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NASA show off new 'Star Wars' type PDA
urk writes "
NASA's got some prototypes of a new 'personal satellite assistant' that could be joining astronauts in 3 yrs time, from telling them about warnings of gas levels, checking on payloads to reading them bed time stories or teaching them russian. It's a little red sphere that floats around the shuttle / space station by itself. It should be able to talk, relay information and have conversations. Star wars comes to life! " The inspiration for this came from the Practice Ball in the Falcon in A New Hope.
OK, these little orbs are really cool and everything, but how much will they cost? I'm not just talking about the cost per ball; I'm talking about all of the research, development, Vomit Comet flights, programming, hardware, man-hours, and evertyhing else that goes into the making of a successful prototype. Correct me if I'm wrong, but NASA has been facing the budgetary squeeze for quite some time now by members of Congress. The space station is barely staying afloat (with no help from the Russians ;-) ), and NASA is struggling to find capital for numerous other projects. Could the money spent on this admittedly cool project have been better used elsewhere?
The astronauts originally wanted a "tricorder"-type device; a hand-held status report would have been just fine, and a floating sphere with voice recognition is overkill for this project. Was there perhaps a simpler and less expensive way to accomplish this task?
Friends don't let friends misuse the subjunctive.
Okay - this may get a bit disjointed.
Propulsion: I would think a stationary, counter-rotating dual blade ducted fan (to solve torque problem) with tubes would be a good way to propel it. Basically, have all the tubes open or closed all the time, but have a tiny wastegate in each to alter the airflow. I would think it could be made lighter than using separate fans for everything.
Another nifty device to have onboard would be a laser pointer:
(remote): Dave, there is a serious oxygen leak over here!
(Dave): Where?
(remote): Right there!
etc... some of those conversations would be much easier if the remote had a means of pointing to exactly what it was talking about.
As far as the voice recognition and control... since it costs about $10k per pound to get those astronauts up there in the first place, I think a ground controller could be paid to sit there & do nothing but watch the feedback from the remotes - if the remote is less than 90% certain what it's doing, he could clarify by keyboard...
I was thinking a compressed gas propulsion system might work, but it would need to be something that can be done with small, lower pressure cartridges (CO2 and Nitrous Oxide come to mind...but I'm not sure I'd want a half-dozen remotes hovering around me farting Carbon Dioxide or Laughing gas...)
Okay, not to throw a light of doubt on this, but I'm not so sure an A/C claiming to work at NASA throwing around some ideas should really be trusted.
Couple reasons:
1) The fans spinning wouldn't be an issue with a simple fixed-axis gyroscopic system like they use in airplanes for the horizon control.
2) You can't use one of those with six fans, that's the biggest proof that this guy doesn't know what he's talking about. To move around in a 2-d surface, you'd need fans to push it in each of the directions in 3-d space (6, unless you're reversing the fans, but that'd mean having air passages through the device, which uses up a lot of the interior space), PLUS you need fans to control orientation in space. Sure, you could use actuators on a system like the one I mentioned above to force it to turn against the interia of the gyroscopes, but if they were doing that, then the stability wouldn't be an issue would it?
There's pleanty of other ways to counteract the tendancy of the device to spin when the fans turn -- like doubling up on the fans, on axis, and spinning them in opposite directions. But that's twelve fans, and still doesn't solve the problem how how to adjuct yaw, pitch, and roll.
I dunno, I just don't find this post that likely to be real.
I also can't imagine that carrying compressed air really would be an issue. Weight isn't an issue, only mass. And anyone whose ever had the luck to see someone knock a valve off a scuba tank can tell you that mass to thrust, you can get a lot of oomph out of compressed gas, especially in a microgravity environment.
You'd think an engineer working on this would know the distinction.
There have been a lot of posts about how fan control would work in 3 space, and the answer is NOT 6 fans (though that would work). The minimum number of control points you need is 4, distributed evenly over the surface of the device.
The four would give you all the mobility you would need, though the control logic would be horrible (but logic is cheap, hardware is expensive) For starters, every adjustment would use all the fans (except for maybee a few distinct special cases).
Also, if it's gyro stabilized, your aditude adjustments would largely be gyro based, with occasional gyro spin downs using the fans.
Personaly, I would stick a dual fan in the core (on axis, spining in alternate directions) and route inflow and out flow with valves leading to external control points. properly engineered, it could be used as a gyro as well.
My $0.02
-Crutcher
-- Crutcher --
#include <disclaimer.h>
Confucius say: Is better to be silent and be thought a fool, than to speak and remove all doubt. I believe the AC; I can't take you seriously.
Time is Nature's way of keeping everything from happening at once... the bitch.
These would make a really *cool* floating, talking beowulf cluster.
It would be pretty much trivial to have straightening vanes on all the fans, so that the net torque is zero... or not. Another solution is contra-rotating fans on opposite faces; they can either produce thrust while cancelling torque, or produce torque while cancelling thrust. This allows the fans to push, twist, or any combination along/around the axis of the fan shafts. Pairs arranged as top/bottom and left/right look easy, but a back/forward pair appears problematic for little things like the camera field of view.
Time is Nature's way of keeping everything from happening at once... the bitch.
Just use the fans for acceleration. Use pitch/roll/yaw gyroscopes for steering. That way you control spin without worring about COE.
-- lk t lv ll th vwls t f wrds. T svs lts f tm t wrt bt ts pn n th ss t rd nd mks m lk lk cmplt dpsht.
I figure I may as well chime in here. I'm one of the research scientists at NASA working on the PSA (though it's been renamed SMR, Spacecraft MicroRobot, nobody seems to want to call it that). Right now, we have a version that floats on an air hockey table in two dimensions (actually, a fifteen ton granite slab is the table, and the PSA has an air pump so that it floats like a hovercraft), just as a proof of concept and to test control algorithms. We are currently designing the gimbal to test the three dimensional (though larger, since it will still be a prototype) version, which we are also designing right now.
As for a few of the things posted by other people: the speech technology is pretty far along. If you look at the NYT this morning, there is an article about a car computer that accepts speech commands. There are still many issues that we need to work on, but it's not that far off.
The current plan for propulsion are a bank of six fans (not pictured on the model). We have four fans on the 2D version, so 6 will give us enough to move in 3D. Compressed air is a nice idea, but the question becomes how to direct it, how to generate it (assumming that you don't want to have to carry a canister, which is very heavy), and how much force you can actually get from it.
I like the image of a PSA avatar (the dancing paperclip).
We can test it in microgravity in two ways: First, we are building the gimbal that I mentioned above, which allows us to test it in a limited range here in the lab. Second, we will use the "Vomit Comet", the plane that goes into a long dive, providing low-gravity for about thirty seconds at a time.
And yes, the fans spinning up in micro-g cause all kinds of control problems. From where I'm sitting, I can see two people that are using up all of our writing pads trying to solve them.