We’re close to taking vacations on Mars…only in the movies. According to experts, at least one round of technological advances remains between us and safe travels to and from the Red Planet. This planet is actually the hardest to land on because the atmosphere’s too thin to slow your movement, but thick enough to kill you. The ratio of mass to heat shield area rises as one scales up from rovers to human missions, and so do the potential issues with it.
Current technology enables us to land a maximum payload of 1 ton on Mars. Scientists like professor Robert Braun are working on potential solutions to this limitation, such as supersonic retrorockets and inflatable heat shields.
Spacesuits could run into serious trouble with the electric effects and fine-grained dust, because neither is well-characterized. Radiation can be managed as a risk, but that’s being worked on too. Radiation in Mars’ orbit is roughly double that in Earth’s.
Technologies aimed at making it possible for humans to travel to Mars include lighter and more affordable plasma rockets, the use of Mars’ resources to make drinking and propellant water, and reliable closed-loop life support systems. These technologies are power-intensive. On the downside, putting a low-cost nuclear reactor on a rocket is unlikely. The weight in Earth orbit would increase if solar power were used instead.
The mass in Earth’s orbit for a Mars mission is 750 tons on average with the deep-space propulsion technology currently available to us and without recycling food or water. The International Space Station informs that we could build a space structure with a mass of 400 tons. However, this project would cost over $100 billion.
As there is neither political will nor scientific ground-clearing to develop this technology, humans cannot travel safely to the Red Planet now, and this isn’t likely to change anytime soon.