(Much busy, so here's a descriptive tidbit to tide you over).
At first sight, the Lupine resembles nothing so much as a junkyard sculpture of a horseshoe crab. The ship is so huge that the fine details are lot once you're far enough away to take it all in.
Originally a combination colonization/freighter/carrier vessel, one of three in the United States Space Force fleet, built back when the vacuum tube was king and the only power source up to the job of folding space to outrace light was not one but five modified Navy-type nuclear reactors,[1] it was intended to pursue the fleeing ships of what came to be known as the "Far Edge" after they swindled the USSF out of their planned Lunar missile base. By the time she was complete, it was already too late, but USSF had to find out the hard way. "Better safe than sorry," especially when your quarry possesses the means to wipe out the Earth several times over.
That, as it turned out, was never the problem. But it was a heady time, when the "black" budget swelled to unaccountable levels and a trip to space was, like as not, one-way journey. Very few people have realized that the primary goal of Project Mercury was perfecting reentry techniques: a late-1950s squirt-booster would get you to Earth orbit and beyond but landing on a celestial body was a much trickier prospect; the airless Moon allowed for "bounce-down," cushioned by JATO[2] units and vast airbags but return to Earth was problematic, as the Sgt. Snodgrass Crater in Nevada testified.
At closer range, Lupine is more "junkyard" and less "arthropod," a collection of various sized structures interconnected by corrugated tubes, vast M.C. Escher arrays of scaffolding and a myriad of random what-is-its, shoved along by acres of MHD and ion rockets underneath.
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1. "How did they condense the working fluid and shed waste heat?" you ask, and considerin' that USN has entire oceans (or at least seas) to cool theirs, it's a good question. The answer, like a lot of things from the early days of the USSF, is unsatisfactory. A lot more water in the loops plus vast radiating area, for one thing; and the even more vast framework of the ship to heat up, as well. At full steam on a long jump, this meant things were...toasty...aboard at the end of it. They'd make orbit and shut as much down as possible, shining brightly in the infrared. Not at all stealthy but in a fighting-type situation, the .mil squirt-boosters would have been dropped off shortly after returning to normal space and before deceleration, so they'd be moving at an appreciable fraction of the speed of light, while the carrier vessel lagged behind.
2. Some readers want me to say "RATO" but here's the deal: we're talkin' about folks back In The Day who had just finished whuppin' Nazis. Germany had RATO units, fueled by flesh-melting T-Stoff; the United States had JATO units, running on good ol' American know-how (also solid rocket fuel). The Brits had real jet engines in theirs but in any case, JATO is what the USSF boys called 'em and so will I. Wikipedia says we're right enough.
BUILDING A 1:1 BALUN
4 years ago
17 comments:
You mean... those hammers didn't really cost $500.00?
You are weaving a fine yarn, dollface. This post might make the basis for the opening chapter of your novel.
D.W., most of those stories about the military vastly overpaying for parts and supplies were media distortions. Shocking, eh? My favorite media story was the one for the (IIRC) $1,000 coffee pot. What the MSM left out, was that it was a 400 cup coffee pot for the C-5.
Sam,
Yes, and the "$10,000 Toilet Seat" was actually a fiberglass port-a-john that was adapted for use in a long-range bomber.
Washington Post cartoonist Herblock used to hang that toilet seat around the neck of Defense Secretary Caspar Weinberger every chance he got, like Minnie Pearl and the price-tag on her hat.
If she's powered by navy style nuclear reactors, I have to wonder how heat is dissipated. If you stay, roughly, with a Navy style layout, you have primary coolant (water) moving through the reactor, heating up then moving to the steam generator (just a big heat exchanger) where the expansion medium (also water) is heated to steam, cooling the coolant, and then the steam goes off to spin turbines and do other such useful functions.
But I've always wondered if a spaceship running a large nuclear reactor could effectively condense the expansion medium without access to a heat sink, like a lake or ocean. Seems radiating would be problematic at best, especially in warp/jump/etc.
Any thoughts?
the "black" budget swelled to unaccountable levelsKind of goes without saying. "Unfathomable" might be a better word, but we're even jaded to that, with our trillions being batted about.
The strap-on re-entry gear of the Mercury program, I'll have you know, was made by a wholly owned subsidiary of the Studebaker Corporation, famous retailer of buggy whips.
"If she's powered by navy style nuclear reactors, I have to wonder how heat is dissipated."
I'd think that with enough copper pipe and cooling fins, the interstellar void would be good for cooling.
Of course, I R not a fizzisist so, failing that, they could just pump the water through the McGuffin.
(I know that some satellites use nukyular reactors. Now you've got me curious... What do they use for coolant?)
The "reactors" on most spacecraft aren't the typical "boil water -- spin turbines" type. They are thermo-electric.
That is they use an array of thermocouples to create current. IOW, heat is good.
In space, fins don't help, because they just radiate to each other, and there is no convection. In addiction, if they are facing the nearest star, the radiators tend to get hotter, and actually hinder cooling.
The space suits evaporate, uhh, something (ammonia?) through a porous plate to stay cool.
Something as big as the Lupine, as close to the sun as Earth is gonna be a real bitch to keep cool.
Ok, now a challenge for some artistic type out there...make an illustration based on Roberta's description.
Why not me do it?? 'Cause art is not one of my few talents.
I love your Lupine stories. But you might want to change them to RATO (Rocket Assisted TakeOff) from JATO (Jet Assisted) for vacuum use. I'm obsessive compulsive. Sorry
"In space, fins don't help, because they just radiate to each other, and there is no convection. In addiction, if they are facing the nearest star, the radiators tend to get hotter, and actually hinder cooling."
Huh. I did not know that. Now I'm going to have to go read about temperature control in space...
Learning new stuff is fun! :)
Yeah, heat dissipation is one of the, if not THE, largest problems in designing large spacecraft.
Also, I have to wonder how the Space Force made the whole fuel/mass ratio of surface to orbit flight economical enough for either colonies to have surface to orbit capability or for a ship to carry boosters and fuel for ferrying.
Or maybe I'm just geeking out excessively, sorry.
Also, you beat me to the thermo-electric plants. I wonder if we'll ever increase their energy/volume/mass ratios enough to make them really useful in manned spaceflight.
Surface-to-orbit is easy -- a squirt-booster uses a pulsed FTL drive, which works perfectly fine even with crude computers and control, as long as the direction of travel is away from the planet; you can correct for errors without slamming into the ground. It's the other direction that's a problem. (Or, rather, it was until fairly recently). And this is why the Far Edge became a mostly space-based culture; they "seed" planets with their excess population.
"in space, fins don't help"
Hm. That would be a huge disapointment to the hundreds of orbital objects that are cooling themselves in that precise manner.
Cooling fins dissipate heat by radiation. it's not as efficient as conduction or convection, but it does work. As is evidenced by that big shining ball in the sky that we're beginning to see these days. The composition of the fins makes them radiate heat at the infrared, while they reflect the solar energy that is pumped at them. A good friend of mine makes a pretty good living designing, testing, and implementing this very system, and the radiators are aluminum tubes shaped like a theta in cross section. Most of the sats you know of, and all the ones you don't, are cooled by this method.
There's fins and fins. What most people think of -- the things on a motorcycle engine or a bit of high-power solid-state electronics -- are designed to work by heating up the air flowing over them (and there's a whole wold of high-level geekery devoted to optimum shape, flow-rate, mass and so on), while the ones used by spacecraft are very different in form: they work better if they are not radiating to one another.
The original-config Lupine carried the resemblance to a horseshoe crab even there, with a set of radiators that resembled the arthropod's book-lungs -- plus a set along the stinger, for the rear two fission plants, making it cruciform in cross-section for about three-quarters of its length. These days, that set's gone, leaving the "book lungs." The fusion/MHD plants that replaced the Navy-style piles provide some of the reaction drive and eject heated material, too. Plus they produce less waste heat.
Heat schmeat. There are materials made to withstand both extremes and the vacuum of space is a good way to keep it from being where it isn't supposed to be. The critical issue isn't heat- you need to generate that, and once generated, why needlessly throw it away? Unless you need to cool something down for service, an object in space which sinks heat can simply stay that way until the energy stored as heat needs to be used.
Other satellites use sandwiches of radioactive material with "solar" cells. Living in an atmosphere, we get kind of hung up on "heat cycles," since the expansion of gases is easy to achieve. In a vacuum, there are other ways of making and using power than just heat management.
NASA Facts in 1965-66 had several good articles on fins in a vacuum, as the research was being done. They should be available somewhere other than my desk drawer.
For your googling pleasure.Jim
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