Mars 96, Russia's contribution to an international three-craft exploration of the Red Planet, is due to be launched by a Proton K booster from the Baikonur Cosmodrome on 16 November. It will follow the US Mars Global Surveyor, launched on 7 November, and the Mars Pathfinder, set for a 2 December launch. The Mars 96 will reach Mars on 12 September, 1997 (Flight International, 30 October-5 November).

The Russian spacecraft has an 800kg orbiter, two 65kg "harpoon" penetrator probes and two 50kg landing stations. Not strictly soft landers, these will hit Mars, like the Luna 9 Moon probe in 1966, bounce along the surface and, once settled, will open four petal-like covers, to expose imaging and weather sensors. The landers include two "time-capsule" CD-Roms, entitled Visions of Earth, containing more than 70 novels, stories and articles documenting Man's fascination with Mars over the centuries.

The two titanium harpoons will be used to assess the temperature and properties of the upper layers of Martian sub-soil to find out whether a permafrost - a remnant of an age when water flowed freely over the planet - may exist beneath the surface. If this is so, then scientists believe that small bacteria may have existed.

The harpoons will be released from the spacecraft before it enters orbit around Mars and will plunge towards the planet at a speed of 5.6 km/s. Cone-shaped tail-planes and inflatable helium balloons will stabilise their flight towards two separate landing sites in the northern hemisphere. They will hit the surface at 96m/s (18,900ft/min), penetrating about 6m (20ft).

The impact will force each harpoon to break into two, with the top half remaining at surface level while the bottom half will plunge into the soil. Data from instruments will be passed through an umbilical cord to a transmitter on the surface end of the penetrator, which will send data to Earth via the orbiter satellite.

The orbiter, equipped with 23 instruments, will survey the planet with imaging equipment contributed by Germany, and instruments from France and the Mullard Space Science Laboratory and the Universities of Sussex and Sheffield, in the UK.

Source: Flight International