Kathryn Thornton is repairing the Hubble telescope, I have cropped the square format of the image so the earth is no longer visible behind her, please check out the original.

The full credit from the NASA Image Library is: This STS-61 onboard photo depicts Astronaut and mission specialist Kathryn Thornton performing the 2nd extra-vehicular activity (EVA) of the STS-61 mission. Thornton, along with astronaut and mission specialist Thomas Akers (out of frame), performed the task of replacing the solar arrays. The EVA lasted 6 hours and 35 minutes. Launched December 1, 1993 aboard the Space Shuttle Orbiter Endeavor, the STS-61 mission was solely dedicated to servicing the HST.