Project Orion: A discussion of Science and Science Fiction

[Codraroll]

But even Verne made some simplifications and mistakes on the scientific front, without it getting in the way of the storytelling. In Five Weeks in a Balloon, the whole endeavour is based on a battery strong enough to provide continuous production of hydrogen from catalyzing water - for five weeks. And in From the Earth to the Moon, he somehow got the idea that landing in water dampens any acceleration to survivable levels - even that of being shot out of a cannon from a standstill to near Earth escape velocity in the span of a couple hundred meters. Just sit in a bathtub during launch and you'll be fine ...

Sure, it reads a bit anachronistically if you know the science, but the story is well told so it really doesn't matter. That's what the whole point of fiction is.

[Gargamel]

1 hour ago, kerbiloid said:

 I mean, if JV could join this forum, he would be puzzled by your advice.

I think he would agree with my main point, which is don’t give the reader a reason to doubt their suspension of belief.     Be it by glossing over details (Epstein Drive), some handwavium (Ghostbuster’s Proton Packs), or the highly detailed (Andy Weir’s The Martian).    

Edited December 6, 2021 by Gargamel

[Scotius]

Listen.

Orion spacecraft is perfectly workable in a sci-fi setting, despite it's inadequacies in real life. Depicting how people using such technology work with and around those shortcomings using hard, realistic science can make for a good, fun read.

But you are keeping this setting, and at the same time attempting to un-gimp Orion by coming with convoluted solutions to its intrinsic problems. And most of those solutions either shift problems elsewhere, or add new drawbacks to already terrible propulsion method.

Let me write an example:

"I want to build a car propelled by shockwaves. It will work by throwing grenades out of the back.

- It's a terrible idea. Explosions will destroy the car.

I will add armored plate at the back.

- It will make the car too heavy to move.

I will use bigger grenades.

- Then you will need more armor. Car will still be too heavy to move with any useful speed.

I know! I will put oil tanks under the car. Oil will be sprayed on the road, making it slick and decreasing friction!

- Then the car will be impossible to maneuver!

I will throw smaller grenades out of the side windows to change course!

- Yet more armor. But fine. And how will you deal with driver being injured by close and repeated explosions?

I will use electromagnetic shock absorbers in the cabin.

- How will you power them?

A small RTG under the driver's seat.

- An RTG? Where will you find Plutonium to fuel it?!?

I have phone number to a group of Lybian terrorists."

Do you get the picture?

 

[kerbiloid]

The attempts to find the simplest solutions can't replace the efforts to learn the physical basement of the subject.

That's about the orion, antimatter, and many-many other things.

[Gargamel]

4 minutes ago, kerbiloid said:

The attempts to find the simplest solutions can't replace the efforts to learn the physical basement of the subject.

That's about the orion, antimatter, and many-many other things.

But asking questions is a good place to start.   I’d rather see someone ask too many questions (for some  ) and get headed in the right direction than have them wander aimlessly.  
 

It’s clear that a number of our members have a passion for sci fiction and possibly writing.   We should encourage them the best we can, and if some of their inquiries get a little bothersome, that’s the beauty of the forums.   You don’t have to answer, some other kind member will pick up the ball and answer the question.   

[Codraroll]

3 hours ago, Gargamel said:

I’d rather see someone ask too many questions (for some  ) and get headed in the right direction than have them wander aimlessly.  

I sometimes get the impression from these threads that it's possible to take both those options, though ...

[sevenperforce]

9 hours ago, Spacescifi said:

Then why does scott manley say you cannot burn pure metallic hydrogen without mixing it with tamer propellants, lest you melt your engine?

He must assume there are limits....

This is not limited to metallic hydrogen. Any modern orbital-class liquid engine would melt instantly if you tried to operate it without a coolant, which is why virtually all¹ modern liquid rocket engines pump their fuel around the combustion chamber and nozzle to act as a coolant. However, if metastable metallic hydrogen existed, its properties would preclude it from being used as a coolant. So you would need an auxiliary propellant, like liquid hydrogen, to provide that coolant effect.

_{1. Some engines use ablative cooling, where the "coolant" is a solid layer coating the inside of the chamber and nozzle that burns off gradually.}

9 hours ago, Spacescifi said:

I just think matters through to how much the tech can be pushed to the limit.

Which I often find scary... because the limit is...  whatever. Undefined. Unknown.

And I do not like unknowns. Ever.

But that's not true. There are well-defined limits to everything.

What you've done (and what you tend to do) is ask questions like, "If there wasn't a limit, where would the limit be?" And that's why these threads can be frustrating.

8 hours ago, Gargamel said:

The details are left to the reader to make the possible logic jumps from the base idea to the details to make it happen, and in doing so, they say to themselves “Ok, yeah, there’s a possibility of that working.”     If you give the nitty gritty details of something, and make one tiny mistake, either in theory or execution, then the whole house of cards comes tumbling down. 

I will point out that it is fine to go the hard-science route and get into the nitty gritty details. The Martian did a great job with this. But the problem arises when you try to mix nitty gritty hard-science details with handwavium. Because that breaks the reader's ability to maintain suspension of disbelief.

9 hours ago, Spacescifi said:

I prefer to have some basis. Something to build upon, something that is not royally overpowered that cannot be countered.

One totally made up drive I just came up with is this:

Anti-Inertia drive: If inertia is a resistance to a change in momentum, this drive lowers that at a constant acceleration rate equal to and in the same direction as your main rocket engine.

In other words, you start off with rockets, but once you activate the anti-inertia drive field you will CONTINUE accelerating in a straight line even at the same rate as you were after cutting off the rocket engines.

See, this is exactly what I'm talking about. An anti-inertia drive is fine. Does it break physics fundamentally? Yes. Does it make any logical sense at all? No. But can you make one and put it into your story? Sure. Of course, what you're describing is WILDLY overpowered, but you are the god of your story, so you can fix that. If you don't your anti-inertia drive to be abused, then just say that it releases "graviton radiation" whenever it is used in a way that would make it too overpowered. You don't have to explain it. Your reader will accept the suspension of disbelief.

But it makes no sense to talk about the nitty gritty details of material thermal properties in a metallic hydrogen engine when you've also got a universe with an anti-inertia drive. It's like trying to rewrite the story of Apollo 13, but with Moon Vampires. One of these things is not like the other.

5 hours ago, kerbiloid said:

The attempts to find the simplest solutions can't replace the efforts to learn the physical basement of the subject.

That's about the orion, antimatter, and many-many other things.

Agreed. It helps to know what you're talking about.

5 hours ago, Gargamel said:

It’s clear that a number of our members have a passion for sci fiction and possibly writing.   We should encourage them the best we can, and if some of their inquiries get a little bothersome, that’s the beauty of the forums.   You don’t have to answer, some other kind member will pick up the ball and answer the question.   

And I agree. That's why I often show up in these threads. I remember when I was just learning all of this stuff.

I will say, however, that I wish he'd just make one thread and stick with it. Otherwise it gets hard to see the rest of the threads I want.

[kerbiloid]

I mean the "learning" from this forum, first of all. But anyway learning.

Say, that the Orion is not just a kick received from a boom, and the bigger boom = the stronger kick.

[Spacescifi]

 

Wikipedia says this amount of antimatter is needed for antimatter catalyzed nuclear pulse propulsion;

The number of antiprotons required for triggering one thermonuclear explosion were calculated in 2005 to be 10¹⁸, which means microgram amounts of antihydrogen.^[7]

 

Scenario: An antimatter neutral glass is developed, but it must remain chilled to remain neutral to antimatter, otherwise it will react like normal mass

Antimatter storage and production has gone up as well.

 

With such scifi technology... would it not be ideal for antimatter catalyzed nuclear pulse orion and NOT ideal for a rocket that tried to utilize it?

 

I say this because any pellet holding the AM must be chilled, and you would need to control where it is so it does not neat up prematurely snd blow up your rocket combustion tank.

Basically, putting a bunch of pellets in chilled propellant is nigh suicidal... since you could hardly control how much energy would be releasd if several pellets go off with the propellant in the combustion chamber.

 

Just seems risky and less controlled. Plus you have to worry about having two sets of rocket nozzles (sea level and vacuum nozzles), whereas you only need the pusher plate with project Orion.

So it would seem that, so long pellets containing AM used to trigger a nuclear fusion blast are the basis of the propulsion system, pulsed propulsion is superior to continous.

I suppose you could make a pulse rocket, but the thrust would be dialed down compared to the orion to avoid destroying the combustion chamber.

 

Especially with this scifi glass that must remain chilled not to not react with the AM that is within the fusion bomblets.

 

Results: Spaceships would use it, and the funny thing is that they could actually outrun or outlast any chemical based missile at range, which would change the notion of space combat as we may think of it.

In fact the only thing that could chase them down at a distance would be other ships using the same tech.

 

 

Edited February 1, 2022 by Spacescifi

[Rakaydos]

Sure. Justify your pulse drive that way. It's scifi, it doesn't matter if we can fridge logic the tech.

Why are you so opposed to proper torch drives, anyway?

[Spacescifi]

2 hours ago, Rakaydos said:

Sure. Justify your pulse drive that way. It's scifi, it doesn't matter if we can fridge logic the tech.

Why are you so opposed to proper torch drives, anyway?

 

I am not per se.

 

But from all the information I have seen torch drives using real physics are actually more dangerous than Project Orion.... especially my version.

NSWR is a continous detonating nuclear rocket plume that if any pipes malfunction could go critical and blast the ship like a nuke.

And any other alternative realistically has to deal with high energy requirements and consequences.

 

You do not do scifi without high energy.

 

Like Sevenperforce said months ago, in theory there is no temperture limit to a thermal rocket...  as long aa exhaust mass flow scales up to take the excess heat away.

Sounds good right? The price to be paid is a far greater volume of propellant to compensate.... to take the excess heat away fast enough.

Meaning that a torch rocket capable of project orion effiency and thrust would be larger still.

 

I even saw the result if you make a classic thermal torch rocket that can accelerate at 1g for hours 

The rocket nozzle for said rocket was wider and larger than the Pentagon building!

 

Just imagine the size of the combustion chamber and the propellant tanks!

 

So I do not hate torch drives, but they do not scale down well at all without lots of radiation exhaust.

Project Orion scales up well, but a torch rocket really requires even more propellant mass if it can match the thrust and delta V of an Orion.

Simply to mitigate the heat.

 

Nothing is free. Radiation or use extra propellant flow to take it away... pick one for a torch drive.

 

Actually for scifi I actually intend for vessels to be able to inhibit gravity so they can float on a planet. So any ship could be an SSTO, but regardless if you use a torch drive or an external pulse drive your exhaust will be devastating.

 

So ascending high via landing/launch rockets is essential, but the grav-inhibitors help since you can float off inertia high up and then engage your external pulse propulsion or torch rocket.

 

So with a direct comparision... a torch rocket that can rival a external pulse propusion will be heavier and larger still, or even more radioactive (NSWR).

Edited February 1, 2022 by Spacescifi

[Gargamel]

8 hours ago, Spacescifi said:

Results: Spaceships would use it, and the funny thing is that they could actually outrun or outlast any chemical based missile at range, which would change the notion of space combat as we may think of it.

Which is fine if everything is unmanned.   Once you through people in the mix, there's a limit to the acceleration they can tolerate and still survive.    That limit is far below what an unmanned missile is capable of, so the missile will always catch the ship unless you can deal with your crew being reduced to paste. 

The human pilot/crew is the limiting factor in high performance vessels, even today. 

[Rakaydos]

A pusher plate sacrifices ISP (lack of containment) and thrust to weight ratio (extra engine mass) for no real benefit.

It made some sort of sence for early Orion because nukes were too damn big, and had ISP and thrust to spare. Losing TWR was the point, and losing ISP was the cost.

But for anything other than fission (NSWR is fission), it's easier and safer to have a smaller, contained (magnetically or otherwise) reaction and extract all the power and ISP potential from a smaller engine, than waste fuel with a big flashy one that you need a heavy pusher to absorb.

[Spacescifi]

11 hours ago, Rakaydos said:

A pusher plate sacrifices ISP (lack of containment) and thrust to weight ratio (extra engine mass) for no real benefit.

It made some sort of sence for early Orion because nukes were too damn big, and had ISP and thrust to spare. Losing TWR was the point, and losing ISP was the cost.

But for anything other than fission (NSWR is fission), it's easier and safer to have a smaller, contained (magnetically or otherwise) reaction and extract all the power and ISP potential from a smaller engine, than waste fuel with a big flashy one that you need a heavy pusher to absorb.

 

I am somewhat familiar with mini-mag Orion.

 

It would have to be a second or third stage though, since doing it in atmosphere would blast the magnetic nozzle with an air shockwave.

 

It's a vacuum only drive that uses material that can be ignited for fusion I think, but are not actual bombs... which makes it safer. I think the pellets are compressed via lasers or something to start the fusion blast and the magnetuc nozzle throws the plasma out as exhaust.

Mini-mag is good for orbit to orbit but too weak for launching from anywhere planet or moon size.

 

There is a scaled up Mag-Orion with better thrust but I read that the nozzle would be giant.

Makes sense I suppose if you are detonating nukes in a magnetic nozzle.

 

That would be more efficient than the standard Orion in space, provided no debris hit and damaged the nozzles from the blast.

Ideally the bomb casing would be made of material that would vaporize and not survive the blast... since we only want the plasm from it anyway.

Magnets can direct plasma.

[sevenperforce]

On 2/1/2022 at 7:16 AM, Spacescifi said:

Like Sevenperforce said months ago, in theory there is no temperture limit to a thermal rocket...  as long aa exhaust mass flow scales up to take the excess heat away.

Sounds good right? The price to be paid is a far greater volume of propellant to compensate.... to take the excess heat away fast enough.

Meaning that a torch rocket capable of project orion effiency and thrust would be larger still.

That is decidedly not what I said. Yes, regenerative cooling allows you to operate your thrust chamber at a higher temperature than the melting point of your materials, but this isn't a question of the "volume" of propellant and it isn't a question of the size of the engine. All modern rocket engines operate at higher temperatures than the melting point of their constituent materials.

In theory, there is a thermal limit on specific impulse if the waste heat produced by your energy source is greater than the heat capacity of your reaction mass. But that is not a problem of scale. That is a problem of energy management. It doesn't matter whether you have a 10-tonne rocket or a 10,000-tonne rocket; the thermal limit on specific impulse is still the same. If the thermal limit on specific impulse is 10,000 seconds then that's the thermal limit whether you have one small engine or one large engine or many small engines.

But you can make the thermal limit whatever you want it to be. Just say that your energy source produces less waste heat or say that your reaction mass has a higher heat capacity. Making the engine bigger won't help you; a bigger engine will just require more propellant at the same efficiency. But changing the thermal characteristics will do the trick. 

On 2/1/2022 at 7:16 AM, Spacescifi said:

I even saw the result if you make a classic thermal torch rocket that can accelerate at 1g for hours 

The rocket nozzle for said rocket was wider and larger than the Pentagon building!

If I recall correctly, that was the rocket nozzle necessary to lift a battleship-sized spacecraft off the ground; it had nothing to do with the acceleration or specific impulse involved.

A rocket that is efficient enough to accelerate at 1g for hours can do so whether it is the size of a cheeseburger or the size of a football stadium. The question is specific impulse and T/W ratio, not total thrust.  

On 2/1/2022 at 7:16 AM, Spacescifi said:

So I do not hate torch drives, but they do not scale down well at all without lots of radiation exhaust.

What is radiation exhaust?

If you have a torch drive then it doesn't matter how big it is. The only reason nuclear pulse propulsion would use pulses and pressure plates is that we don't have a way to make small controlled nuclear reactions with high thrust and high efficiency. If you have a torch drive, then you don't need nuclear pulse propulsion.

On 2/1/2022 at 7:16 AM, Spacescifi said:

Actually for scifi I actually intend for vessels to be able to inhibit gravity so they can float on a planet. So any ship could be an SSTO, but regardless if you use a torch drive or an external pulse drive your exhaust will be devastating.

So ascending high via landing/launch rockets is essential, but the grav-inhibitors help since you can float off inertia high up and then engage your external pulse propulsion or torch rocket.

If you have grav-inhibitors, why in the world would you need high thrust at all? Just float up to the top of the atmosphere and accelerate slowly with low-thrust, high-efficiency engines, like VASIMR. Then your exhaust isn't a problem at all.

On 2/1/2022 at 7:16 AM, Spacescifi said:

So with a direct comparision... a torch rocket that can rival a external pulse propusion will be heavier and larger still, or even more radioactive (NSWR).

No, it won't be. If you have an energy source that can produce enough energy for 1 gee of thrust for long periods of time, you can scale it down as far as you want and it's no big deal. 

[Spacescifi]

1 hour ago, sevenperforce said:

That is decidedly not what I said. Yes, regenerative cooling allows you to operate your thrust chamber at a higher temperature than the melting point of your materials, but this isn't a question of the "volume" of propellant and it isn't a question of the size of the engine. All modern rocket engines operate at higher temperatures than the melting point of their constituent materials.

In theory, there is a thermal limit on specific impulse if the waste heat produced by your energy source is greater than the heat capacity of your reaction mass. But that is not a problem of scale. That is a problem of energy management. It doesn't matter whether you have a 10-tonne rocket or a 10,000-tonne rocket; the thermal limit on specific impulse is still the same. If the thermal limit on specific impulse is 10,000 seconds then that's the thermal limit whether you have one small engine or one large engine or many small engines.

But you can make the thermal limit whatever you want it to be. Just say that your energy source produces less waste heat or say that your reaction mass has a higher heat capacity. Making the engine bigger won't help you; a bigger engine will just require more propellant at the same efficiency. But changing the thermal characteristics will do the trick. 

If I recall correctly, that was the rocket nozzle necessary to lift a battleship-sized spacecraft off the ground; it had nothing to do with the acceleration or specific impulse involved.

A rocket that is efficient enough to accelerate at 1g for hours can do so whether it is the size of a cheeseburger or the size of a football stadium. The question is specific impulse and T/W ratio, not total thrust.  

What is radiation exhaust?

If you have a torch drive then it doesn't matter how big it is. The only reason nuclear pulse propulsion would use pulses and pressure plates is that we don't have a way to make small controlled nuclear reactions with high thrust and high efficiency. If you have a torch drive, then you don't need nuclear pulse propulsion.

If you have grav-inhibitors, why in the world would you need high thrust at all? Just float up to the top of the atmosphere and accelerate slowly with low-thrust, high-efficiency engines, like VASIMR. Then your exhaust isn't a problem at all.

No, it won't be. If you have an energy source that can produce enough energy for 1 gee of thrust for long periods of time, you can scale it down as far as you want and it's no big deal. 

 

Unless we fundamentally change some properties of the exhaust we shoot out of rockets we can forget torch drive efficiency.

 

The higher the efficiency the higher the heat load.... using methods we know and theorized so far.

 

That is why if we change exhaust properties THEN we could have perhaps have higher efficiency.

 

Besides get thrown out exhaust does no work... other than heat.

 

But if it was magnetized.... or repelled magnetically in addition to the normal thermal forces shooting it out... it may add efficiency.

Realistically not so much though because we have yet to make high enough lightweight power sources to make that kind of difference. The weight counters the efficiency.

 

So long our battery storage go up dramatically per the weight of the battery, efficiency will always be lacking.

It's all about compact, lightweight power.... lots of it.

 

If you have that, any propellant you have can get you farther than with less power.

Edited February 3, 2022 by Spacescifi

[kerbiloid]

If attach the grav-inhibitors to the nuke charges, they can shoot them up from the ground instead of carrying, and the orion gets much lighter.

Edited February 3, 2022 by kerbiloid

[Shpaget]

Don't we already have an antimatter orion thread?

 

[sevenperforce]

14 hours ago, Spacescifi said:

Unless we fundamentally change some properties of the exhaust we shoot out of rockets we can forget torch drive efficiency.

No, the issue is getting a power source with sufficiently high specific energy. Any exhaust/propellant will work just fine, as long as you have high enough specific energy.

Of course, we don't have a torch drive energy source. But if we did, you could run it on anything. Liquid hydrogen, liquid methane, even water. It would work just fine.

If your fiction wants a torch drive, then give it one. Take something on the fringes of our understanding and pretend that (a) we figure it out, (b) it produces energy, and (c) it's controllable. For example:

Like most personal starships, the Marauder was powered by gimballed twin plasma thrusters, each drawing energy from its own miniaturized dark matter powerplant. The first dark matter annihilators, made possible after the discovery of stable monopoles in the late 21st century, had been huge, hulking behemoths capable of providing power to entire cities. Physical monopoles were only stable above a certain size. But once DeepMind IV abruptly solved the chromodynamics equations for dark matter particles, it was only a matter of months before virtual monopoles of any size could be produced on 3D-printed substrates, paving the way for consumer-grade dark matter powerplants.

Of course, dark matter powerplants didn't actually contain any dark matter; dark matter couldn't be contained. What the powerplants did was create a virtual Casimir field, mediated by monopoles, which forced ambient dark matter particles to collide and annihilate. Since all planets were surrounded by dark matter halos, this meant a dark matter powerplant could tap into virtually unlimited energy anywhere inside a planet's gravity well.

The Marauder's twin thrusters were modest in size, each weighing only around five tonnes. Cooled by the liquid water which also served as the propellant, the outside of the engine was barely warm to the touch during operation, while the core temperature reached over 30,000 K. Each engine produced twenty times its own weight in thrust...a far cry from the high thrust-to-weight ratio of chemical rocket engines, but enough to accelerate the entire ship at 1 gee with the tanks full and 2 gees with the tanks almost empty. The Marauder's tanks could carry enough water to keep the engines running continuously for two hours at an average specific impulse of 14,000 seconds. With just under 98 km/s of delta-v, the ship could shuttle between Earth and the Moon in less than a day and could do a round-trip between any two bodies in the solar system without requiring aerocapture.

 See how simple that is?

Just write what you want to write and fit the science to your story, not the other way around.

14 hours ago, Spacescifi said:

The higher the efficiency the higher the heat load.... using methods we know and theorized so far.

No, the higher the core temperature, the higher the efficiency. As long as you aren't trying to eschew propellant almost entirely, you won't have any trouble with heat. 

14 hours ago, Spacescifi said:

That is why if we change exhaust properties THEN we could have perhaps have higher efficiency.

Besides get thrown out exhaust does no work... other than heat.

That is abjectly false. The whole point of regenerative cooling is that you suck up waste heat before the propellant is injected into the chamber and blown out the nozzle. The exhaust is literally precisely what is doing the work. That is the nature of a reaction engine.

14 hours ago, Spacescifi said:

Realistically not so much though because we have yet to make high enough lightweight power sources to make that kind of difference. The weight counters the efficiency.

No, the weight does not counter efficiency. Weight can cause problems for thrust-to-weight ratio, but since you are going to have antigravity, your T/W ratio doesn't really matter.

[KSK]

14 hours ago, kerbiloid said:

If attach the grav-inhibitors to the nuke charges, they can shoot them up from the ground instead of carrying, and the orion gets much lighter.

Tsar Splasha - the mother of all space fountains.

[magnemoe]

2 hours ago, KSK said:

Tsar Splasha - the mother of all space fountains.

Kind of the asteroid redirect using multiple orion pulse charge probes from one intercept burn from upper stage.  You drop so you get an series of bursts so the next probe avoid most of ejection fragments and if one fails you have backups.
However firing nukes to the pusher plate does not make much sense, rater push an magazine reload so you can reload before braking, this require that the ship is launched at time to catch the refueling payload or you can not brake. 
Very dangerous and only an option for an desperate interstellar orion or perhaps asteroid redirection, as long as it don't hit anything populated like the moon its just an financial loss if it fails. 
Obviously if you tried to do stuff like this you would need an space force flag officer on the board and he would kind of be an political commissar. Even if the charges are not technical nuclear bombs an tinkerer could make it one. 

[Rakaydos]

I missed the existance of grav inhibitors.

From there, NPP is NOT the model you want to follow. You want the model of an unpopular dreamer called John Powell, called Airship to Orbit. Replace the gasbags with grav-nullifiers (which is what buoyancy basically is), and presume that the theoretical drag reductions actually work, and done. 

[kerbiloid]

First of all, a clarification is required.

Does the grav-inhibitor just neutralizes the gravity or inverts it?

For example the antigrav repulsor which is keeping an antigrav taxi in SW or 5thElement.
It obviously opposes the gravity, not just lets them float in midair.

If instead of the gravneutralizers use gravinvertors, it' probably possible to compress any piece of matter to the fusion conditions just by putting two of them against each other.

[Spacescifi]

 

The Scenario: This is not for scifi but is simply a consideration of what would REALLY happen.

 

1. FTL warp is allowed so don't question that otherwise the whole scenario breaks.

2. Teleportation is NOT allowed in order for the discussion to take place (nevermind how OP it could be weaponized but seldom is in ST).

3 . The 'Enterprise' is shaped like the letter T, made of two thick cylinders. It has an Orion pusher plate at the rear, with the 'hammerhead' being the front. Piston plates are on the perimeter sides of the pusher plate but not the perimeter above or below. Why? The ship is a belly lander, so it has rocket engine slots full of nozzles in three areas on the belly. One slot near the pusher plate, and two near the opposite ends of the 'hammerhead' providing tri-axial landing thrust. The initial boost to space is down using a reusable booster with a pusher plate of it's own, but any planets the 'Enterprise' lands or launches on or from thereafter will be on it's own with the intent of in situ refueling of the tri-axial landing engines.

4: The 'Enterprise' uses antimatter catalyzed pure fusion bombs for pulse propulsion. In other words no fission is involved. As such the bombs are smaller than nukes but just as powerful.

 

The Main Discussion: You cannot orbit some random earth clone planet and land in a matter of minutes.... right? It is my understanding that deorbiting takes about 6 hours if you do not want to burn up.

Granted you could deorbit faster but that would require burning fuel for a powered retroburn (or bombs in the case of the 'Enterprise'. Now obviously without a teleporter the 'Enterprise' would be cautious about landing on the new planet of the week.... simply because it involves costs that cannot be readily replenished just anywhere (the bombs) and likely terrifying the locals (the bombs again). So what realistically is an option to get down and up again on an Earth-like world?

 

It would take time cruising for deorbiting, but getting back up won't be a big issue.

 

The idea? A pusher plate shuttlecraft that lands on the ocean near the coast!

Since pure fusion bombs are smaller than nukes, they could fit on a shuttle, and the bomb yield could be throttlee down enough not to kill the crew with g-force either.

Bonus? A four man away team on a shuttle loaded with bombs, gliding wings, abd a pusher plate sounds about right to me!

 

Pros: Can visit strange worlds.

Cons: Always starts at the beach coastline so forget starting elsewhere unless landing on an airless moon.

 

Alternatives: If a world ALREADY has advanced scifi tech in theory one could shoot 'elevator tractor beams' to boost a stationary platform into LEO. All a shuttle would have to do is slowly deorbit and then boost to slow for landing on the platform, which would retract back to the surface of the planet carrying the shuttle. Big enough platforms could carry ships as well, restocking them with fuel or bomvs before boosting to spqce again via elevator beams/platform.

 

Question: Am I right about the time required to deorbit safely? Faster is only possible with powered deorbits?

 

Edited March 28, 2022 by Spacescifi

[wumpus]

Time to de-orbit is largely based on the Enterprise's delta-v and the altitude of the orbit.  As far as the 21st century is concerned, the Enterprise has infinite delta-v (even with only "impulse engines") and the distance to the surface is presumably in the hundreds of kilometers (trivial for the enterprise).  The only question boils down to whether the location the shuttle wants to land is "close" to where the Enterprise is: it can be a 45 minute delay if it is in an "ISS level orbit" to get around.  To land (at such a location) any faster, the shuttle would have to massively accelerate, keep the acceleration going to "orbit" around the planet via thrust (far faster than mere gravity would allow), and then decelerate down to the planet's surface.

But then, Star Trek (and similar Sci-Fi) assume that each planet has a uniform surface, and landing at any one point gets you to wherever you want to go.