Show off your Knowledge of Experimental Rocketry

#1

I’d post this in a question thread, but anyone who does know the answer would be uber awesome anyway so I’ll ask for people to show off their knowledge. Anyway, to my question:

I’ve been looking into space propulsion technologies as part of research for a script I’m writing. Mars missions, particularly manned ones, are prohibitively expensive and very long- it takes months, if not years, for a manned mission because current gen rockets are inefficient and unwieldy to time the precise gaps necessary to make a Mars shot.

Enter the VASIMR design. It’s a really neat idea, and supposedly it could make a journey to mars in about 40 days, which beats the ever living shit out of current gen rocketry. Problem is, it only works in orbit.

The circumstances in my screenplay dictate a launch from a lunar based Linear Induction Motor to act as the first stage, using a track that runs a long distance on the Moon’s surface. The question I want to ask though, is not about the mars journey itself but the power sources of this rocket and the LIM track.

One of my characters has a tracker in her blood stream that the bad guys have been using to chase her down with. The good guys need to get it out, so the plan is to expose the tracked character to a heavy duty electromagnetic field to fry the circuitry in the tracking device. They can’t just cut the tracker out of her because it’s blood-borne and decentralized, and they’re on a mining barge so a dialysis machine isn’t practical to get. Could they utilize the EM fields generated by a VASIMR rocket or a magnetized track rail to disable electronic devices, without frying the character in the process?

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#2

“One of my characters has a tracker in her blood stream that the bad guys have been using to chase her down with. The good guys need to get it out”

A mining ship would have a ton of medical equipment due to the nature of it’s operations. Look into Intra-operative autologous transfusion using a Hemobag that filters the blood and returns it to the patient clean. Check it out here: http://www.mybloodfirst.com/

Perhaps you could use something like what North Korea uses for your launch:

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#3

http://www.mybloodfirst.com/hemobag/how-the-hemobag-works

Interesting tech. How common is it in today’s hospitals?

The mining barge in the script is pretty decently stocked, but good tech of any sort is tough to come by because the earth got nuked to hell. The spaceships, colonization tech, rocket tech, guns, are all pre-war. There’s new robots, but a lot of that is based on tech from pre-war, and an immense brain drain resulted because a huge swath of the population was killed in the war.

I’d looked into stuff they carry on spaceships- exercise equipment is a must to keep decent muscle mass for the journey, there’s been games of zero-G basketball, that sort of thing.

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#4

If you’re going to go to Mars in 40 days, then you’re going to be traveling pretty fast at certain periods of the trip (the middle- since you’re continuously accelerating halfway and decelerating for the other half). This is even more relevant if you have an advanced ship that can travel at 1G during the whole trip- you’d get there between 1.7 to 4.6 days (depending on how far away mars is from Earth at the time). Still, constant acceleration travel is pretty much the holy grail of STL travel- master that and the solar system’s yours.

Because you’d be going extremely fast in the middle of each trip, you’d need protection from everything- mere hydrogen atoms can be extremely dangerous at these speeds if they impact the ship. One possible solution to this is using magnetic fields to divert those pesky stray particles away. The shields would need to be positioned away from the rest of the vessel so they don’t screw up electronics on-board.

These magnets would take lots of energy to run, so you need a reactor of some kind to power them.

If you do choose to shield the ship with magnets, you could send your character, in a space suit, out of the ship to float next to the magnets. They’ll get the job done, believe me. Just make sure the suit doesn’t have magnetic materials in its construction, and attach them to a rope or line of some kind so they can be pulled back in: The magnet will screw up the electronics in their EMU (extravehicular mobility unit). Hopefully, you have some spares to replace it. At least the tracking device (however it sends off its signal…) will be rendered useless.

Also (and this may or may not be true depending on the design of your ship), you can’t do the EVA during 1G acceleration, since they would “fall” right past the ship! In your case, this may not matter since you’d be going anywhere between .01G to .002G. As long as you hold on to the ship, you’re fine. If this was a movie script, this would be one of those scenes where your character has to exit the ship to do something risky- all good sci-fi movies have an EVA scene. :slight_smile:

P.S. If you choose a 1G ship design, and there’s no time to do it before you leave, and there’s no way to easily hold onto the ship when you’re heading towards the magnets, then you could do it mid way- there would be a brief time where the engines stop and the ship turns around. This would make the EVA very risky, adding lots of tension- if you wait too long to start decelerating you’ll overshoot past Mars!

Then again, you could just wait until you reach Mars. Problem solved!

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#5

I’m assuming by “1G” design you mean artificial gravity generators. I decided to forgo those since there’s no currently feasible way to design an artificial gravity generator. You can use weights in your shoes or an electro-magnetized floor to walk, but it would put unnecessary drain on the ship’s power. Most of that power is going to have to go to the engines to get to Mars in 40 days. In the script I’ve got a handrail system for people to get around in low/zero G. Some of them can move in the tracks, others are just handrails with grip patterns on them for something stable to hold onto.

As for the craft design, I haven’t drawn it yet. The prototype VASIMR in this video seems to have some kind of “solar sail” like setup. That would be tricky to get an EMU past the sail without catching it on something.

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#6

1G = Earth standard gravity. 2G = twice Earth standard gravity. Etc. He means the ship is accelerating fast enough for the pull towards the back of the ship to equal standard Earth gravity.

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#7

The concept of 1G travel is simple:
First, you point the craft in the direction you want to go, and you accelerate at 9.8 m/s^2 until you reach the halfway point (actually, slightly before the halfway point to make room for the next step).
Second, you turn the craft 180 degrees so that you point away from your intended destination.
Third, you decelerate at 9.8 m/s^2 until you reach your destination.

The concept incorporates high-speed transportation with artificial gravity. It allows you to move around the entirety of the ship in simulated gravity (as opposed to using a centrifuge, which limits the simulated gravity to the spinning part of the ship), and it is much closer to present-day technology than energized simulated gravity fields.

Funny enough, it’s something I came up with independently before finding out that others had come up with the idea.

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#8

Hm. Perhaps they could make a smaller Dyson Sphere type craft with a floor that rotates independently of the engine array casing. Accelerate to 1G in whatever way is needed, and the floor will go to the direction necessary for riders to enjoy the benefits of Earth gravity with ease. That’s actually pretty fucking sweet.

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