Project Underwater spaceport?

[garyw]

You've also got two other problems:

1. the landing tunnel slopes downwards so when you land (and you are landing downhill which is weird) you will GAIN speed as gravity pulls you that way. The exact opposite of what you want.

2. The reverse for launch but with a suitable assistance (catapult?) you can probably overcome that.

also i would have thought that the wind effects of the landing tunnel would be very different to that of the free air outside. I'd also wonder who you'd handle problems like leaking hydrazine. In an enclosed space that stuff is leathal.

 

[dumbo2007]

Perhaps a better way to have a launch pad in the ocean could be this : https://docs.google.com/drawings/d/1ytijZEkUn-AN1skYEiAPn2sccLYdS86yK7k4coeyFHY/edit?hl=en_GB

Have smaller tugs which can be joined to make bigger runways anywhere in the ocean. Then move the chunk on which the space craft lands only to the docking port of the undersea base. This solves the problem of moving around large runways and yet allows arbitrarily large runways to be assembled anywhere in the ocean.

 

[T.Neo]

What about sea-launched rockets, like Sea Dragon?

How could we simulate these in Orbiter in a half-decent manner? Just sink the thing half into the planet by putting the touchdown points midway along its length?

 

[dumbo2007]

I was reading about the sea dragon here : http://www.astronautix.com/lvs/searagon.htm

From the article :

After fueling, the tanks at the launcher base would be flooded, and the vehicle would reach a vertical position in the open ocean. Launch would follow. The concept was proven with tests of the earlier Sea Bee and Sea Horse vehicles.

How exactly does it reach the vertical position ? Is it hoisted by cranes on the floating base ?

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Ah ok got more info here : http://www.astronautix.com/lvs/seahorse.htm

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In actual operation, it was planned to tow the missile to its launch site, flood attached compartments so that the missile rode vertically in the water, and then fire it.

Seems ballast tanks were attached to the rocket and flooded so that the rocket would swing up to a vertical position with a part of it submerged. Then it would be ignited from that position

Just sink the thing half into the planet by putting the touchdown points midway along its length?

Touchdown points is one option. It could also be forced into position using an attachment point and the position during launch be simulated without orbiter (Because launching half submerged would involve buoyancy and drag initially), once its clear off the water, its velocity and acceleration can be set to whatever it should be after passing through the water for 2 seconds (or whatever time) and let Orbiter take over.

What about water seeping into cracks in the body of the rocket and freezing due to cryogenic temperatures

 

[T.Neo]

What about water seeping into cracks in the body of the rocket and freezing due to cryogenic temperatures

That is more an engineering issue than the technicality of simulating the launch in Orbiter, but I believe the original document stated that coatings, sealants and insulation were enough to alleviate issues of water intrusion and ice formation.

There are two very interesting documents on Sea Dragon that can be found in the external links section of the Wikipedia article.

Apparently, the vernier engines on the second stage would to be ignited from launch. I would imagine that this vehicle would be one amazing sight to see lift off out of the water...

 

[dumbo2007]

You mean like this :

I don't think the engine was ignited underwater though.

Here is a sea launch though not for a submerged rocket :

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Umm hold on, how could the 2nd stage engine ignite with the 1st stage still connected ?

 

[T.Neo]

You mean like this :

No, not like that. There the missile is (if I'm not mistaken) blown out of the launch tube (and the water) by steam or compressed gas, the motor ignites only after the vehicle has surface.

Sea Dragon would have ignited its engines while submerged. I believe though that Robert Truax (the originator of Sea Dragon) also had a part to play in the idea of submarine launched ballistic missles, so there is a relation.

Umm hold on, how could the 2nd stage engine ignite with the 1st stage still connected ?

Second stage vernier engines. They're seperate from the main second stage engine and there's four of them.

 

[dumbo2007]

Woops, yes of course

 

[Mojave]

You could create another cloud layer that looks like water. Place it over the land, and make the clouds stand still with just an animation. The only problem with that is it will overlap the actual land part of the earth.

 

[_Designer_]

For the take off I was also thinking about a catapult, where all you would need to do is have the thrusters ready for when you fly.

the catapult will send the spacecraft through the tunnel at a decent speed to make it out of the runway and ready to start the thrusters when up and ready to fly.

The landing tunnel now, I think thinking, you get in, hit the brakes and an escalator or something would lock onto it and take it downwards back to the hangar.

I think this can work, the challenge would be landing in-game really.

 

[RisingFury]

Space vehicles that land horizontally need a long runway to stop as is. If the runway is sloped down, not even brakes are gonna help. Those brakes are designed to stop the vehicle on a level runway.

Flying into the tunnel and not smashing into the wall won't be easy either. I mean, you don't see planes flying into tunnels at airports, do you?
The transition into the tunnel would be very rough. If there's crosswind outside, the plane will have to compensate. Because there's no crosswind in the tunnel, the plane, now turned slightly sideways, will fly into the wall.

If air is traveling into or out of the tunnel, the plane will lose or gain lift. Crashing into the ground or into the ceiling.


A better approach would be a runway on the surface and you'd let your vehicles taxi / be towed into the underwater base.

 

[jangofett287]

on the Good side, the water should protect you from radiation if your base is launching nuclear powered rockets!

 

[dumbo2007]

Yes, sloped tunnels may work only on the moon or space with low/no gravity. When there is atmosphere things get tougher to line up.

 

[_Designer_]

Maybe you can adjust the slope depending on your speed?

And plus, the runway should either be 10x bigger or 15x bigger so you can get a reasonable space to land.

Very true! my model scale is not precise. We can have it run for miles until it eventually levels to the ground (as far as landing goes).

For take-off, I still stand for an idea of having a catapult with extreme launching capabilities that will throw the spacecraft into the air and once in the air, can engage the thrusters and continue to climb into space.

 

[dumbo2007]

Yes but rather than have the catapult work against gravity during take-off and thus reduce its efficiency, why not have it work horizontally to impart sufficient velocity for liftoff from the ground (for gliders). The wings will take care of adding a vertical component to the velocity after that, anyway.

That brings up the question of whether its more efficient to impart the vertical velocity using an upward firing catapult, or with wings.

 

[selden]

Landing in a tunnel might be similar to landing on an aircraft carrier, but would be even less forgiving. It'd have the advantage of not constantly moving, but that's also a disadvantage in windy conditions.

So far as placement is concerned, why not make it in the flooded caldera of a volcanic island? That'd make it possible to make it underwater but above sea level.

 

[garyw]

Landing in a tunnel might be similar to landing on an aircraft carrier, but would be even less forgiving. It'd have the advantage of not constantly moving, but that's also a disadvantage in windy conditions.

Not at all, its very different.

With an aircraft carrier you've got wind moving over the deck, the deck might be heeling a little but the landing is fairly simple. Landing gear on those aircraft is strengthend and you land with little flare. most of the work is handled by the arrestor system.

Landing in a tunnel gives you very strange air currents at the entrance to the tunnel, you've got no air heading down the tunnel unless artifical and you've got this weird downhill slope to land on.

Personally I think landing in a tunnel is a daft option. There are no down hill tunnel landing strips for good reason and as for doing this for spacecraft - Are you going to strengthing the gear for this? The cost alone is insane. You are better off landing on a strip like at KSC or Ascension.

 

[_Designer_]

I can figure something out to fix the draft problem, but can you do it in blender or is it C? I wanna make this daunting task possible, I think we can do it, just landing will be the hardest part, lol.

 

[jangofett287]

I've been thinking about the problem, and have come up with a workable solution. You add to the landing tunnel a 'Pontoon' like landing strip. The pontoon has controllable ballast tanks, so can be submerged when not required. The plane/Spacecraft is then towed into the base from the top of the tunnel by a chain system. (like what you get on the lift hills of roller coasters only in reverse)

 

[garyw]

I've been thinking about the problem, and have come up with a workable solution. You add to the landing tunnel a 'Pontoon' like landing strip. The pontoon has controllable ballast tanks, so can be submerged when not required.

Everytime you bring the landing strip up from the water it will need to be cleaned of seaweed and other ocean stuff.

You'll also have a more expensive time operating it because salt water is very corrosive.