Remember when I went to the NASA Social at Palmdale and got to see the SOFIA aircraft?
This was in 2015, nine years ago, and they’ve unfortunately retired her now. But that big door in side, just forward of the tail, would open up inside to expose a huge infrared telescope.
Inside, folks would attach their equipment and experiments (like this one from a group at Cornell Universaity) and the mirror and experiments would seemingly bounce and dance around as the plane flew above a big chunk of the atmosphere. But in fact the telescope tracking systems were keeping the telescope perfectly still with astonishing precision, while the plane bounced and moved around it.
Amazing!

