Nyrath
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Posts posted by Nyrath
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Re: NASA plans 'Armageddon' spacecraft to blast asteroid
That just points out that nothing is sure but death & taxes...
And taxes are worse, since death at least does not happen to you every year.
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Re: NASA micro-satellite eyes space bacteria
You want that in alphabetical order' date=' or in order of probability?[/quote']and each and every one is a plot seed.
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Re: Planetary Distribution
My question: Is this the normal arrangement? Do we know enough about extrasolar planets to know whether other solar systems share this structure (terrestrial planets in close' date=' Jovian planets farther out)? Do the mechanics of stellar- and solar system formation favor this arrangement? Or can there be gas giants intermixed with the smaller rocky planets? (Okay, so that's four questions, but you get the idea.)[/quote']The original conventional wisdom among astronomers was that gas giants only form in the outer solar system due to the heat and radiation from the central sun driving off the hydrogen which is a gas giant's main component.
Then they started detecting lots of extrasolar gas giants that were exceedingly close to their primary star. Now the question is open.
I saw one theory that while gas giants may only form in the outer solar system, the chaotic process of solar system creation might nudge a gas giant into a closer orbit.
Bottom line is: nobody knows.
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NASA's Marshall Space Flight Center has designed a nuclear-warhead-carrying spacecraft, to be launched by the US agency's proposed 's Ares V cargo launch vehicle, to deflect an asteroid that could threaten all life on Earth.
Interesting design. Should be easy to translate into a Hero system vehicle.
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NASA is preparing to launch a tiny satellite loaded with yeast and anti-fungal drugs early next month in order to better understand how bacteria becomes nastier in space.
http://www.theregister.co.uk/2009/04/29/nasa_pharmasat_mission/
Waitaminute. Am I the only one who is thinking about Project Scoop from the movie THE ANDROMEDA STRAIN?
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Re: Mercury hides a monster impact
Fascinating. Thanx for the post' date=' Nyrath![/quote']You're welcome!
This Just in: Mercury More Exciting Than Mars
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http://blogs.discovermagazine.com/badastronomy/2009/05/03/mercury-hides-a-monster-impact/
"How the heck do you hide a terrifyingly huge impact basin easily big enough to stretch from San Francisco to Los Angeles?"
"Easy. Put it on Mercury."
What caused this impact crater?
An ancient alien battlecruiser colliding with Mercury? (and is it still there, buried under the surface, just waiting for some adventurers to stumble on the entrance?)
How about the asteroid-cell of some imprisoned Cthulhu-like eldar space god? (and is it still there, buried under the surface, just waiting for some foolhardy adventurers to fail to decipher the "DO NOT OPEN!" alien inscription on the door?)
What if it was just an asteroid colliding with Mercury, which is the only known way of creating large deposits of priceless Unobtanium ore?
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Re: Where can we live??
Also' date=' habitability and alien life are two very different things.[/quote']Also note that "habitable" means "Human habitable".
Earth is the ultimate example of human habitable, but it would be very uninhabitable to the organic hydrogen dirigibles of Jupiter or the living lava of Mercury.
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Re: Where can we live??
from http://www.eldacur.com/~brons/NerdCorner/StarGen/StarGen.html
The definition of "Unbreathably thin atmosphere" and "Unbreathably thick atmosphere" are based on Dole. He gives 72mm of Mercury as the minimal inspired partial pressure of Oxygen. I've therefore used it as an absolute minimum total pressure in the descriptions. He gives 8 atmospheres as the pressure at which turbulence makes it impossible to inhale.The rest of these labels are arbitrary and I'll happily change them if anyone can suggest better values.
In order to evaluate the breathability of the atmosphere, I took a formula from Dole to calculate the inspired partial pressure for a gas. I used this to compare each of the gases from Keris's model to the maximums and minimums listed in Dole. This allows me to categorize a planet's atmosphere as breathable, unbreathable (too little oxygen) or poisonous.
Dole's HABITABLE PLANETS FOR MAN is a bit dated. However, it is available as a free download here:
http://www.rand.org/pubs/commercial_books/CB179-1/
The current recommended book is World Building by Stephen L. Gillett
http://search.barnesandnoble.com/booksearch/isbninquiry.asp?ISBN=158297134X
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Windows software, sort of a solar system simulator. Not directly useful to a campaign, but you can use it to make some killer eye-candy as campaign window dressing.
"...and now players, after you've hacked into the Imperial computers you see the following classified file {runs Universe Sandbox simulation their computer}. My goodness, it's a simulation of the MacGuffin System. Oh, no, what's happening to the planet orbits? Yikes, its a black hole! Now players, what are you going to do with this explosive information, hmmmm?"
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Re: Hard sci-fi adventures?
Warning: Geek-talk starting...
What acceleration do you expect the engine to be able to develop? Alternately' date=' what are the mass of the ship and the thrust of the engine? For reference, the Shuttle orbiter's maximum landing mass is 100 metric tons. I am having a hard time finding masses for lightweight reactors at the moment.[/quote']A VASIMR in "low gear" (i.e., increase the thrust at the expense of the specific impulse) will produce a (pretty wimpy) 400 Newtons of thrust per engine with a specific impulse of 2,300 seconds. In "high gear" (low thrust + high specific impulse) it produces a (even more wimpy) 40 Newtons per engine with a specific impulse of 30,000 seconds.
Low thrust is only a concern in two situations: take-off/landing and dodging during combat. Which means that the VASIMR is great for interplanetary exploration but lousy for combat. Perhaps some auxiliary chemical rockets can be added for combat (by comparison the Space Shuttle's chemical rocket main engine cluster produces a thrust of a whopping 7,000,000 Newtons with an abysmal specific impulse of 440 seconds).
For an advanced nuclear power plant, figure about 0.493 kilograms per kilowatt produced. One VASIMR engine requires about 10 megawatts which is 10,000 kilowatts. This would make the power plant about 5 metric tons.
What do you expect the endurance of the ship to be' date=' and where does it get restocked?[/quote']If the ship has a closed ecological life support system, in theory the crew will have food and oxygen forever. In practice the system will probably not be 100% efficient, and the crew will revolt if fed a diet of green slime algae for months. In that case, figure on 2.3 kilogram of food per person per day (i.e., with 10 people, it will be 23 kilos per day).
If you want a spartan habitable area, figure on ten cubic meters per person. This is incredibly cramped. A more reasonable allowance is 17 to 20 cubic meters per person. So 10 people x 20 m^3 = 200 cubic meters. This could be a cylinder 7 meters long by 3 meters in radius.
However, having said all that, this is probably more geeky detail than your average Star Hero campaign needs.
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Re: Hard sci-fi adventures?
I've also been thinking up an early military spacecraft design. How does this sound?The spacecraft will be slightly larger than the space shuttle. It will have a maximum crew of ten. The crew will have to strap themselves in their seats while moving. The seats are always facing forward, so they'll feel the acceleration pressing against them.
The engine will be a fission-powered VASIMR drive. The main engine will be aft, but there will be smaller thrusters along the other sides of the ship, including "top" and "bottom" to aid in course correction.
The crew will be composed of a pilot/commander, co-pilot/XO, engineer, navigator, radioman/electronic warfare officer, and 2-3 gunners. A doctor may or may not be on board.
The spacecraft is armed with two missiles, a railgun, and four autocannons. The railgun is stationary and pointed forward, while the autocannons can swivel 180 degrees in the "up-down" and "sideways" axes. The missiles are also launched forward, but they can be guided by a gunner. The main engine is used to counter the change in momentum caused when the missiles and railgun are fired, while the thrusters are used to counter the change in momentum caused when the autocannons are fired. The railgun has a limited amount of ammunition and thus can only fire a few salvos.
The spacecraft has a range from Earth to Mars.
Not bad. There should be an officer who also has to maintain the hydroponic farm in life support and/or the life support system.
Just be sure you have enough crew so the ship can be adequately manned while some of the crew is sleeping.
A real-world VASIMR could do Earth-Mars in about a month, but you can adjust that a bit up or down depending upon your campaign.
Keep in mind that while under thrust "forwards" will seem like "up", that is, the direction the exhaust is traveling is the direction of "down".
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Re: Hard sci-fi adventures?
That's important to remember. Would suppressors help?Yes. This applies to firearms as well, the metal spaceship hull will add the echo chamber effect. Cut lose with a submachine gun, and your ears will be ringing for a long time.
This could count as "flash vs. hearing"
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Re: Hard sci-fi adventures?
If you are inside a spacecraft, shaped charges will damage the hearing of everybody without earplugs. They are hard on the ears in the best case, the interior of a metal spacecraft is going to be an echo chamber that will magnify the damage.
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Re: Hard sci-fi adventures?
Sorta like firemen use to cut people out of cars?Exactly. Except a bit more compact so one person can carry it.
One would think that whipping one out and waving it at your opponent would count as a presence attack.
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Re: Hard sci-fi adventures?
I seem to remember a novel by Harry Harrison that featured weapons like this. They were like giant scissors. You carried a couple on your belt.In combat, you'd try to attach one to your opponent's arms or legs and hit the "on" button. Your opponent would abruptly become less interested in attacking you and more interested in removing the weapon before it snipped off their leg.
It is apparently in the anthology Body Armor: 2000 (ed. Joe Haldeman), and it may or may not be by Harry Harrision.
"drillgers" -- Diamond drill with gas vents to propell it forward
scissor-clamps -- hydraulic scissors designed to cut your leg off -- slowly.
swords and axes -- each with propellants to move the blade by reaction as well as force of arm
cattle-prods -- electric shock (useful only against non-insulated suits)
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Re: Hard sci-fi adventures?
Shoot' date=' why not big Clamps with electric moters....attack to foe, and let'er rip! (or umm crush...)[/quote']I seem to remember a novel by Harry Harrison that featured weapons like this. They were like giant scissors. You carried a couple on your belt.
In combat, you'd try to attach one to your opponent's arms or legs and hit the "on" button. Your opponent would abruptly become less interested in attacking you and more interested in removing the weapon before it snipped off their leg.
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Re: Hard sci-fi adventures?
Air has considerably lower viscosity than water; I'm not sure how really relevant this is.Well, it does share the enhanced difficulty with Newton's Laws that one finds in a microgravity environment. For instance, in both cases, the combatant who has a solid object to brace on has an advantage over a free-floating combatant.
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Re: Hard sci-fi adventures?
OK' date=' that's an objection that makes sense... weapons would have to be one-handed so you could get a grip with the other hand on something bolted down. Freefall melee combat would be a rather unique skill, I think.[/quote']Somebody mentioned that one can use similar tactics to the ones used by, say, US Navy SEALS for hand-to-hand combat underwater while wearing SCUBA gear.
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Re: Hard sci-fi adventures?
Um... huh?Have you ever seen what a sword or mace or axe does to unprotected flesh and bone? You think a flexible skintight garment is going to protect someone from that?
Well, there is also the minor matter of using such a weapon in free fall. As you draw back for the strike, Newton's Laws will make your body rotate in the opposite direction. This is why a hammer is incredibly difficult to use in free fall.
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Re: Hard sci-fi adventures?
You are assuming current-standard pressure suits here; there is also the "skin suit" or "space activity suit" concept. Granted' date=' this approach is not without problems as well - they would need to be individually tailored to specific users, even more so than pressure suits. Then again... I have a faint recollection in the back of my head of a story in which skin suits were refined to the point of being the standard basic spacer clothing, needing only gloves and a helmet for basic vacuum protection.[/quote']Yes, also know as the "Mechanical Counter Pressure Suit".
http://en.wikipedia.org/wiki/Space_activity_suit
http://www.marssociety.org.au/marsskin.php
http://www.projectrho.com/rocket/rocket3m.html (scroll down to "Mechanical Counter Pressure Suit")
The story you are thinking about is probably one of the Honor Harrington novels, but it also appears prominently in "Tinker" and EXILED TO GLORY by Jerry Pournelle.
http://en.wikipedia.org/wiki/Spacesuits_in_fiction#Skintight_spacesuits
Pournelle notes that such suits might be improved by a loose overall. This is because such a suit is about as modest as wearing a coat of paint.
Ripsaw MS1 Like Laumer's Bolo
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