NASA astronaut afraid of heights shares space experience

When NASA astronaut Joseph Acaba went out for a spacewalk during a recent trip into space, he held on tight to the railing. That's because Acaba is afraid of heights.

That was one of the highlights of Acaba's talk this week to employees at the Stennis Space Center on the Mississippi Gulf Coast.

Acaba was making his first public appearance since returning Feb. 28 from the International Space Station. He says during the next year or so NASA astronauts will be flying on commercial flights, calling it a "big step." He says going to space is difficult and will never become routine but in the near future there will be more opportunities for people to fly there. He says the ultimate goal is to get humans to Mars.

NASA is also poised to launch its first lander to Mars since 2012, an unmanned spacecraft called InSight that aims to listen for quakes and unravel the mystery of how rocky planets like Earth form. It is scheduled to launch on Saturday at 7:05 am Eastern time (1105 GMT) from Vandenberg Air Force Base in California, and if all goes as planned, it should land on the Red Planet November 26.

Since the Earth and Mars likely formed by similar processes 4.5 billion years ago, the US space agency hopes the lander -- officially known as Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) -- will shed light on what made them so different.

"How we get from a ball of featureless rock into a planet that may or may not support life is a key question in planetary science," said Bruce Banerdt, InSight principal investigator at NASA's Jet Propulsion Laboratory in Pasadena, California.

With inputs from agencies