I've been working for some periods at more than 5,000 m (with long periods of acclimatization at 3000) and I ensure you it is really demanding for an healthy westerner, specially if you have to spend the night there. Also, remember you wouldn't be selecting personnel among mountaineers or natives but among extremely good engineers and technician coming from any region of the US, etc. So, "without too many problem" is really overstating, trust me... Not mentioning 7,000. At that altitude the risk of emphysema is large. O2 bottles and oxygen enriched environments still help but as soon as you work outdoor your brain becomes quite unreliable. I can't really see such a highly demanding business to be operated there.
OK, first of all, I know this is totally crazy and politically impossible (and the technical challenges would be daunting as well), but what level of performance improvement could be expected from current launch vehicles if they were launched from the summit of Mount Kilimanjaro in Africa?IIRC, that was actually proposed by some SF writer (Clarke?) back in the 1950s.Mount Kilimanjaro is almost on the equator (3 degrees South) and is 19'341 ft (5'895 m) high. Being a volcano, it also has a rather gentle slope which could make the construction of roads and tracks up to the summit possible, as well as a large caldera (several in fact) which could be paved for the launch platforms. And it is inactive.What performance improvement would a Falcon 9, for example, have if launched from such a launch site, nearly 20'000 ft up?
Quote from: Eerie on 12/20/2014 09:47 amIf we use a mountain anyway, why not build an electromagnetic mass driver into the slope? The volcano will provide geothermal power. :-)*stabs EM mass driver on mountain slope in the heart**checks for movement**stabs it once more just to be sure*Now stay dead!
If we use a mountain anyway, why not build an electromagnetic mass driver into the slope? The volcano will provide geothermal power. :-)
The observatory I was working with, ALMA, until a few months ago, forbidden to sleep in the facility overnight. We had one of the most powerful supercomputer of the world there, and it was ok to stay there during the day. However, we got a quite high number of fatalities due to people accidents during construction because of stupid behaviours due to high-altitude sickness. We had to establish very hard rules for workers, including stiff driving rules. And still, 99% of the high-tech work was done (on purpose) at 3000.
The local indigenous population probably would not allow something like that. They barely let the telescopes be built on their sacred mountains.
Why the limitation to 0.5 km/s?
Thanks for the cartoon, Tass. However, LACK and EXCESS of O2 have completely different effects... Xkcd quite wrong on this account :)
Quote from: Vultur on 12/29/2014 02:25 amWhy the limitation to 0.5 km/s?It's not good to travel at high speeds through a thick atmosphere. It causes excessive heating and drag. This is why rockets typically do a vertical ascent before they turn sideways for the major horizontal burn to achieve orbital speed.Concorde would go mach 2 (about .68 km/s) at 18 km altitude. Even at this altitude it'd get pretty hot. At 6 km mountaintops, air density would be roughly triple that of 18 km altitude.
It's not good to travel at high speeds through a thick atmosphere. It causes excessive heating and drag. This is why rockets typically do a vertical ascent before they turn sideways for the major horizontal burn to achieve orbital speed.
A booster starting it's burn at 18 km altitude and a horizontal velocity of .83 km/s has some advantage over a regular booster.
Quote from: Hop_David on 12/28/2014 11:54 pmA booster starting it's burn at 18 km altitude and a horizontal velocity of .83 km/s has some advantage over a regular booster.There's also disadvantage; it has to start with very large AoA while surviving ~8 kPa dynamic pressure or have wings.