jccooper

75 ms·

811.
by jccooper 12y ago
They lease a bunch of agricultural land, and the entity they lease the land from (city of McGregor) doesn't want to ruin the land by leaving it in the hands of a bunch of rocket scientists, so they are required to hire a farmer to mana
812.
by jccooper 12y ago
Who knows? Weather and technical issues can scrub a launch, which is why they don't say in their PR materials. But it's scheduled for Friday 19 Dec. 1:22 pm. https://www.kennedyspacecenter.com/events/2014&#x2F
813.
by jccooper 12y ago
There are now LH2 composite tasks at a decent tech readiness level http://www.nasa.gov/press/2014/august/nasa-completes-success...
814.
by jccooper 12y ago
It's published to be able to run at 70%, which is quite nice. But 70% is still way too much to match stage weight. It's been said to be capable of 60% (or maybe 40%, depending on how you interpret a three-character tweet). But eve
815.
by jccooper 12y ago
A single Merlin engine, even at low throttle, has quite a bit more thrust than a (nearly) empty F9-1 stage has weight. Thus, it cannot hover; once it slows to 0, it quickly starts going up again. Thus the landing profile is the "hover-
816.
by jccooper 12y ago
And it never even flew that mission profile.
817.
by jccooper 12y ago
Yeah, it's just a more-aggressive synonym for "oldspace". Couldn't say where it came from. The EELV and Ariane were a reasonable approach at the time to make rockets a bit more affordable. Any way to do reusability at th
818.
by jccooper 12y ago
Sure. There are all-solid ICBMs, so there are flying examples. See Minotaur, a 5-stage solid booster made from converted ICBMs. An earlier design for the Ariane 6 was 4 identical solid boosters, 3 on the 1st, and one for the 2nd stage--befo
819.
by jccooper 12y ago
A high thrust-to-weight air-breathing flyback first stage is certainly attractive. Load up a bunch of fighter jet engines on it, and go: no need for engine development or carrying a bunch of oxidizer. Main obstacle there is that optimum sta
820.
by jccooper 12y ago
Yeah, no one else has made any announcements wrt re-usability. It seems odd, but I guess that's why they call it "dino-space". Ariane 6 seems to be in response to the SpaceX challenge, at least; they aim to halve the cost per
821.
by jccooper 12y ago
Probably not. You only need a few seconds of propellant for landing: a mostly-empty stage weighs much less than a full one, and even one engine is enough to slow it down real fast. I've done some really rough guess-numbers before, land
822.
by jccooper 12y ago
Weeks mostly have to do with the market cycle, which has been anywhere from 4 to ten days depending on the local economy. The Chinese in particular used 5 or 10 day weeks for quite some time. That works better for lunation than 7. The seven
823.
by jccooper 12y ago
Half a foot, six inches. Third of a foot, four inches. Quarter of a foot, three inches. Sixth, eighth, and twelfth also go into whole inches. For bigger projects, yards are fairly easy to decompose too, into whole feet and inches. It's
824.
by jccooper 12y ago
It was the whole town in 1901, which is about the eastern third of the island, but not the whole island. The seawall goes to about 7 Mile Rd; past that it's the natural height of the barrier island--which is not much. The end of this v
825.
by jccooper 12y ago
That's about entirely backwards. Flinging a metal tube off of Earth is much harder than keeping a few apes alive in a can. The tolerances and requirements in rocketry are much more severe, the dimensions unfortunately super-human scale
826.
by jccooper 12y ago
Up to 12G is okay, in a proper body position. Mercury routinely came in at 8G, and those guys were usually trying to control the thing semi-manually, since the automatic systems weren't that good. These days the monkey in the can won&#
827.
by jccooper 12y ago
I use fossil; like it a lot. If you use/would like to use fossil, you might also want to take a look at http://chiselapp.com It's a bit github-ish; online repository hosting, private or public, and free. (I'd happ
828.
by jccooper 12y ago
Curriculum standards vary widely across the US, but it's very common to require some foreign language learning. Only a few states (mostly midwestern) have no requirement, but even there it's basically required for college applicat
829.
by jccooper 12y ago
The post-Grasshopper "F9R" testbed has flown with these before. You can see it here: https://www.youtube.com/watch?v=DgLBIdVg3EM
830.
by jccooper 12y ago
Well known as "pumped storage". They're competing with it, but dry and upside down. Is it more economical? Maybe. Is it safer? See http://en.wikipedia.org/wiki/Taum_Sauk_Hydroelectric_Power_S... At least
831.
by jccooper 12y ago
There is a brief mention of efficiency, but that doesn't seem to be a big point. The port structure does make me think it might be a bit dirty--kinda two-stroke-y. But not all engines go in cars. Might be a nice one for aviation--thoug
832.
by jccooper 12y ago
Detroit uses a property tax assessment system, like many (most? haven't checked) states, that is based on "fair market value". However, a foreclosure sale doesn't count (in their eyes) as a "fair market" sale.
833.
by jccooper 12y ago
I doubt the article is being precise, first, and might use one for the other. That said: ignition means the electrical system that fires the spark plugs. Starter is the motor that starts the mechanical bits moving, so the ignition can do it
834.
by jccooper 12y ago
See also: http://www.americanprairie.org/ -- an effort to link public and private lands to create a 3 million acre preserve of the Great Plains ecosystem. That's pretty big, but not even close to the scale this article
835.
by jccooper 12y ago
Somewhere around object persistence and planning actions: I once saw a rodeo clown's dog in a comedy bit where the clown would remove something from a barrel and the dog would put it back in when he turned around. Once, the dog missed
836.
by jccooper 12y ago
Just to be clear to people not following the link: physical 3D models. But today you could also make electronic 3D models (in, say, Blender) and shoot them from various angles to get sprite images. Later 3D-looking sprite-based games did
837.
by jccooper 12y ago
Cerebrospinal fluid in this case and most; it's the general purpose volume-filler of the central nervous system.
838.
by jccooper 12y ago
What's interesting is that the reported test is from 2012. (Which they do say at the top, but didn't really register until the end.) I'm a bit surprised it was so competent back then.
839.
by jccooper 12y ago
A credit card will take something like 3% of the transaction. Thus the "cash discount" idea. And personal checks are plenty risky for fraud and insufficient funds.
840.
by jccooper 12y ago
Better that they did what they could, certainly. I expect a modern study would take into account DNA, molecular, and even RNA analysis where possible, which were not concerns at the time. (Modern sample preservation techniques have to consi

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