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  • Every 26 months, Mars and Earth are at their closest distance, which is about 57 million kilometers apart.

  • During this time, if an unmanned NASA spacecraft were to leave Earth, traveling at 58,000 kilometers

  • per hour, it would take a little over 40 days to get to the Red Planet.

  • Not bad, right?

  • Well, a quick trip would only be possible if the spacecraft followed a direct path, undisturbed by the wrath of the solar system and weight of life sustaining resources.

  • Unfortunately, space travel is far more complicated than a straight line.

  • So ideally, how long does it take to get to Mars?

  • The solar system is constantly shifting, and the orbital mechanics behind each of the planets makes space travel really complex.

  • Because Earth and Mars have elliptical orbits, the distance between them varies considerably,

  • and in order to send a spacecraft to Mars, the planets have to line up just right.

  • It takes Earth one year to orbit the Sun, while it takes Mars about 1.9 years.

  • So, every time Mars completes a single orbit, Earth goes around the sun almost twice.

  • Historically, for NASA, the best launch window to Mars occurs every 2 years and 2 months or 26 months.

  • During this time, a spacecraft can utilize what is considered the most energy efficient path to Mars known as the Hohmann Transfer orbit.

  • On this trajectory, the spacecraft follows an elliptical orbit around the Sun that intersects the orbit of Mars.

  • It uses fuel to increase speed and velocity to break free of Earth's gravity field.

  • And the spacecraft uses more fuel to decelerate in order to be captured into the Martian orbit.

  • Then, it can ride Mars's orbital wave until it's ready to touch down on the surface.

  • While the Hohmann transfer is considered the most efficient trajectory to get to Mars,

  • the journey is still estimated to take roughly 260 days or eight to nine months with a manned spacecraft powered by chemical propulsion,

  • so NASA and private companies are trying to develop more efficient propulsion systems that can get humans to Mars faster than the chemical rockets used in the past.

  • Specifically, a type of electric propulsion system that propels a spacecraft by accelerating a stream of electrically charged atoms, known as ions.

  • And a nuclear thermal propulsion system that uses low-enriched uranium as its power source.

  • But even if we do engineer a faster way to get to Mars, a round trip is still estimated to take multiple months.

  • And that means we also have to solve problems of human health and resource requirements during extended deep space missions.

  • Clearly, time is just one of many obstacles standing in the way of our Martian dreams.

  • But still, NASA says it plans to send humans to Mars in the 2030s.

  • So do you think it's actually going to happen?

  • Let us know in the comments below and tell us what other obstacles you want us to explain.

  • If you want to see more Space Crafts check out this playlist here.

  • And be sure to let us know in the comments what astronomical phenomena you want to learn more about.

  • Thanks for watching Seeker! Don't forget to subscribe.

Every 26 months, Mars and Earth are at their closest distance, which is about 57 million kilometers apart.


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火星に行くにはどのくらいの時間がかかりますか? (How Long Does It Take to Get to Mars?)

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    Jerry Liu に公開 2021 年 01 月 14 日