Stephen Hawking: 'Human race has no future' without space travel

Stephen Hawking is a supporter of space travel, in part, because he thinks the survival of humanity depends on it.

Hawking shared these thoughts in an afterword for Julian Guthrie's book "How to Make a Spaceship: A Band of Renegades, an Epic Race, and the Birth of Private Spaceflight."

SEE ALSO: Stephen Hawking is worried about the threat posed by our alien overlords

In the piece, the physicist writes, "I believe in the possibility of commercial space travel – for exploration and for the preservation of humanity."

See Stephen Hawking through the years:

Hawking goes on to warn, "I believe that life on Earth is at an ever-increasing risk of being wiped out by a disaster, such as a sudden nuclear war, a genetically engineered virus, or other dangers. I think the human race has no future if it doesn't go to space."

As such, he says, "We need to inspire the next generation to become engaged in space and in science in general, to ask questions: What will we find when we go to space? Is there alien life, or are we alone? What will a sunset on Mars look like?"

Hawking also reveals that he has accepted a seat on Richard Branson's Virgin Galactic SpaceShipTwo vehicle, VSS Unity, should it venture into space.

Stephen Hawking warns contacting aliens could be like "Native Americans encountering Columbus":