️<unk>️<unk>️<unk>️  ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️ ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️ ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️ Dr Bertolami from the University of Porto was speaking to MailOnline. Dr Bertolami from the University of Porto was speaking to MailOnline. ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️ In total a manned mission would last three to four years, which poses major problems, such as exposure to radiation.<unk> In total a manned mission would last three to four years, which poses major problems, such as exposure to radiation. Theoretical physicist Dr Orfeu Bertolami from the University of Porto, together with his colleagues Dr André Guerra and Dr Paulo Gil, carried out a study comparing different space propulsion methods for a manned mission to Mars. <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> Option 2 - Least technological risk <unk> Send humans into lunar orbit <unk> Visit an asteroid in its own orbit <unk> Return to the moon's surface <unk> Explore Martian moons Deimos and Phobos <unk> Enter orbit around Mars <unk> Land on the red planet <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️ En dépit de ce que les gens disent, nous sommes loin d'atteindre Mars,<unk> a déclaré à MailOnline. One particular issue is radiation.<unk> One particular issue is radiation. Astronauts on a mission to and from Mars will be outside of Earth's...<unk> Astronauts on a mission to and from Mars will be outside of Earth's...
<unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> He studied different types of propulsion that could get humans to Mars.<unk> He studied different types of propulsion that could get humans to Mars. In total a manned mission would last three to four years, which poses major problems, such as exposure to radiation.<unk> In total a manned mission would last three to four years, which poses major problems, such as exposure to radiation. <unk> <unk> <unk> I would like to be a bit more optimistic, but I<unk>m afraid this is how it is<unk>