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-   -   Precision Launch Pads? (http://www.oldrocketforum.com/showthread.php?t=8457)

Beowulf 01-18-2011 11:28 AM

Precision Launch Pads?
 
After our flight on Saturday , I am very interested in building a launch pad that allows for more accurate targeting than our basic Estes one. I have an old german equatorial mount, to which I am thinking about attaching a platform. The idea is that I could adjust the tripod to level the pad, and then set the launch angle and direction using the mount.

What I'd really like to be able to do is to enter the current environmental conditions into an application and then use the calculated rod deflection and direction in order to return the rocket close to the launch pad. Heck, if I could make it land back on the rod, then I would!

My question is this: has this type of project been done before? I don't see a similar thread having been posted previously, which leads me to suspect if such a thread exists, that it has been archived. Either that, or the idea itself is folly. What do you all think? Thanks for your feedback!

GregGleason 01-18-2011 11:50 AM

Were it not for the atmosphere, it would be a fun project. What I mean by that is that winds aloft and wind shear wreak havoc with flight profiles, and therefore have a lot of "say" on where a rocket lands. It might be a fun science fair project in NASA's VAB, since you do not have the wind influence (when the doors are closed) that you have at a more typical launch.

More often than not, when I have left the launch rod toward dead-center, it's a better flight. For me, things sometimes have gone awry when I begin tilting the rod.

Greg

mycrofte 01-18-2011 05:23 PM

Many times, the wind at ground level and just above the tree line are a bit different. Causing a rocket to either veer off course (most notably the sci-fi Viper) or the chute to carry it several blocks more than planned...

Beowulf 01-23-2011 10:32 AM

Thanks for the comments. I realize that the wind at higher altitudes is going to be different than that at the launch site. It also occurs to me that wind is three dimensional: it won't exert a purely orthogonal force to the flight of the rocket.

However, I was thinking that I could project where I thought the rocket would land, and then use a GPS to mark the actual landing site. The difference between the two would be a combination of two factors: environmental effects, and then imperfections in the build of the rocket itself. I was playfully thinking of the latter quantity as "rocket fudge."

Over consecutive launches on the same day, environmental effects might be consistent enough to include as rough estimates. I'm not expecting to predict the exact spot in which the rocket will land, although I do think it would be cool to have a contest to accurately predict the landing site. If I could bring the rockets down within 50 yards of the launch site, then I think that would be a success.

I'll update this thread with my progress. It could still be a fool's errand, but at the moment it's very intriguing for me! :cool:

GregGleason 01-23-2011 09:13 PM

Please post the results. My guess is that the lower the impulse, the tighter the CEP will be.

Greg

Mark II 01-24-2011 12:03 AM

I think that this is more art than science. You develop a feel for where your rockets will land based on your knowledge of the specific field, your experience launching rockets in it under various conditions, and your experience launching your specific rockets with various motors. It all gets combined and processed in your brain to produce something akin to an intuitive feel for the process. I wish it could be reduced to a set of equations, I really do. No expert system or artificial intelligence ever invented has ever had anything like the information processing power of the human brain, nor has any technology ever had anything approaching the incredibly tight coordination of eye, hand and mind. The quadrillions of computations that are executed between our ears every second take place at a level just below consciousness, and they produce results that we perceive as intuition and experience-derived knowledge. I suspect that the most successful predictions of the landing spots for our unguided model rockets will be achieved through the use of these stupendously powerful tools.

Bill 01-24-2011 12:54 AM

Quote:
Originally Posted by Mark II
I think that this is more art than science. You develop a feel for where your rockets will land based on your knowledge of the specific field, your experience launching rockets in it under various conditions, and your experience launching your specific rockets with various motors. It all gets combined and processed in your brain to produce something akin to an intuitive feel for the process. I wish it could be reduced to a set of equations, I really do. No expert system or artificial intelligence ever invented has ever had anything like the information processing power of the human brain, nor has any technology ever had anything approaching the incredibly tight coordination of eye, hand and mind. The quadrillions of computations that are executed between our ears every second take place at a level just below consciousness, and they produce results that we perceive as intuition and experience-derived knowledge. I suspect that the most successful predictions of the landing spots for our unguided model rockets will be achieved through the use of these stupendously powerful tools.




In other pursuits, this is sometimes known as a "home field advantage."


Bill

Mark II 01-24-2011 01:28 AM

Quote:
Originally Posted by Bill
In other pursuits, this is sometimes known as a "home field advantage."


Bill
Except that it can be acquired anywhere. One just has to spend a little bit of time at a location and launch some rockets there. None of us ever go to totally new and unfamiliar launch fields all that often. We all do almost all of our launching at a restricted number of sites. Over time the peerless technology that we were all born with gathers the high quality data and performs the ultra-sophisticated multivariate analyses that enable us to fly our rockets in them with ever-improving skill.

Doug Sams 01-24-2011 09:37 AM

Quote:
Originally Posted by Bill
In other pursuits, this is sometimes known as a "home field advantage."
Home field advantage stops working when a representative of the national club comes over and changes the angle on your rod with the result your rocket ends up in a tree :eek:

Doug

.

Tedster 01-26-2011 01:52 AM

Lercari Engineering
 
Remember Lercari Engineering in 1972? I still have their catalog. They sold several motorized launchers and even an automatic countdown ignition system complete with a nixie tube display! Their motorized launchers tilted your rocket in azimuth and elevation. Had microprocessors been abundant in 1972 they probably would have tried just what you described!

Tedster


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