scrape_r_rational/data/cache2/5s82ay.md

## [RT] Sideways in Hyperspace: Interlude α: Martians

* Author: u/Sagebrysh  *Rank 7 Pragmatist**
* URL: https://sidewaysfiction.wordpress.com/2017/02/05/martians/
* Score: 12

* Created: 2017-02-05T15:54:21

### Post:

[Link to content](https://sidewaysfiction.wordpress.com/2017/02/05/martians/)

### Comments:

> **u/thrawnca** [+3]  *Carbon-based biped* (3 hours later)
> 
> Interesting take on Martian colonisation. I didn't feel like the scale of expansion was very realistic, though. The environmental hazards alone would make industry on Mars a much trickier prospect. Sure, it would expand, but being able to fight Earth within the first century? Being able to dedicate its economy to military production? It felt overly optimistic to me.
> 
> Also, I was a little surprised at the idea that anyone would expect profit from colonising Mars. I would expect it to be a huge money sink, without the possibility of much return for a very, very long time. The advantage of low wages can't easily offset the cost of interplanetary shipping.
> 
> But maybe all this is influenced by having read The Sands of Mars a bunch of years ago...
> 
> No doubt Mars giving Earth the finger was fun to write :D

> **u/MaxMahem** [+3]  (2 days later)
> 
> Blegh, I was enjoying this series, but I thought this chapter was terrible. Some thoughts:
> 
> * The characterization is sloppy and one dimensional. Evil Corpratists Earth, Good Socialist Mars. Blegh.
> 
> * The idea of Mars as a 'for profit' colony investment is kind of silly. Unless transfer costs are reduced *immensely*, something the chapter doesn't touch on, it's hard to imagine what Mars could be producing that would return a profit on Earth. Having to rely on 'transfer windows' implies they are still using some sort of low-ish ISP propulsion source or that some other factor constrains them to using orbits that require minimal delta-V.
> 
> ##### Mars would have the *highest* safety standards.
> * Mars at this point is still under Earth control and presumably subject to OSHA or whatever other national safety standard that would be applicable. It's hard to imagine liberal democracies turning their back on them. But whatever, perhaps the *evil* corporations have overturned these.
> 
> * It still doesn't make *economic* sense. With such a low population and with the cost of sending a new employee to Mars being so high, along with these employees presumably being highly skilled laborers in their own right, all combines to make their lives very very economically important. Even to *evil* corporations who might otherwise disregard the value of human life, the cost of replacing a martian laborer would be astronomic.
> 
> ##### The Earth-Mars space engagement is silly.
> * "Engage them in space" now we're just getting silly. Without much better engines (if they have them, why are they waiting on launch windows?) you can't do this. An 'encounter' between ships going inwards from Mars and outwards from Earth would be two ships whizzing past each other at several km/s.
> 
> * Even if you did have engines that could do this, why would you want to rendezvous in deep space? You would be spending a stupid amount of fuel (burn away from Mars, turnover, then burn to match orbital velocity with incoming ships) which I can only assume would not be ideal tactically. You would be committing all your acceleration to this maneuver while the Earth ships would still have theirs to do with as they please.
> 
> * Why did the Earth ships accept engagement? If you have all the fuel to waste on such a silly maneuver, can't the Earth ships as well? Presumably they know they are not outfitted for orbital combat and would burn away from an incoming fleet? Did the 'heroic' Martians just blow up a bunch of troop transports?
> 
> * If all you planned to do was shoot missiles at them anyways, why even build warships and not just missiles to begin with.
> 
> ##### The battle of Earth Luna is silly.
> * The battle over Earth also doesn't make any sense. You can't "loop back around" in space. I mean I guess you could be in a high elliptical orbit or something, but then your approach is hardly unknown. In fact well you can't easily hide in space right? Especially if you are lighting off high-thrust engines.
> 
> This part is the silliest thing ever so I thought I'd quote it:
> >  The Martian forces scattered, trying to outrun the missiles as they climbed out of Earth’s gravity well, but the much greater acceleration tolerance afforded by the nonliving missiles ensured they caught up to the ships hauling the fragile humans. After a week’s pursuit, the missiles finally caught up with their quarry as they attempted to loop back around and land on the Earth.
> 
> * If you are accelerating for a *week* at rates high enough to make the acceleration tolerance difference between missiles and humans relevant then... Jesus. All of my wut. 1 weeks acceleration at a 'measly' 1G puts you at nearly **6,000 km/s!** That's *10 times* Solar escape velocity! If you did it in a straight line you would be 24AU's out, which is beyond Uranus's orbit!
> 
> * Even for engines with a *lot* of ISP this is a very very non-trivial amount of delta-V. Lets say they are using Fusion torches with a very large ISP 50,000s (not sure why they would care about launch windows with such engines, but whatever). For a very very light 'warship' weight of 100 metric tons, such a craft would require like 15 *million* metric tons of fuel to perform such a maneuver. (Actually more because there is still the Earth intercept burn and the Earth capture burn, but those are penuts compared to the 6,000 km/s burn). There would be a billion other problems like an engine capable of pushing two and half Pyramids of Giza's at 1G would be accelerating at a lot lot more then 1G after it had burned through its propellant load. And of course such an engine would be a devastating weapon in its own right.
> 
> * You obviously wouldn't be 'looping' back around towards earth with such acceleration. You are way, way, way over Earth's escape velocity. Maybe you could loop around I dunno Jupiter or something :P.
> 
> * Even if we ignore some of the silliness of the above statements, the moon is still along ways away from Earth. Recall that it took the Apollo missions *3 days* to reach the moon. If we assume engines that make waiting for transit windows reasonable (IE not ISP of 50,000s) then the moon is still likely a long transit time from Earth. You don't just pop-out in your 'escape shuttle' and make the trip.
> 
> * You can't hide in space. Not if you are firing off large high-thrust rockets. Once you fire off your warfleet's engines on Mars, Earth will know you are coming. They could have launched their missiles then.
> 
> * And really a 'martian fleet survivor' guerrilla campaign on Earth? Come-on now.
> 
> ##### You can't hide you're space rocks either
> * Just like you can't hide your space fleets or whatever, you can't hide your space death rocks either. A 500m asteroid is detectable with *today's* technology. Especially if its an Armor out beyond Earths orbit. But it *certainly* isn't tough to find once it lights off its SUPER-GIANT-ENGINES to push it into a new orbit.
> 
> * And these engines are super-giant. If it impacts at 60 km/s retrograde it still needs to pick-up 30 km/s from somewhere (Earths orbital velocity is 30 km/s so lets say you get that energy 'for free'). A 500m asteriod would have a volume of ~6.5e10L and might weigh 300 mega tons (assuming 5 g/cm^3 density). This though is a task at least contemplative with the 50,000s ISP engines we considered before.

---