Ad Astra Observatory

OK, so I measured the yard, and it doesn’t look like I’m going to be able to get the “peekaboo” view between the house and the shop, at least not for a permanent setup. It’s just too close to the street.

By the same token, I don’t really want a north-roll-off roof, because of the same problem. However, since I’m going to be stuck in a place where the house is blocking Seattle’s light pollution anyway, I might be able to swing a west-roll-off roof, and have most of the south wall roll away, too. It’s a thought.

My ruminations have come down to essentially 3 options:

– west-roll-off roof, 12×16, single story
– 10′ HomeDome in a two-story high tower (warm room below, dome above)
– 12.5′ SkyShed POD MAX dome (or dome + observatory), single story

My wife has some concerns about the weatherproofing ability of a roll off, and frankly I agree; I would need to spend some time thinking about how to design a roll off system that’s easy to handle but also rain and snow proof.

The two-story dome has some merit; going “vertical” could help in several ways; less ground effect on seeing, more sky because I can see more over the top of the house, maybe even better protection from local light pollution. There may be some problems with permits. This is also the most complicated build of the three.

At the moment, I’m leaning toward the SkyShed POD MAX. It’s due for release this summer, it’s more than spacious enough for even my most pie-in-the-sky dream scopes, and if I buy the “observatory” option, it comes with walls, so all I need to build is a deck to put it on.

The benefit of a roll-off is that I can run two scopes at once, and it’s a fairly straightforward build, with lots of framing stuff that your average joe contractor has seen before (2×4 framing, 16″ on-center studs, etc). The drawback is weatherproofing, as I’ve mentioned, and the extra footprint required for the roll off structure.

The benefit of a dome is that I can buy one pre-made, so there’s very little startup work to get going. It’s going to be a big enough project as it is without having to add a complete engineering design to the process. Domes also offer a lot of benefit; better wind, light, and dew protection, and a lot of “cool factor”. The biggest drawback of a dome is that you can only put a single telescope inside. I survived for a lot of years with only one scope in CA, but I really want to be able to have the flexibility to do visual or planetary work while the main scope is crunching away on DSO’s.

My wife has authorized two domes. Actually, she worded it as “no more than two domes” 🙂
So, the plan might be to build or buy an ~8′ dome sometime in the future, and use that as a secondary mount point, perhaps as a storage area, and perhaps as a warm room.

I have a feeling that once the main scope goes in, I’m not going to be in a rush to put in a second observatory.

I took some measurements with Trixie, and it looks like she requires exactly 8′ of swing in all directions. With a CW bar that extends below the baseplate of the mount, and a telescope that does the same (when pointed at zenith), I’m going to have to do some calculations with regard to pier height. The constraining factors are that I’d like to be able to view down nearly to the horizon (meaning the pier must be tall enough to allow the scope to clear the observatory wall), but the scope can’t scrape the ceiling of the dome when pointed at zenith when it is off-center by 2′ or so (meaning the pier must be short enough not to shove the scope through the ceiling). The floor must be far enough below the scope not to interfere with the scope or CW shaft (meaning a tall pier to help it clear the floor), but I need to be able to get up to the eyepiece on a Newtonian, which gets way up in the air quickly (meaning a short pier or some kind of scaffolding to allow me to get up there and work comfortably with heavy and delicate instruments). This is going to take some 3D modeling.

I still feel like I’m early in the design phase. At the same time, I think I’m on the right track to a solution. There are just dozens of little details that still need to be worked out.