...and great was the fall thereof.

That old autumnal equinox popped up, and sure enough, it feels like fall today. I like fall and spring the best; sorta chilly in the mornings, nice in the afternoons. (Spring's best of all, though, because there's none of those annoying falling leaves.)

No soccer practice last night due to all the rain from yesterday, which meant time to actually sit down with everyone and eat supper, which was about like sitting down to eat at a restaurant with six strangers. "Hello, my name is Mr. Oglesby--and who might you be?" "Daaaaaaaddeeee, I'm Jonathan!! You know, your son?!" "I have a SON!?" Giggles all around. And you know, for it to be a bunch of strangers, that lady sitting next to me sure didn't seem to mind me rubbing on her leg...

Anyway, food, then homework--Rebecca has had an assignment for weeks now to fix an Alka Seltzer powered rocket out of a paper tube. She finally brought home the instructions last night, which was very convenient seeing as how it's due today. ::sigh:: (At least they come by their procrastination honestly.)

She has started off making a tube out of notebook paper, without realizing that the pattern was printed on her instruction sheet. Which meant her tube was not what you would call correct.

Enter Father, the Rocket Scientist.

First, we needed a film canister. You're supposed to plop an Alka Seltzer into it with some water and shove it into the end of the paper tube and when enough pressure builds up, it blasts off. In theory.

Got one of the myriad black plastic canisters from the pile of junk strewn throughout the house and sat down and we redid the paper tube so that it fit nice and snug around the canister, then retaped the pretty blue construction paper fins onto the side, and finished it off with a paper nose cone.

Found the Alka Seltzer box and began moving the rocket from the assembly area to launch pad 1A at Cape Possumaveral. Dropped in the tablet, slammed on the lid, shoved the paper onto the can, and sat the whole mess down on the patio table.

...5
...4
...3
...2
...1!

...1!

ONE!

"Daddy, is it going to..."

pfft.

The little lid popped off and the tube fell over. Well now, that was disappointing. I gathered up the remaining bit of Alka Seltzer and put some more water in the can and tried it one more time. pfft.

Well, by the hairs of Robert Goddard, this is supposed to do something better than this, surely! Got another tablet and took the can out of the paper and just sat it there on the table, and relit the wick. Pop. It went up about a foot this time, unencumbered as it was by any sort of payload.

Hmm. I did some quick calculations and figured that the lid had a friction coefficient which was not high enough to allow sufficient reaction force to build up in the pressure vessel. "Honey, I think we nee..." "We need one of those clear cans with the tight lid, because that one's coming off too quick and Kelli says she used one like that and it went really high." Well, yeah.

So, off to plunder some more. Mom supplied another canister, and by this time, we had also gathered another member of Mission Control in the form of a little boy.

Once again, we rebuilt the rocket, which by this time was thoroughly soaked toward the exhaust end, and installed the new motor. Water, tablet, shove, place, countdown.

...5
...4
...3

POPPPP!

Cooooool. The whole mess lifted up off the table a good two feet--the launch team examined the recovered vehicle and found that the motor had driven itself two inches up into the body of the rocket tube, which is pretty danged neat, you know. If it had been dry, it might have held better. We still had some more Alka Seltzer, so we did one more firing, which once again let out a satisfying pop. Alas, our launch vehicle was beyond repair--the structural integrity had been greatly compromised by the combined effects of dihydrogen monoxide and the wear of repeated motor replacements.

But that didn't mean we couldn't do more motor testing!!

So we went and got yet more tablets and filled up the canister with water out of the flower pot (it was more convenient than going back inside the house each time) and did two more runs.

POPPPP!! Nearly to the eave of the house!! We received a dignitary who wished to review our testing procedures, and the kids were nearly beside themselves telling Mommy how the water!, and the paper!, and it BLOWED up!, and it fell over!, and it popped!, and it WENT WAY UP HIGH!, and then!, and!, and!..."SHHH--y'all are going to make the neighbors call the police!!"

Final set up for launch, water, tablet, place can on table, countdown...

...5
...4
...3
...2
...1

ONNNNNNNE!

"Mommy, look, it's going to pop...NOW! 2...1...NOW!"

NOW!

POPFOOOMMMMM!!

Danged thing popped all the way up onto the roof--20 feet up at least.

There was great joy in the power and success of the test--but no small amount of sadness at the miscalculation of the orbital trajectory which led to the loss of the test motor. And Mom, being the source of new funding and equipment, was in none too good of a mood about having to take out yet another roll of film so Rebecca could have another canister. But after much cajolery and backroom dealing, a new canister was procured.

And we had to rebuild a tube around it. This time, we made it a bit stronger, with better paper, and reinforced the nozzle end, and put a little paper strap across the top of the canister to hold it in place. Be interesting to hear how the launch goes today.

WHAT WILL ALSO BE INTERESTING, is that due to the horrid influences of the real world, I have to put up my blog toys and get some work done. Meeting in ten minutes, and other garbage to do, and then, yet another continuing education seminar to attend. Oddly enough, it's going to be held out at the Barber Motorsports Park--some sort of irony or something or other in that, eh?

And there'll be little blogging tomorrow, too, because I have my bimonthly bureaucratic exercise in bureaucratic excess, with all the attendent note taking and transcribing, and ANOTHER continuing ed seminar that afternoon!!

SO, not much possumy fun in the next couple of days--run up to the blogroll above and see what everyone else is doing, or go visit THE PROBOSCIS, the official campus newspaper of Weevil State University. You'll be glad you did! Maybe.
posted by Terry at 8:55:00 AM