Why is Elon Musk's Mars mission considered most ambitious? Find out here

The surface of Mars directly below NASA's Mars Perseverance rover is seen using the Rover Down-Look Camera in an image acquired February 22. (Image: NASA/JPL-Caltech/Handout via Reuters)

While several countries including the UAE, China and the US vying to send a human on Mars, SpaceX founder Elon Musk's vision to achieve the feat in 2026 is considered the most ambitious.

Last month, Musk said in an interview with Peter Diamandis, founder and chairman of the X Prize Foundation, that "a bunch of people probably will die in the beginning" of the Mars mission.

Scientists and researchers have warned of numerous challenges including cosmic radiation, dust storms and lack of oxygen and water for Mars missions.

One such challenge is that Mars and Earth are separated by a varying distance of 35 million miles and 249 million miles, because of their elliptical orbits. While moon missions take only a few days, a Mars mission will only have a small window available when the two planets are ideally aligned for space travel, Bloomberg explained in a report.

It still remains a hurdle, the report added, that there is no solution figured out yet on how to bring back the spacecraft back from Mars. "It’s not the case that we would bring the rocket fuel with us," Joseph Michalski, an associate professor who explores the habitability of Mars at the University of Hong Kong told the publication. "It’s just too heavy."

Another fear among scientists is that of solar flares which are considered 'the most powerful type of explosion in the solar system.' A flare is the equivalent of 100 million hydrogen bombs.

With Mars thinner atmosphere, it lacks the global magnetic shield which protects humans from solar and cosmic radiation. During dust storms on the red planet, the sun can be blocked out for months.

During such a storm, "it’s almost like midnight on the surface of Mars for two months," Nilton Renno, a professor at the University of Michigan whose research interests include astrobiology told Bloomberg. "If you are there with solar panels for power, you very likely don’t survive. You don’t have enough energy to keep things warm enough."

Without enough water on Mars, the feat is impossible for humans. However, the planet has some surface ice which can be utilised to fulfill the purpose.