You can now backup your entire user account (profile, rockets, launches). All rockets, launches, images, comments, postings from others about your rockets/launches including images are all included in the archive.
To do so, go to your profile page and tap the backup button as displayed here:
These files can be quite big, so it could take some time to download. I also stream live as the archive is being built, so you won't know the completed file size while it downloads. The file will just continue to download until done.
