[jr2]

Alright, Nuke, what was that nuclear reactor using salt or whatever you were talking about?  This thread on the BuldTheEnterprise Forums made me remember but I can't remember all the little details.  I wish I could search within specific user's posts...

[Legate Damar]

This isn't supposed to happen for another 200 years... there must be a temporal agent influencing the past.

Don't worry humans, I'll enlist the resources of the Obsidian Order to undo this distortion of the timeline.

Might want to let them know about a cardassian in communication with the human race a couple hundred years before first contact. 

You could also point out the lack of a Eugenics War in the 1990's.  I mean, come on!  Without the Eugenics Wars, we don't get Kahn, and without Kahn, history will proceed into the 23rd century with a distinct lack of KAAAAHHHHN!!

I thought it was obvious that the Eugenics Wars took place behind the scenes, under the mask of several seemingly unrelated global conflicts...

[General Battuta]

Alright, Nuke, what was that nuclear reactor using salt or whatever you were talking about?  This thread on the BuldTheEnterprise Forums made me remember but I can't remember all the little details.  I wish I could search within specific user's posts...

you have google, just enter 'molten salt reactor'

[Klaustrophobia]

I don't think that was nuke who brought that up.  But if you were wondering if a liquid sodium reactor would solve the problem they are discussing there, no.  First of all, the sodium would only be the intermediary.  You can't spin a turbine with it, you still need steam (or other high-pressure gas) for that.  And no matter what you cool it with, you still have to get rid of the substantial waste heat.  This applies to EVERY form of energy generation, not just fission, as it is a product of the conversion cycle, not the source of the energy.  If you can't radiate it all, the only remaining option is to have vast quantities of expendable coolant to blow overboard.

[General Battuta]

Even if you have an awesome reactor you still need propellant. Lots and lots of propellant. This design doesn't do a great job on that front.

[Klaustrophobia]

I didn't look very closely, but I thought it said ion engine.  Which doesn't seem the least bit practical for a ship of this size. 

[BlueFlames]

This isn't supposed to happen for another 200 years... there must be a temporal agent influencing the past.

Don't worry humans, I'll enlist the resources of the Obsidian Order to undo this distortion of the timeline.

Might want to let them know about a cardassian in communication with the human race a couple hundred years before first contact. 

You could also point out the lack of a Eugenics War in the 1990's.  I mean, come on!  Without the Eugenics Wars, we don't get Kahn, and without Kahn, history will proceed into the 23rd century with a distinct lack of KAAAAHHHHN!!

I thought it was obvious that the Eugenics Wars took place behind the scenes, under the mask of several seemingly unrelated global conflicts...

Really?  I mean, we can tot up all of the casualties from all of the military conflicts occuring between 1993 and 1996, but I don't think you're going to come up with the 30 million corpses that historians of the 23rd and 24th centuries agree were generated by the Eugenics Wars.

It also doesn't explain the presence of an uppity Legate showing up on an internet message board, three and a half centuries before his birth.  You should take care, when telling the temporal branch of the Obsidian Order that there are continuity errors in need of addressing.

[jr2]

As far as heat goes, the aluminum hull is going to be used.  IDK if that would be enough though.  That and the idea of using the heat to produce hydrogen was put forward.

[Legate Damar]

This isn't supposed to happen for another 200 years... there must be a temporal agent influencing the past.

Don't worry humans, I'll enlist the resources of the Obsidian Order to undo this distortion of the timeline.

Might want to let them know about a cardassian in communication with the human race a couple hundred years before first contact. 

You could also point out the lack of a Eugenics War in the 1990's.  I mean, come on!  Without the Eugenics Wars, we don't get Kahn, and without Kahn, history will proceed into the 23rd century with a distinct lack of KAAAAHHHHN!!

I thought it was obvious that the Eugenics Wars took place behind the scenes, under the mask of several seemingly unrelated global conflicts...

Really?  I mean, we can tot up all of the casualties from all of the military conflicts occuring between 1993 and 1996, but I don't think you're going to come up with the 30 million corpses that historians of the 23rd and 24th centuries agree were generated by the Eugenics Wars.

You mean the casualties that you know of...

It also doesn't explain the presence of an uppity Legate showing up on an internet message board, three and a half centuries before his birth.  You should take care, when telling the temporal branch of the Obsidian Order that there are continuity errors in need of addressing.

I have special dispensation

[deathfun]

Even if you have an awesome reactor you still need propellant. Lots and lots of propellant. This design doesn't do a great job on that front.

I didn't look very closely, but I thought it said ion engine.  Which doesn't seem the least bit practical for a ship of this size.

"While the ship will not travel at warp speed, with an ion propulsion engine powered by a 1.5GW nuclear reactor, it can travel at a constant acceleration so that the ship can easily get to key points of interest in our solar system. Three additional nuclear reactors would create all of the electricity needed for operation of the ship."

"The Gen1 Enterprise will be powered by three ion propulsion engines. These will provide constant acceleration, and versions of this technology are already used in spacecrafts. These engines are powered by electricity, and thus using nuclear reactors to generate this electricity is a natural fit. "

[General Battuta]

I didn't look very closely, but I thought it said ion engine.  Which doesn't seem the least bit practical for a ship of this size. 

An ion engine still needs propellant, and in large quantities. The designer might think that electricity alone is enough for an engine, but he's wrong; it still needs fuel, fuel, and some extra fuel. The great advantage to ion engines is their excellent specific impulse, but he'll still need to pack argon (or xenon, or something similar) propellant in quantity.

[Dragon]

Perhaps a Bussard Ramjet could take care of that, and it'd even be fitting with the overall theme (the original Enterprise also had it).

[General Battuta]

I suspect it wouldn't. Nowhere near enough velocity, nowhere near enough density. It's not clear whether Bussard ramjets will work even at high relativistic velocities.

Bear in mind that to collect one kilogram of hydrogen the ramjet scoop must sweep, with 100% efficiency, a volume about equal to that of the earth. This isn't enough for a ram-assisted ion rocket.

[deathfun]

I didn't look very closely, but I thought it said ion engine.  Which doesn't seem the least bit practical for a ship of this size. 

An ion engine still needs propellant, and in large quantities. The designer might think that electricity alone is enough for an engine, but he's wrong; it still needs fuel, fuel, and some extra fuel. The great advantage to ion engines is their excellent specific impulse, but he'll still need to pack argon (or xenon, or something similar) propellant in quantity.

To coincide with General's response as it lacked an actual source
http://www.nasa.gov/centers/glenn/about/fs21grc.html
"Ion thrusters use inert gas for propellant, eliminating the risk of explosions associated with chemical propulsion. The usual propellant is xenon, but other gases such as krypton and argon may be used."


As for how much, you could calculate this by use of the Deep Space One probe
"Deep Space 1 carries 178 pounds (81 kilograms) of xenon propellant, which is capable of fueling engine operation at one-half throttle for over 20 months. Ion propulsion will increase the speed of DS1 by 7900 miles per hour (12,700 kilometers per hour) over the course of the mission."
http://www.nasa.gov/centers/glenn/about/fs08grc.html

[Mikes]

Put it on Kickstarter and we may be cruising the solar system in a couple of years...  :coughs:


Other thoughts: Sometimes one really wishes we were alone in space just so that no one can see what we're doing huh? LOL.

Closing thoughts: This really does have all the amusement value of watching a 5 year old build his own spaceship.

[Legate Damar]

Other thoughts: Sometimes one really wishes we were alone in space just so that no one can see what we're doing huh? LOL.

Too late 

[jr2]

http://www.buildtheenterprise.org/propellant

The tanks on the Enterprise will be most likely Argon, 55 million pounds, and three refueling depots, each with 55 million pounds.  IDK exactly how we're going to fill said depots.. though they were suggesting Skylon to get up to the Enterprise and back.

Cost for 220 million pounds of Argon: $4 billion
Cost for 220 million pounds of Xenon: $500 billion

http://www.buildtheenterprise.org/forum/ion-propulsion-engines/hydrogen-is-not-dangerous-in-space
Hydrogen was mentioned, but the author was afraid it would explode (he mentioned Hindenburg), until someone pointed out that unless you put your hydrogen tanks beside your oxygen supply, Hydrogen is inert.  Someone also mentioned that the explosion of the Hindenburg was most likely due to the coating of alumnized rubber dope which was similar in composition to solid rocket fuel that they were using on the skin (There was a note by Hindenburg company engineers that they were aware of this issue). The flames were yellow in hue, and Hydrogen burns clear / blue.  Most of the Hydrogen in the Hindenburg likely escaped into the atmosphere before having a chance to be ignited in the conflagration of the coating on the Hindenburg.  So, the Hydrogen was actually likely safe. But they took unnecessary risks with the coating and got bit.

See Larry Niven's N-Space books for details regarding ramscoop ships. But yea, at any speed less than a significant fraction of light, there just isn't enough interstellar hydrogen- it's something like 1 atom per cubic meter, isn't it? In any case, while hydrogen is ~75% of the universe, it's not like it's sitting out in pure form in convenient barrels.

BTE-Dan, I think that you should look up the Hindenburg explosion analysis that was done by Nasa. Granted that it was night, but the fire of the Hindenberg was yellow. Hydrogen burns clear or with a blue cast. When freed in the Hindenburg situation, the hydrogen went straight up since it is very light. The real culprit of Hindenburg was the aluminized rubber fabric dope used on its hull which is similar to the recipe for solid rocket booster fuel, and the static electricity of the landing mast. This is why the skin immediately and completely burned away. There is a note by the Hindenburg company engineers that they were aware of the flammable nature of the aluminized rubber and nitrocellulose dope. Lighting a piece of that fabric was like lighting a fuse.
The real problem with hydrogen from an engineering standpoint is that it requires very close tolerances in valves and fittings and tanks to keep it from escaping as it is very low molecular weight and is sometimes used to test valves because it is so slippery. It also requires a relatively large volume for storage even in liquid form, as compared to heavier fuels. I note that Elon Musk has used Kerosene for his new rocket, Falcon for a more compact solution
The other remarkable thing about liquid hydrogen is that the Nasa rocket nozzles use it as coolent to keep them from being overheated by the plasmas. It flows through many little tubes in the bell of the rocket. It also gets preheated that way.
Hydrogen is generally useful for running power cells as well and making water for the humans if oxygen is abundant, from say regolith.

[General Battuta]

The tanks on the Enterprise won't be anything because it's a ****ty design that will never be built (thank ****)

e: if he wanted to fix it the first step would be to make a change akin to Dragon's suggestion, but he won't because then 'it's not the enterprise'

[The E]

I just looked at the site, and oh my god I had no idea this idea was _this_ terrible.

It's almost as if this project was conceived by a bunch of fanboys with way more enthusiasm than skill.

I mean, the original design for the TV Enterprise was specifically chosen to be a departure from the then-current missile and airplane-like designs in order to imply a level of technology far beyond that prevailing at the time. Even in-universe, the design requires technological aids (like, say, an impulse drive, warp drive, dilithium reactor, artificial gravity) to be practical, none of which we know how to do.

If you really want to build a spaceship from SF for realsies, I would suggest a more practical design, like, say, the one from 2001: A Space Odyssey, or Babylon 5's Omega.

[jr2]

If you really want to build a spaceship from SF for realsies, I would suggest a more practical design, like, say, the one from 2001: A Space Odyssey, or Babylon 5's Omega.

I was wondering about that.  Although, I get the saucer section.  (For the 1G gravity magneto-wheel-whatever-you-call-it)  BTW, he hasn't kept the scale of the Enterprise.  It's actually like 3 X larger AFAIK. (Someone said this was for the gravity wheel, otherwise, motion sickness might result as it would have to spin faster to produce 1G?? -I don't get that part, but OK).

The main (engineering from the SF world) section + two nacelles fits nicely in with triple redundancy, but, I don't really see how it's necessary, as nothing should really be that problematic that you can't have all three triple-redundancy systems in the same hull section.  I guess someone could say that it's to prevent losing all three systems with a meteor strike, but if you get a strike that big, you're screwed anyways (lop one of the nacelles off or disable it, and you're gonna have to shut down the other nacelle just to keep it pointing straight, and you're still going to have to counteract the now lopsided mass, unless the other nacelle was only damaged and shut down).

If physical distance between the reactors / engines is a big plus, then the design makes sense.  If not.. well, what the E said.

EDIT: I get the part about the gravity wheel having to spin faster.  I don't get why this would produce motion sickness.  You're inside.  No windows, only viewports.  Being pinned to the outer wall by centrifugal force to simulate gravity.  I really don't see how this would produce motion sickness just because you are travelling slower/faster... you're still pinned with 1G and no external references, darn it.