AP Photo

The days between January 27 and February 1 are the most difficult week of the year for NASA. The annual space program shiva, honoring the three disasters that claimed 17 astronauts’ lives, is always fraught with emotion and regret. But it’s also a time to think about what those astronauts were doing and why, and that means it’s also a time to be proud, and to remember what we have learned since their loss.