My Problems With Interstellar Act 3

One of my biggest pet peeves in all cinema, is consumables. A consumable is a finite resource (bullets, food, air, fuel, money...etc.). When gunfights are prolonged without the need for reloading, or when characters have a seemingly unlimited supply of ammo, or go for days without food or water, it bothers me. In the case of Interstellar, fuel is used as a convenient plot device, after ignoring it in the second act.

When the crew leaves Earth, they use a large rocket to get into space. The reason for this is simple: a large amount of fuel is required to lift a given mass into orbit, and keep it there. The greater the mass, the larger the rocket. The physics behind this is well known, and isn't anything new. The movie uses it at the beginning of Act 2 (launching into space).

This scene is accurate. To lift the spacecraft into orbit for rendezvous and docking requires a lot of fuel. Where Interstellar goes wrong is on Miller's Planet. They use a Ranger spacecraft to descend to the planet's surface. Miller's planet is a water world, with gravity greater than 1 G. Because of these two facts, we know something about its size. Worlds larger than Earth are generally completely covered in water. The scenes on this planet are accurate - right up to the point that they leave.

Why, you ask?

Because the Ranger spacecraft leaves with the fuel it has on-board. Not a big rocket like it needed on Earth. This is a plot-hole so large I can fit a Saturn V in it. In order to reach escape velocity on a planet larger than Earth, you need to be going much faster. Don't believe me? Here is a calculator that will quickly do the math for you.

For all that Interstellar gets right on the majority of the science in the movie, it flunks basic rocket science in this one scene. AARRGGGGGHHHH!! It drives me crazy every time I see it, and my wife is getting tired of my tirades when I lose my mind as I watch it.

Fuel is key. As you can see from the clip, there is no big rocket to get them off a super-earth. NO NO NO!!! This is bad science. For a factual article on this, visit NASA (Here).

This continues to be an issue that is only half dealt with for the remainder of the film. The expenditure of fuel and the thrust required to escape the gravitational pull of celestial bodies becomes a plot point near the climax of the film. After visiting Dr. Mann's planet, they are forced to venture to Edmond's planet, but only one can make the trip. They use Ranger 2 and Lander 1 as rocket boosters. After their fuel is expended, during the escape burn, they are jettisoned to save on weight. This is accurate, but a very terrible idea for real astronauts. The best chance for survival is for both living astronauts to be on the same ship, not jettison the only competent pilot. True this is the emotional pinch of the film, but it makes no logical sense.

The other issue is using the gravity of a black hole to slingshot themselves to another planet. Although black holes aren't the cosmic vacuums that we've been led to believe, they are not to be approached. This would be reckless at best, and bordering on suicidal. There would be no way to accurately calculate exactly where the actual event horizon is, because you would not know the mass of the collapsed star inside. If you want to try it, HERE is a calculator. In addition, the Hawking radiation around the accretion disc would probably fry the crew. Black holes are not to be used as navigation aids by humans. PERIOD.

While I still very much enjoy this film, this major point brings my overall liking down a notch.All this hard science entertainment, that overlooks the basics, is making me angry. Now I have to go relax before I have a stroke.