By G.G. Kochemasov

Bothering all planetologiests losses of spacecrafts (SC) in martian orbit have a direct bearing on the regular wave planetology discussed at this symposium. The dramatic loss of Mars-Observer in 1993 prompted searches for causes of one "enigmatic" phenomenon: spacecrafts near Venus work well, near Mars often fall (generalization done by V.V. Novikov, Sternberg Inst.).

Between 1961 and 1993 40 spacecrafts were launched to these planets: 24 to Venus and 16 to Mars. Of 16 martian SC serious troubles and losses occured in 9 cases,this gives safety (stability) factor of 0,438. Of 24 venusian SC essential failures developed in 4 cases, safety factor 0,834. Such "benevolent" venusian and "severe" martian orbits were explained in two publications [1, 2].

The interference of individual standing warping waves of 4 directions, lengths of which are connected with orbital frequencies, produces small granulas in Venus (p R/6) and large ones in Mars ( p R/2). Venusian spheres are warped evenly, body sphericity is rather high; martian spheres are stressed in one direction and extended in perpendicular one, this causes flattening, dumb-bells appearance and low sphericity. Geometric sphericity (or stability) factors can be determined as the area ratio of the circumscribed in a circle figure to this circle. The figure shape depends on the wave number and is hexagon for Venus and elongated rectangle for Mars. Sphericity factors are 0,830 and 0,420 respectively and they are rather near to the above shown safety factors (0,834 and 0,438).

From 1996 to 1999 four SC were launched to Mars: Mars Pathfinder (1996), Mars Global Surveyer (1996), Mars Climate Orbiter (1998), Mars Polar Lander (1999). Two of them (MCO & MPL) disappeared in the martian atmosphere. A serious trouble was also with the highly successful MGS. So, the safety factor is still about 0,5 as predicted earlier [1, 2]. Flattening a rotating body with atmosphere requires density sectoring of this highly mobile medium (Theorem 4). The heterogeneous changing atmosphere is behind of this safety factor.

[1] Kochemasov G.G. On losses of spacecrafts in martian orbit //Astronomicheskiy Tsircular, Astronomy Inst.RAS, #1556, 1994, 37-38.