Space dynamics analysis of the spacecraft Mars-96 abnormal flight

MARS-96 spacecraft was launched from the Bykonur launch site in 1996, November IG-th at 23(h)48(m)52.75(s) Of Moscow time (MT) according to the programme. After manoeuvering in the near-earth space the SC had to be injected to the interplanetary trajectory to Mars. It must be happened last November on 17-th at 1(h)10(m) 56.5(s) MT The process of the SC putting on the near-earth orbit was monitored with navigation measurements made by tracking stations in the vicinity of the launch site, in Barnaul, Eniseysk, Ulan-Ude and Ussuriysk. On present evidence it may be argued that: the launch-vehicle ''Proton'' operated in the standard mode. At the end of its operation SC coordinates deviation from theoretical values didn't exceed 1,5 km; SC injection into base near-earth orbit was brought up by the booster block within the required accuracy. SC flight monitoring of the subsequent phases of SC injection into the interplanetary trajectory was based only on the measurements of Centre of Deep Space Communications (CDSC) in Evpatoria and a tracking station in Ussuriysk. Unfortunately, SC manoeuvring monitoring on near-earth orbit was not envisaged and this fact greatly complicated MARS-96 abnormal flight analysis. Processing and analysis of available ballistic and navigational data and results of numerous simulations permitted to draw the following conclusions: 1. The booster block had not been shined into the high-apogee orbit, as it was provided in the program and railed down during 20-th revolution at 18-th of November 1996 at 4(h)20(m) MT The coordinates of the point of its railing-down are: phi = 50,9 degrees S, lambda = 168,1 degrees W. 2. MARS-96 SC after separation from the booster block acquired a velocity increment because of the autonomous power unit operation, the value of which includes the component for deceleration and entered the atmosphere at the end of the third revolution at 17-th of November at 4(h) MT and discontinued functioning in the water of Pacific Ocean. The coordinates of the point of its falling down are: phi = 25,1 degrees S, lambda = 75,4 degrees W.