By John L
A trip to Mars would depend on where the Earth is in relation to that planet. The orbits of the two planets would have to be aligned so that the distance is as short as possible to make the trip quicker. The speed of the spacecraft would be a factor as well. There have been several probes sent to Mars, so there is a good amount of information on how long it takes to get there.
Mars is much farther away from the Sun than Earth is. While Earth is an average of 93 million miles from the Sun, Mars orbits the star at an average distance of 142 million miles. So while it takes Earth 365 days to complete one rotation around the Sun, it takes Mars almost twice as long, 686 days, to complete one revolution around.
The very first spacecraft from Earth to reach Mars was Mariner 4 in 1965, which sent back 22 pictures of the Martian surface. Mars 2 landed on Mars as did the Viking landers in 1976. After 20 years of no missions to Mars the Mars Pathfinder went there in 1997. The Mars Expedition Rovers arrived on Mars in 2004 and sent back a lot of information, and in 2008 the Phoenix lander set down on Mars in search of water.
On May 30, 1971, the Mariner 9 probe was launched, arriving at Mars on November 14 of that same year. Viking 1 and 2 were launched within weeks of each other in 1976 and took almost a year to get to Mars because of where Mars was in its orbit. Pathfinder took off on December 4, 1996, and was orbiting Mars in July of 1997, while Spirit left the Earth on June10, 2003, and was on Mars in 6 months.
It has been estimated that a rocket to Mars would take 260 days to arrive there under the right circumstances, where the two planets are as close as they get to each other during their orbits. This is factoring in a trip under the current speeds that rockets can travel. Nuclear-powered rockets would theoretically be able to cut that time in more than half.
In the past 50 years there have been dozens of mission sent to Mars. However, nearly two-thirds of these spacecrafts have experienced some sort of problem that kept them from successfully completing their missions. Often times an unknown cause has made these spacecraft fail, leading to speculation of a “Mars curse” or an Earth-Mars version of the “Bermuda Triangle.”