Seven astronauts boarded the shuttle today, led by Cdr. Scott Altman at Florida’s Kennedy Space Center this afternoon. Despite one warning signal right after liftoff, they safely reached orbit within eight minutes and are cruising space at more than 17,200 miles per hour.

The desination is the Hubble Space Telescope, whose batteries, cameras and gyroscopes are in need of replacement, located 350 miles out in orbit where the team will begin five days of space walks to repair the telescope.

NASA has openly discussed the threat of micro-meteorites hitting the orbiter while the astronauts are fixing Hubble. Earlier this year two satellites collided over Siberia, which has increased the risk even more, as space junk from that collision drifts lower. Once Atlantis fixes Hubble, it will immediately move to a lower altitude to reduce chances of getting hit by space junk.