Wednesday, August 13, 2008

Packing up and Heading out!

After much discussion with the folks at Zero-G, we're ready to head off and do some experiments!  The big news is that they've figured out a way to let us do Diet Coke & Mentos!!!  The solution turned out to be doing the experiment inside a portable glove-box.  This means we will be able to definitely answer the important question of "when the hero traps you outside your space fortress, can you rocket your way back to the airlock using only your favorite diet soda and minty candy?"

Above you see the complete experimental loadout.  The hard-disc gyroscope consists of a 7200 rpm drive unit that contains the platters from several dead hard drives.  The enclosure is a cheap USB enclosure that has the virtue of needing only a simple 12v power supply.  Testing showed that the best batteries to use were a set of 10 1.2v 2000mah NiMH cells; regular alkaline cells simply cannot source the required amperage, and even high-discharge lithium cells are borderline.

As a backup to the hard drive, we're also taking along a manual PowerBall gyroscopic hand exerciser.  Attached to the red pull-cord of the PowerBall are a 0.500" spherical rare-earth magnet and a matching ball-bearing.  These will be used both for pendulum experiments at 1/3 and 1/6G, as well as perhaps some ZeroG sillyness, using a blowtube (not in picture) to fire one past the other.  Both have one hemisphere painted red to make their rotational motion more evident on video.

For the Diet-Coke and Mentos experiment, a series of tests, some of them spectacularly unsuccessful, have resulted in the development of a deployment system that should work in Zero-G.  After the Diet Coke is uncapped and the gas pressure is allowed to equalize, a plastic sheet from a ziplock bag is placed over the mouth of the bottle, and a Spangler Geyser Tube is screwed on.  The Mentos are then inserted into the tube, and the first one in has a thumbtack affixed to it with modelling clay. The restriction nozzle of the Geyser Tube having been previously removed, deployment is achieved using a short length of plastic water pipe to ram the Mentos into the Coke.

Here is a video of the final test of the deployment system, filmed at 300fps using the Exilim camera.

Finally, last but not least, I have packed 4 pairs of Peril Sensitive Sunglasses. We won't need them, of course, but the Zero-G staff might!

1 comment:

Mamacita (Mamacita) said...

That is SO COOL! We are huge fans of Steve Spangler's Mentos Geyser and I can't wait to try your take on it.

My son will probably do it for us, as he's the actual scientist/builder here.

Thanks for posting this.

Have you signed up for Steve Spangler's Experiment of the Week? There are tons of great suggestions for experiments, and he sends you one every week in your email, absolutely FREE.