How Long Does it Take to Get to Mars?
Written by Fraser Cain
Want to travel to Mars? Just aim your rocket at the Red Planet, fire your engines and you'll get there. Right? Wrong. To use the least amount of possible fuel when traveling to other planets, spacecraft follow what are called Hohmann Transfer Orbits. These are curved paths that take advantage of the orbital velocity of the planet to reach their destination.
When traveling to Mars, a spaceship already has the orbital velocity of going around the Earth. It then fires its rockets to put it onto a transfer orbit with the final destination of Mars. Once it reaches Mars, it either fires its rockets again, or uses a process called aerobraking to use the Martian atmosphere to slow it down.
Earth and Mars have to be at the right positions in their orbit for this method to work, and the launch window only comes around once every 25 months.
This method uses a relatively small amount of fuel. How long does it take to get to Mars using this method? About 214 days.
Engineers have proposed more energetic ways of getting to Mars. Instead of using this relatively slow method of traveling between Earth and Mars, you could fire a nuclear rocket and shorten the time significantly. This would very helpful when humans travel to Mars – you want to minimize their journey as much as possible.
A nuclear rocket could shorten the Mars travel time down to about 4 months. A human mission could launch for Mars and take 4 months to get there. Astronauts could explore the surface of Mars for a couple of months, and then take another 4 months to get home. The whole journey would take less than an Earth year.
This detailed article explains how difficult it is to land on Mars. And then, there's always the Mars curse. Why have so many missions to Mars failed?
Want to learn more about orbits? NASA has information about interplanetary orbits. Here's a Wikipedia article about the nuclear thermal rocket.
Finally, if you'd like to learn more about Mars in general, we have done several podcast episodes about the Red Planet at Astronomy Cast. Episode 52: Mars, and Episode 91: The Search for Water on Mars. We also discussed orbits in Episode 84: Getting Around the Solar System.
Filed under: Astronomy
