Spacedocks

The Columbia-catastrophy and the actual mission of Discovery have caused or involve some innovations:

1. There are in-space inspections of the heatshield of the Space Shuttle by the astronauts.

2. A special boom has been developed which temporarily has been attached to the "crane"-arm of the bay of the Shuttle to scan the heat-shield.

3. May be the astronauts will or must repair the Shuttle in-space while docked to the ISS.

This has led be back to the thought of in-space-construction or -production although this is a horror to engineers because of docking and much more. The reason are the points listed - perhaps there are more to be found.

What about a spacedock the vehicles don't have to fly or move into?

The vehicles simply could dock to a spacedock like they dock to the ISS or - futurely to Bigelow's Nautilus. But then a hangar or a bay or something like that could move from the station-part of the spacedock in a manner that the vehicle is enclosed in it. That hangar or bay could be equipped with the scanners currently provided by the special boom of the Shuttle. It could include utilities and tools assiting repairs of vehicles needed. This could be developed further later.

To move the hangar or bay to the vehicle and away from it after the repairs are done the method could be used by which the robotic crane of the ISS is moved along the sides of the ISS. The crane is moving along rails if I remeber right.

An alternative could be something like an an inflatable and deflatable hangar .

What about such thoughts?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

I doub that there's many people actually against that idea, Ekke. If we only had the lift capacity to get the things up there, we'd be in business.

It is an idea for a future project. After the ASP will be won there may be a significant growth of passenger traffic into the orbit. Safety will be made a topic again by the FAA - pointing to the Space Shuttle. People like Rutan will think about it. Spacedocks may be the solution then.

But they mustn't be as expensive as the ISS is - a way should be found to keep them cheaper than Nautilus.

I was thinking about concepts of a spacedock merely - like Bigelow's inflatbales are a new concept for space stations while the ISS is another older concept of a space station.

Could Bigelow's way to develop and to install a private space station a way to a private spacedock too? Could that be the way to get a spacedock which is totally funded privately? Could a spacedock developed out of or as attachment for Nautilus?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

I guess the advantage of having a spacedock is in the ability to enclose the vehicle you are working on and pressurize that enclosure so that your space mechanics can work on it without cumbersome pressure suits. Not to mention that you could then regulate the temperature so that you wouldn't have to worry so much about the behavior of adhesives.It would of course be a HUGE undertaking. I guess that we just need a huge increase in manned space travel in general for that. And yes, if Bigelow succeeds I think we could see that.

You are expressing most of what I have in mind.

There is at least one thing which could be added: critical parts could be set to artificial reentry conditions and situations to find out what would happen on reentry if they aren't replaced, repaired and so on. Another possibility is to generate environments similar to those where the critical parts have been produced and installed in.

What should such a spacedock be capable of at least to increase safety of reentry of private passenger vehicles? And which way could it be equipped part by part? What modifications of Nautilus are required or possible to add a spacedock to it or to modify or change it into one?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

Science fiction and plausibility. Spacedocks? So when we see a small space ship fly into the landing bay of a humungous imperial starship the mind is asked to do a couple of things to avoid losing the plot (if any). These things are to not think about the following ...

i) that big hangar door is wide open

ii) those guys walking about on the deck are not being sucked into outerspace.

So, obviously our moviemaker has some sort of arm-waving explanation for this about forcefields and such ... and hence we finally wind around to my questions ...

i) Has anyone made what could be called a forcefield (in the hollywood sense of course, after all a wooden door could be conceived of as a species of forcefield)?

ii) can forcefields (even in theory) support 1 atmosphere pressure on one side and hard vacuum on the other?

Please supply links with your supporting arguments. You have thirty minutes to complete the test. All scores will be final, unless you are both exceedingly pretty and prepared to discuss matters in private.

DKH

Some comments because of movies in which spacedocks are used: I used that word as an analog to docks for ocean ships because I couldn't find a better one. Something like the spacedocks used in movies like Star Trek I don't have in mind - I consider them to be quite too monumental, oversized, utopic and silly. No force fields should be required and it seems to be quite better and more comfortably if a vehicle docks to a station like to the ISS or - in the future - to Bigelow's Nautilus and then equipment for repair, inspection and the like moves itself around the vehicle. The boom the crew of the Shuttle used for a first inspection could be part of a spacedock and the Shuttle wouldn't need one no more then. Even the inspections by satellites proposed after the Columbia-catastrophy wouldn't be required then no more.

I would like to read answers to your questions, Dr_Keith_H - they may be catalysts for practical and feasable ideas I think.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

Huh? Where in the blue blazes did you come up with that, Keith? Nobody mentioned forcefields. They failed the AM/FM test (actual machines vs. freakin' magic) so badly, I for one hadn't even considered them jokingly. The type of spacedock we're talking about is a physical structure, with big airlock doors and the like. It wouldn't be terribly hard to build -- just look at the bottom of any coke can or wine bottle for the shape of the doors (it needn't even be that drastic a curve; the pressure differential isn't really all that great).

Yeah I know, nobody mentioned forcefields, that's why I did (and I explained the leadup thought processes involved, didn't you read that?) ... I was just wondering about alternatives to the airlock idea, because I thought that to have a giant airlock seems a bit ... I dunno ... stupid. I have no commonsense argument against it though.

I went looking for info on force fields and ... urgh ... there is so much science fiction that I got discouraged about it.

Nevertheless. Although limited to very specific circumstances a magnetic field is a simple and true force field. So force fields as a concept do pass the AM/FM test afterall. So there is likely someone out there doing experiments in this direction.

That a joker like yourself doesn't consider them is probably no great loss.

DKH

It would still be pretty massive of a structure. Such "hangars" were contemplated back during the Dyna Soar/Gemini days, up into the mid/late 1960's for the big space stations planned at the time.

One problem then as now: you'd likely kill any crew workign on the spacecraft. The Shuttle, for example, emits a lot of hydrazine, as would Soyuz. You would have to design your vehicle to be *astonishingly* "green" in order for it to be safe to work on in a small pressurized environment.

For emissions a solution should be searched for.The points from which they occur are known I suppose. If that's right really equipment could be installed provided to move the emissions directly into space or special containers where they can be cooled and pressurized.

I mainly have in mind spacedocks similar to Bigelow's inflatable spacestations - they will have to be deflatable in difference to Nautilus etc. and their inflation will have to be different to the inflation of Nautilus.

Regarding magnetic fields - are the astronauts using magnetic boots already while being carried by the Canadarm under the Space Shuttle or doing an EVA at all? Wouldn't magnetic boots be something which should be provided at a spacedock?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

Not that hard if you use LOX/LH2 and either drain (if storage facilities are available) or vent (if they're not) the fuel tanks.

And Dr. Keith: the problem with using a magnetic field as one of the magical "force fields" is that whatever it's supposed to be holding has to be magnetized as well -- and ionized air smells bad.

It was just an example to put the lie to your earlier blanket statement about force fields. I wrote nothing suggesting an intent to use magnetic force fields in any way.

DKH

Hello, Scott Lowther,

the thoughts about a spacedock as I have in mind them are principle ones as a lesson to learn by the current and former problems the Space Shuttle had. In so far spacedocks don't need to be designed especially for the Space Shuttle - and don't forget that the Shuttle is going to be retired.

It could be done reverse - a spacedock could be designed and then would set standards for the design of vehicles. There have been a lot of different designs of vehicles in the past and one principle for designing a spacedock could be that all of these vehicles or a majority of them should be able to use that spacedock. The existing designs of future vehicles could be included too - or there could be several different designs.

Another - and supposedly better - alternative principle could be to adjust independent designs of vehicles and independent designs of spacedocks to each other. This too would result in standardization.

Such preliminary thoughts or meta-ideas have to do with infrastructural views and holism merely - all Earth-bound vehicles are standardized by the infrastructure they need partially also.

Hello, spacecowboy,

would it be possible to ionize air locally only - close to the magnetic field? And would the ions move along the field lines? I was suspecting that they simply may pass the field where it is weakest - in the midst between the two poles perhaps. Which would mean that the field has no impact.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)

Some CAV designs may use gold gas thrusters instead of hydrazine--though that would certainly be in the transtage--unless it was a hybrid with the oxidant--LOX perhaps--used in the cold gas thruster.

In this fashion--the LOX gas would be good for astronauts rather than poisonous. If laughing gas were used--they'd suffer no cold burns from GOX-gas and be no worse than high.

Space Station Freedom was going to have some mini-shipyard--but was pared down. Increased lift will make spacedocks and a lot of other larger structures possible--and with less assembly.