A mini-book describing Writers on the Moon in our payload...
Originally, my thought was to send a mini-paper book listing all the authors participating in Writers on the Moon. That turned out to be technically challenging when we expanded to take 125 authors, plus I realized that, for our future anthropologist, it might not be as helpful as a short description of what we were attempting with the project. Yes, they would have the MoonChip (the hexagonal metal medallion inscribed with our name and website), which would survive no matter what. But the website might not survive (despite putting it in my will). And the SDcards might not survive (despite being protected from radiation). This tiny paper book might be all that would survive of the IDEA of what we were doing, even if all else failed. Plus it was a first-level README of the entire project. Anyone opening the capsule would be able to understand what they were holding in their hands (assuming they could read or translate English).
Paper is incredibly durable under the right conditions. We have manuscripts that are hundreds, even thousands of years old. It’s entirely possible that the paper book could survive in the airless, frigid environment on the moon indefinitely. But I wanted to give it the best chance by using archival paper and careful handling.
Best practice for archiving is acid-free, ligand-free, preferably 100% cotton paper. Turns out that regular printer inks weren’t too shabby for archiving purposes, which is good, because that’s all I had (Canon Laser Printer). Unfortunately, most archival paper tends to be heavier (thicker), and we needed something thin for the payload. Standard print paper is about 80 gsm (grams per square meter), and archival papers started at 160 gsm and went up from there. 20 lb paper is 75 gsm, which was 0.004″ thick, and that was about what we needed. At the time I was purchasing paper, I wasn’t sure how many pages we would need for the book (how many authors we would have), plus I wasn’t sure if the SDcards would measure true to spec (ie would they be thicker than I thought? Would we be able to fit one or two?). So thin was better.
It took some searching, but I found some 100% cotton, acid-free, ligand-free 80gsm paper and I figured that was the best I could do (I actually found two different sources, ordered both, and used the one that looked best).
Okay, I had paper and ink and words… time to make a book!
I wore gloves for the assembly to keep my human oils to myself and practiced a few times sewing the book together with cotton thread. I would have liked to make something fancier with a “cover” and everything but there just wasn’t room in the payload. Sometimes, simple is best.
The next question was how thick was the book and how would that affect the stackup, ie Would I have enough room for a second SDcard?
Time for the calipers!
Thickness of the capsule = 0.125″ = 125 thousandths
Estimated STACKUP = mini book (44) + metal sheet (26) + mem card (40) = 110 (out of 125)
Actual STACKUP = mini book (32) + Moonchip (24) + mem card (30) = 86 (out of 125)
Since everything actually measured smaller than estimated, I definitely had room to include the second SDcard! Yay!
FINAL STACKUP = mini book (32) + Moonchip (24) + 2 * mem card (30) = 116 (out of 125)
Just as a cautionary note, I told Astrobotic they could leave out the second SDcard if they wanted (they were exact duplicates).*
*see previous post re: why a second chip was a good way to guard against radiation damage.
With the mini-book made, all that was left to do was download the payload to the SDcards, package it up, and ship!
(See next blog post for the official shipping of the payload!)
