One of the most exciting space exploration projects in recent years has been the journey to Mars. In our lifetime, it will be possible for human beings to visit the red planet, and if you’re interested in going, you’ve probably wondered how long it would take to get to Mars. The answer to this question depends on a number of factors, such as the route you take to get there, and the timing of launch with planetary alignment.
In this article, we’ll look at Mars and why it takes as long as it does to reach the planet.
Mars – Quick Facts
- Distance From The Sun: 227,940,000 km (141,635,349 mi)
- Radius: 3,400 km (2,113 mi)
- Temperature: -153 to 20 °C ( -225 to 70 °F)
- Day Length: 24.6 Earth days
- Year Length: 687 Earth days
- Number of Moons: 2
- Closest Distance to Earth: – 54.6 million km
- Furthest distance to Earth: – 401 million km
- Next Launch Window For Quickest Transit: – September 2022
How far is Earth from Mars?
The closest that Earth and Mars approach each other is when Mars is at its closest position to the sun (perihelion) and Earth is at its farthest (aphelion). When this happens, the planets can reach as close as 54.6 million km apart. However, such a close approach is so rare, that it has never been recorded or observed in the entire history of the human race. There are a number of factors responsible for this, including the planet’s elliptical and slightly tilted orbits, and gravitational influences from other Planets.
In 2003 we were lucky enough to have witnessed the closest approach between Mars and the Earth in 60,000 years, according to NASA. On this approach, the planets were only 56 million km apart. It will be over 250 years until the planets are that close again, in 2287!
The two planets are at their farthest distance from each other when they are both at their farthest from the sun (aphelion), and on opposite sides of the sun. At this point, they can be 401 million km apart. The average distance between Mars and Earth is 225 million km.
How Long Would it Take to Get to Mars?
The time it takes to travel to Mars depends on a number of things. The first is distance. For every launch there is a window of time which offers the most economical and efficient journey time. A launch window takes into account many factors including the timing of the the planets closest approach, the type of propulsion/ rocket system used, mission objectives and also the weather.
In terms of mission objectives, if you plan on stopping at Mars, the flight time will be significantly different to if the mission is simply to conduct a fly-by. For instance the Mariner 7 mission flew past Mars in the late 60’s in an incredible 128 day journey time!
Journey time to Mars would depend on the distance between the Planets at the time of the launch, but also require that the orbit speed and direction are taken into account to choose the most efficient path. As well as the efficiency requirements of fuel, mass of the space craft, speed of craft and whether the craft is manned or unmanned.
It would be uneconomical to launch at the same time that the Planets were in closest approach, as the distance between the Planets would be growing each day, increasing the flight time and the fuel requirements for the trip.
What is the Shortest Trip?
The shortest trip to Mars so far, was a fly-by of the Mariner 7 mission in 1969. The shortest orbital mission was two years later in 1971 with the Mariner 9 orbital mission. The quickest mission for putting a lander on Mars was MER Opportunity Rover mission in 2003 which had a flight time of 201 days.
How Often Does The Closest Approach Occur?
The Close approach between Mars and the Earth happens roughly every 26 months. As we have discussed elsewhere above though, not all close approaches are the same. They can occur a few days either side of opposition, and the closest distance on each occurrence will also differ.
Missions To Mars
Mars is a close neighbor, and given it’s rocky, earth-like terrain it is one of our best chances of finding life elsewhere in the Solar System. As such, there have already been many missions to Mars. From the first early probes and fly-by’s to the latest rovers testing out new technologies and collecting samples. Here are a selection of mars missions with their flight times:
| Mission | Type | Year | Flight Time | Active? | Achievements |
|---|---|---|---|---|---|
| Mariner 4 | Fly-By | 1965 | 288 Days | No | First close-up photos of Craters |
| Mariner 6 | Fly-By | 1969 | 155 Days | No | Analysed surface and atmosphere |
| Mariner 7 | Fly-By | 1969 | 128 Days | No | Analysed surface and atmosphere |
| Mariner 9 | Orbital | 1971 | 168 Days | No | First mission to orbit Mars & photograph 100% of the Martian surface. |
| Viking 1 | Lander | 1975 | 304 Days | No | First NASA mission to land on Mars |
| Viking 2 | Orbital/Lander | 1975 | 333 Days | No | First mission along with Viking 1 to conduct biological research on the Martian surface. |
| Mars Global Surveyor | Orbital | 1996 | 308 Days | No | Studied atmosphere, surface and interior and was the first to calculate weather maps. First succesful mission since the 1970’s |
| Mars Pathfiinder | Lander/Rover | 1996 | 212 Days | No | First lander with robotic rover to land on Mars. First mission to try an airbag landing. |
| Mars Odyssey | Orbiter | 2001 | 200 Days | Yes | Longest serving spacecraft at Mars. Still active today as relay for rovers and landers on Mars. |
| Mars Express | Orbiter | 2003 | 201 Days | Yes | Europe’s (ESA) first spacecraft to visit another planet. Carried Beagle 2 Rover which was lost on landing. |
| Mars Exploration Rover (MER) – Spirit | Rover | 2003 | 208 Days | No | One of a pair of geological rovers delivered to opposite sides of Mars. Operated for 6 years. |
| MER – Opportunity | Rover | 2003 | 201 Days | No | One of a pair of geological rovers delivered to opposite sides of Mars. Only retired in 2019. |
| Mars Reconnaissance Orbiter | Orbiter | 2005 | 210 Days | Yes | Contains most powerful camera sent to another planet, sending back HD images of the surface. |
| Phoenix Lander | Lander/Rover | 2007 | 295 Days | No | Looked for signs of past life and water on Mars. |
| Mars Science Lab/ Curiosity Rover | Rover | 2011 | 254 Days | Yes | Largest rover sent to Mars so far. Successfully tested a new landing method. |
| MAVEN | Orbiter | 2013 | 307 Days | Yes | Second mission in the scout program, measuring climate change. |
| Exo Mars ESA/Roscosmos Mission | Orbiter/Lander | 2013 | 322 Days | Yes | Lander lost on landing. Orbiter still active, exploring if life ever existed on Mars. |
| Mars Insight Lander | Lander | 2018 | 205 Days | Yes | Studies the interior of Mars to determine how the terrestrial planets form. |
| Hope Orbiter | Orbiter | 2020 | 205 Days | Yes | The UAE’s first orbital mission to Mars. |
| Tianwen 1 & Zhurong Rover | Orbiter/Rover | 2020 | 202 Days | Yes | China’s first successful orbital and lander mission to Mars. |
| Mars Perseverance Rover | Rover | 2020 | 204 Days | Yes | Tested new landing tech, and launched the first helicopter on Mars. |
- Mariner 3 was lost during launch
- Mariner 8 lost during launch
- Mars Observer lost prior to entering Mars orbit
- Mars Climate Orbiter lost on arrival at Mars
- Mars Polar Lander lost on arrival at Mars