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International Space Station Gyroscope Fails
b00m3rang writes "Reuters reports that one of the three working gyroscopes that keep the international space station stable and in the right position stopped working, just hours after a new two-man crew moved in for a half-year stay."
Which way is up?
The Erogenous Zone
The article clearly states that ONE of three failed. The story posted makes it sound like the ISS is now starting to spin out of control.
All they need to do is a spacewalk out and restart it.
He stressed, however, "We're not dealing with a safety issue," and added it would take several weeks to determine when to schedule the spacewalk.
There are two gyroscopes still functioning, and that is enough to stabilize the station, Suffredini said. If one of these remaining gyroscopes fails, the station will rely on thrusters to keep it steady.
Too bad they can't do that for Hubble too.
(\_/)
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I wonder why they would place the circuit breakers outside the space station. If those ciruit breakers are like anything in my house, they go out all the time. Or maybe it is just my power company with all the brown outs in the summer.
I'm glad the story says this is not a critical system or a threat to the astronauts. Still, I wonder why the circuit breaker is not in a place easy to get to.
This gives me another idea. I wonder if they have a special escape pod attached to the space station, so if some critical system goes, they can escape.
Rosco: "If brains were gunpowder, Enos couldn't blow his nose."
Or is this picture a little creepy? The american astronaut looks like a serial killer or something and the russian looks like he's afraid because the american looks like a killer...
Reuters reports that the gyroscope that keeps the international space station stable and in the right position stopped working, just hours after a new two-man crew moved in for a half-year stay."
Did you phrase it that way because you're a professional reporter and are used to getting paid to scare people into buying the crap you write, or are you just being a troll?
The article (and common sense) state that there's redundant functionalirty involved, i.e., there are two gyroscopes left that can handle the load and if that fails they can still keep it going with thrusters for over 6 months.
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NASA has finally decided it's time the ISS had centrifugal artificial gravity.
In Soviet Russia, spacestation rotates you!!
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Simple intro
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It seems that over history, the spacefaring versions of our technology are quite inferior to what we have planet-side. On typical space vehicles, this is because the vehicles were built so long ago. The ISS is a relatively new invention, and the number of bangs, bumps and hiccups seems to be more or less consistant with it's much older counterparts.
I think you misunderstand the problem. Engineering gadgets here on earth is simple compared to engineering gadgets to be deployed in space. We've lived in the relatively friendly environment of the earth for our entire racial life. Space is a hostile environment which we have only been exploring in a limited fashion in the last fifty years or so.
Compare the space shuttles to your car. Sure, they probably cost more in maintenance than your car, but they were engineered in the 70s, and with a couple of exceptions, they're still operational. I'll be the ISS has been in continuous operation for longer than any gadget in your house.
Anyway, the first problem is that they have to engineer devices that are capable of withstanding the amount of thrust they'll be under just to be launched out of the atmosphere. Second problem is that these same devices have to survive in vacuum, and in atmosphere (they're built down here). Third problem is they have to last for a long time, because solving the first two problems is so expensive that building replacements is very cost prohibitive. Fourth problem is that they're built by the lowest bidder, and frequently also engineered by the lowest bidder. :)
It's too easy to point at something in space and compare it's performance to any given gadget you own. Now try strapping that gadget to a rocket and launching it into orbit, and if it survives, then you can make your comparison.
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Ever tried to twist a gyroscope? You can use them in two ways: if you don't try to push them, they stay oriented the same way so yo have a directional reference. But if you ty to move, they "push" back. This gives you something to "push against" in order to twist yourself in space. You don't need to spend expensive reaction mass hauled up from earth, you just use electricity from your solar cells, and you get a much smoother and more accurate control than thrusters.
However, a single gyro can only handle positioning about two axes - you can rotate it about its spin axus as much as you like. So for three axis rotational stabilisation you need at least two gyros at 90 degrees to each other.
Consciousness is an illusion caused by an excess of self consciousness.
If you're wondering how a gyroscope works and what it does:
How stuff works has a nice article.
Nasa's also got a page about how they're used in space shuttles
From the article:
... is outside (the station) and that implies we'll have to do an EVA," Suffredini said in a telephone news conference, using the acronym for extra-vehicular activity, or spacewalk."
"At this time, the box that holds that particular circuit breaker
Right...The controls for the fence are in the shack across the lot, past all the dinosaurs; the satellite uplink is in the shack across the lot, past all the marauding aliens; the circuit breaker is in the box, outside the space station. Go fix it Dave.
Any of the astronauts wearing a red shirt by the way?
Compare the space shuttles to your car. Sure, they probably cost more in maintenance than your car, but they were engineered in the 70s, and with a couple of exceptions, they're still operational.
I'd just like to point out that those "couple of exceptions" are actually 40% of the fleet, and that their removal from service resulted in the sudden and violent death of everybody inside.
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They will resume thruster orientation maintained by the Russian modules. the Zarya Control module (Formerly the FGB Tug), and the Zvezda Service Module which is how the altitude and orientation were maintained until the Gyroscopes were installed as a part of the Z1 Truss.
Zarya was launched in November 1998.
Unity was attached by Shuttle Endeavour in December 1998.
Zvedza docked to the fledgling station on July 25th, 2000.
The Z1 Truss was installed by Shuttle Discovery in October, 2000.
The Control Moment Gyroscopes which are an integral part of the Z1 Truss, weren't activated until Assembly Mission 5A in February 2001.
Yes, this is a big deal, it will not however, result in the station tumbling out of control and dooming it forever.
However, that is not the type of gyroscope that has failed here! In the last couple decades, gyroscopes have been used as actuators to actually provide the TORQUES necessary to MANEUVER space vehicles. This is very different from the much more common use of gyros simply to determine attitude. In fact, these gyroscopes are more correctly referred to as Control Moment Gyrospcopes or CMGs. (Incidently, they come in two flavors, single and dual gimbaled - with the ISS using the much less common and more complex [read prone to failure] dual gimbaled CMGs (DGCMG)).
A CMG works as a torque amplifier. You essentially spin up the inner element to a high rpm (usually 3000-5000 rpm) and then apply a small torque to the outer gimbal. The the gyroscopic rigidity of the inner rotating element resists this torque and the result is a much-amplified reaction torque imparted on the vehicle.
Traditionally, three-axis stabilized spacecraft that require fine pointing control have used reaction wheels or momentum wheels for control. CMGs allow for orders of more magnitude of more torque (for an equivalent mass alternative) and more momentum storage (unfortunately, momentum is conserved even in space, so if you impart an angular rate to a spacecraft, you must have some element inside the spacecraft to 'store' an equal an opposite momentum - this is what actually limits a spacecraft's slew rate). The downside of CMGs is that they are mechanically complex (don't even get me talking about null-spaces) and that high rpm inner element must be lubricated extremely well if you want the vehicle to perform for years without an oil change (as those are hard to come by in LEO); thus they tend to higher failure rates. The solution to this has tended to be to add redundant CMGs (which is probably still a better option than using less capable alternatives.)
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