New Mars Forums

Um, look at the problems of low-pressure plasma containment for fusion research...

My guess on the internal pressure for this scheme would be combustion chamber of rocket engine-- Just before it spontaneously disassembled.

Mind you, if he cares to try it, I'd be interested in the numbers.

Heavens !! Marineris could resemble a chunk of the 'golden age' tropical-swamp Venus that never was...

How big could you grow rain-forest or mangrove in low g ?? Most of that flora is pre-adapted to thrive in shadow-- which would be tree-top illumination on Mars.

If you don't mind, I'll pass on the Brontosaurus, though I imagine feral pigs might get rather large...

http://en.wikipedia.org/wiki/Atmospheric_pressure
http://hyperphysics.phy-astr.gsu.edu/hb … arfor.html

How do those Martian figures compare to Terrestial pressure / altitude tables for the bottom five or ten miles ??

http://sablesys.com/baro-altitude.html

Per my question in other sub-forum, what would the conditions be in / around Valles Marineris ??

My naive reading of the numbers suggests that Mars' pressure drops slower with altitude than Earth's so, for valley-floor at 15 PSI, Marineris' rim would be 'Everest High Camp' rather than 'Everest Peak'. Is this so ??

Similarly, if the rim was 'Andean Altiplano', what would conditions be like at mid-wall and down in the Bottomlands ??

I've been following Alan Bond's multi-cycle engines for a while so, when I read that they had tested Sabre's extraordinary heat-exchanger, I had a few questions...

Okay, for commercial reasons he could not give details but he *did* state that the heat-exchanger core 'sang' as an Aeolian Harp during spin-down...

I commented that this might provide some interesting diagnostics via fourier analysis etc as filaments heated, stretched, bowed etc etc. Naturally, he could not comment-- Beyond a Smiley.

http://www.reactionengines.co.uk/index.html

Too true.

Snag is NASA, ESA, Russia etc-- D'uh, we ALL believed NASA's forecasts for Shuttle costs & schedules. Big Expendable launchers had no place in the grand plan.

I've seen the arguments about Saturn5 being 'old tech'. but it worked *just fine*, would have done nicely to loft modules, capsules, even a lifting-body or two. Didn't happen. The Shuttle was expected to under-cut expendables' costs, turn-around in less time than it took to build and test an expendable...

The only realistic jobs for expendables beyond 'national pride' were polar orbit and other 'out of plane' paths. Even interplanetary probes would ride Shuttle to low-orbit, courtesy of 'Inertial Upper Stage'.

So, ESA put their money into building modules to suit a Shuttle lift. And, lo, NASA screwed up. And the ISS was scaled back, down-sized, down-sized twice more, deferred, delayed, crewed to a bare minimum. And, lo, NASA screwed up again.

( Analogy is building a range of custom cab-overs for the pick-up trucks you've seen in the new brochure, then learning the trucks will be a year late, twice the price and a five-star lemon with-all... )

Now, ESA, Japan, China, Russia, Brazil, SeaLaunch etc etc are re-learning the Saturn5 skills, building bigger and bigger expendable launchers.

Surprise, surprise, NASA's official shuttle-replacement Orion rides a Big Expendable launcher.

By the time Orion flies, three or four other groups will have similar lift capacity, several private 'reusable' launchers will be prototyped, and 'fly to orbit' tech may be pushing them hard...

Did you check the SABRE links ? That improbable heat-exchanger *works* and, IMHO, is as significant a development as 'Lancashire' tubed boilers...

Brilliant !!

We could even build wondrous space stations at L4 & L5 using material rail-gunned from Moon !! Perhaps even a Bernal Sphere or two !!

Unfortunately, we're still at the 'Coracles, Sewn-Plank & Clinker-Built' stage of space-ship building. Alas & Alack, the 'Great Endeavour' is currently careened whilst that sprung plank is laboriously repaired...

FWIW, I've been in British Interplanetary Society long enough to want to weep over NASA's decades of bumbling...

I could not get the recent document to open, but that may be my paranoid firewall's doing...

Um, the theory is questionable, but the science looks good. If it works and is reproducible, then there are, indeed, possibilities.

IMHO, one such rotating whatsit could be considered analogous to a homopolar motor or generator: Interesting, but limited by topology.

But, take two or more, turn them sideways-- Assemblages may have interesting multi-polar and far-field effects. Whether or not these have any use is another matter entirely.

FWIW, the recent generation of super-cooled space-telescopes may supply ways to keep cryo-kit cool long enough to try these effects under lower gravity...

I don't know if it was an arcane math joke, but I've heard a suggestion that Alcubierre's 'bubble of space' does not need 'exotic matter' if you use a Limacon of Pascal configuration with ship in pocket...

( Something about cancelling unwanted infinities ;- )

Of course, it still leaves the interesting problem of how to make any such bubble...

Um, I suspect Dook has been caught out by magneto-gravitics and frame-dragging. They're real, they require correction for eg GPS but, so far, they are vanishingly small on our familiar mass-scale. Now, were some-one to find a 'giant mg effect'...

The discovery of the tilted shoreline linked to precession etc seems to confirm a Young Wet Mars...

Okay, I'll not get into the knotty issue of 'when last', whether 1 aeon ago, or three...

Given a time when parts of Mars were wet, so above freezing at sea level, what would conditions have been like in Valles Marineris ??

That's a big, big canyon. How many miles deep ?? Five ?? Yeah, right...

IMHO, nearest Terrestial equivalent would be the Messinian Event, when the Med dried up.

Are there any estimates of temperatures, pressures and weather atop the plateau, mid-wall and down in the Valles Bottomlands ??