Selenian Boondocks: Latest MSS Update

26 July 2006

What we've been up to lately:

Anonymous said...: Cool! Like an Erector Srt on steroids...; 10:17 PM
Anonymous said...: Are those 80cu/ft dive tanks?; 7:38 AM
Karl Hallowell said...: I'm curious about those tanks as well. Since a large number of tanks would seem to be a drawback, I gather there's some benefit, like being cheap and off the shelf, that drove your decision to use them.; 2:07 PM
Jon Goff said...: Mike,
Actually they're SCBA tanks and a little bit smaller than 80scf (unless you happened to run them at a little higher than their DOT rating....)

Karl,
They were cheap and off the shelf, but the main reason we bought them (back in January) was that the quoted lead time for higher pressure carbon fiber tanks was a couple months after when we thought we'd be initially flying. In hindsight, waiting and going with fewer carbon fiber tanks would've made more sense, and we'll probably upgrade to them in the near future.

When we were first building the vehicle, we didn't know how deep we'd be able to throttle, and had been using 50% throttle as a conservative estimate, which meant that the vehicle had to weigh more than 1000lb, or we wouldn't be able to land it! So a lot of our initial structural and pressurization system decisions were actually driven around trying to add mass instead of take it away.

After we get this flying, we've got a series of upgrades we're going to make to it though that should drive the mass way down, and thus drive the flight duration way up.

~Jon; 2:33 PM