During re-entry, the guy on television says that the heat shield was damaged in the explosion three days earlier. Apollo 13 splashed down on April 17, and the explosion was on April 13, so it was four days, not three. [Actually, the explosion took place at 03:06 on April 14, 1970, so it really was only three days.]

In the seen where Hanks is Barbecuing in his back yard there is a bug zapper. Bug zappers did not come out until the late 1970's. [Bug zappers were available as early as 1967, probably earlier. In 1967 stoned hippies in San Francisco's Haight-Ashbury receive painful electric shocks and blistered tongues when they lick bug zappers, mistaking them for "psychedelic" black lights. Governor Ronald Reagan announces that it serves them right.]

During the TV broadcast, Gene Kranz confirms with the EECOM that the cryo stir will be on both hydrogen and both oxygen tanks. But when the astronauts get the instructions for the stir, it is just on the oxygen tanks. What happened to the hydrogen tanks? [They could have been waiting for the OK on the oxygen tank stir to tell them to go ahead and stir the hydrogen tanks as well. They waited for confirmation with the roll before proceeding, so it makes sense.]

When the three astronauts travel around the moon, the radio contact breaks down. During this radio silence, they spot their planned landing site, Fra Mauro, on the surface of the moon. Just after this sight, Houston can get in contact with them again. So, only then, the spaceship comes out from behind the moon. But Fra Mauro is on the visible side on the moon, almost in the middle of it. How could the astronauts see Fra Mauro while they were still on the back side of the moon? [The visible "side" of the moon does not change, as the moon happens to rotate on it's axis at the same speed it goes round the earth. So far so good. Howver, it is perfectly possible to fly (or stand) in the middle of the visible side and not have radio contact with a given point on earth, simply because the transmitter you are trying to contact is over the earth's horizon from your point of view. They would then need to continue further on their trajectory to get radio line-of-sight back.]

During the launch scene, there is a shot where the plume of flame is going backwards, as if it is going back into the rocket. [This shot is not a gaff as it was shot this way. It IS a FX shot but look out for the falling ice. Rockets, like any other motor, need to be "throttled up" as a result the initial fireball is effectively "sucked" back under the rocket when it hits full power. All the Apollo launches showed this behaviour and the FX crew actually shot it using real fire and flame rather than add it as a post production digital effect. Ron Howard says so on the DVD commentary.]

When the astronauts have rounded the moon there is a scene where Houston is helping them to make a blind LM burn, we see Hanks and Paxton at the controls of the LM and Bacon timing them. Well Hanks and Paxton are standing velcro'd to the floor looking out the two large triangular LM windows at a distant earth. Hanks lines up the optical lunar distance rangefinder on the Earths terminator and they fire the engine merrily rocketing off towards the Earth. This is in error, the LM engine is under their feet pointing down and 90 degrees away from the imaginary line between the Moon and Earth. The astronauts should be looking out of the small rectangular docking hatch in the roof of the LM ABOVE their heads because that is where the Earth would be and certainly not out in front of them. Obviously the LM engine is not behind their backs when they fired it but under their feet pointing down so the Earth is opposite the engine and thus above their heads, not in front of them in the nice big movie friendly windows. [The original contributer is right, the way Tom Hanks is looking would mean that he would have to be 90 degrees to the line. But in real life, this was the way it actually was. On the Apollo 13, Jim Lovell was trying to correct the course, not move forward and correct the course., He was in no hurry to risk screwing his course up more. So the use of the "movie friendly windows" is correct, the computer animated LM is wrong.]

In the scenes at the Lovell's home, as the crew nears re-entry, the priest, (who is wearing Catholic priest clothes), is wearing a wedding ring. [Catholic priests do, in fact, wear wedding rings. They are 'married' to the Church. Nuns wear them as well - they are 'brides of Christ.' It serves the same purpose as someone who is married to another human wearing a wedding ring - it shows their commitment.]

After the spacecraft has lifted off and is in space, Houston tells the crew to shut down the engines. Just as Hanks says, "that, gentlemen, is how we do that," we see the engine turning off. A couple of scenes later, when we see the spacecraft heading towards the moon (with the moon in the backround), you can see a flame coming out of the engine and once again it shuts down, when it was already turned off. [This sequence actually depicts two separate burns, but is correct. The first shutdown of the S4B completed the initial ride into Earth orbit. After a quick systems check, the spacecraft is positioned for translunar injection (pointed toward the moon). The S4B booster is then ignited again to send the ship to the moon, which is what is shown in the film.]

On their way towards decent to Earth, there was a point made about them not being heavy enough, due to not returning "moon rocks". At this point they still have the base of the LEM attached, which is normally left on the moon. I don't know how much this weighs, but wouldn't this counteract any weight issues? [They'd already allowed for the LEM, they'd just forgotten about the moon rocks].

At the part where they launch the Saturn 5 rocket the arms go the same direction. The arms are supposed to go one on the left, one on the right and so on. That is because the tower has to be balanced. [The swing arms DO arc away, 84 degrees in fact, in the SAME direction at launch - with the exception of the crew access arm containing the so-called "White Room" which swings 135 degrees in the other direction. Also, the film depicted the maintenance arms detaching one after the other as the shot panned down the launch vehicle - in fact the arms all swung away simultaneously, accelerating very rapidly as they did so, before braking abruptly when clear.]

When Lovell is talking to his wife on Earth about the moon she asks him where is her mountain (Mt Marilyn) He shows her it is near the top right of the moon's face. When he is behind the moon Bill Paxton mentions "There is Mt Marilyn" Then "Look at that Tsiolkovsky crater" Tsiolkovsky is on the far side of the moon so couldn't be anywhere near Mt Marilyn. [If you're in the right place, you can see the far side and near side at the same time - obviously not all of both sides, but it's like if you're hovering over the Atlantic you could see the UK and USA, even though they're miles apart].

When the Apollo 13 rocket is taking off the arms that hold the rocket in place come off at different times, when they should have come off at the same time or the rocket would have crashed. [The arms holding the rocket in place are at the base of the rocket, and we only ever see one of these. The arms further up just hold connections such as fuel lines and power cables, and only have to come off quickly enough so they don't hit the rocket - they don't have to detach at the same time].

There is a shot of Ed Harris, and lying on his desk is a pack of Camel cigarettes. On the pack there is a surgeon general's warning. However, in 1970 there were no warnings on cigarette packs. [Correction - apparently warnings were introduced in 1966. It's possible that the wrong warning was used (it changed several times over the years) - can anyone read it?]

After their slingshot around the back of the moon, the movie's tenseness calms as Tom Hanks turns his head to look out one of the module's windows at the moon, and then turns his head to the other adjacent window to look at a serene view of the earth. The tenseness shouldn't have calmed. If the moon is on one side of you and the earth is on the other ... you're going the wrong way. [Correction - space modules don't have a "front" - they can travel in any direction at any attitude. He's going the right way, just not pointed in the direction he's going].

As the Apollo 13 crew is readying to "slingshot" around the back of the moon, burn calculations are being made by Houston which are relayed to the crew. Tom Hanks is calculating total fuel amounts in the various fuel tanks by mathematical addition using a slide rule. You don't add and subtract with a slide rule. You multiply and divide. [Wrong - the only time a slide rule is seen is when the crew are transferring from the Command Module to the Lunar Module and they need to convert the gimbal angles. Lovell (Hanks) is attempting to work out the conversions using pencil and paper. He asks for confirmation that he has got the figures right. At this point we see one of the flight controllers using a slide rule to check the calculations, which DO involve multiplication and division]. [Wrong again - the slide rule is being used when transferring the gimbal angles from the CM to the LM. (The offsets between the two would have been measured earlier in the flight.) The LM angles are the three CM angles with the offsets added or taken away. No multiplication or division are involved]