Jump to content
Objectivism Online Forum

Space Tug

Rate this topic


Recommended Posts

The Kessler syndrome, also called the Kessler effect, collisional cascading or ablation cascade is a scenario in which the density of objects in Low Earth Orbit (LEO) is high enough that collisions between objects could cause a cascade where each collision generates space debris that increases the likelihood of further collisions. One implication is that the distribution of debris in orbit could render space activities and the use of satellites in specific orbital ranges impractical for many generations. Every satellite, space probe, and manned mission has the potential to produce space debris. A cascading Kessler syndrome becomes more likely as satellites in orbit increase in number. The most commonly used orbits for both manned and unmanned space vehicles are Low Earth Orbit (LEO). Clearly, the number of space debris that naturally falls back into the atmosphere is less than the number of those generated by the collision of existing space debris. Even if all space activity and launch were halted tomorrow, the debris population would continue to increase exponentially, leading to a situation in which some orbits would become impassable in the long run. This is a quote from an article on spacelegalissues. The article is almost 2 years old. Has any effective solution been proposed since then? Or is it a contrived problem? If we look at the number of launches this year ...

Link to post
Share on other sites

At the moment it is a contrived problem.  While it's true that we're steadily increasing the number of satellites launched per year and that eventually this will become a problem, one has to remember that there's plenty of empty space in space.

 

Since the volume of a sphere is 4/3 times pi times its radius cubed, the Earth (which has a radius of roughly 4,000 miles) has a volume of 268 billion cubic miles.  According to a quick google search there are roughly 21,000 artificial objects orbiting the Earth.

Let's arbitrarily say that we'll only ever put satellites at an altitude of less than a thousand miles.  This would truly be arbitrary (the moon, after all, orbits the Earth at over two hundred times that height) but I have to pick a number for the math to work, and if we pick a thousand miles up then the total size of the shell we can play in (after subtracting the volume of all the dirt we cannot play in) would be 255 billion cubic miles.

That would give each satellite about 21 million cubic miles of elbow room.  EACH.  So it'll be quite a while before Kessler syndrome will be a problem that's actually worth worrying about.

And at that time I look forward to the emergence of private space garbage collectors who'll solve that problem!  :thumbsup:

 

For the time being, though, there seem to be a lot of people who're desperately searching for reasons why space travel is a bad idea and Kessler syndrome seems to be a convenient one that some of them have latched onto.  The kinds of distances we're talking about are measured in millions or even billions of miles between each object; they're not going to collide with each other.  There is, after all, plenty of space in space.

Edited by Harrison Danneskjold
Link to post
Share on other sites
On 3/1/2021 at 11:39 PM, Harrison Danneskjold said:

At the moment it is a contrived problem.  While it's true that we're steadily increasing the number of satellites launched per year and that eventually this will become a problem, one has to remember that there's plenty of empty space in space.

 

Since the volume of a sphere is 4/3 times pi times its radius cubed, the Earth (which has a radius of roughly 4,000 miles) has a volume of 268 billion cubic miles.  According to a quick google search there are roughly 21,000 artificial objects orbiting the Earth.

Let's arbitrarily say that we'll only ever put satellites at an altitude of less than a thousand miles.  This would truly be arbitrary (the moon, after all, orbits the Earth at over two hundred times that height) but I have to pick a number for the math to work, and if we pick a thousand miles up then the total size of the shell we can play in (after subtracting the volume of all the dirt we cannot play in) would be 255 billion cubic miles.

That would give each satellite about 21 million cubic miles of elbow room.  EACH.  So it'll be quite a while before Kessler syndrome will be a problem that's actually worth worrying about.

And at that time I look forward to the emergence of private space garbage collectors who'll solve that problem!  :thumbsup:

 

For the time being, though, there seem to be a lot of people who're desperately searching for reasons why space travel is a bad idea and Kessler syndrome seems to be a convenient one that some of them have latched onto.  The kinds of distances we're talking about are measured in millions or even billions of miles between each object; they're not going to collide with each other.  There is, after all, plenty of space in space.

No, I'm not looking for a reason why space travel is a bad idea. I'm rather looking for a reason why a space tug is good. I love the idea that we will have a tool to displace, move and maintain satellites.
There are other ways though. For example, refuelling satellites so that they can continue their work.

Link to post
Share on other sites
12 hours ago, TommyJo said:

No, I'm not looking for a reason why space travel is a bad idea.

Sorry; I didn't think you were.  Those who're engaged in the dishonest search for space problems don't usually ask about their solutions.  :P  I was more mentioning why I think we've all heard so much about this non-issue.

5 hours ago, MisterSwig said:

The RemoveDebris satellite was deployed a couple years ago. Apparently it can catch space debris with a net and a harpoon.

Space harpoons sound fantastic on so many different levels.  I love it!

12 hours ago, TommyJo said:

There are other ways though. For example, refuelling satellites so that they can continue their work.

Of course.

When the space immediately above Earth starts to become crowded enough that collisions could happen I imagine people will start coordinating their orbital traffic in a much more structured way.  It's not really a different kind of problem than coordinating the traffic of cars; it's just that this will be three dimensional instead of two (so it probably won't be too different from what we currently do with air traffic).  People will find ways to maintain those satellites that remain useful and maybe the ones which don't will be reclaimed by the harpoons of space-garbage-collectors.

Although, if I used a harpoon in space (even via remote control) I'd have to wear an eye patch into work every day and punctuate my sentences with things like "avast"!  It's only rational.

870956675_FailuretoTerraformMars.thumb.jpg.eecefd292843d0be979e7216ec90da6c.jpg

If these are the kinds of things you find interesting, though, then you really need to read Robert Zubrin (if you haven't already).

Edited by Harrison Danneskjold
Epic Quote
Link to post
Share on other sites

Yes, I have already received advice to read Zubrin. I'm going to do it this weekend. I have already read a few interviews. And I love it.
I'm really interested in how the space industry can develop, so I pay attention not only to the most advertised projects. But also for projects and startups that are just beginning their journey. For example, the Skyrora company and their SkyHy rocket interested me. I looked at what they were doing and found out that they have developed their own multifunctional space tug, fuel and a lot of interesting things.

Link to post
Share on other sites
20 minutes ago, Doug Morris said:

How much would this cost?

Terraforming Mars?  Probably the combined wealth produced by the entire world over a period of several decades; some mind-boggling number like that.  But it is a finite number which could be produced.

 

PS:

 

The context of that quote is not that he's suggesting we seize all the money that currently exists in order to do something beautiful (like terraforming Mars) with it but that private citizens like Elon Musk should be left free to do whatever they're capable of and that any smart young people who are interested in such things should learn a thing or two about Engineering and make themselves capable of changing worlds.  If I remember correctly he even suggests that NASA should be dissolved because they aren't actually doing anything that's important to colonizing other worlds; they're basically just a multi-billion-dollar publicity stunt.

Edited by Harrison Danneskjold
Link to post
Share on other sites
12 hours ago, Harrison Danneskjold said:

Although, if I used a harpoon in space (even via remote control) I'd have to wear an eye patch into work every day and punctuate my sentences with things like "avast"!  It's only rational.

And I'd want to play this song while I'm hunting for space debris.

 

Link to post
Share on other sites
4 hours ago, TommyJo said:

Yes, I have already received advice to read Zubrin. I'm going to do it this weekend. I have already read a few interviews. And I love it.
I'm really interested in how the space industry can develop, so I pay attention not only to the most advertised projects. But also for projects and startups that are just beginning their journey. For example, the Skyrora company and their SkyHy rocket interested me. I looked at what they were doing and found out that they have developed their own multifunctional space tug, fuel and a lot of interesting things.

Excellent.

 

I personally think the next best step in the development of space industry would be asteroid mining.  There are quite a few technical hurdles that'd have to be worked out, but whoever successfully does so will stand to make exactly the mind-boggling quantities of profit that would be necessary for any kind of terraforming project.

Link to post
Share on other sites
5 hours ago, Harrison Danneskjold said:

I personally think the next best step in the development of space industry would be asteroid mining.

I've read that asteroid mining is not feasible in the near future. There is no infrastructure for it. First you would need a moon base to process ore. Bringing it back to Earth is too costly.

Link to post
Share on other sites
4 hours ago, MisterSwig said:

I've read that asteroid mining is not feasible in the near future. There is no infrastructure for it. First you would need a moon base to process ore. Bringing it back to Earth is too costly.

That really depends on how you intend to do it.  A solid one-ton chunk of platinum ore (even if it's totally raw and full of dumb rocks) would pay for almost any conceivable retrieval system with a fortune left over, if one could just manage to get it back here.

 

Six years ago I also would've said that it's not feasible in the near future.  Actually, I would've gone a step further and pointed out that according to the Outer Space Treaty we signed with the Soviet Union, any hypothetical fortunes technically belong to the human species as a whole (which, as Robert Zubrin and I agree, is the single biggest reason why nobody else has done so yet).  Since then I've seen Elon Musk single-handedly revolutionize the industry and Barack Obama (of all people) indicate that such cold war treaties need not be worried about by modern-day innovators.

 

Now I'd have to look into the details of any particular plan to say whether it is or is not feasible.

 

PS:

 

That damn treaty is the reason I gave up on trying to do these things myself.  If I'd known at the time that a future president was going to shrug the whole thing off I never would've done that.  Sometimes hindsight sucks.

Edited by Harrison Danneskjold
postscript
Link to post
Share on other sites

Come to think of it, I really wouldn't bother refining anything at all in space. Whatever you collect is going to have to come down the old-fashioned way, either inside of some sort of protective casing (which costs money and makes the whole endeavor more complicated) or naked. The one and only downside of the latter being that a significant portion of your cargo might be incinerated. Given all of that it only makes sense to drop the worst possible quality of ore in large quantities and do the refining and polishing with whatever can actually be recovered.

Link to post
Share on other sites
8 hours ago, Harrison Danneskjold said:

That really depends on how you intend to do it.  A solid one-ton chunk of platinum ore (even if it's totally raw and full of dumb rocks) would pay for almost any conceivable retrieval system with a fortune left over, if one could just manage to get it back here.

I don't think so. It requires processing two or three tons of ore in order to extract a single ounce of pure platinum, worth around $1150 today. That's nowhere near what it would cost to transport 4000-6000 pounds of ore to Earth's surface and then process it under environmental and political conditions here. At least two multimillion-dollar companies looked into this problem and failed to find a solution. Best case scenario is processing the ore on the asteroid, and even that is too expensive given how much equipment would have to be transported to the asteroid, only to be abandoned afterward.

Mining asteroids for water seems to be the more likely pursuit after space tourism. In addition to being necessary for human survival, water can be used to create propellant for refueling ships already in space.

Edited by MisterSwig
Link to post
Share on other sites
On 3/4/2021 at 11:01 PM, Harrison Danneskjold said:

Barack Obama (of all people) indicate that such cold war treaties need not be worried about by modern-day innovators

What happens if Russia makes a stink?  What happens if a future POTUS says different?  What happens if anyone sues on the basis of the treaty?

What provision is there for protecting rights in space?

Link to post
Share on other sites

One person on an island has no need for a provision for protection of individual rights.

As you migrate to two or more - at what point on the continuum does fences make for good neighbors move to establishing institutions among men to secure their individual rights? The development of communities in the new world under English, French and Spanish influence as it moved toward the conditions that gave rise to the Declaration of Independence should be rife with case studies to tease out pro and con aspects.

As to an intellectual on that front, C. Bradley Thompson comes to mind.

Link to post
Share on other sites
7 hours ago, Doug Morris said:

What provision is there for protecting rights in space?

Currently, none whatsoever.  We can only hope that this POTUS allows that horrible treaty to be violated (which is extremely likely since he was Obama's VP) and the next POTUS and the next, until the treaty is either scrapped or enforced.

6 hours ago, dream_weaver said:

One person on an island has no need for a provision for protection of individual rights.

Yes, but if one goes out and extracts something valuable from some desert island in the hopes of bringing it back home then one's rights could still be violated at that point.

 

It's entirely possible that the first person to turn that sort of profit would find it immediately confiscated by some faceless bureaucrat, never to be seen again.  And maybe I'm being naive to draw any conclusions whatsoever from their promises not to do any confiscation.  Still, I prefer it over any promises of the alternative.

Link to post
Share on other sites
2 minutes ago, Harrison Danneskjold said:

Yes, but if one goes out and extracts something valuable from some desert island in the hopes of bringing it back home then one's rights could still be violated at that point.

When a ship returns to port from international waters, the captain relinquishes legal sovereignty to the nation where the port is taken. This differs from space as international waters, as well as "islands" in space that might become nations, in and of themselves.

Link to post
Share on other sites
  • 3 weeks later...
On 3/1/2021 at 4:39 PM, Harrison Danneskjold said:

According to a quick google search there are roughly 21,000 artificial objects orbiting the Earth.

An NPR article I just read says 

According to a recent report by NASA, at least 26,000 of the millions of pieces of space junk are the size of a softball. Orbiting along at 17,500 mph, they could "destroy a satellite on impact." More than 500,000 pieces are a "mission-ending threat" because of their ability to impact protective systems, fuel tanks and spacecraft cabins.

And the most common debris, more than 100 million pieces, is the size of a grain of salt and could puncture a spacesuit, "amplifying the risk of catastrophic collisions to spacecraft and crew," the report said.

On 3/1/2021 at 4:39 PM, Harrison Danneskjold said:

Let's arbitrarily say that we'll only ever put satellites at an altitude of less than a thousand miles.  This would truly be arbitrary (the moon, after all, orbits the Earth at over two hundred times that height) but I have to pick a number for the math to work, and if we pick a thousand miles up then the total size of the shell we can play in (after subtracting the volume of all the dirt we cannot play in) would be 255 billion cubic miles.

How uniformly is space junk distributed in this volume?

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...