Space Travel & Exploration

[Endus]

That's...not how orbital mechanics works, dude. This shit can literally be accomplished with sound mathematics and a few nukes.

People tend to forget that the real complexity in orbital dynamics is in minimizing travel time, not in arriving to a particular orbital location. We try and find optimal launch windows for missions for two reasons; because there are people involved and we want them at risk for as little time as possible and using as few resources as possible (mostly relevant to the Moon missions so far), or simply to minimize the delay between launch and the need to manage on-site operations, like with Mars landers. We CAN pick and choose those launch windows, and our targets are relatively close, and we have a set boost vector we can use, and we minimize the amount of weight being used in all cases to maximize the effectiveness of those rockets, because the longer a delay, the more chance of something going wrong, and with these operations, that's usually a failure at the further points in the operation, meaning rescue efforts are highly problematic.

With an orbital mining relocation, the start point of the operation is still going to occur at a critical window, but the complex operations occur largely after we get boosters attached to the rock. And there's less of a time crunch; if a longer path is safer or more fuel-conservative, but takes years longer, that's an acceptable compromise. The other factor to consider is that while we've used orbital acceleration with our various long-range probes like Voyager and such, the converse, orbital deceleration, is also a thing. And conveniently, if we're talking about ending up in a Lagrange point, there's a convenient gravity mass nearby to use for repeated orbital braking maneuvers. You'd need boosters mostly for adjusting the trajectory for each pass, rather than trying to push the rock like a launch vehicle. It already has plenty of delta-V; the boosters are for trajectory adjustment and braking.

And while we might need a bunch more in the final approach, this is very much a case where we can send up additional boosters as the mission goes on; unlike most other missions, this thing would be getting closer to Earth for longer periods over time. If we're using multiple cycles of orbital deceleration to bleed off delta-V, each pass is another opportunity to load up more boosters (and I'm presuming we're designing them to not be retrievable).

Would that many boosters cost a lot? Sure. Trillions, though? The entire Space Shuttle program over 30 years cost $192 billion, and that was 131 missions total. And there's a lot that went into the Shuttle program that wouldn't be needed for launching unmanned missions like these. Once you factor in refining and setting up shop and everything, I'm sure the cost would be in the hundreds of billions, particularly as there's inflation to consider, but that doesn't seem unfeasible, particularly spread out over years.

The USA spends three-quarters-of-a-trillion-a-year on military bullshit. That price tag would easily cover this, in spades. So don't tell me the money doesn't exist. It's just that the USA prioritizes blowing up other human beings over space innovation.

[Corvus]

New little video from NASA on Visions of the Future.



Live action version of some posters tehy made years back (and which are very cool). Nice little bit of inspiration even if most of us won't be alive to see it take place.

[PACOX]

The USA spends three-quarters-of-a-trillion-a-year on military bullshit. That price tag would easily cover this, in spades. So don't tell me the money doesn't exist. It's just that the USA prioritizes blowing up other human beings over space innovation.

Money isn't the issue. The US throws a lot a lot of money at space - directly and indirectly. It's mismanaged. The military spends a lot of money on space. We can think funneling space money through DoD for GPS. The shuttle would have been a thing is money was actually a concern (its a concern but I think it's overstated) because those things weren't cheap, efficient, or necessary for the role they filled. Money was wasted keeping the shuttles around for as long as we did, and money was wasted not having a replacement. Actually we had two possible replacements in human rating the Atlas V and Delta IV (which are practically human-rated now) but the 'right' people wouldn't have been profited.


SLS is not cheap or an efficient use of money. We would have saved money building an entirely new rocket (SLS uses refurbished parts). The issue is mismanagement of funds and politics gatekeeping science.

The current bottleneck US agencies face is propulsion. How do we get around spending most of a rockets fuel on just lifting more fuel. You're limited on what, where, and when you can launch based on trying to just lift the mass of your fuel off the ground.

Or mass to thrust ratios right now? Lots of room for improvement.

Give more money to NASA but not before unchaining them from politics. Allow NASA to shift funds to actualizing research. NASA had enough funding to do what SpaceX did with the Falcon 9, they weren't allowed to because of all the political hoops.

[Zuben]

Give more money to NASA but not before unchaining them from politics. Allow NASA to shift funds to actualizing research. NASA had enough funding to do what SpaceX did with the Falcon 9, they weren't allowed to because of all the political hoops.

Far easier to just include the private sector and give them missions and budgets than change the nature of politics.

[Easo]

That's...not how orbital mechanics works, dude. This shit can literally be accomplished with sound mathematics and a few nukes.

How your nukes are going to help towing a rock at least few hundred meters in size closer to Earth? You, what, want to nuke it to move it's orbit? And I say at minimum few hundred meters, it has to pay off in resources acquired from it, I really doubt small ones are worth the investment.

We need crapload of engines and fuel over there to move it back to us, but first we will spend engines and fuel getting to said rock. How? That tech is simply not there, not matter what someone thinks about overbudgeted military.

[Zuben]

Easier? Yes. Better? Not really. But this is where we are.

I would include a third question there: Faster? Yes. Changing politics is so gargantuan a task that including the private sector in our current situation accelerates advancement in tech and ambitions from how it otherwise would be. Now, do we want faster if the price to pay is surrendering the space frontier to commercial interests? That's another good discussion to have, but at face value it seems to accumulate desirable results.

[Easo]

I mean, they’re planning on going to Mars to pick up rocks and then bring them back to Earth. Within the next 10 years.

Dude. Asteroids hundreds of meters to kilometers in size vs fistful of rocks? Yes, sure, Mars has gravity and you have to land, different challenge, but still, scale applies.

[Endus]

Yeah. You know what it takes to move an asteroid? 15 tons of fuel and a rocket to push it through. That’s it. Once you have those things in Earth orbit you just have to drag them to where you need them. Which doesn’t take nearly as much effort as some people seem to think. Unless you’re in some massive hurry at least. It’s far harder to land on Mars, pick up samples, and then fly back to Earth.

I think what people miss is that the asteroid moving project is a wildly different approach. Almost all missions we've run in space have significant mass constraints, because of the lift costs, but also because they want to cram as much science into those missions as possible, to make them as cost-efficient as they can. So you're trimming down kilograms and grams so you can add more kilograms of new equipment or features, to expand capabilities. And if you're doing manned flights, you can add all the equipment necessary to sustain the crew, particularly if there's resupply for the ISS going on.

With the kind of booster missions to move an asteroid we're talking about, the devices we'd need are almost ridiculously simple. The complexity is in the attachment system, where you'd want to drill the booster into the rock to secure it. The smart approach is to assume pre-emptively that some of these will fail, so you overengineer and launch more than the minimum you need to begin with. Just thinking about it, it's probably smarter to have the system disassemble on approach, so the booster module itself attaches directly, and the fuel tank is moved to one side (from the standard rocket orientation where the tank sits on "top" of the booster). Attaching it without doing so means the booster's on the end of a pole, and any side pressure could cause that to crumple, changing the angle; better to not risk it. But that's all we really need; a booster module with some maneuvering jets for final approach, a fuel tank that can be set free and remain connected by flexible hosing, and a mechanism to (I assume) screw into the asteroid itself to secure the booster. And some communications tech for remote operations; you can get around the sightlines to the asteroid if you network the boosters on-site and thus any of them being visible means you can control any of the others they're connected to.

Otherwise, that's it. Booster. Big fuel tank. Attachment system. Communications. No need for experiments, life support, habitats, any of that. And we're not going that far; we're talking a near-Earth object, and the smart play is to use a close approach to get the boosters onto it.

Falcon Heavy can put 64 metric tons into space every launch. Sure, the bulk of that for this kind of operation would be fuel, but it isn't gonna take 60 tons of fuel to get these things onto that kind of rock. And sure; you'd want multiple boosters, but we can set this up pretty easily with repeated launches, ahead of the mission window; the asteroid booster systems can sit in orbit as their numbers add up until the mission window arrives, and then they can all boost together. Heck, if you really want, you could tie them around a central booster whose sole purpose is to drive the on-site boosters to the rock.

And, like you said, no worries about falling into/pulling back out of gravity wells. Just clean orbital pathing until you near the Lagrange point of choice where you'd have to bleed the last of your delta-V so it'll settle into place.

[Elegiac]

How your nukes are going to help towing a rock at least few hundred meters in size closer to Earth?

Gee, if only some mincing man-hungry queen in Cambridge had described what happens when you apply force to an object in a vacuum.

It doesn't need to be "towed", despite what you've seen in science fiction. The hurdles are entirely infrastructural, not technological.

And I say at minimum few hundred meters, it has to pay off in resources acquired from it, I really doubt small ones are worth the investment.

This is a very different claim from "we don't have the technology to do it".

We need crapload of engines and fuel over there to move it back to us, but first we will spend engines and fuel getting to said rock. How? That tech is simply not there, not matter what someone thinks about overbudgeted military.

Pretty sure we've had the technological capability to put shit into space and move it long distances for over half a century, bro.

Again, you're confusing a lack of infrastructure with a technological inability, which is a you problem and doesn't dispute that it's an issue of a lack of investment.

[Easo]

Gee, if only some mincing man-hungry queen in Cambridge had described what happens when you apply force to an object in a vacuum.

It doesn't need to be "towed", despite what you've seen in science fiction. The hurdles are entirely infrastructural, not technological.

This is a very different claim from "we don't have the technology to do it".


Pretty sure we've had the technological capability to put shit into space and move it long distances for over half a century, bro.

Again, you're confusing a lack of infrastructure with a technological inability, which is a you problem and doesn't dispute that it's an issue of a lack of investment.

Your smartarsness attempts suck. Do you realize that nuclear explosion BREAKS THINGS APPART? Yes, even in space. Nuke is not a shaped charge, you cannot seriously expect it to propel an asteroid in the right direction with enough precision.

It is not a different claim, it is connected to it. We do not have the tech.

Long distances, half century? *Takes a look at the small probes sent* Yes, well, good luck with that.

Yeah. You know what it takes to move an asteroid? 15 tons of fuel and a rocket to push it through. That’s it. Once you have those things in Earth orbit you just have to drag them to where you need them. Which doesn’t take nearly as much effort as some people seem to think. Unless you’re in some massive hurry at least. It’s far harder to land on Mars, pick up samples, and then fly back to Earth.

Things in space still have mass. Good luck breaking the orbit of that 1km rock before fuel runs out with that "rocket".

[Endus]

Your smartarsness attempts suck. Do you realize that nuclear explosion BREAKS THINGS APPART? Yes, even in space. Nuke is not a shaped charge, you cannot seriously expect it to propel an asteroid in the right direction with enough precision.

The difference between a nuclear bomb detonation and a standard chemical rocket is mostly one of control. The chemical rocket is a controlled and directed explosion.

Just launching nukes at a rock would be inefficient, because a lot of that potential delta-V would be expended in directions that aren't useful, but it's definitely not pointless.

Plus, even if we were using nukes, you're basically talking about Project Orion, which only became unfeasible due to anti-nuclear treaties, not because the technology wasn't functional. So thrust-by-atomic-detonation isn't a new technology. It's a 60-year-old technology.

Things in space still have mass. Good luck breaking the orbit of that 1km rock before fuel runs out with that "rocket".

You really don't seem to understand how little it takes to "break" an orbit. It's not like orbital paths are ruts that tend to keep objects in their paths. The only real reason orbital paths are "stable" in any meaningful sense is because the solar system is billions of years old and any "unstable" paths already impacted with something else or was captured into a different orbit or the like. Small changes in delta-V can lead to massive changes in orbital path, and that will increasingly diverge over time.

"Mass" doesn't "stick" things to their current orbital path. It just increases the force needed to achieve a particular delta-V.

Also, why are you assuming we're talking about one rocket? The reason I suggested this would likely cost tens if not hundreds of billions is because I assumed it would take dozens to hundreds of rockets. Each packing dozens of tons of fuel, after launch to Earth's orbit.

[Elegiac]

Your smartarsness attempts suck. Do you realize that nuclear explosion BREAKS THINGS APPART?

Maybe if you bury them, sure. But we're not talking about that, we're talking about applications of force to the surface of an asteroid. Which is what boosters are - effectively controlled explosions.

Nuke is not a shaped charge, you cannot seriously expect it to propel an asteroid in the right direction with enough precision.

I can, because I have a basic understanding of how orbital mechanics work. It is a fucking vacuum, dude; altering trajectories can happen with fairly minute applications of force. That's literally how ion engines work.

It might not be the most *efficient* way of doing such, but the technological capacity and mathematical know-how to accomplish it has been around for decades.

It is not a different claim, it is connected to it. We do not have the tech.

Again, we do. You just keep insisting that high costs and long scales of time are a technological impediment, when they really aren't.

Long distances, half century? *Takes a look at the small probes sent* Yes, well, good luck with that.

You keep cycling back to you not understanding what constitutes an infrastructural hurdle with a technological one. Rofl.

[Endus]

Again, we do. You just keep insisting that high costs and long scales of time are a technological impediment, when they really aren't.

Like, sure, the investment I'm suggesting, on the higher end, let's say like $400 billion? That's double the cost of the Shuttle program and every single mission it launched in its 30-year lifespan. So clearly, on the higher end.

It's also half the USA's military investment for one year. It's not a particularly high figure; the issue is that the amount spent on space investment has effectively been trivial for most of human history. What I'm proposing is just making an actual effort with moderate investment. You can't tell me that's unreasonable when you can carve off half the military budget for a single year, remaining with more military expenditures than the next 9 countries in the Top Ten for military spending, and cover the whole thing.

This is also pretty unfair because I'm valuing the cost of more than a hundred Shuttle launches, which were significantly more expensive than Falcon Heavy launches (about $1 billion per, as compared to $90 million for a Falcon Heavy launch), where the Falcon Heavy can also lift more than twice the payload of the Shuttle rockets. I'm erring WAY on the side of caution, here.

[Easo]

The difference between a nuclear bomb detonation and a standard chemical rocket is mostly one of control. The chemical rocket is a controlled and directed explosion.

Just launching nukes at a rock would be inefficient, because a lot of that potential delta-V would be expended in directions that aren't useful, but it's definitely not pointless.

Plus, even if we were using nukes, you're basically talking about Project Orion, which only became unfeasible due to anti-nuclear treaties, not because the technology wasn't functional. So thrust-by-atomic-detonation isn't a new technology. It's a 60-year-old technology.



You really don't seem to understand how little it takes to "break" an orbit. It's not like orbital paths are ruts that tend to keep objects in their paths. The only real reason orbital paths are "stable" in any meaningful sense is because the solar system is billions of years old and any "unstable" paths already impacted with something else or was captured into a different orbit or the like. Small changes in delta-V can lead to massive changes in orbital path, and that will increasingly diverge over time.

"Mass" doesn't "stick" things to their current orbital path. It just increases the force needed to achieve a particular delta-V.

Also, why are you assuming we're talking about one rocket? The reason I suggested this would likely cost tens if not hundreds of billions is because I assumed it would take dozens to hundreds of rockets. Each packing dozens of tons of fuel, after launch to Earth's orbit.

I am not basically talking about nuclear propulsion, but using nukes as such. Look what Elegiac wrote.
And yes, you can't control nuclear explosion, well, aside from yield. Good luck calculating that explosion on the asteroid, which are known to be quit uneven. Maybe in the future.

Because, Endus, that poster clearly said that "luuuuul, just 15 tons of fuel and a rocket". I was repeatedly saying about sticking crapload of engines on it for a reason.

Maybe if you bury them, sure. But we're not talking about that, we're talking about applications of force to the surface of an asteroid. Which is what boosters are - effectively controlled explosions.



I can, because I have a basic understanding of how orbital mechanics work. It is a fucking vacuum, dude; altering trajectories can happen with fairly minute applications of force. That's literally how ion engines work.

It might not be the most *efficient* way of doing such, but the technological capacity and mathematical know-how to accomplish it has been around for decades.



Again, we do. You just keep insisting that high costs and long scales of time are a technological impediment, when they really aren't.



You keep cycling back to you not understanding what constitutes an infrastructural hurdle with a technological one. Rofl.

Again, nukes, on an uneven surface. Good luck. Also, I wanna see what happens with enough detonations on said rock, because you absolutly will not bring something in Earth's orbit with just one push.
I have a feeling you think we can just scale up existing stuff to "make it work". Nope.

Ion engines? Infancy, but likely the real solution to this.

[Elegiac]

Like, sure, the investment I'm suggesting, on the higher end, let's say like $400 billion? That's double the cost of the Shuttle program and every single mission it launched in its 30-year lifespan. So clearly, on the higher end.

It's also half the USA's military investment for one year. It's not a particularly high figure; the issue is that the amount spent on space investment has effectively been trivial for most of human history. What I'm proposing is just making an actual effort with moderate investment. You can't tell me that's unreasonable when you can carve off half the military budget for a single year, remaining with more military expenditures than the next 9 countries in the Top Ten for military spending, and cover the whole thing.

This is also pretty unfair because I'm valuing the cost of more than a hundred Shuttle launches, which were significantly more expensive than Falcon Heavy launches (about $1 billion per, as compared to $90 million for a Falcon Heavy launch), where the Falcon Heavy can also lift more than twice the payload of the Shuttle rockets. I'm erring WAY on the side of caution, here.

But noooo we don't have the technology because my entire understanding of this shit comes from movies and video games rather than actually understanding that space travel does not obey the laws of narrative convenience. /s

- - - Updated - - -

Good luck calculating that explosion on the asteroid, which are known to be quit uneven.

*facepalm*

We've gone from "we don't have the tech" to "we don't have the math."

Which is still wrong, by the way. We've had the math for a while.

because you absolutly will not bring something in Earth's orbit with just one push.

That's why I said "a few".

[Endus]

Ion engines? Infancy, but likely the real solution to this.

The advantage of ion engines is tiny amounts of thrust over VERY long periods, by sipping fuel.

That's . . . not really functional on a mass this size, and particularly not when we're dealing with near-Earth objects this size. I'm not contradicting myself; ion engines COULD shift the mass into a new orbit that gets it into position, but the thrust is so much less that it'll take FAR longer, likely decades to centuries, and if anything goes hinky, there's basically no chance to correct because that small thrust will provide little means to divert its course in the short term. With big-ass chemical rockets, we always have the "burn everything we've got and pray" option.

I'm a big fan of ion engines, and if we were talking about capturing Belt asteroids over the long term, sure, that's an option. Near-Earth objects to get this started, I don't see them as somehow more reasonable, and it's weird that you'd be calling for that kind of innovative technology while poo-pooing tried-and-tested methods that we clearly have the capacity to employ.

[Elegiac]

The advantage of ion engines is tiny amounts of thrust over VERY long periods, by sipping fuel.

That's . . . not really functional on a mass this size, and particularly not when we're dealing with near-Earth objects this size. I'm not contradicting myself; ion engines COULD shift the mass into a new orbit that gets it into position, but the thrust is so much less that it'll take FAR longer, likely decades to centuries, and if anything goes hinky, there's basically no chance to correct because that small thrust will provide little means to divert its course in the short term. With big-ass chemical rockets, we always have the "burn everything we've got and pray" option.

I'm a big fan of ion engines, and if we were talking about capturing Belt asteroids over the long term, sure, that's an option. Near-Earth objects to get this started, I don't see them as somehow more reasonable, and it's weird that you'd be calling for that kind of innovative technology while poo-pooing tried-and-tested methods that we clearly have the capacity to employ.

I really don't think people understand how much of a spit and string affair the Apollo Program actually was, speaking of tried and tested methods. It is still baffling that humanity managed to accomplish multiple lunar landings with the collective processing power of less than an iPhone.

[PACOX]

SLS 100% stacked



Wet rehearsal in December (fueling then unfueling at the launch pad)

Maiden launch aimed for February.

Artemis 1 graphics

[plz delete account]

The difference between a nuclear bomb detonation and a standard chemical rocket is mostly one of control. The chemical rocket is a controlled and directed explosion.

Just launching nukes at a rock would be inefficient, because a lot of that potential delta-V would be expended in directions that aren't useful, but it's definitely not pointless.

Plus, even if we were using nukes, you're basically talking about Project Orion, which only became unfeasible due to anti-nuclear treaties, not because the technology wasn't functional. So thrust-by-atomic-detonation isn't a new technology. It's a 60-year-old technology.



You really don't seem to understand how little it takes to "break" an orbit. It's not like orbital paths are ruts that tend to keep objects in their paths. The only real reason orbital paths are "stable" in any meaningful sense is because the solar system is billions of years old and any "unstable" paths already impacted with something else or was captured into a different orbit or the like. Small changes in delta-V can lead to massive changes in orbital path, and that will increasingly diverge over time.

"Mass" doesn't "stick" things to their current orbital path. It just increases the force needed to achieve a particular delta-V.

Also, why are you assuming we're talking about one rocket? The reason I suggested this would likely cost tens if not hundreds of billions is because I assumed it would take dozens to hundreds of rockets. Each packing dozens of tons of fuel, after launch to Earth's orbit.

Daily reminder we've just barely advanced to the point where NERVA is legal again. Unlikely to see Project Orion.

- - - Updated - - -

SLS 100% stacked



Wet rehearsal in December (fueling then unfueling at the launch pad)

Maiden launch aimed for February.

Artemis 1 graphics

WDR is more than just the spacex style fueling and unfueling.

[cubby]

Artemis scheduled for text flight in February. Great news!