Really big ships taking off and landing

[Zor]

One thing that is common in science fiction are big ships which can get multiple kilometers in length and weighing millions of tonnes, if not more. The way i see it, this makes the most sense if these huge craft spend their entire operational lifetime in space, using smaller shuttles and suchlike to move stuff from the ship to the surface and vice versa. The only time these ships would get to a planet's surface would be after they were decomissioned and Recyled into domestic service robots or if they crash landed with results similar to that which put an end to the dinosaurs.

But their are several instances of really big spacecraft landing in sci-fi, or floating near the surface. This always has seemed off to me, and when you think about it, it gets rather silly. If you have some sort of reaction drive, your going to be spewing radiation all over the place and char burning a fair amount of the surounding landscape if your getting spaceborn. If you have some sort of anti-gravity system or a reactionless drive or something, the effect that a kilometer long brick (most sci-fi starships are rather chunky) moving rapidly through the air is going to have a major effect on local atmospheric conditions. Especially (like in LoGH) you have fleets of thousands of hundreds of 600 meter long ships taking off from planetary bases en mass.

Do you think that this is a legitimate point or not?

Zor

[Xon]

If you have a setting where the ships are capable of at least more than 1 gee acceleration and capable of taking any type of punishment, taking off and landing should be trivial. It might make an utter mess of the enviroment by dumping that much heat into it, but even a slightly more advanced nation than RL with access to significant lift capacity could deploy solar sails/mirrors to reduce the sunlight hitting the planet to offset the heat being dumped onto the planet if they really wanted to.

[Imperial528]

Well, I have designed large ships capable of landing on a planetary surface. Although I would have it be done in industrial areas with suitable facilities, with the ship being supported by planetary repulsors and tractor beams rather than its own main drive, for both landing and takeoff. Unless of course it is an uninhabited world and the ship needs to land, in which case, shore leave is constrained to NBC suit-wearing personnel.


Of course, any sci-fi with particle shields which can change shape could merely make the shield into the most aerodynamic shape possible for a "fast lift off" rather than a slow one consisting of hovering to the upper atmosphere and then firing the main engines.

[Cykeisme]

If a ship was using reaction drives, the damage a multi-million ton craft would cause to a planetary surface at liftoff would so immense that any aerodynamic atmospheric disturbance would be insignificant!

Since this is SD.Net, I suppose a discussion of Star Wars in particular would not be out of place; it's justified there by the fact that they use anti-gravity technology ("repulsorlifts"), and radiate waste heat as neutrinos. The combination of these technologies virtually eliminates the punishment the planet would otherwise take, and atmospheric pressure waves can be minimized since the ship can take off as slowly and gently as it needs to.

[Sky Captain]

If antigravity technology is lacking then landing in the middle of large ocean could be an option to reduce environmental destruction. Sure, the ship would vaporize large quantities of water and cook all sealife in vicinity but at least there won't be cities or forests burned to ground. Also millions of tons of vaporized water would come down simply as rain while millions of tons of vaporized rock (if landing on solid ground) could stay in the air much longer and create negative climatic effects.

[GrandMasterTerwynn]

I wouldn't want to be within a hundred kilometers of a multi-megaton sci-fi ship taking off from the surface of the planet. If you think about the energy required to accelerate one up to over a gee (and the timeframe this energy is to be delivered,) the land below it will become a lake of fucking lava, and scour everything for kilometers around with supersonic winds. Not to mention anyone that has line-of-sight to the ship will have their eyeballs roasted by the enormous column of superheated plasma.

Unless the ship is being propelled by fairy dust and elf magic, in which case, the partial vacuum left by a giant ship boosting up through the atmosphere (and all the displaced air coming back down) will merely generate storm-force to hurricane-force winds. Either way, you wouldn't do either one to a planet that is inhabited, and certainly not anywhere near places of habitation.

[Sarevok]

^^

The above could make excellent plot opportunities in a space opera if taken into account. Imagine during a moment of desperation the captain of an Accamalator vessel deciding to use main engines instead of repulsors to take off. It would make quite a climatic scene. A pity soft scifi writters resort to made up technobabble for surprise when certain characteristics of the a soft scifi spaceship would create believable yet unexpected situations. Take trek for example. You need to take down a big enemy ship that is normally beyond the hero ships combat powers. Why fire a technobabble particle beam when the engines themselves offer a deus ex machina solution ? Most viewers are not that familiar with the Kzinti lesson and would be utterly stunned if it were shown on televised scifi just what a torchships reaction drives can do if used as a weapon...

[Temujin]

The problem is I don't think the average viewer would get it. For most of them engines are engines and make you go. Weapons are weapons and used for going pew pew and blowing shit up. It's akin to the brain bugs Mike lays out on his site, and example being exploding fusion reactors. Most people are convinced that's the way they operate, and you could waste all day trying to argue with them why it isn't.

[Sarevok]

The problem is I don't think the average viewer would get it. For most of them engines are engines and make you go. Weapons are weapons and used for going pew pew and blowing shit up. It's akin to the brain bugs Mike lays out on his site, and example being exploding fusion reactors. Most people are convinced that's the way they operate, and you could waste all day trying to argue with them why it isn't.

Uh no. Torchship engines igniting in an atmosphere would produce some of amazing scenes of destruction. Audiences like pretty special effects. And a massive warship destroying everything as it rises from the surface above a column of fire and smoke is something never done before. Any movie that takes power of a torchships engines into account is going to be filming amazing action scenes never done before in visual scifi. Huge explosions are a huge draw for audiences if you ask me.

[Temujin]

While I agree it would make for an awesome scene, and I would absolutely love to see it in a movie/TV show (I know I certainly would use it if I was producing one), I really have my doubts that the average moviegoer would or could truly appreciated it. Sure, they understand that something up close to the engines will get fried, but I don't believe they really understand or appreciate the sheer levels of power that a Torchship would be putting out. I think it would equate to a lot of "no way" and "that's silly, that's not real" type responses. And I think a lot of that is precisely due to the kind of scenes in movies like Star Wars that they've become accustomed to.

[andrewgpaul]

Alastair Reynolds' Redemption Ark and Absolution Gap novels feature a 4km-long interstellar "lighthugger" (so-called because it travels at 0.9c or above) landing on a planet. It does so tail-down, like a 50s B-movie rocket, so that the gravitational force is along the same axis as its engine thrust. While they do have the added complications of landing in a kilometre of water and several of its compartments not being watertight, the landing seems to go reasonably well. When it finally takes off again, several years and a novel later, it does make mention of those remaining behind having to evacuate to a safe distance before it cranks up the engines.

Star Wars and Star Trek, of course, cheat by using magic anti-gravity, so none of the above discussion is relevant.

[Sarevok]

While I agree it would make for an awesome scene, and I would absolutely love to see it in a movie/TV show (I know I certainly would use it if I was producing one), I really have my doubts that the average moviegoer would or could truly appreciated it. Sure, they understand that something up close to the engines will get fried, but I don't believe they really understand or appreciate the sheer levels of power that a Torchship would be putting out. I think it would equate to a lot of "no way" and "that's silly, that's not real" type responses. And I think a lot of that is precisely due to the kind of scenes in movies like Star Wars that they've become accustomed to.

Well people have seen the immense plume of fire a spaceshuttle launch creates. So if the effects designers take a cue from that they can conjure something up believable.

[Themightytom]

I always wondered what a rapid exit, or entry would do within an atmosphere. Assuming your super advanced technology can deal with heat from engines, radiation, etc, what about displacing air? Or plunking into an ocean, wouldn't that cause a Tsunami? VACATING an ocean would cause at least a whirpool wouldn't it? if we're talking about multi kilometer ships?

[Lord of the Abyss]

While I agree it would make for an awesome scene, and I would absolutely love to see it in a movie/TV show (I know I certainly would use it if I was producing one), I really have my doubts that the average moviegoer would or could truly appreciated it. Sure, they understand that something up close to the engines will get fried, but I don't believe they really understand or appreciate the sheer levels of power that a Torchship would be putting out. I think it would equate to a lot of "no way" and "that's silly, that's not real" type responses. And I think a lot of that is precisely due to the kind of scenes in movies like Star Wars that they've become accustomed to.

I think that could be gotten around just by using the term "nuclear engines" a lot. Then people would find a hugely destructive liftoff believable.

[Mayabird]

This has been addressed before. The earliest example I have on hand is this little quote from "The Ballad of Lost C'Mell," which was published in 1962 (emphasis mine):

Earthport had been build during mankind's biggest mechanical splurge. Though men had had nuclear rockets since the beginning of consecutive history, they had used chemical rockets to load the interplanetary ion-drive and nuclear-drive vehicles or to assemble the photonic sail-ships for interstellar cruises. Impatient with the troubles of taking things bit by bit into the sky, they had worked out a billion-ton rocket, only to find that it ruined whatever countryside it touched in landing.

They used the rocket as a giant building-city after that.


This may also have been a shameless plug for the story and the overarching series it's in for those who haven't read them, because it is excellent.

[Junghalli]

While I agree it would make for an awesome scene, and I would absolutely love to see it in a movie/TV show (I know I certainly would use it if I was producing one), I really have my doubts that the average moviegoer would or could truly appreciated it.

I don't think audiences would have a problem with the idea that having stuff spewed at you from the back end of a powerful nuclear reactor at close range would be bad for you. I also don't think people would really have a problem with a destructive lift-off; in my experience people seem to generally get that you wouldn't want to be too close to an Orion rocket taking off. Just mention that it's nuclear.

Mind you, I think the Kziniti Lesson is somewhat overhyped, at least when it comes to space combat. Sure, being in the exhaust stream of any serious interstellar drive is probably going to be like being hit with a nuke ... if you're close to it. But I doubt it would be very well focused so I imagine it would probably spread out pretty quickly, making if a fairly short range and therefore probably shitty weapon. As I remember, in the archetypal example the Angel's Pencil was using a photon drive, which is actually more or less a giant laser of ridiculous power, which is probably why it worked so well there.

Of course then again in visual SF ships tend to fight within ranges of a few kilometers or less, so...

[Sarevok]

The range issue could be moot in a boarding scenario where one spacecraft has to dock with another. Using the drive as a last ditch weapon of unexpected consequence would be a brilliant move. At least better than typical technobabble ways to escape.

[Junghalli]

The range issue could be moot in a boarding scenario where one spacecraft has to dock with another. Using the drive as a last ditch weapon of unexpected consequence would be a brilliant move. At least better than typical technobabble ways to escape.

Problem with that is for the most part it sort of requires the enemy commander to be an idiot.

"Sir the enemy is rotating to bring his rocket in line with us. His ... 2.5 terawatt nuclear rocket... at close range... Should I move our ship out of the way?"

"Don't bother."

"Should I order him to stop or we shoot?"

"Don't bother."

*Ten seconds later*

"OH FUCK MY SHIP WHAT HAPPEN?!!"

[Axiomatic]

Yeah, it does only work if the enemy is utterly surprised by the fact that the plucky inventive humans have figured out how to rotate a ship in space.

[Imperial528]

It would work against the Borg, and quite well.

Shame ST engine technology never seems to work that way.

[Batman]

Yeah, it does only work if the enemy is utterly surprised by the fact that the plucky inventive humans have figured out how to rotate a ship in space.

Given that the people DRIVING those ships rarely use their (demonstrated, BTW, as per TSFS the refit E-Nil could pitch, roll and yaw) maneuverability to its full potential and Star Trek characters ( Starfleet and otherwise) rarely think about it they possibly might be. Case in point-TWOK. When Kirk is presented with Khan's inability to think three dimensionally, he-essentially reacts two dimensionally. Sure, he dips a little relative to Reliant, but henever changes the orientation of the ship. Like to go below and pitch up, so he's facing Reliant's underside (her biggest target profile) while the big E presents her SMALLEST (directly ahead)? And that's Starfleet's hero captain we're talking about.

[iborg]

In any remotely coherent universe there would be rules of conduct to avoid things like huge warships lighting up their main engines in atmosphere/where they'd do lots of damage, just like IRL planes are usually forbidden from doing very low passes over cities at supersonic speeds and such. Safe behaviors would be drilled into starship operators ab initio, like "don't point your main nuclear rocket straight down at a planet lest you burn out a city/fry orbiting satellites" or like in Mass Effect the prohibition in using kinetic weapons if the rounds would hit an inhabited planet in case of a miss.
It's something I plan to use in a scene some day in my fics. A warship caught landed/near the ground by an enemy fleet has to scramble off into space, but they'll have to jettison every safety rule to do so and end up carving a huge furrow of destruction on the ground.

[Lord of the Abyss]

Yeah, it does only work if the enemy is utterly surprised by the fact that the plucky inventive humans have figured out how to rotate a ship in space.

Or if as in Niven's story, the aliens in question have the assurance of a telepath the enemy is unarmed, and haven't thought of a ship drive as dangerous in generations if ever (the Kzin stole their technology IIRC; they may never have used reaction drives). Or if as also in Known Space the "drive" in question is a launching laser and not a ship in the first place.

The sneakiest use of the Kzinti Lesson that I've come across was in Voyage From Yesteryear, where the local colonists mentioned to the imperialistic newcomers that their old colony vessel the Kuan-Yin was in the process of being refitted with an antimatter drive. When the more warlike types among the newcomers detached the military section of their ship, they had the Lesson in mind (if not under that name) and moved their warcraft so the planet was between it and the Kuan-Yin. They congratulated themselves on their prudence before they started issuing surrender demands - then were obliterated by a beam of antimatter from a base on one of the moons. "We told them that we weren't done refitting the ship. Not our fault if they didn't believe us."

[Batman]

Assuming the ship in question HAS a way to get orbital on antigravity or something, how HIGH an orbit would it need to be before they can fire up their main engines without undue worry about wear and tear on the planet, and UNTIL they do, what's the fastest acceleration they can afford without the displaced (and presumably superheated/ionized for the high end figures) seriously fucking up the local airspace/weather patterns/countryside?

[Junghalli]

The one place where I can think of rocket exhaust having serious weaponization potential is terrorism. Unassuming freighter pulls up to giant space station for routine docking and then at the last minute turns its rocket on the station and fires it up.

Even that has some relatively easy countermeasures but I can sort of see it as something you could pull off without the intended target being implausibly stupid. Maybe.

In any remotely coherent universe there would be rules of conduct to avoid things like huge warships lighting up their main engines in atmosphere/where they'd do lots of damage, just like IRL planes are usually forbidden from doing very low passes over cities at supersonic speeds and such.

Although if they're taking off from a planetary surface that opens up the question of what they're using to get to safe heights.

As I remember one of the proposals for Orion was to use booster rockets similar to what the space shuttle uses to get it up to some height before starting with the propulsion bombs.

Eh, it generally really makes a lot more sense to leave the giant spaceships in orbit and use shuttles/mass drivers/space elevators/whatever for ground to orbit transportation.