Live coverage: International Space Station crew lands in Kazakhstan

Five years ago Tuesday, NASA’s New Horizons spacecraft barreled by Pluto for a high-speed encounter that gave humanity its first close-up look at a distant world that puzzled astronomers and planetary scientists for nearly a century. Scientists are now planning how to go back.

Two astronauts floated outside the International Space Station early Friday for the first of four planned spacewalks to wrap up a complex multi-year job to replace 48 aging batteries in the lab’s solar power system with 24 more powerful lithium-ion units.

When the first Delta 2 rocket took off on Valentine’s Day 1989, ideas like navigating by smartphone and driving robots on Mars were science fiction. More than 150 launches over the last 30 years helped change all that.