ISS assembly. Although the FGB Zarya, the first Russian-built ISS element already orbiting, was specially modified before launch to provide some control functions for the ISS (that had previously been made on the SM), the FGB engines" thrust will not be sufficient to provide an effective control for ISS, when the station is fully assembled. The latter function can be fulfilled by the ICM but, by the nature of its unmanned reconnaissance status, the US module could not provide living quarters for cosmonauts the second function of the SM). Meanwhile, the first US module able to accommodate cosmonauts, the Habitation Module, is far from competion and could not be deployed in less than in 24 months. This means that, without the SM, the station would operate for a lengthy period of time in autonomous mode, without a permanent human presence. Associated article: www.concise.org. 7th February 2000

Article ID: 1434