NASA maintains a database of astronaut photography in eol.jsc.nasa.gov that we can search by many parameters, including focal length. By searching for focal length above 28mm, we can ensure the resulting images are not fisheye.
Flat-Earthers claim all NASA images are fisheye. In reality, most images in eol.jsc.nasa.gov are not fisheye. NASA also preserves the images’ EXIF data containing the camera & lens info. Sometimes even the raw images are available.
To search the images by focal length, we can go to https://eol.jsc.nasa.gov/SearchPhotos/, then turn on “Show Advanced Options”. It will reveal many advanced options that we can use, including minimum and maximum focal length. We can pick “28mm” as the minimum focal length, and all the results will be non-fisheye images.’
All fisheye lenses have a focal length of 17mm or less. Therefore, by limiting the results to having a focal length of 17mm or higher, we can be sure the images are non-fisheye. 28mm is the closest option above 17mm that they make available to choose. Anyone web-savvy enough will be able to modify the form to choose a number below 28mm but above 17mm, and it will give us ultra-wide imagery but still rectilinear.
There are however lenses wider than 17mm, but still rectilinear & non-fisheye, including the Nikkor 14-24mm f/2.8 that they have in the ISS. Just because the lens’ focal length is wider than 17mm, it does not mean it must be a fisheye lens.