EP 5
Six Minutes of Terror
The most perilous part of the journey to the Red Planet is the six minutes it will take to travel from the top of the Mars atmosphere to its surface – the six minutes of terror.
Landing on Mars is a complex three-step process: entry, descent and landing. Entry into Mars’ atmosphere begins 125 kms above the surface and lasts about two minutes, with the spacecraft hurtling towards Mars at about 16,000 kms an hour. Only a specially designed inflatable aeroshell outside the Mars Lander will protect the capsule and its occupants from a friction created temperature of 4,000 Celsius. The heat shield must also act as a brake.
NASA Chief Engineer Rob Manning explains the particular problem of Mars – it does not have enough atmosphere for a spaceship to emulate a landing on Earth – and yet it has too much atmosphere to simulate a moon landing.
Within the first two minutes of descent, the heat shield will reduce the craft’s kinetic energy by 90 per cent, and, typically, a parachute system is deployed to further decrease speed. But recent test results have not been good and designer Leonid Gorshkov at Russia’s Energia Space Corporation has decided parachutes are too risky. The Russians are experimenting with descent engines.
At the final stage, the astronauts have about 90 seconds to find a landing site that is not only safe but has, or has had, water. Only on such a site can past or present life forms be discovered. In 2005, NASA’s Mars Reconnaissance Orbiter took high-resolution images of the planet to help locate future landing sites. Bob Richards of Optech Industries in Toronto is testing a new generation guidance system, Lidar, which will help the Mars Lander spot obstacles within seconds with a colour-coding radar-like system.
Most space agencies plan to send a 40-ton Habitat to Mars ahead of the crew. The astronauts must land close to that advance module, their supply base for 18 months. If they fail to do so, they will die. Filmmaker James Cameron offers an interesting solution.
Every time an astronaut steps out of the Habitat, only their spacesuits will protect them from Mars’ hostile environment. A current prototype flexible suit has 20,000 parts, costs $10- million dollars and weighs 95 kilos – too heavy a load. It must protect the astronauts from organ-damaging radiation, penetrating fine dust, dangerous electrical storms and the carbon dioxide of the Mars atmosphere.
It is only after the crew are safely on the planet’s surface that the real purpose of the mission can begin – the search for life on Mars
