Photos: Atlas 5 on the pad at sunset

Five years after winning $1 billion from NASA to mount the first U.S. asteroid sample return mission, scientists and engineers will get their last look at the OSIRIS-REx spacecraft this week as it is closed up inside the nose cone of an Atlas 5 rocket for launch in September.

Rocket-builder United Launch Alliance unveiled a first-of-a-kind website Wednesday that shows potential customers exactly what it will cost to buy an Atlas 5 booster, along with expected savings based on the rocket’s demonstrated reliability, ULA’s on-time launch record and the company’s sophisticated guidance system.

The early months of NASA’s OSIRIS-REx mission’s exploration of asteroid Bennu have revealed big surprises, scientists said Tuesday, including plumes of particles streaming away from the asteroid, sometimes with enough velocity for rocks to break out of Bennu’s tenuous gravitational grip and escape into space.