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Yeah, I've been in scramble mode, getting the house ready for the 4th.

For portable observatories you have a few choices.

First and cheapest is an observing tent made by Kendrik that is similar to a rolloff (zipoff) and "warmroom" (conventional tent) attached to it. There is also a Chinese copy on the market. These would do well probably for small scopes, but would nave no wind, dew or light protection, plus I think they would heat up quite a bit during the day. These go for ~$200-$400 or so.

Next choice would be the Astrogazer. This is what I ended up with for star parties. It's a conduit/PVC structure coverd by heavy duty weatherproofed ripstop nylon. It offers wind, dew and light proection, can easily fit a 14" SCT scope or a dob up to about 16". They also run very cool during the day. One plus is the size, 10 feet in diameter which is large enough to hold several people and gear. It can also store in a closet or corner of the basement or garage when not in use. The downside to it is that it is not lockable so you really can't lock up and go sight seeing during the day if you have expensive gear in it. It is pretty weatherproof but there is no floor so there would be a leakage issue there. The roof is relatively waterproof so I wouldn't be concerned about heavy rain. High winds (40+) can be an issue. I've had it up in winds like this. There is a risk of the dome blowing off unless it is wired to the base and the base is augmented with heavy stakes (I use aircraft landing tiedowns). I still pull a trailer to take it as my small colorado can't fit the observatory and all the gear I take. With a large van or truck it probably wouldn't be an issue. Setup is about an hour and 15 minutes with a little practice. The AG, I haven't priced one in a while but they should be under $2000.

The next option is the an Exploradome on a tilt trailer. This was absolutely the easiest setup. The trailer tilts, then the "saddle" that holds the observatory is tilted and the observatory is up in one piece and ready to go. Literally it is 10 minutes until you're loading the scope inside. Just take off the straps, slide some counter weights to the back of the trailer, tilt it, (the observatory is right at its tipping point), then a little shoulder to get it past the tipping point. A winch rope keeps it from falling the rest of the way, Just crank the winch until the observatory is down, take off a couple more straps and it's ready to go. To load up takes about 20 minutes, but it's mainly just checking the straps and making sure it's ready to trail. Just back the trailer up to the observatory, tilt it, slide the lip under the bottom, put a couple of straps around the base and mid section, use the winch to crank it over, set it on the bed, then move the counterweights so the trailer bed goes level, then add a couple more straps to make sure everything is secure and away you go. This was by far the most portable rig. That I could lock up the gear and leave at a remote site was a real plus. The Exploradome provided the best wind, dew and light protection. The downside though was that it was a bear to pull with my little 5 cylinder truck. Also another thing is it is only comfortable for one or two people. When I had it at star parties, everybody wanted in, especially on windy or dewy nights! The whole rig is like pulling a camper, a small one, but it still needs a reasonable tow vehicle which mine was not. The whole weight of the trailer and dome was less than 2000 lbs, but the windage on the observatory and the height made it like pulling a small camper. After I got the Astrogazer I ended up using the Exploradome as my home observatory and the Astrogazer as my portable. This whole rig, with the trailer would be probably about $4000 or so, but it does provide a real observatory and fast setup time.

The last option would be a POD. These were designed as portables but to my knowledge, nobody has actually used one for this purpose (set up and tear down) on a regular star party basis. The downside as a portable would be the assembly and small size. Transporting one is going to take an entire vehicle or trailer, then it would have to be assembled. I think the dome quarters are something like 90 lbs and that means one person would have to lift 180 lbs per dome side up onto the wall. I would think a very level surface would be required as well (where the AG's legs can be adjusted 6" and the Exploradome had a solid bottom with a center hole for the tripod). I have never seen anything published on POD setup times, but I'm guessing with two people with tools and a level surface, it would probably still take the better part of a couple of hours. A bare bones POD (no bays) and shipping is probably going to be well over $2000. I would also worry about the wear and tear on the plastic and bolt holes etc from setup and teardowns.

Overall I think the Astrogazer is the best price point for a portable observatory. It's large and roomy, easy to store, can be set up by one person. The only downside is not being able to lock it up. That's not a real issue at a regular star party, but I wouldn't leave expensive small stuff in it and run to town.

Well, hope this helps.

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