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CEV Revolutionary Gimballed Thrusters
simonbp writes "A Tennessee Tech Professor has proposed an innovative gimbal mount for 'inclusion to the design of [NASA's] CEV (Crew Exploration Vehicle), revolutionizing the vehicle's RCS (Reaction Control System) and solar panel orientation capabilities.' This will allow for nimble maneuvering and for the solar cells to maximize power production."
What's the symbol for a nimble gimbal??
Didn't the Soyuz 11A511U have Gimballed Thrusters?
The theory of relativity doesn't work right in Arkansas.
If you're like me and are wondering what the heck a gimbal is, wikipedia has an article. Not being an engineer, I still only have but the fuzziest idea of what's going on here; blame a liberal arts background.
Here is a video model of the joint in action. Frankly, I can't help thinking of a Rube Goldberg machine when I look at it.
... MS owns the copyright to the word 'innovative'. They will be releasing this new design in 6 months after copying it.
The original CSM had gimballed engines. So they announced they are going to do the same damn thing that they did in the 60's? Snore.
I found the "Any" key.
Sorry! Slashcode diddled the spaces in the URL.
Here's the working link.
Starbuck: "Where's Pravana? He's gotta fix that fraakin gimbal or I'm gonna have his ass"
Tyrol: "He's dead"
Starbuck: "How many did we lose in the attack?"
Tyrol: "85"
There are a couple of weak links to this solution, but nice design none the less.
The connecting joints and hoses will be subject to flex failure.
No doubt they will use appropriate materials to counter repetative wear.
Also, as with most space equipment, they will most likely make a redundant system.
Any chance of harnessing this space-age technology to use here on earth?
Women- the final frontier...
Gimball looks to me like a perfectly cromulent word!
Hosting 20G hd, 1Tb bw! ssh $7.95
The original shuttle had gimballed engines, now they're using it for the RCS as well? Big fucking deal. May as well post an article about how the toilet's going to have a different colour of soap.
The original design with millions of RCS thrusters all over the place was stupid anyway.
As a rocket engine gimbal, this doesn't look promising. It's a rather bulky mechanism; the linkage is much larger than the engine bell. It requires fifteen bearings, not including the three motors. The standard solution, a gimbal ring arrangement, only requires four. The bearings also have to handle off-center loads, never a good thing. Bearings in space are headaches; lubrication is tough and temperature changes can jam them.
The motors are in a weak position from a leverage standpoint; the engine thrust is applied directly to the motor shafts, so they (and their gear trains) must be strong enough to overpower the thruster. In a gimbal ring arrangement, the bearings are usually placed so that the center of thrust is at the center of the gimbal, so that the bearings, not the actuators, take almost all the thrust. Very large engines, like the Space Shuttle and Saturn V main engines, have been successfully gimballed that way.
The three motors don't seem to add redundancy; it looks like they all have to be working.
For comparison, here's a simple gimbal from Amadillo Aerospace, Carmack's rocket program.
In reality, having many fixed reaction thrusters is probably more reliable than have a few steerable ones. Fewer moving parts.
Gimbals have been around since...well, if you believe Needham, at least the 10th Century AD in China. A gimbal is just a way of mounting something so it can rotate relative to something else while still being attached to it and moving linearly with it, and the main application has been on boats where equipment like lamps and compasses is suspended in mounts so it can swing. http://www.sailgb.com/p/captains_cabin_lamp/ is a picture of a small gimballed lamp. So long as the centre of gravity of the equipment is below the plane of the mount, the boat can rock underneath and the lamp, compass, cooker or whatever will stay more or less upright.
By using an outer pair of pivots to hold a ring which then has another pair of pivots at 90 degress to which the equipment is attached, you get two axis gimbals which allow for rocking and for pitch, which is important on small boats. It isn't practical to suspend (say) a marine stove from a chain because it would swing all over the place, whereas suspending it from pivots near the top means that the base can swing a bit while the pans stay more or less in the same place.
So all the stuff in Wikipedia about Euler angles is all very well, but a gimbal is just a way of allowing one thing to be attached to another while being able to rotate in one, two or three dimensions relative to it. There are various designs and obviously the Canfield one is a clever one, but there is nothing mysterious about gimbals themselves.
Pining for the fjords
If you're just curious about what this new gimbal looks like, tntech.edu has a video showing how it works. Or, for those who don't like Coral cache, here's a link to the original site.
Ewige Blumenkraft.
I hope this idea is adopted. We're talking major cost and energy savings.
The video illustrates exactly how the gimbal works.
It's quite neat actually.
Too bad the video is a few MB over 50, otherwise they could have coralized the link.
I won't post a link here, because they say that they don't want their server to go down in flames.
[Fuck Beta]
o0t!
I went to the site, where it says a video of the device in action can be seen at the link on the bottom of the page.
But guess what friends, when you click on the link, you are rejected because you are not a friggin member.
It might for all I know, be a great idea, but screw em and the camel that rode in on them.
Whyinhell does Taco post these stories without checking them out for veracity?
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No Cheers, Gene
bugmenot.com
Most vehicles in space use a combination of thrusters and reaction wheels. Essentually a flywheel on each axis is spun up or down to rotate the vehicle. Eventually the wheel is moving too fast and a thruster is used to spin the vehicle so that the wheel can be slowed down. For moving the vehicle it is important to have the thrust vector point at the CG of the vehicle, else a torque is produced causing spinning which requires an additional thruster to compensate. By the way the solid rocket boosters on the Space Shuttle are gimbled. As others have said simplicity and redundancy are important considerations in space design. Look up for example the Apollo Luner Orbiter engine design.
Well you see, it revolves, so naturally "Revolutionary" was quick to come from that, and they kind of just went with the flow to get "innovative".
was not working....
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To think that I have any useful contribution to make to Wikipedia. That doesn't stop me trying to explain to someone who is not an engineer why he did not understand the wikipedia article. My rantings on slashdot are just trivial observations of day to day things with no lasting value. I certainly do not have the technical expertise or authority to contribute to an encyclopaedia.
Pining for the fjords
I am a Mechanical Engineering Undergraduate who attends TTU and does research for the department in which this design originated. I work in the lab where the device was first prototyped. Just as an FYI, the device is revolutionary because of the elimination of repetitive structures. Granted the bearing are an issue but the gimble can achieve a full 360 degree spherical change in attitude with only the use of 3 stepper motors. Nothing else does exactly that at this time. That's why the device is interesting to NASA. Think of replacing the current arrangement of 5 motors with just one. Can you say cost savings? Just thought I would post my 2 cents since I have had to demo the device on several occassions and have first hand experience with the mechanism. OUT
Also the control valving is highly decoupled from the combustion chamber which means high dribble volume and terrible min Ibit. Those simple stepper motors also have to operate at 165R for prolonged periods- this denies you most lubricants and requires special resolvers and the like. There is also no way that such a mechanism can deliver the frequency response of multiple small thrusters pointed in multiple directions. There is also the need to interface either a fiber optic or high voltage spark igniter lead to the thruster across large motions- could be a problem for the non-optical approach.
The issue is : just what problem are we trying to solve? is it cost of the combustion chamber? Number of valves? Weight? Overall complexity? Or is this just an interesting exercise for a kinematics class? The vehicle attitude control function can be performed two active and two standby modules- not four fully active as was used on Apollo. This is highly optimal for cryogenic thrusters since it minimizes the number of lines which must be chilled and pure 6 DOF operations are rare as opposed to simple maneuvers with coupled rotations and translations. This solution was proposed to NASA and rejected as being "just too different from what Apollo did". I cannot imagine them actually flying this contraption.
http_//www.newpath4.com/enginewow.htm . Everyone knowst secure21.htm
water is INERT. What everyone is just coming to find out is that non-nuclear fusion engines do not make any combustion pollution because NOTHING IS COMBUSTING. Why, they're everywhere. I have one myself!
http://www.newpath4.com/millenialdawnpowerandligh
Mmmmm, gumball thrusters *drool*