fun fact: the designer of the AMP suits in the movie also designed a real life bipedal mech that now has been built and being tested by a wealthy South Korean automaker, the mechanized suit works but like early bipedal robot designs its has to still wear a harness to keep itself from falling over but the builders said it can walk on its own two feet. So yes the human tech in Avatar is very achievable by today's tech and is inspiring people to actually build these things

One hitch -> Departure from Earth is aided by a light sail, BUT arrival and departure from Pandora does NOT have that advantage. SOOO, explain how the acceleration and deceleration from 0.7C takes the SAME time?

I would said it's almost misfortune for the ISV to be at Avatar universe. It should deserved an entire its own of space exploration franchise. Realistic hard sci-fi version of Star Trek!

@@paulmoffat9306The departure from earth is via the lightsail/ shield from an unbelievably powerful laser accelerating it to .7c. The main anti-matter propulsion is used only for arrival and departure of Pandora, with the assumption they refuel at Pandora for that trip back to Earth. Then the laser is used to decelerate the spacecraft towards Earth.

@@paulmoffat9306 i would guess the sail is just incorporated to use less fuel on the two occasions it can be used on top of the engines.

I understand and agree with you to a point about what you're saying, and I could be wrong but I think with Star Trek the dilithium crystals are doing the job that the superconductors would be in reality, I didn't really watch Star Trek TOS to know when they started using the term but I know by the time of TNG that that's when I heard the term so they just might not have known about the superconductors then. I was watching another video and it said how the show changed how it described a warp field to a warp bubble when real-life science showed that for a warp drive to work in real life, it would need to create a bubble around the ship in order to warp space to allow the ship to move faster than the speed of light, and it was said that the people at Star Trek did that a lot as far as changing the scientific things in the show when scientists in the real world showed how something in the show would really be done in reality, I think the only reason they still use 'dilithium crystals' now is that at the speed that the Enterprise and other ships in the Star Trek Universe travel that the way the ships work in Avatar wouldn't be able the reach the speeds in Trek. I was already a fan but the fact that the people behind the shows were willing to change the science in the show to meet current scientific knowledge when necessary only made me love the Star Trek Franchise more.

@@barrywhite6060 The function of dilithium in warp drive was inconsistent in TOS (as was the entire drive), TAS and tie-in fiction, and was depicted with a consistent purpose only from TNG courtesy of Okuda and Sternbach -- i.e., it moderates the matter-antimatter reaction to produce a plasma stream suitable for the warp coils. (Don't get me started on "warp plasma.") Magnetic constriction is used to transport the reactants into the warp core and the plasma to the warp coils -- that's a different function than magnetic fields as the nozzles of an antimatter rocket. The "warp bubble" dialogue in TNG (1990) and the technical manual (1991) actually predate the "Alcubierre" proposal (1994).

okay, but dilithium (Li 2)isn't a magical substance. In theory, Lithium can exist as Li2. What it can do, well anyone can speculate. We haven't observed any diatomic lithium, but the theories say it can exist.

Were already on the antimatter part, just need to contain it for storage

There's just an issue with the shields, since they're there only during the cruise phase and not as effective (because not spaced) during the other phases

Although it was a shame seeing the hero losing in both movies.

Initially they were just going to use CGI, but Cameron built the ships without the producers' knowledge so they just went with it.

I agree! Although its design has its flaws, it is by far one of the most realistic fictional ships depicted. Thanks for watching!

ISV is capable of 1.5G acceleration, sky crane ain't the point, the problem with atmospheric entry is the heat from surrouding air will melt the ship (the plume will heat surrouding air to temperature high than the temperature of the sun). However, it is a cool scene, so I'll let that pass.

@8749236 thanks for that👍there's since been a wonderful video that illustrates your point by Spacedock, 'Analysing the ISV landing' from a realistic perspective

The atmospheric entry with the antimatter engines is unrealistic as hell as the plumes are basically constant nuclear explosions concentrated in two narrow plumes, if these plumes would encounter an atmosphere they would immediately heat up and ionize the entire atmosphere below the ISV, this would create giant pressure waves that would destroy the ship and everything in a radius of hundreds or perhaps thousands of miles.

I mean yes but there's two big problems 1. Gamma radiation scatters, which would instantly kill the crew, unlike NASA which uses chemical engines 2. the entire surface below the ship would also get irradiated

Yeah, I get you. For the first five months of the voyage, you should just pray to never encounter a grain of dust on the way.

Presumably the solar sail can act as a shield for the earth outbound portion, but just that phase only, on return it would be in the wrong orientation. Ideally you'd want to be able to let some of the projected shields go off into space as disposables so that they can continue clearing debris from the ship's path even during deceleration. Even then you'd still be stuck without shielding when accelerating out from Pandora.

Also during the flip the ship is not shielded from interstellar dust and a single dust grain at 0.7c can destroy it. A more likely scenario is that the ship always faces forward and has the solar sail deploy behind it. In addition the antimatter rockets can fire both directions. They fire forwards slightly angled to decelerate and can while fire backwards to accelerate. This would make a more reasonable design without ever needing to flip the ship

That's why Spice is very important so the Navigator can use the substances to see safer routes to travel space. "He who controls the spice, controls the universe."

it's never mentioned, but it's easy to put a second shield right in front of the sail towards the direction of travel. The ship was designed with "good enough for the movie" mentality and first impressions.

Me too!

Possibly one of the most craziest and insane ship I watched when I was young.

Avatar is a ridiculous script, poorly executed. But the visuals were so great, I let it pass.

I couldn't give a crap about the story, but the demonstration of concepts in science using Disney level budgets for visuals makes me fully erect 👍

Valkyrie shuttle (its been told in avatar 2009 game, in those wiki modules) that it goes to polyphemus to gather hydrogen, or antimmatter for refueling for the ISV

According to the comics and wiki, about 12 total have ever been built, the oldest and first one was later abandoned around the gas giant. and in Avatar 2 they send 10 ships to pandora, so probably 1 left back on earth or on other missions

@@habeebadesina8468 it’s a good question how they sent 10 ships at once. That is a lot of photonic propulsion needed all at once.

@@d5kenn Well according to the movie, they're here for the planet; but if i was in charge of the RDA, i'd diversify and invest in colonising the rest of the solar system, asteroids and such, Pandora can't sustain 10 billion humans arriving at once, so the idea of resettling everyone on pandora is dumb. It's better to send a few there to ease the pressure on earth, and locate other habitable exoplanets, it shouldn't take long anyway if a trip to alpha centauri is just 6 years, they can afford to go to other star systems

​@habeebadesina8468 dividing like that for long periods of time might cause some systems to develop independence and break away from a unified humanity. I would say after at least 100 or so years on Pandora, it would be fine to try to find other habitable places. It's important for everyone to work together this early on in our efforts to abandon Earth and colonise another planet. An example of this would be The Martians from call of duty: infinite warfare. It started out as an resource grab for Earth, but after spending so much time on Mars, they didn't see themselves as being from Earth anymore, and a large war broke out between the two.

Or maybe it's the cylinder between the Valkyrie loading arms. That would make more sense than what I said earlier.

Maybe equipments (like the AMP suits) had magnetic feet.

They mentioned that the crew modul would create artificial gravity by rotating, not while in transit, i guess the massive force of 0.7c would help with that.

@@ABW941 I actually meant about the landing module here: 7:01 The one with legs, and orange, and is bigger than the habatation module.

@@xinguan2681 Cryo, most likely.

@@caav56 6:59 Where’s all the room for that? Unless the entire Starships spins for gravity…

Exactly. And in addition, at the beginning of the trip, interstellar dust can also destroy the sail when it is facing forward, that sail is extremely fragile. I think a few points need to be adjusted to make this journey more logical.

@artworkdt2077 Yes, the flight shown in the video has a few flaws, but there are solutions for them. Hopefully if we actually do travel to other stars, they pre plan it correctly. I don’t want to be hearing "oops" from the stellar engineer while the interstellar ship is blown to pieces because of dust hitting it at relativistic velocities

what is FTL?

​@@artworkdt2077faster than light

You are so knowledgeable. I have a few questions. - Why does antimatter only require a few kilograms, but H2 requires tons? I thought they needed about the same amount. And can we estimate the required mass of antimatter, matter, for this trip? Some say hundreds of tons of antimatter fuel are needed for this trip. - When the sail is used, the shield will be at the back of the ship, so how will the ship and the sail protect against interstellar dust? - When the ship flips in the middle of the trip to decelerate, the shield will no longer be in the right direction to protect the ship. So how will the ship protect against interstellar dust?

​@artworkdt2077 OP didn't gave the answers so I'll do 1- since 10grams of antimatter=nuclear bomb you dont need a whole lot of antimatter, as for the H2, most of it is there to absorb energy from the matter-antimatter reactions, like H2 in NTP engines (that's why its called reaction mass) 2- the used part of the sail is facing the same direction as the shield, which was also designed to protect the crew from the laser (the sail also folds in when they are in interstellar space) 3- the ship is launched backwards and flips before getting to interstellar space (and the antimatter engines are also backwards, pointing in the shields direction [thats why they need that big truss and the engine was given a slight angle {otherwise it would blow the shield}] and when they are accelerating the ship they are still in the centauri system and can perform a flip before reaching interstellar space)

Most of what i wrote is in the video

@@artworkdt2077 apologies, I could have sworn I responded: 1 a single gram of antimatter annihilates itself and the single gram of matter it comes in contact with to release 43 kilotons of energy in TNT equivalent. That's about 2 bombs that were dropped on Hiroshima. The simple answer to the question of why fuel ratios are different is that manufacturing 1g of antimatter for every 1g of reaction mass is simply impossibly impractical, so we'll just take what we can get. The energy transfer is still impressive and antimatter is used to cheat around the infinite loop of "more mass requires more fuel that means more mass that requires more fuel, etc". Antimatter ships need not have mass ratio more than 4.9:1, meaning 3.9 units of mass of reaction fluid for every 1 unit of mass of the ship's dry weight. For interstellar travel, mass of antimatter can be scaled up to kilograms, but probably still grams. I'm sure calculating the necessary exact masses would involve a lot of complex maths, that can be summed up as "reaction mass in tons, and antimatter catalhst in grams, or maybe kilograms". 2 The shield can easily be moved around the ship, but really the shield need only ever face one way and that's at the direction of travel. It's used for protecting the ship's shadow, but not the sail, which can be left to the elements. 3 The ship never flips halfway, that defeats the point of having two separate propulsion systems. Imagine the ship as a train that only go forwards or backwards. The laser pushes it awar from Earth, and engines are used to brake. On the trip home, engines are used to push the ship away from Pandora, and the laser is used to brake it. The ship never flips halfway. That said, the shield can always be moved around the ship with tugs, and it would maintain ship's velocity. It would be like moving furniture around the room.

@@TheElMuffin ​Thank you for your response, perhaps KZfaq has quietly deleted your comment, I have encountered that situation many times. Your responses are very detailed, I will study them. As for the ship, does it flip in the middle of the journey? I think yes, because by design the nanosail part is at the back of the ship (the side near the propulsion system). If the sail is in that position, the ship must depart exactly as mentioned in the video. I have a hypothesis that the shields are only intended to prevent cosmic rays from harming passengers, and during the ship's flip, the shields will move to ensure the passenger compartment is covered. And the ship itself is sturdy enough to withstand space dust. Regardless, this shield is not large enough to cover the entire ship. So with this hypothesis, in the early stages of the trip, the shields do not need to move to the forward position to block space dust, but the giant propulsion system will do that. It's big enough and sturdy enough to cover the passenger compartment in the back. What do you think about this? ... Or maybe I was thinking wrong. The nano sail actually doesn't have to be like a parachute pulling the ship like in the video. Maybe it's flat and on the front, receiving 100% of the laser beam and pushing the ship.

true

But war innovates. Look at human history. Countless inventions were brought up from the neccessity of war. I argue the opposite. We will only reach this amount of technological advancement through a few wars. Obviously not big enough ones where they do more harm than good tho.

Relativity. The ship experiences no forces once its done accelerating to 0.7c.

same reason than our planet turn around the sun when our sun move around milky way and milky way move in space, in space nothing will stop you

the ship already decelerated at good speed, they only use the plum like a weapon, so they dont need to burn equivalent to 0.7c to nuke the area is nearly impossible to fission oxygen, hydrogen, carbon, nitrogen, those atoms are too light, fission is more with heavy atom fusion those atoms require pressure and temperature you only find in blue giant core star going to dying, so you cant sustain nuclear fusion in open atmosphere

I thought they could control the output, not using 100% while landing that base thing.

@ABW941 Throttling a rocket engine isn't going to affect the exhaust velocity very much. Think of it as reducing the rate of fire of a machine gun. It doesn't change how dangerous individual rounds are.

@@anticarrrot If iam not missing something then this is not like a rocke engine, but more like a very simple jet engine, however the smallest unit of fuel (one antimatter atom of H) would still produce an energy output like a small nuke.

@@ABW941 That's my point. The energy output of this engine is going to be enormous. In space that's mostly okay. But in an atmosphere, all of that energy will come out of the engine (it is a rocket, but it doesn't really matter at these energy levels) and hit the atmosphere and ground. Exhaust velocity at this speed is effectly nuclear radiation. When that radiation interacts with the atmosphere, it will scatter all over the place, and superheat the air in exactly the same way the nuclear radiation coming out of a nuclear bomb does. It's not completely impossible to do something like this, but you'd want the cable to be at least a 100km long in order to keep the ISV and it's engines above most of the atmosphere. That way the fireballs (ceggs? Cylinders?) produced when the exhaust hitting the thick part of the atmosphere is far below the ship, and far above the capsule being dropped to the ground. If this kind of thing interests you, there's a website called Atomic Rockets that goes into all the detail you can possible want to know (and then some) about the real physics behind fission engines, fusion engines, and antimatter engines, as well as their uses, effects, and problems.

Imagine signing your employment contract with RDA and didn't even bother to go through the details and missing this euthanisation clause entirely.

Oh, do not worry. In the sequels all those beautiful vehicles will be used by the good guys. Scientists. But they need to bring RDA down first 🙂

They went there on a far bigger and slower starships

you mean irl or in the movie ? irl photon sail may provide more acceleration, because you dont need to carry fuel, the sail may be accelerated by a very powerful laser, for example the sun if you can gathering 1/1000000 sun energy output it is equivalent to 1000 tsar bomba every second

@@vkobevk I mean in the explanation in this video. At one travel phase, the ship uses the sail and the antimatter engine at the same time, and that made me think if that is possible without wasting useless engine power and without overtaking your own sail. Imagine, if the sail accelerates the ship at, let's say, 1G (it won't be constant, for sure over time it will decrease, but for simplicity we will assume constant 1G), and now you turn On your ship engines and apply Thrust... it may be something like turning On the engine and pressing the gas pedal on a car that is being towed by cable from another car... ¿?

@@alamos8 well only james cameron know reason but like i say irl you dont need to turn on anti matter engine, you only need the laser on the sail to accelerate

​@@alamos8 I think you got that wrong. The ship uses the sail to accelerate for five months, and it uses the antimatter engine to slow down over the last five months, while the sail is retracted after acceleration. When returning to earth it uses the antimatter engine to accelerate, and the sail to slow down.

canonically the antimatter engines dont fire during the acceleration phase, only the sail is used. this video got that part wrong. if it used both one way and only one the other, the time spent under G load wouldnt be 5.5 months each way

Time dilation

Exactly what I was thinking. Maybe in the third movie newer ships will have three engines and can get to Pandora even quicker!

The exhaust plume won't scatter any radiation in vacuum. Unless you're directly behind the nozzle, you're safe. All that matters is distance from the engines themselves. Which is the reason why the engines are pulling and not pushing - a kilometer long structure that can withstand tension would be much lighter than a kilometer long structure that can withstand compression.

There was at least one predecessor to the ISV Venture Star and other Capital Star-class ships, a ship that was four times as massive as the current design. It uses cold superconductors (because no unobtanium was available when building it), which require much bigger radiators.

2:22 Ah, there you go; that's what I was talking about, except that the ship can, & _must_ actually accelerate to even faster then _that,_ as that figure of velocity is only the average for the whole trip

They euthanize the passengers so they don’t wake up and starve to death. They can’t keep 300+ people alive for 4-5 years

In case of malfunction, they are killed, because they can’t be on life support, everyone is asleep and the function is obviously separate for each person.