stutterwarp tech

[jcrocker]

Greetings all - I am trying to design a small unmanned drone that would be placed in deep space [or fly itself out] a light month or a light year from a system. It would watch the skies for a while, and then come home.

Here are some questions of a technical nature that I would appreciate some feedback on.

1. The smallest stutterwarp drive in the Naval Architect's Manual is 0.01 MW, or ten thousand watts. Are smaller drives available, or is 0.01 MW the smallest you can make a drive and still have it work?

2. Can unmanned drones come to 'all stop'? I tend to think no, but I want to be certain.

3. Say a ship parks one of these drones a light-year out, and the drone is supposed to sit there for a few months or a year, watching the skies. Can the drone fire up its own drive system a few months later when it's time for it to go home, or must it have the stutterwarp drive active the whole time? If the latter, I'm assuming that it can hold the 'cycle' rate low enough to make effective stellar observations.

3b. If the engine must be active, what is the longest time it could sit and 'idle' without suffering breakdown? A month? A year? And would it have to idle at full power the whole time?

Any input would be appreciated.

Jon

 

[mike wightman]

What you need are the "anatomy of a missile" rules - the design of stutterwarp missiles and drones.
It's in an issue of Challenge...

One thing though. If the drone is too far out then an incoming stutterwarping ship will be able to beat the drone back to the home system by the time the drone has detected it.

 

[mike wightman]

Found it, issue 36.

Power plant and drive are one quarter of the normal size (and yes, 0.01MW is the smallest).

Cost for the power plant is one tenth, cost of the stutterwarp is one twentieth of listed ship mounted costs.

 

[jcrocker]

Ah, thank you, I'd forgotten about that article.

That answers question 1, but leaves the others.

And come to think of it, if you must have the drone in 'park' for a year with the engine running, I don't know if I'd want the cheapest version of the drive, maybe I'll cut it back but not so much as the article suggests.

 

[mike wightman]

Yeh, the problem with the missile drives is that they are only meant to last for a few hours at a time.

As to drones coming to an all stop, they can in Star Cruiser. A ship, missile, or drone can opt not to use any of its movement allowance.

The problem is T2300 still suffers from a lack of 21st century computer capability. Limited AI drones should be possible IMHO.

 

[mctesla]

Is this intended to be an early warning system, or a Sentinel ala Invasion?

 

[GJD]

If it was an observatory, or an early warning platform, then it could theoretically stutter out to the limit and power down the drive without taking it offline. Any charge built up on the coils would probably slowly dissipate over a long period of time, even without a gravity well of the required ammount (as no object can hold a charge indefinitly

)

If the platform enters a solar orbit, in the far reaches of a system, it could theoretically stay out there for years without using its main drives, after all we have probes that whiz around our solar system for years with much lower tech levels.

In deep space it still has to run station keeping maneouvers to remain in one point, as gravity from local stars will still affect it, even if only minutely, but these could probabluy be done with low powered thrusters, ion jets or somesuch system.

However, if you want to 'anchor' it in one spot, effectivly fighting against gravity, closer in to a system then stutterwarp will need to be running.

Stutter drives can be run for station keeping purposes in a planetary orbit, and effectivly discharge as quickly as the charge builds up. This probably wouldn't be the case in the out reaches of a system, so you'd need to calculate the 'effective distance' travelled to calculate how much charge would build up. I Imagine calculating the gravitational attraction at a given distance, and then converting this into acceleration, then comparing that to the 'speed' of the stutter drive could wield some sort of ratio for working out how 'far' a day or month's worth of station keeping activity would equate to.

G.

 

[jcrocker]

I've been working on an idea for the last few weeks for an early warning system for radiation surges - specifically Gamma Ray Bursts. With zero warning, a wave of hard radiation would sweep over a system at light speed - planets would be safe behind their magnetoshperes and atmospheres, but a lot of ships could get their electronics fried, or their crews killed.

Then the tsunami hit Asia, showing what can happen when waves hit with no warning.

Admittedly, not every GRB would be a problem. There are probably a couple every day that we don't notice, they're so weak. They've just launched the SWIFT satellite to try and learn more about GRBs, in fact.

http://news.bbc.co.uk/2/hi/science/nature/4156289.stm

The small ones, no problem - ships have radiation shielding, they can handle the 'everyday' GRBs.

But every so often would be "The Big One", like the quake in California that they statistically know is lurking somewhere in the next few decades or so. Or the wave that just hit Asia. With just a little warning...

If it were only a bunch of merchants that were at risk, probably no one would worry a great deal.

But look at it from a Great Power's point of view - with no warning, a killer wave arrives at light speed and kills your crews and fries the computers on your ships. All contact with a system is lost, and if you send a ship to find out what the problem is, you might kill that ship as well.

Without warning, you could watch as a large portion of your fleet and crews get wiped out. With warning, you send some ships to 'hide' behind a planet with a strong magnetic field, or try to 'skip' through the wave in stutterwarp out in interstellar space.

The warning drones wouldn't need to station-keep. I was thinking that you'd send a few cheap [my first model is 660 000 Lv] drones out. They'd take position themselves a couple light-months to a year outside the system, come to 'all stop', and wait until their radiation detectors read a GRB or other threat over some threshold value.

If they pick up a threat, they power up and fly home. They give at least a couple month's warning, even with cheap 'old commercial' drives.

I don't see much need for a sophisticated AI program on the things - the programming would be fairly simple for a society flying fusion plants into combat situations. Anything below level X gets recorded and ignored, anything above and it flies home.

Yes, they'd need to be maintained, but it would be a celestial equivalent to the Coast Guard keeping navigation buoys in working order.

Jon

 

[aramis]

I'd say the whole issue of the missile drives is one f the powerplant, more than the drive itself.

 

[mike wightman]

I've just thought of a problem.
The stutterwarp drone would stop, but the system it's come from won't.
Stutterwarp doesn't involve any real vector changes.
So when you launch your early warning drone you'd have to make sure it has the correct vector to remain on station relative to the system before engaging the stutterwarp.

 

[BMonnery]

For AOM see http://www.geocities.com/Area51/9292/2300/AOM.htm

Note that all the canon missiles needed redoing to fit the system if you use it. It also renders the idea of dodging missiles obsolete (as if it wasn't already).

There's no reason a missile can't all stop, but it has a very limited endurance, since no maintenance can be carried out.

Parking a drone 1 ly ahead brings problems. Missiles and drones use a lot of equipment from their mother. An independent drone would need workstations.

Bryn

 

[jcrocker]

The return vector shouldn't be a problem, just have a transmitter broadcast a signal from the home system, and program the drone to return on that - coming in above the system's ecliptic so you don't ram a gas giant until 'above' the beacon, then heading straight down.

The maintenance could be a problem. The price probably won't drop too much overall [despite the relative cheapness of most missile drives] since you'd need really robust systems to park out there for a several month stretch.

I'm not certain where the workstations would be needed, unless you mean on a ship that comes out to emplace/maintain the drone, and that would be a temporary thing - most ship designs have a spare station on the bridge that could be used for the twenty minutes or so a status check would take.

 

[mike wightman]

The warning drones wouldn't need to station-keep. I was thinking that you'd send a few cheap [my first model is 660 000 Lv] drones out. They'd take position themselves a couple light-months to a year outside the system, come to 'all stop', and wait until their radiation detectors read a GRB or other threat over some threshold value.

Why not take them out by manned ships, drop them off, and then they only come back if they have something to report.

That would make them one shot, just like missiles.

 

[BMonnery]

At 1 ly no signal will be readable. The signal strength decreases by inverse square law. At 1 ly the signal strength will be 4x10^-14 of that at one hex.

A workstation is also the computing system. So a nav workstation is the nav computer (working back, the machinery itself is 2m3/ tons).

Bryn

 

[GJD]

2m3/tons? C'mon, lets have a bit of a reality check here. To fly out to a 1 light month distance, sit there until it hears a GRB and then head home is a darn sight less than the Huygens, Voyager, Galilleo or any of a dozen other 20th century probes have done, and they didn't need 2m3 of navigation equipment to do it.

Granted, flying with stutterwarp isn't like dusting crops, kid, but even so, fo simple stuff like that you shouldn't need a full nav workstation.

I also don't think that a 6 month duration, or even a year, is unreasonable. Add some solar cells and an isotope power source and they should be able to sit and stare into deep space for ages.

If the signal is too attenuated at those distances (and it would take a month to get home anyway...) how far is the gravity ripple from a stutterwarp detectable from? They could pulse the drive to provide a 'heartbeat' signal to show that they are still operating. I'm not sure how fast this propogates either, but I'm assuming its speed of light again.

G.

 

[jcrocker]

True, at 1 ly you'd be unable to track the signal, but you'd only need it for 'final approach' anyway - the star system would move, but not *that* much relative to the parked probe. I wasn't planning on giving it any sensors - the people on the ground would have to pre-program a dead-reckoning course to get it within range of the homing beacon. After that, it orients itself according to the beam, and follows a predetermined course home.

Originally I was thinking of having the probes parked out in deep space by ship [gives those PCs something to do, if nothing else], then I thought the probes could swim themselves out to target. Now maybe I'll stick with them being placed by ship, so they swim home only if triggered. We're back to one-shot systems which are cheapter. I won't go with ones as cheap as in Anatomy of a Missile, though, to reflect the lack of maintenance and need of reliability.

An isotope power supply is interesting - you'd need a lot less power that way. But would that provide enough heat to keep everything from freezing solid? Not that this issue is really addressed in the design system, so I could just ignore it, but it would be nice to not break too many laws of physics.

A 'stutter signal' wouldn't be of much use, I think - limited to lightspeed, the warning would arrive after the event is was supposed to warn of. But even a slow, cheap 'old commercial' drive has an efficiency measured in 'ly per day' which makes it great for such a warning system.

Workstations on the drone - I wasn't planning on that. Given that the out-of-date PC on my desktop would have qualified as a 'supercomputer' back in the 80s, it would probably have enough computing power to get an 'old commercial' drive back in one piece. So what if it takes a week to make the trip, put it out far enough and you still get a month's warning - which is all that you need. I'll allow some space and cost for the computers, but it won't be a couple of cubic meters.

 

[mike wightman]

How about putting the thing in a protective package - armour and insulation - which can be jettisoned by explosive bolts before the early warning drone warps back.

 

[GJD]

If its detecting a GRB, you want to protect it from the GRB EMP (to avoid it going MIA) to be able to report back, then it's got to pass through the wavefront again on the way back

G.

 

[mctesla]

Very cool idea, Jon! Be sure to post once you've completed the design. I'm curious how it turns out.

 

[jcrocker]

Thanks for the compliment!

For the radiation surge - I was planning on slapping some shielding/armour on the design for the detection phase. Do you think a faraday cage would do it, or would lead be needed as well?

Also, I should have clarified - the reason I was not planning on having anything like a nav workstation is because the probe would not navigate home, it would follow a pre-designated program written by someone on the ground. Not a very long program, relatively speaking.

To find the home system - how about the ship setting the probe centers the home star in the photosensitive sighting device? The drone then keeps pointed toward the star at all times. Not the most elegant way to get it back, and a little longer than plotting a proper course, but it would work.

And I was able to find this page, with values for radioisotope thermal generators:

http://www.qrg.northwestern.edu/projects/vss/docs/Power/3-what-are-the-fuels-for-rtgs.html

It's amazing what you can find on line these days.