Longest microgravity sequence

[Obviousman]

I'm hoping one of out film buffs can answer this:

What was the longest sequence of film where we could confirm microgravity and on which flight / when did it occur?

I'm talking about a sequence of film where you can see something floating / spinning / whatever.

[Obviousman]

Oh - this should be a lunar mission, not Apollo 7 or 9.

[ChrLz]

Dunno, but I like this non-Apollo one.  It's only a few minutes long, but worth watching - I like the guy's lengthy efforts to actually move himself..

And I understand that if you take into account basic physics and aeronautical limitations, 25-30 seconds is the limit for simulating microG in any aircraft.  Much longer would involve exceeding service ceilings or .. hitting the ground.

[Peter B]

Dunno, but I like this non-Apollo one.  It's only a few minutes long, but worth watching - I like the guy's lengthy efforts to actually move himself..

Heh. Like Mercury, he has a rotational RCS but not a translational one...

[ka9q]

That actually demonstrates something interesting: you can turn yourself around even while conserving angular momentum. This is how cats manage to upright themselves while falling.

I keep wondering how I might use that principle in a spacecraft attitude control system.

[ka9q]

Oh - this should be a lunar mission, not Apollo 7 or 9.

Lunar missions were during the days of film so you're likely to find your selection limited by the length of a film magazine and the need to conserve same during a mission. If you're looking for uninterrupted duration, look for a recorded TV broadcast. Apollo translunar and transearth coasts provided something we're used to now, but which was a real novelty during the Apollo days: long video transmissions not limited by tracking station passes in low earth orbit.

[Peter B]

That actually demonstrates something interesting: you can turn yourself around even while conserving angular momentum. This is how cats manage to upright themselves while falling.

Yes. But isn't it also how divers start and stop somersaults and twists while diving?

I keep wondering how I might use that principle in a spacecraft attitude control system.

I remember a coffee table science fiction book in my high school library (a book which was popular with the SF geeks) which presented a pretend future history of solar system exploration (things like a tracked vehicle with sealed cabin and headlights which was used for exploring Titan). Among its sidebar "reports" was one in which the RCS failed on a spacecraft and the crew managed to change its facing by pulling themselves hand over hand around circular tracks. (Or at least, that's what I vaguely remember - they may not have been as precise as that.)

[Trebor]

There was a clip From Apollo 8 where they were spinning and throwing a torch around the CM.
But I can't seem to find it at the moment....

[Mag40]

This is the vid that hunchbacked says is in water. No, really he does actually claim that!

[Allan F]

Yes. But isn't it also how divers start and stop somersaults and twists while diving?

No, they open and close the body to control the speed of the rotation. The rotation starts when they jump, and never stops. It's like a ice skater doing a pirouette - when they pull arms and legs in close, the spin increases, but the momentum is preserved.

Also, Hubble is using gyroscopes to turn in space, without using fuel. Increase the spin on one axis, and the whole spacecraft turns the other way. Decrease the same amount, and the spacecraft stops it's turn and stays stable.

[smartcooky]

Yes. But isn't it also how divers start and stop somersaults and twists while diving?

No, they open and close the body to control the speed of the rotation. The rotation starts when they jump, and never stops. It's like a ice skater doing a pirouette - when they pull arms and legs in close, the spin increases, but the momentum is preserved.

Also, Hubble is using gyroscopes to turn in space, without using fuel. Increase the spin on one axis, and the whole spacecraft turns the other way. Decrease the same amount, and the spacecraft stops it's turn and stays stable.

Its called "Conservation of Angular Momentum", and its precisely the same reason why we get neutron stars that are the physical size of the earth, with a mass greater than that of the sun, and rotating at 600 revolutions.... per second!!!