Tesla and SpaceX founder Elon Musk told an audience at South by Southwest that his timeline for sending a space vehicle to Mars could mark its first milestone early next year.

The privately-funded venture, announced in September 2017, aims to send a cargo mission to the Red Planet by 2022. SpaceX's ultimate objective is to plant the seeds to put a human colony on Mars.

Musk held a surprise question and answer session at the annual technology and culture festival in Austin, Texas on Sunday. The billionaire told attendees that "we are building the first Mars, or interplanetary ship, and I think we'll be able to do short trips, flights by first half of next year."

Mindful of elevating expectations too high, Musk hedged a bit. "Although sometimes, my timelines are a little, you know..." he said to laughter.