Astronauts are aiming for an extra-long spacewalk Friday to give the international space station more fresh batteries.

A Northern Virginia aerospace company won a $1.9 billion contract from NASA yesterday to fly cargo missions to the space station from a launch site on Virginia’s Wallops Island.

BOSTON—Your work is dangerous, and your co-workers rely on you to stay alive. But you can never get far from those colleagues. You can’t see your family for months, even years. The food isn’t great. And forget stepping out for some fresh air. No wonder the adventure of space flight can also be stressful, isolating and depressing. So scientists are working on giving a computer the ability to offer some of the understanding guidance—if not all the warmth—of a human therapist, before psychological problems or interpersonal conflicts compromise a mission.