The Stars are not Far, Mars Mission 2071. Options

[knasser]

[Draconis]

C'mon argue more physics. I want to see digital blood.
If physics classes where this amusing I might have stayed awake through them.

[FrankTrollman]

Uh... sure.

Plasma expansion is a refrigerant. The phase shift and volume expansion absorb energy and reduce temperature.

Discuss. ;)

-Frank

[Demerzel]

I'd like to think the Physics classes I tought while working on my Masters were this fun. I don't think I'd get a majority of votes from my students however.

[FrankTrollman]

Oh, and a significant portion of energy popping out of fusion reactions does so in the form of neutrinos, which are close to non-interactive with normal matter. That means that a very large proportion of energy loss comes in a form that does not neat to be thermally dissapated - it's simply a form of radiation which passes harmlessly through your ship in equal measures in all directions.

So the heat sink problem isn't as bad as you might think for looking at the numbr of joules and the efficiency of the propulsion.

-Frank

[Demerzel]

Well first off, your statement regarding the expanding plasma would work as a refrigerant is true, however what it would be cooling is the core of your reactor and that cooling would have to be compensated by some energy releasing reaction (such as fusion) or else your core would peter out before very long…

Then as to your heat exiting as neutrino statement. Well, energy is lost from the fusion reaction in the form of neutrinos. However the efficiency numbers I used to give you a simple feasibility for your rocket were based purely on the electricity production. Basically if you’re unwilling to use a simple rocket and insist on some sort of ion drive you have to convert the heat energy generated by your energy source (fusion/fission/combustion of methane byproducts from consumption of beans) into electrical energy to create the voltage differential you want to use to accelerate your reaction mass.

Without even talking about the efficiency of your fusion process, just the heat engine necessary to run your power generator has an efficiency limit. The Carnot efficiency is the maximum possible based on thermodynamic principals. Basically if I give you for free a 50% efficient generation process I’m being extremely generous. So without even considering the unusable heat generated in your fusion core (for example those nasty neutrons that cannot be contained in your magnetic bottle because they are neutral and turn your stable isotopes in your ships hull (or your body) into radioactive sources.

Frankly I basically spotted you a fusion rocket with a core as hot as the sun and you said I was being unreasonable. Where in fact if you had that we’d be regularly flying to Saturn to bring back Ice from the rings to use as reaction mass because that would be freakishly amazingly efficient as long as you don’t want to do it all in one day…

The key resource that will allow space travel in our solar system is patience.

[Draconis]

Ah there we go.....

[Garrowolf]

okay so the physics lesson was interesting but I thought I might point out something.

If the whole point of going fast was having to do with the comfort of the crew then I can think of a better solution entirely within Shadowrun tech. Just put everyone in a small centrifuge in the center of the ship in long term sleep. Then connect them to the main computer in hot sim. Make sure you have several small independant power sources so they are not in danger easily.

The actual ship may be a large rocket but for the crew it could be the enterprise d. Just give them lots of drones that they can control in VR and they can fix things. Then rotate the crew stifts with the frame rate of on duty personel varying with need of reaction so during the dull portions of the trip you experience time at a fast pace and when you are in danger it goes to normal time. You might only need a few days worth of experience to cover the entire several month trip.

That way there is no negative mental impact and you don't have to waste energy.

[hyzmarca]

If they're in artificial hibernation under artificial gravity for 6 months then they're all going to die from infected bed sores before they reach Mars. If they're in artificial hibernation without artificial gravity for 6 months then they're likely to die of heart failure the second they try to move.

The problem isn't the comfort of the crew. The problem is the massive health problems associated with low gravity environments. The heart doesn't have to work against gravity so it weakens dramatically, for example. Bones become brittle. Muscles lose mass and tone. Really, a low gravity environment is very dangerous to human health and so is 6 months of artificial hibernation.

[Garrowolf]

so you either have some sort of acceleration gel or you have some drones change the sheets. Maybe the bed vibrates to massage their butts.

Hyzmarca, it seems like you are just arguing against the possibility instead of offering alternate ideas. Do you just not like the idea of space travel or do you think it should only occur at a certain tech level where all the problems are solved?

[FrankTrollman]

Shadowrun technology provides the ability to keeppeople alive in gravity free hibernation for years - like Roxborough. Unfortunately, it is like Roxborough: your body no longer functions if you ever take it out of the zero gravity holding pattern.

I have no idea how Zero-G life extension is supposed to work, but it does exist in canon Shadowrun. It isn't part of the plan if you intend for the crew to ever accomplish anything at the end of their journey, however.

---

In general, Shadowrun movement is split harshly into the Haves and the Have-nots. On Earth, there are those able to use Movement on their vehicles and transport goods faster using less fuel and in less danger than anyone else. And then there's the people who can't and they have to deal with the fact that the oil has run out and they are stuck with methane vehicles running slow routes.

In space there are people who can afford to make and operate a fusion engine, which costs a crap tonne of :nuyen: and runs off of fuel found on the Lunar surface by Ares' mining station - and there's everybody else who has to come up with ridiculously contrived methods to keep their people alive in space at low gravity for long journeys.

That's how Shadowrun movement works. There is an incredibly limited amount of frieght that is so fast that it might as well be teleported; and then everything else is stuck moving at the slow ponderous speed of a cammel caravan. Literarily this allows players to either skip from one location to the next with what amounts to a cut and a bit of locative subtitles or make a slow and dangerous journey from one land to another overcoming challenges the whole way. Both stories can exist in the Shadowrun world because fast transport exists and yet it is limited in availability.

Not everything in space moves at the fast speed. Only the big things. The expensive things. The things that absolutely, positively, have to make it to Mars by Saturday morning.

-Frank

[hyzmarca]

[The Jopp]

Ok, I’m no-brainer when it comes to these subjects but when it comes to crew survival there are several options in SR 2070.

The Crew – Medical Solution
Submerge crew in shock-absorbing gel while wearing life sustaining suits (I’m talking a kind of wetsuit here, not a primitive 2006 space suit). Add some basic cyberware for drone control as mentioned earlier.

The suits will include smart materials and myomer muscle bundles that massage the astronauts muscles so that their bodies muscle mass does not degenerate. Then we add Bone Augmentation to strengthen the bones for the long journey and possible some plastic bonelacing as support.

An expert Autodoc system (or even better – a medically trained astronaut that takes care of the crews health AND and Autodoc that can dispense nanites and drugs that can monitor their health.

The Crew – Alternative Cyber Solution
If we go fully extreme we add fully cyborged astronauts with complete limb replacements so that they mostly need spares. This way they can also skip survival suits with massage – An artificial hearth might be good as well since the hearth muscle might be affected by low gravity for an extended time.

The Ship
As I said, I’m no Physics major (or minor for that matter so I’ll just wing it here.

What technology exists in SR4? Particle Accelerator? Fusion Plants? Ritual magic? New materials.

1. The ship has as little metal components as possible and is made of new light smart materials significantly reducing weight (new material for us but have existed for 10-20 years in SR4.)

2. Ritual Magic. Ritual Magic boosts the ship up into the upper atmosphere where it ignites booster rockets (this also reduces weight.)

3. Improvements in engine design have improved fuel economy of booster rockets.

4. The entire crew is rigger trained to handle drones as most EVA will be done by them.

5. No actual landing will take place on mars by humans, a lander with several different drones will be sent down and/or flown over the area.

6. Solar powered High Altitude drones will simply drift over the planet and send data back to earth.

7. Every available sensor technology will be searching the planet for life.


IF a landing is to take place by human crew the cost will increase significantly and the only reason for actually taking such a cost is to se if an awakened individual can sense anything of the planets biosphere.

IF an awakened individual is going on the trip then there is extra costs in case of expert training to NOT use magical abilities in space (think about it, it’s like Unlearning how to breathe – for a mage it is a natural thing to use magic – like walking.)

IF an awakened individual is going it might be required to have a small biosphere onboard (a small area filled with plants perhaps).

IF sending down a mage then they might manage with a small one-man shuttle – thus conserving fuel and space.

Another solution might be to send down awakened animals and monitor them.

[Garrowolf]

why not a probe with that biolum stuff that glows around magic. Then send them all around on drones. Just have enough to get readings of yes/no without the risk to a mage.

[The Jopp]

[hyzmarca]

There is no need for Rube Goldberg sleep chambers when simulated gravity works just fine.

I still say with blood-god exploit is the best fastest and safest way to go about space travel in SR.


For coolness, people should land on Mars and they should be heavily armed just in case the aliens are hostile. Unmanned probes suck.

[FrankTrollman]

In 2064, there had already been at least three landings on Mars, with various levels of secrecy and various numbers of humans onboard since the Awakening. Project Discovery (NASA), Project Cydonis (Ares), and Project Tereshkova (Yamatetsu).

In 2070, Evo has a permanent base on Mars.

In 2071, getting to Mars has never been easier.

-Frank

[Demerzel]

Easier than ever it may very well be, but a weekend trip it is not.

A 6-month trip is also long compared to what I’d expect out of SR4 level technology. A low-energy transfer orbit will take something like 18 months. The Mars Direct Plan calls for a high-energy transfer orbit that will take 6 months. If you maintain constant acceleration with a reasonable value (more like .01 to .04 g rather than 1g) you can shorten that significantly.

I’m not prepared to take the time necessary to calculate this kind of thing, it’s not a time commitment I’m willing to take on for a DSF argument, besides it’s not like Frank would believe my calculations anyhow. But be a little conservative in your estimate and say it would take 1 to 2 months, the health problems aren’t nearly as huge and likely can be mitigated with SR level medicine, and you’re not abusing science like a red headed stepchild.

Plan ahead and you can send important things like landing craft and extra reaction mass ahead of the trip on a low energy orbit. But let’s consider the past 50 years of advancement in space technology and project that ahead, with a fracturing of nations worldwide global strife and all the problems associated with that . . .

[FrankTrollman]

If you are going nuclear at all, and you can do it at .1 G, you can do it at 1 G.

The problem with increasing acceleration is that 10 times the acceleration requires 10 times the energy per kilogram for your journey. That means that you need 10 times the fuel. For a chemical propellant, that's a big deal, because the fuel is the vast majority of the mass. So you need 10 times as much fuel per kilogram and have almost 8 times as much mass and that needs 10 times as much fuel and so on and so forth - ithere's non-fuel mass in there so it doesn't go to infinity, but the total fuel requirements are impractically large.

But Nuclear drives don't work that way. The vast majority of the mass is the reactor itself. The fusionable materials are measured in kilograms, not tonnes. Putting in ten times as much fuel just means you can't take quite as many ham and turkey sandwichs, it doesn't mean that your vehicle is some whole number more massive overall.

That's the breakpoint. Once fuel to get energy out of isn't the primary source of mass, acceleration is pretty much arbitrary all the way up to the point where you'd kill the crew.

Nuclear engines propel the USS Nimitz through water on less than two kilograms of fuel per day, and that's fission. It's 100 tonnes and was built in 1975, I'm sure that in 100 years there has been some progress in this field.

The basic rocketry nightmare - that faster acceleration needs more fuel which means more mass which means more fuel which means more mass.... does not apply to a nuclear engine in any meaningful way. The engine is massive, expensive, and technically difficult. The fuel is expensive, rare, and dangerous - but the fuel isn't massive. It's man-portable if it for some reason came to that.

If you can keep a submarine moving around under water for five years, you can keep a spacecraft going at 9.8 m/s^2 for five days.

-Frank

[kzt]

[Demerzel]

Wow, I can’t believe you still believe that after all this…

[Butterblume]

[Demerzel]

[knasser]

[FrankTrollman]

Yes, those are kilotonnes, not tonnes. Sorry, it was supposed to be ktonnes. Sigh.

Anyway, Nuclear Fusion is a state function. The path to completion is irrelevent and the energy output is the same regardless. Maybe the entire reaction is kept in magnetic containment and ejected whole out the back? Maybe the emmitted photns are collected by a pigment and then released as lasers out the back? I don't know.

I don't even care, because fusion power is not possible with the technology of 2006 and it is possible with the technology of the 2070 awakened world. The energy put out by the reaction is predictable and known based on the stability of the isotopes at the beginning and the end. And that energy is many thousands of times greater than what is needed to propel thee craft across the divide of space.

1G isn't a big deal. We can do better than that with our knees, and we do very time we climb stairs. The big deal is maintaining that kind of acceleraton for long distances and time periods. But seriously, when you're using nuclear power, the long time frames and distances are of no concern. The Sun has maintained for billions of years, performing the same reactions for dozens of hours is not the technical hurdle.

-Frank