First of all make a dumb search by a given phrase

Check the first link and get the post on the CollectSpace forum with that phrase. Also there is a link to the original post at HobbySpace:

The site doesn’t exist anymore and domain is parked. Then check the archive.org with the snapshots of this site. Selecting different dates in the top of the page we can find the latest saved snapshots of the site:

So the last update of Eric Hartwell’s post was on April 25, 2007

Let’s visit the wiki article about Apollo 17 mission to find out who was the Ronald. There is Ronald E. Evans Command Module Pilot in the crew.

Return back to the Hartwell’s post and find any mentioning of camera’s images counter value by Ronald:

Don’t forget about the note about how does frame counter work in analog cameras. Usually the first frame was not usable, so reduce this number by 1.

The challenge is solved!!

Used tools and services:

• Wikipedia
• Google Text Search
• Web.archive.org