Stats: Atlas 5 and Delta 4 histories and backlogs (updated April 20)

Take a walk around NASA’s OSIRIS-REx spacecraft less than three weeks before its Sept. 8 launch on top of an Atlas 5 rocket. Rich Kuhns, the mission’s program manager from Lockheed Martin, points out some of the major features on the probe.

NASA safety advisors on Thursday lauded hardware milestones on Boeing and SpaceX commercial crew capsules, but said multiple technical issues, including problems with parachutes, must be resolved before the human-rated ships are ready to carry astronauts, adding that both companies continue to pursue schedules that appear to be unachievable.

Helium leaks and thruster issues prompted NASA to extend their stay aboard the space station indefinitely — Wednesday marked their 35th day in orbit — while engineers carry out tests and analysis to better understand what caused the problems and to make sure the spacecraft can safely being Wilmore and Williams home.