During 1997, the decays included those of Cosmoses 2313 and 2326. Still in orbit is their sister satellite Cosmos 2335. All of these have their operational orbit maintained, until the boosting jets are nearly depleted. They are then partially de-orbited to allow natural atmospheric decay to occur. Details are given in table below: Catalog International Popular Launch Lowering Days in Number Designation Name Date Date upper orbit 23596 1995-28A Cosmos 2313 1995 Jun 8 1997 Apr 23 685 23748 1995-71A Cosmos 2326 1995 Dec 20 1997 Oct 9 659 24670 1996-69A Cosmos 2335 1996 Dec 11 Still in upper orbit Assuming the orbit maintenance mechanism is similar if not identical for these three, it is probable that Cosmos 2335 will remain in its present orbit for a similar period to its predecessors. My guess is that it will be a slightly shorter period, since it will have to offset the effects of slightly higher average atmospheric drag as air densities increase as we move away from solar minimum. So a figure of around 630 days might be expected. If this value proves to be anywhere near accurate then we could expect Cosmos 2335 to be lowered at the beginning of September 1998. Once we have the precise date, we can then consider till what date in 1999 the next satellite in this series (25088,1997-79A,Cosmos2347,1997 Dec 9) is likely to last. Whilst on the subject of decaying Cosmoses, observers should note that Cosmos 1043 (#11055) is entering a last brief visibility period before its reentry in March. ----------------------------------------------------------------------------- best wishes Russell Eberst @ North: 55 degrees, 56 minutes, 55 seconds West: 3 degrees, 8 minutes, 18 seconds: 43metres (150 feet) above sea-level -----------------------------------------------------------------------------