He is well versed in the subject of space exploration. The Chris Hadfield's impressive CV would make more than one aspiring astronaut dizzy. For nearly 20 years he has participated in two NASA shuttle launches, had a short stay on the Russian Soyuz vessel and lived on board the ISS, which he even commanded. This man even boasts 166 days spent in orbit! Now retired with all this experience, he has just shared his knowledge of astronomy during a master class for an online course. And it is his point of view regarding the conquest of Mars that interests us in particular today. The technological means are there‘We could have sent people to Mars decades ago. The technology dating back to my childhood that has allowed us to go to the moon is able to take us to Mars,’ says the soon to be 59 year-old former astronaut to Business Insider. And this conquest of the Red Planet does not seem to be a recent project since in 1952 a NASA scientist had already started work on a mission to reach Mars.But having the technological means does not necessarily mean it can be done without the risk of loss of life, and it is on this point that Chris Hadfield insists on. ‘The majority of astronauts sent there on a mission would not be coming back’ he warns. We already know about the risks that astronauts incur each time they go on a mission, and we mustn’t forget about all the times that space exploration has ended up in, or flirted with disaster. From the fire that left three dead during a training session on the ground before the Apollo 1 launch, to the Challenger shuttle explosion in 1986 which caused the deaths of seven astronauts, including one civilian. While the Apollo 13 mission avoided tragedy the famous phrase ‘Houston, we have a problem’ will forever remain in our memories. A very high risk for humansFor a trip to Mars the dangers would be increased.‘Mars is further than we think. The Red Planet is 660 times further than the moon. A return flight could take 500 days or involve staying in a kind of small tube for 3 years,’ said the former commander of the ISS.Space travel is also not without consequences on health either. Thus a necessarily longer journey to the planet Mars would expose astronauts even more to potential explosions, radiation, malnutrition and even starvation. And for the moment there is still the need to invent lighter and more protective capsules.And tomorrow?Asked about ambitious current projects being put forward by NASA, SpaceX or Blue Origin, Chris Hadfield is disappointed that their plans still include the use of fuel to propel their shuttles.‘It’s like we’re still using a sail or pedal boat to try and go around the world.’ A kind of techno-spatial anachronism! Indeed, the use of chemical propellants is not as effective as one might think, and above all requires sacrifices to be made. Engineers who design shuttles are forced to reduce protections against radiation and limit the space reserved for food, tools and living spaces to make room for the fuel needed for travel. But space fans hoping for a Mars mission in this lifetime can be reassured, since the Canadian astronaut thinks that ‘someone will eventually invent the ideal shuttle which has not yet been thought of.’Check out the video above for more!