The Mars Curiosity mission has revealed far more about the planet and its history since it arrived there two years ago, than any previous mission before it. Now, award-winning science writer Mark Kaufman is publishing a new book which examines the Curiosity mission close-up. Kaufman not only explores the current mission and its implications, but also opens up about how future missions, perhaps led by innovative companies like Elon Musk's SpaceX, could shape the future of humanity and help to define our place among in the universe. 

According to National Geographic, in spite of all the recent developments by private companies in spacecraft technology, Kaufman is still leery of agreeing with those like Elon Musk who claim the next few decades could see private citizens travel to Mars and make their home there. 

"Let's just say that a lot of things would have to go right in order for that to happen," Kaufman says. "There are some big challenges. But the architecture for sending humans to Mars is entirely understood. The issue is: Is there money? And is there public support? Though [Musk] has the advantage of potentially doing some of that on his own."

One of the major obstacles in the way of journeying to Mars with current technology, is the length of time it would take to get there, says Kaufman.

"It takes about nine months to get to Mars, and we know that the radiation exposure for that time is probably in the hazardous range," he states. It may not kill you, but it would make you a fairly sick puppy. And so they need to get there quicker."

NASA recently successfully tested a new space engine which if they could harness it, might very well provide much faster and more efficient space travel for future interplanetary travelers.

Another issue facing martian astronauts is how they would get home: "It turns out that leaving Mars is very difficult," Kaufman tells National Geographic. "Even though the atmosphere is quite thin, it still is an atmosphere. So it's not like being on the moon, where they were able to just shoot up, back in the Apollo days. They'd need a fairly sophisticated and powerful rocket to get them out. They don't know how to do that right now."

Kaufman acknowledged that to put humans on Mars would require "hundreds of billions [of dollars] over decades." Also, there's no guarantee that going to Mars would be economically viable. If there ends up being no precious resources companies can mine and export, would it still be worth it to go? Kaufman thinks so. 

"[It is a] magnificent challenge, like going to the moon in previous generations, [and it] could define humankind."