How Many Mistakes in Gravity, the Movie with Sandra Bullock

I realize it was necessary for the story line, but it was really coincidental that the ISS, the Russian, and the Chinese space stations were in such close proximity.

I did not see this movie but a forgivable mistake I noticed in the teasers and advertisements is the hair. It doesn't float as it should in a micro gravity environment. Instead of filming scenes in the vomit comet, as they did in Apollo 13, they tried to achieve all effects with cables and computer graphics.

Did it come with the hair spray make?

A fictional work that's not factual?!? Well duh...it's not a documentary....who cares, Sandra B is hot....

....Sandra B is hot....

You think so? Better than some of the folk at Walmart I suppose. Just average I reckon.

Different strokes and all that mate....

...or is that why she is wearing a tshirt?

George did not have to die. When Sandra had stopped George there would have been no force on the lanyard, he would just have floated along with Sandra

Well I never watched it, so did I make a mistake or the right call.

Heck, it couldn't have been any worse than "The Core", an entertaining CGI romp outside of reality if ever their was one. So bad it was good.

_{Jack -Sending all power to Coney Island as we speak.}

I'm glad I watched it before this criticism. It certainly was more believable than The Core, but I liked that too. You have to turn off your "scientific appraisal" to watch science fiction movies. Now the question: Should I watch Star Trek Into Darkness?

Now the question: Should I watch Star Trek Into Darkness?

Sure, but turn off your "common sense" as well. The opening scenes, while pretty are...........staggeringly bad. Stop a volcanic eruption with a cold fusion device that freezes it using the cold fusion reaction, hide the enterprise under water for no reason, and while your there steal a religious text and break the prime directive unnecessarily when they could have just beamed down to the surface without anyone knowing.

Star Wars Episodes 1-3 bad. You have been warned.

"Gravity" definitely tried to stay accurate. It's main purpose is entertainment of course, so a balance needed to be met. Even the most critical viewers who demand 100% accuracy would probably agree that the hours long procedure of removing the EMU (space suit) and all the gear involved would not make for exciting screen time. (Spoiler alert: When Bullock eventually gets back inside the ISS, she has her suit off in seconds.) So you have to give movies like this some leeway if you want them to ever be produced.

Another compromise they had to make was that the debris that destroyed the ISS was from satellites, but these are of course not found anywhere near the orbit of the ISS. That's not to say the ISS is not in danger of collisions with small debris at all, they regularly have to maneuver the entire craft to dodge known debris. Even then, they're not invincible:

But if the entire movie focused around the complications (albeit certainly threatening) of small debris punching a hole in one or two pieces of sensitive equipment, again it wouldn't be very entertaining.

Oh yeah, he totally didn't have to die. That kind of disappointed me. But then again, the "sole survivor" aspect of it, alone in space trying to get back without dying, was pretty fun.

This is nothing like "The Core". You can tell they really tried to stay accurate. At first I thought the portrayal of the destruction of the ISS was a dig, but it seems like it might have been more of an attempt to raise awareness of how space debris is kind of becoming a problem. Or I'm probably just looking into it all too far.

Anyway, good movie, worth a watch.

The big one was the transition from an orbit of 347 miles to the ISS's orbit of 230 miles is simply not possible with the thrusters in a space suit, let alone navigating to the ISS.

Good catch!

Which direction was it circling.

If orbiting period was 90 (actually about 97 minutes) minutes for the Hubble and the debris were orbiting in the opposite direction it would return in about 47 minutes!

If they were going in the same direction, then the debris field and the Hubble would be virtually stationary to each other.

I made the leap of faith that the debris were from geostationary satellites and the obital period of 90 minutes was the ISS orbit. The ISS was running into the debris, not the other way round! I really enjoyed the movie and just accepted the writers licence. Good discussion stuff later with the family too.

Geosationary orbit is around 32000km.

That's a long way away for it to be a problem for LEO hardware.

The reverse orbit scenario is more plausable but yeh, then it would be 40 odd minutes between encounters as pointed out by a previous poster.

I was just wondering whether a polar orbitting craft at the same orbital height would meet up with an equatorial or inclined orbit craft......but waving my hands around at synchronised rates around an imaginary body in front of my face still comes with a period/2 path intersection interval....right?

That's for circular orbits...how about if one orbit was circular, eg the ISS, and the debris was in a highly elliptical orbit....too hard for this old brain now.

Need simulation sw to check. Later maybe or someone else here can dig one up on the interweb and fiddle with the orbits to see if a 90minute intersect interval is really possible.

Yes, once the debris drifted down to LEO they would would not be there for long nor would they be stationary relative to any body orbiting at LEO.

Yes, everyone seems to be familiar with an orbit of 90 minutes from other flights and ISS, etc. But for the debris to arrive again after 90 minutes would have required the astronauts to remain geosynchronus. Big writers license for fast thrills and drama.

remain geosynchronus ???

geosync is not acheivable at that altitude.

Never seen the movie, will someday.

Everything I've read about what the guys who've been there and done that think of the movie is very positive.

How can you find fault with it when the male star looks like Buzz Lightyear.

I paid for 90mins of escapism, not to critique a fiction as if it were an engineering proposal. Therfore, I agree with SE (#3).

Nothing wrong with escapism.

Another form of escapism, dare I say entertainment, for engineers, is to find the continuity lapses, especially when the marketing of this cineplay did draw focus to the creative piece's supposed realism.

I haven't seen it yet. It will be on the telly soon enough.

I threw a tub of popcorn at the screen, a few minutes later it came round and hit me on the back of the head.

Yeah that Sandra Bullock is always hanging round here attention seeking Mrs Cat has to hiss at her and chase her off

Del

I watched it in 3D, twice. :) It is a REALLY cool movie, and the astronauts who commented about it recommended it. They said the Earth simulation was the best they've seen, for one thing.

Accuracy was discussed all over at the time, just not here.

There are many other samples of artistic license taken. Some that haven't been mentioned here yet: Her space suit undergarments wouldn't be nearly as brief (and not nearly as... attractive). Matching velocities is a painstaking process. A poorly-trained person would more likely blow up a Soyuz than successfully fly it from point to point.

The biggest and most unfortunate glitch was the one about letting George Clooney go. It was a fundamental part of the story, and wrongly executed.

I did like the puffs of fire that occured before the big excessive fires. I don't think that many people know that a candle will not stay lit without gravity. Fires don't act like we know them to act when in microgravity. The larger fires were over done. Maybe they ignited the propane tank for the bar-be-q or something. Lots of action, and it was fun. Just distracting because of so many factors including proximity to other stations, etc.

I also had a hard time watching it, especially the part where she had let George go even though there was no force acting on him to push him away.

The fact they were in the same orbit as debris travelling at 20.000 mph different velocity, and the fact that they could see debris travelling that fast, were also hard for me to get past.

I don't mind "writers license" in something like Star Trek or something obviously fictional. It is the mix of realistic and unrealistic that bugs me. It's like they are trying to pass it off as realistic.

Maybe that is why my wife doesn't like watching movies with me.

Jeeeeeeeezzzzzzzzzzzzzz.

And I thought I was a critical old fart.

Gravity IS NOT a documentary film.

Gravity is a 2013 British-American 3D science fiction thriller^[3][4] and space drama film.^[5][6]

As I said earlier, the film is endorsed by real live, breathing astronauts.

That's good enough to make me want to see it.

As far as the orbiting satellite debris is concerned, there's probably some basis in fact for its orbit and velocity. Remember what triggered the whole event was a Russian missile hitting a spy satellite.

We know nothing about whether it was an impact-missile or one with an explosive warhead and its angle of impact, but from what I remember about the physics of collisions, the center of mas of all the pieces tends to travel with the vector sum of the two original bodies plus the momentum/force from the explosives.

If so and the missile's path was tangent to the spy satellite, then the satellite would have broken up and it's center of mass accelerated into a new orbit achieving speeds that could account for the 90 minute orbit relative to the SSI and Shuttle.

Also, I'm surprised nobody has brought up the "I am woman, I am strong" aspect of the movie, kind of parallels Sigourney Weaver in "Aliens; sole survivor, doing without men, piloting an escape ship back to earth, surviving, etc.

But, each orbit of ISS would not necessarily coincide with debris, unless the entire debris field orbit was filled with debris,or the orbits were complimentary.

So, what now?

Eventually, that is what happens as the field disperses over time. It forms a ring or donut out of most of the debris.

Initially, that field would be a clump of debris that would have their own orbit and period. As they spread out they form more of a ring.

If the initial clump had a similar orbital period to the ISS, but at a more perpendicular inclination it could be possible for a 90 minute intersect on the next orbital pass of the ISS.

OK.

Never been there, but I believe you are right, as usual.

Assuming that the cluster of debris had the same average orbit altitude then they could intersect again after each making one orbit.

Or three or ten orbits, not necessarily every time.

But I concede that the debris may distribute itself evenly over the orbit.

Good Answer, nice graphics. It is hard to think in terms of 3D, even in space.