Science ISV Venture Star Discussion thead

[MaverickSawyer]

OK, since we :threadjacked: the development thread of the ISV Venture Star, I'm moving my comments here.
This is open to all discussions about the Venture Star ship from James Cameron's Avatar, from propulsion to life support and logistics.
ISV Venture Star stats.

Project Rho/Atomic Rockets page on the Venture Star.

 

[T.Neo]

I think the Venture Star would vanish in a blindingly brilliant light of blinding brilliance the moment the engines turned on.

Venture Star and HVIPS- exploding spaceships since 2009... :uhh:

 

[jedidia]

There is a thread lying around somewhere in which this was already discussed...

 

[MaverickSawyer]

Really? the search didn't turn anything up...

 

[Scruce]

Really? the search didn't turn anything up...

[Idea] ISV Venture Star (Avatar)

 

[MaverickSawyer]

I'm looking at more of a technical discussion of if it were to really to be built in the future. I'm an engineering student. I love trying to figurre out how things work, and I figred that there may be others here who share that interest. It could also be helpful for making an addon more realistic.
:2cents:

 

[T.Neo]

I'm looking at more of a technical discussion of if it were to really to be built in the future.

In that case, my first suggestion would be: fix the engines. The way they are portrayed in the movie, they'd vanish in a blindingly brilliant light of blinding brilliance the moment they'd be turned on.

Also the laser array, it is of an ungodly magnitude.

You don't need that high an acceleration.

 

[Ark]

Or 6 ISVs unable to properly replenish their supplies and propellant for the return trip...

I think I read somewhere that the concept was to have a collider or natural antimatter miner on station in Alpha Centauri to generate fuel for resupply. If you're gonna manufacture huge quantities of antimatter, space is the place to do it, not on a planet in close proximity to the only bubble of habitable atmosphere for light years.

Overall I don't think it's an entirely bad system for shuttling back and forth to our nearest system. The laser sail thing does seem unnecessarily complex if you already have the ability to generate enough antimatter to brake from .7c. Ditch the sails and death rays on Mercury and just burn more antimatter. If you can build one Moon-circling collider to fuel the damn things, you can build 2.

 

[T.Neo]

I think I read somewhere that the concept was to have a collider or natural antimatter miner on station in Alpha Centauri to generate fuel for resupply. If you're gonna manufacture huge quantities of antimatter, space is the place to do it, not on a planet in close proximity to the only bubble of habitable atmosphere for light years.

Indeed, but antimatter isn't the only supply they might need to return home...

Overall I don't think it's an entirely bad system for shuttling back and forth to our nearest system. The laser sail thing does seem unnecessarily complex if you already have the ability to generate enough antimatter to brake from .7c. Ditch the sails and death rays on Mercury and just burn more antimatter. If you can build one Moon-circling collider to fuel the damn things, you can build 2.

The benefit of the lightsail is you don't have to carry the reaction mass with you. The disadvantage is that the thing has to be pretty large, but not as large as the Death Star the ISV would need.

I'm still very weary when people say "just use a lightsail". Sure, it means you can remove infrastructure from the vehicle... but just because the infrastructure is somewhere else, does not mean it is not of concern.

 

[MaverickSawyer]

good points by all. The key is the life support systems. It cannot support even a four man crew for the equivalent of 4 years (courtesy of time dilation). that is the reason for the hustle between systems.
Antimatter reactions are dangerous, there is no question of that. After all, who wants to be bombarded by gamma radiation for more than a few rays? The big question is, how could they contain the reaction? magnetic bottles are fine for charged particles, but not radiation. The engine would need incredible cooling systems to run even for a short time. those radiators don't seem like they would be enough.

 

[T.Neo]

It cannot support even a four man crew for the equivalent of 4 years

Really? What figures convinced you of this?

The big question is, how could they contain the reaction? magnetic bottles are fine for charged particles, but not radiation. The engine would need incredible cooling systems to run even for a short time. those radiators don't seem like they would be enough.

You can try to reflect photons away, but you can't reflect gamma rays. The engines on the ISV wouldn't work even if they didn't have problems with trying to contain absurd amounts of energy.

The engines are probably also too small, larger engines would be cooler due to the inverse square law. But you're now talking absolutely gigantic engines...

The radiators are far too small as well.

 

[MaverickSawyer]

I stand corrected. Three crew teams of five men, rotated on duty and cryo.

Crew: 25
The ship’s functioning is largely automated, using triply-redundant, radiation-hardened computers, but emergency manual control is provided for all functions. The minimal crew is cross-trained in all specialties. There are three crew teams of five each, who serve for 20-month tours, and are in cryosleep for the balance of the voyage. This seeming waste of mass was necessitated by the experience of mid- 21st Century space missions when crew members proved psychologically unstable after two years in close confinement. There are two main functions of the human crew: monitoring the power and propulsion systems, and supervising the developing avatars. Humans have the ability to notice anomalies too subtle for the automated monitors, in spite of these systems’ tremendous sophistication. In addition to the 15 flight crew there are 10 medical crew in cryosleep, who are awakened before the rest of the passengers to assist with their recovery from suspension.

 

[Hlynkacg]

Atomic Rockets did a pretty thurough breakdown of the design here.

My old "skytrain" idea was essentially the ISV scaled down to more manageable (realistic) proportions.

 

[jedidia]

The benefit of the lightsail is you don't have to carry the reaction mass with you.

The benefit of a lightsail in this case is also that it isn't as unholy expensive as anitmatter. This is a business venture star we're talking about after all (though that business cannot possibly pay of for a mere 20 million dollars per kilogram payload anyways...)

 

[HR_Oso]

You can collect antiprotons from Jupiter-Io plasma flux, or from Jupiter magnetic poles. I've read there's a natural antimatter generation factory. Saturn and our Van Allen belts are good natural sources, too.

 

[jedidia]

Not in the needed amounts, you can't...

 

[Izack]

The radiators are far too small as well.

And furthermore should be redesigned to look more like, you know, the sort of radiators that actually work in space, not in your car. :lol:

Funny how trying to be somewhat realistic but still cool brings more criticism from the nerds than being totally ridiculous.

 

[T.Neo]

And furthermore should be redesigned to look more like, you know, the sort of radiators that actually work in space, not in your car.

Indeed...

Funny how trying to be somewhat realistic but still cool brings more criticism from the nerds than being totally ridiculous.

I think that is because totally ridiculous has its unwritten criticism. That, and/or it is kind of like the difference between a wacky comedy, and a serious drama.

 

[Izack]

I think that is because totally ridiculous has its unwritten criticism. That, and/or it is kind of like the difference between a wacky comedy, and a serious drama.

You've got a point, if we pretend that 'serious drama' isn't an oxymoron. :lol:

There's only so far a movie can go while making a profit, though. We may as well stick with literature for hardcore realism...

 

[T.Neo]

There's only so far a movie can go while making a profit, though. We may as well stick with literature for hardcore realism...

Perhaps, but I doubt the exact details of the ISV would have made any difference in whether Avatar was successful or not. They're just part of the science-y backstory, probably unnoticed and forgotten by most people.