The fuselage, which formed the ascent stage, would then be
winched vertically for the return to the fleet of mother ships
in Mars orbit after 400 days on the surface. There were two
kinds of landing boats. The first sent to the surface from Mars
orbit would separate from the Cargo Ship in a 1000 km altitude
circular equatorial orbit. The 200 metric ton thrust engine
would fire for 17.2 seconds in a 173 m/s deorbit burn, setting
the perigee of the descent ellipse at 155 km. The re-entry
calculations were based on the Martian atmosphere having a
surface pressure 0.084 bar (ten times more than the actual
figure that would only become known in 1965). The long gliding
re-entry, on immense wings of 2810 sq m area, would last for 86
minutes and extend over 12,655 km, over half way around the
planet. The glider had the cross range to reach any point on the
Martian surface, from the equator to the polar ice caps. Peak
heating during re-entry would be 649 Kelvin, and maximum
g-forces would be only 0.12. The glider woul