Getting astronauts to Mars will take all the spacefaring expertise the United States can muster, including advanced propulsion technologies such as solar-electric engines and perhaps even nuclear rockets, according to NASA Administrator Charlie Bolden.
In statements made during a visit to the Aerojet Rocketdyne plant here last Thursday (May 28), Bolden stressed that he'd like to slash the travel time required to send astronauts to Mars.
The supermassive black hole is 40 million times as massive as the sun and powers a quasar that existed 700 million years after the Big Bang.
The asteroid zoomed by Earth at a perfectly safe distance of around 1.8 million miles (2.9 kilometers).
Images show surprise changes to the spacecraft as it interacted with the atmosphere.