A helicopter similar to the Ingenuity Mars Helicopter is airborne at left.
This illustration shows NASA astronauts working on the surface of Mars. Life on Mars would be possible and several simulation trials have already been done on Earth to see how people would cope with such an existence. SpaceX plans to launch several cargo flights including critical infrastructure such as greenhouses, solar panels and - you guessed it - a fuel-production facility for return missions to Earth. We would need to build a climate-controlled place just to live there. The gravity on Mars is 38% of Earth’s (so you’d feel lighter) but the air is principally carbon dioxide (CO₂) with several percent of nitrogen, so it’s completely unbreathable.
So we need to be very selective about where we choose to live on Mars and how we manage temperature during the night. The average winter temperature at the Earth’s South Pole is about -49℃. Mars has a maximum temperature of 30℃, which sounds quite pleasant, but its minimum temperature is -140℃, and its average temperature is -63℃. The thin atmosphere on Mars means it can’t retain heat as well as Earth does, so life on Mars is characterised by large extremes in temperature during the day/night cycle. The latter, once again, requires more fuel.Ī Martian day lasts 24 hours and 37 minutes but the similarities with Earth stop there. Some missions have landed on airbags (such as NASA’s Pathfinder mission) while others have used thrusters (NASA’s Phoenix mission). That means less potential for drag, so it isn’t possible to land safely without some kind of aid. This allows the craft to land safely on the Earth’s surface (provided it can survive the related heating).īut the atmosphere on Mars is about 100 times thinner than Earth’s. The next challenge is landing.Ī spacecraft entering Earth is able to use the drag generated by interaction with the atmosphere to slow down. Suppose our spacecraft and crew get to Mars. Basically, without going into too much detail, this is where a spacecraft does a single burn into an elliptical transfer orbit from one planet to the other.Ī Hohmann transfer between Earth and Mars takes around 259 days (between eight and nine months) and is only possible approximately every two years due to the different orbits around the Sun of Earth and Mars.Ī spacecraft could reach Mars in a shorter time (SpaceX is claiming six months) but - you guessed it - it would cost more fuel to do it that way. Clearly this is something humans would not want to do.īoth Earth and Mars have (almost) circular orbits and a manoeuvre known as the Hohmann transfer is the most fuel-efficient way to travel between two planets. This saves a lot of fuel, but can result in missions that take years to reach their destinations. They use what are called gravity assist maneuvers to effectively slingshot around different planets to gain enough momentum to reach their target.
Missions that send spacecraft with no crew to the outer planets often travel complex trajectories around the Sun. Credit: SpaceX Time mattersĪnother challenge, intimately connected with fuel, is time. Concept art of SpaceX’s Dragon landing on Mars.