This idea was used in The Moon Is A Harsh Mistress. They loaded up the cargo containers they were sending to Earth with rocks and used them exactly as dropping a rock on something to destroy it
It is a pretty great book, although it’s a shame that Heinlein spent so much of his time being a douchey libertarian warhawk.
This idea was expanded upon in The Expanse series as well, with the added benefit of using small asteroids and pushing then into highly elliptical orbits designed to hit Earth at random times anywhere from a few weeks to several years later so your Inner System opponents have to spend a huge chunk of their resources watching for them without knowing if/when any other rocks will hit.
It’s funny, because tracking big rocks months/years in advance is what we currently do really well, and iirc we update all trajectories of all known objects orbiting earth at least every 11 days, and the main problem is figuring out which is which when they are maneuverable, not where they are going.
There’s currently about 750 000 things being tracked in earth orbit. The total number of asteroids is about twice that, so without upgrades we can still refresh each object every month, and with active space flight I’d guess that would be done much much more often.
Although, doing the math, enough Epstein drives (guesstimating tens) on a smaller asteroid could yield up to 1 m/s² acceleration, meaning an asteroid could traverse the distance from asteroid belt to earth in about a week.
It’s not nearly as easy as you’d think in the case of rocks being dropped from the moon. The crux of the issue is that:
We are not well equipped for space situational awareness in cislunar space
There are many orders of magnitude more volume to observe in cislunar space than in the space below the GEO belt
The previous two bullets mean it’s difficult to find a non cooperative target once you lose it and the precision of any observations is poor. The sheer volume of space that need to be observed makes this issue nearly impossible to fix.
Trajectories in cislunar space are highly chaotic due to multi-body effects. Combine this with poor estimates of position and velocity, and our predictions of the future diverge rapidly from truth when propagating cislunar orbits.
The Tl;dr is that we can’t effectively track non-cooperative objects in cislunar space over any extended period of time.
Sure! AFRL released a document called a primer on cislunar space targeted towards military personnel that does a great job of explaining it in easily understood terms.
Well, if the rocks are sufficiently small and plenty as well as stealth coated (or at least painted black) they are still a nuisance with deadly potential.
In The Expanse the group responsible for the attack stole the most advanced stealth coating in the Expanse universe to paint the asteroids, leaving Earth unable to detect them with anything but their most powerful sensors.
Nah, this is 200 times escape velocity, there is no possible orbit at that speed, just careening out to another galaxy, floating endless in the galactic cluster, or leaving the cluster altogether.
Any orbit would take millions of years anyway, so they can just cruse around, ingoring orbit altogether.
There isn’t if you don’t have a jump drive. It’s it a natural orbit, no. It’s a highly modified orbit using technology we don’t not have and cannot fully understand even in the books the method is not fully explained.
KSR did something similar in 2312 where multiple small asteroids were programmed to impact at the same point same time which had the effect of a larger impact thanks to kinetics but undetectable due to being small objects of various origins that would have looked random even if detected
Oh, thanks for reminding me about 2312. I read that one a few years ago when I first discovered that he had written more than just the Mars Trilogy, but I should probably revisit since I sandwiched it between two of the Climate in the Capitol books and clearly I don’t remember it that well.
This idea was used in The Moon Is A Harsh Mistress. They loaded up the cargo containers they were sending to Earth with rocks and used them exactly as dropping a rock on something to destroy it
Great book :)
It is a pretty great book, although it’s a shame that Heinlein spent so much of his time being a douchey libertarian warhawk.
This idea was expanded upon in The Expanse series as well, with the added benefit of using small asteroids and pushing then into highly elliptical orbits designed to hit Earth at random times anywhere from a few weeks to several years later so your Inner System opponents have to spend a huge chunk of their resources watching for them without knowing if/when any other rocks will hit.
It’s funny, because tracking big rocks months/years in advance is what we currently do really well, and iirc we update all trajectories of all known objects orbiting earth at least every 11 days, and the main problem is figuring out which is which when they are maneuverable, not where they are going.
There’s currently about 750 000 things being tracked in earth orbit. The total number of asteroids is about twice that, so without upgrades we can still refresh each object every month, and with active space flight I’d guess that would be done much much more often.
Although, doing the math, enough Epstein drives (guesstimating tens) on a smaller asteroid could yield up to 1 m/s² acceleration, meaning an asteroid could traverse the distance from asteroid belt to earth in about a week.
It’s not nearly as easy as you’d think in the case of rocks being dropped from the moon. The crux of the issue is that:
The Tl;dr is that we can’t effectively track non-cooperative objects in cislunar space over any extended period of time.
This is fascinating, could you perhaps link to some reading on the topic?
Sure! AFRL released a document called a primer on cislunar space targeted towards military personnel that does a great job of explaining it in easily understood terms.
Thank you!
Well, if the rocks are sufficiently small and plenty as well as stealth coated (or at least painted black) they are still a nuisance with deadly potential.
In The Expanse the group responsible for the attack stole the most advanced stealth coating in the Expanse universe to paint the asteroids, leaving Earth unable to detect them with anything but their most powerful sensors.
The expeditionary force series expanded that further with guided asteroids accelerated to near light speed orbiting the galaxy.
What time scale is that story on, that a 300,000 year delay on a weapon is feasible?
Normal human time scale. The projectiles have jump drives. When a object jumps it retains its momentum.
So basically they have these projectiles traveling at 30% of light, with the ability to jump into position to strike a target.
Well that answers my second question, which was how something could orbit at 200 times orbital speed.
The answer is there was never any orbit.
They have jump drives homie, when they start to escape they can jump back
Also speed wouldn’t be an issue if the orbit is extremely extremely elliptical.
Nah, this is 200 times escape velocity, there is no possible orbit at that speed, just careening out to another galaxy, floating endless in the galactic cluster, or leaving the cluster altogether.
Any orbit would take millions of years anyway, so they can just cruse around, ingoring orbit altogether.
There isn’t if you don’t have a jump drive. It’s it a natural orbit, no. It’s a highly modified orbit using technology we don’t not have and cannot fully understand even in the books the method is not fully explained.
KSR did something similar in 2312 where multiple small asteroids were programmed to impact at the same point same time which had the effect of a larger impact thanks to kinetics but undetectable due to being small objects of various origins that would have looked random even if detected
Oh, thanks for reminding me about 2312. I read that one a few years ago when I first discovered that he had written more than just the Mars Trilogy, but I should probably revisit since I sandwiched it between two of the Climate in the Capitol books and clearly I don’t remember it that well.
TANSTAAFL