PARIS emerges triumphant from hypobaric chamber

First up, try the Mk 2 release mechanism, operating at an ascent rate of 1,000 feet a minute:

Lovely. Obviously, we've speeded up the vid for your viewing pleasure, and you'll note that the plunger rod extended in small "jerks" as the pressure in the oxygen tube built to the point where it overcame the friction in the system, and pushed the release rod out a little bit.

The first drop came at 33,000 ft, so we took the whole thing apart and compressed the oxygen tube further to remove some surplus air. The second drop was at 48,500 ft, which more than satisfied us given that it's nigh on impossible to accurately calibrate the mechanism.

One thing is certain, though: the Mk 2 will definitely release the Vulture 1, and whatever the final altitude, it's going to be a bloody long way up.

A final note on the Mk 2: Yes, we know the plunger rod droops as it comes out of the PVC tube. We're putting together a simple guide system to keep it on the straight and narrow.

The results from the other stuff in the chamber proved interesting:

• Neither the styrofoam nor the polystyrene expanded at all, but the coarse packing foam surprisingly did. Presumably air bleeds out from the first two, but the large bubbles of air in the last have nowhere to go.
• Both straws were unaffected by the change in altitude. Either the air escaped through the surface of the fully-sealed straw, or it's strong enough to take the pressure.
• The Mk 1 didn't work again, even with the grease.

And finally, we'd like to note that the Kodak Zx1 video camera - destined for the main payload box - was in the chamber, and grabbed some of the footage in the above vid. It shut itself down after 30 minutes, and then one minute into a second run, so we'll have to see if the pressure drop has done it some damage.

In the meantime, it's beers all round here at PARIS headquarters, and hearty applause for Tim D'Oyly, Chas Taylor and QinetiQ, without whose help PARIS would currently be going nowhere.

As it is, we're ready to move into the final straight, and prepare for launch... ®

Additional PARIS resources

• Our dedicated PARIS section, with all previous updates, is right here.
• New to PARIS? We have a basic mission summary here (pdf).
• Our Flickr page, with all previous photos.
• Check out our YouTube channel - currently featuring a few kit tests.