FFmpeg is not the most appropriate tool to use for lens correction of still images. While it may work, it is not really meant to be used that way. Since you are already aware of the documentation, it's a matter of reading and applying it.

• lensfun: The lens has to be in the lensfun database. NASA equipment is not typically available to the general public, so they are unlikely to be added to the database.

• lenscorrection: You need to calculate k1 and k2, based on this equation:

  r_src = r_tgt * (1 + k1 * (r_tgt / r_0)^2 + k2 * (r_tgt / r_0)^4)
  

  Other parameters, like cx and cy, can be assumed. There is an OpenCV camera calibration example that calculates the parameters from photos of recognized targets (eg, chessboard pattern). Then you would plug the values into the command:

  ffmpeg -i in-file -vf "lenscorrection=cx=0.5:cy=0.5:k1=[]:k2=[]" out-file
  

  Unless NASA has taken and released calibration images, this approach is unlikely to work.

  See also:

  • Video Production: Correct lens distortion with ffmpeg
  • StackOverflow: Is there a way to remove GoPro fisheye using ffmpeg

Other tools to consider:

• Hugin: Can calculate and apply lens correction parameters. Cannot be used to find k1 and k2 because it uses a different lens correction model. Will apply generic corrections that may be good enough if lens specifications are known (or guessed).

• Photoshop: Adaptive Wide Angle Filter

• RawTherapee, and other raw processing applications: Usually include a distortion correction tool with parameters you can tweak for a good-enough approximation.

Note: Some images released by NASA may already be corrected for distortion.