Going to Mars: A mission fraught with risk
Throwing a dart at a moving target
The favourable period for launching a spacecraft from the Earth to another celestial body is called a launch window. To save energy, and thus reduce the spacecraft's total payload, space engineers take advantage of the Earth's solar orbit and daily rotation. The rocket trajectory must bring the craft to where the planet will be by the time the trip is finished. It's a bit like throwing a dart at a moving target, where you extrapolate where the target will be to ensure that the projectile meets the target. In the case of Mars, the dance of the Martian and Earth orbits creates launch windows every 26 months. Each window last a few weeks, but on a given day, certain times are best for taking advantage of the Earth's rotation.
The scientific community is currently characterizing cosmic rays and how hazardous they may be to an astronaut's health. For example, the International Space Station crew is subjected to twice the level of radiation they would receive on Earth. In the long run, such exposure increases the risk of cancer and damage to the skin and eyes. So scientists are looking for ways to protect astronauts with more effective technologies, particularly in the composition of new types of shielding. CSA's EVARM experiment came about for just that reason.
Hazards of entering into the Martian atmosphere
Entry into the Martian atmosphere is a crucial stage of the mission and represents a massive obstacle to its success. Various factors—such as the density of the Martian atmosphere, a sandstorm, an outcrop of rock, the spacecraft's speed, a faulty trajectory, a lack of fuel, or an electronic glitch—could jeopardize a mission. Many missions have, in fact, failed at this stage.
The 20-minute communications lag
Another difficulty is the communications lag between Earth and a spacecraft travelling to Mars. Depending on the distance between the two, it can take almost 20 minutes to send commands, and then another 20 minutes before a response is received. Scientists must react quickly when problems arise, and then wait with great patience for the response, which will arrive 40 minutes after they send the initial signal. This also means that robots and systems we send to Mars must be able to make some of their own decisions, or at least know to wait for a command if something is not right.
Surviving two years of isolation and stress
A round trip between Earth and Mars will take two years or more. Astronauts will spend those two years in a confined environment, seeing the same people every day, far from family and friends and with no access to a clinic for medical emergencies. While interplanetary space travel is decades in the future, scientists are conducting research today to ensure that future astronauts are well prepared to overcome any and all difficulties that may arise affecting the crew's physical or mental health.
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