The force of the push is calculated to push the space junk de-orbiting craft up to the next level where the next space junk is saving fuel. It can push the craft up to the next level as well as adjusting its orbit to rendezvous with the next piece of space junk
So it's using the junk it's de-orbiting as its reaction mass so it could stay up for a much longer time getting rid of a lot more space junk.
The power for these pushes is generated by motors or rail gun mechanisms powered by onboard nuclear power systems so very little fuel would be needed.
When it's reached the outer space junk it could even give one last push to force it back into the Earth for re-use while pushing that outer space junk into the Sun or otherwise away from the Earth.-- doctorremulac3, Jun 03 2024 Sort of like this. https://www.youtube...watch?v=9yDiNLlwlDE [doctorremulac3, Jun 03 2024] Link for clarification https://en.wikipedi...wiki/Quotation_mark [doctorremulac3, Jun 03 2024] Deorbit Systems https://www.nasa.go...oa/deorbit-systems/Jump to sec 13.3 & 13.4 for current passive & active state of the art systems [a1, Jun 03 2024] Only vaguely related idea ... Near_20Earth_20Orbi...ation_20Corporation [normzone, Jun 03 2024] Lining up, calculating the appropriate delta V, then catapulting the old satellite towards Earth https://www.dropbox...8s&st=uop76oap&dl=0the reaction thus entering the catapult ship into the appropriate phasing orbit to rendezvous with the next target. Ramrod, only partially shown, might be 100 feet long. [doctorremulac3, Jun 04 2024] Slingshot alternative https://www.dropbox...io&st=yt89vvq5&dl=0 [doctorremulac3, Jun 05 2024] I don't know whether this would work, but I like the idea. [+]-- pertinax, Jun 03 2024 Thank you pert. It's a weird one, I know. Could possibly work though. Certainly worth looking into.-- doctorremulac3, Jun 03 2024 Is this really suggesting *bumping into* bits of space debris to push them into a lower orbit where they'll burn up?-- hippo, Jun 03 2024 By the "really" I assume that I need to clear this up.
So to clarify: No. Not even close.
(Double checks to see if I said "bumping into" as the quotation marks suggest, perhaps in some sort of semi-conscious state where I somehow kept typing. Nope.)
See link for clarification.-- doctorremulac3, Jun 03 2024 Let's not say "bumping into" it then - but how does your Hop Along apply a force / push a satellite into a different orbit?-- a1, Jun 03 2024 And those aren’t quotation marks; they’re asterisks, commonly used to denote emphasis in text where bold and underline formatting isn’t allowed.-- hippo, Jun 03 2024 Hmm, that’s very interesting.
Let’s form a team. I’ll handle the astrophysics and you can check the spelling.-- doctorremulac3, Jun 03 2024 Is it really spelling if letters are not involved? Wouldn't that be punctuation? Oh, and (link). Can I be on this team also?-- normzone, Jun 03 2024 You’re in, but we’ve got documentation covered. Can you bring the donuts?-- doctorremulac3, Jun 03 2024 Wouldn't "bumping into" or even getting close enuf such that the items touched cause breakage and create additional bits of orbiting shit that would need to be chased down afterwards and bumped into again, creating an infinite amount of smaller orbiting chaff?
[+]-- whatrock, Jun 03 2024 I’m gonna do a drawing. Picture a huge tarp looking affair with poles spreading it into a trampoline. There’s a very long pole attached that runs through a hole in the catapult ship. The pole is driven through the ship pushing the satellite towards Earth and the catapult ship in the opposite direction towards its next target.
It’d be a funny looking affair because by necessity that push pole might have to be 100 feet long to get the target up to speed gradually enough that it didn’t shatter. Plus the trampoline part would have to be as light as possible so you don’t loose that reaction by slamming the brakes on something very heavy moving pretty fast.
Still got some spelling and punctuation errors to work through but other than that the idea of using the old satellites as reaction mass might be worth looking into.-- doctorremulac3, Jun 03 2024 // the pole is driven through the ship pushing the satellite towards Earth and the catapult ship in the opposite direction //
Sounds like giant pool cue. But unless you very carefully match velocities between HopAlong and the target, you're gonna get a lot of broken bits (as [whatrock] mentioned).
Consider also that unless HopAlong is much more massive than the target, just poking the target with a stick won't change its orbit by much. The lighter of the two will get the biggest change in velocity.-- a1, Jun 03 2024 Maybe it’s me.-- doctorremulac3, Jun 03 2024 Could be. Just can't be sure without seeing some numbers. How much your vessel weighs and what size targets it's gonna poke, how you'll chase down the first target and match velocities, and how you calculate each push to get it up to the next one and match velocities each time.
"You are in circular orbit around a planet. You are being overtaken by another object, also in circular orbit, moving several km./sec. faster. You accelerate to try and catch up. See you later, accelerator. Much later."-John Brunner, Shockwave Rider, 1975-- a1, Jun 04 2024 So whatrock, that's integral to this proposal, not blowing stuff up and basically destroying the space environment. The picture in the link shows the idea but to clarify:
1- The two crafts rendezvous. The catapult ship's initial phasing orbit with the target satellite established by a standard chemical rocket.
2- The craft analyzes its target and prepares for the catapult out of orbit / push to next target maneuver. To calculate the necessary delta V for the de-orbital push and counter push to the next target phasing orbit the target craft is evaluated.
a) A camera on a robotic arm completely scans the craft for loose parts, establishes a report on structural elements and how they might be affected by being pushed to 100 miles per hour or so in a few seconds.
b) The padded pushing mechanism closes on the target like a baseball glove. To calculate the weight it gently tugs it back and forth measuring the force to distance ratio to determine how much mass we're dealing with. This should be accurate to within a few ounces. So to move a 10,000 lb satellite 1 inch in one second I believe you'd use J = F̅Δt (oops, that got scrambled) which will be the core number for determining the necessary push to reach the necessary delta V to get both crafts in their desired disposition.
This gentle shaking can also determine how well the craft will stand up to the catapult maneuver, but any satellite is going to be designed from the start to structurally handle some pretty big G forces.
3- The craft once properly lined up pushes the target satellite from a relative 0 to perhaps 100 miles per hour pushing a satellite directly downward would add to its radial error, but it's more effective to reduce its along-track velocity to lower its perigee into the denser layers of the atmosphere, where drag will further slow it down and lead to re-entry. Of course the trajectory would also be determined by the next orbital station alongside the next target.-- doctorremulac3, Jun 04 2024 In the illustration I'm going to add stencils of targets "killed" on the side of my catapult ship. Add an element of fun eh?-- doctorremulac3, Jun 04 2024 //The two crafts rendezvous// - this sounds very expensive. The target will be moving at thousands of miles per hour in a random direction. Once that's dealt with, the next target will be moving at thousands of miles per hour in a different direction. You'll need a lot of fuel to get a craft into orbit and able to do more than one of these manoeuvres (and then more fuel to carry that fuel into orbit).-- hippo, Jun 04 2024 //random direction// Uhh...
//You'll need a lot of fuel to get a craft into orbit and able to do more than one of these manoeuvres (and then more fuel to carry that fuel into orbit).//
Well, you get an A for spelling on the first one at least. Misspelled maneuvers on the second one. Since this is an American operation we do maneuvers not maneuauveror... however you spell it.
Read the part about using the target satellite as reaction mass. It's the whole point
And if I suggested using magic other than a standard chemical rocket to achieve the first phasing orbit I must have made a booboo, thanks for helping. Couldn't do this without you.-- doctorremulac3, Jun 04 2024 Ah, a booboo feelings bone. Aaaaand, we're done.-- doctorremulac3, Jun 04 2024 Haven't read all the annos yet, but I think you'd burn more fuel for the rendezvous than what you'd gain by the push, not even counting the fuel to get you there in the first place.
Hitting them in even slightly the wrong angle would be impossible to account for in terms of your trajectory. The resultant orbit could then go rogue pretty fast into some other important stuff. Afraid this would make space that much harder to navigate. Imagine billiards operating at miles per second and trying to hit a pocket a few thousand miles away based on a cue ball shot with some random wind directions thrown in on the way up.
But bun for the interest. Seems like a fun one to bounce off of the XKCD guy.
I'm curious as to what remains bouncy in the weird temps of space at either radiant heat extremes or quite chilly.-- RayfordSteele, Jun 05 2024 So to clarify, all interactions between the two satellites are very controlled. No sudden impacts or strikes. Original title referred to “hopping” which was probably the wrong word.
The plunger on the right that pushes the old satellite is about 100 feet long so it's only partially shown. Need to get up to some pretty high speed to push both crafts away from each other and the appropriate velocities and you have to get up to speed without shattering everything and spreading more space junk. The contact assembly is padded and very flexible but strong enough to impart the necessary force.
When the satellites rendezvous the catapult ship grabs the target and moves it back and forth to weigh it. It then calculates the velocity and trajectory necessary to de-orbit the vehicle while using the resulting reaction to reach the next target. The push, while resulting in high speed would be gradual to keep the target satellite intact.
So it would be very controlled with each case having specific customized forces and angles used for that specific satellite and orbit.-- doctorremulac3, Jun 05 2024 I'm going to look into another one that uses pull cables to pull instead of push. Might need less mass, get up to higher speeds but the piston still looks most promising.-- doctorremulac3, Jun 05 2024 [doc], that's a great explanation and I really do like this concept. But while I think you might be able to de-orbit a satellite by pushing against it, I don't think the pusher will be able to use the reaction to chase up to another satellite[*].
Here's why: The force you will be applying will come entirely from the motion of the plunger - whether powered by a nuclear reactor, solar panels, stretched rubber bands, etc. No matter how careful or abrupt the push, the delta-v will be divided between the two satellites in proportion to their respective masses. Plainly out, the heavier one's orbital velocity won't be affected as much as the lighter one.
Imagine Stan Laurel and Oliver Hardy standing on a smooth frozen lake. Stan reaches out and pushes Ollie. Ollie hardly moves, while Stan goes zinging off at high speed. If it happened the other way around, Ollie pushing Stan - we can assume Ollie is stronger and can push harder, but the effect won't look much different. The heavy one's velocity changes a little bit, the light one gets most of the effect.
Do you see your pusher more as Stan or as Ollie?
[*] And I might be wrong - the only way to know will be for someone to model it. Anybody here play KSP and want to try it?-- a1, Jun 05 2024 If Laurel, or whoever the fat one is, pushes Hardy at 200 miles per hour Laurel's moving quite quickly in the other direction. Only 50 miles per hour? Okay, so? Since it's unimportant how fast the target satellite moves since that's only about trajectory, not speed, you can adjust that push to whatever you need to get your catapult satellite to it's next rendezvous point.
The catapult satellite is about the average weight of the satellites it's hunting and that weight can be adjusted for various missions. One might be going after 2,000 pound average satellites. Future missions after 2,500 pound satellites etc.-- doctorremulac3, Jun 05 2024 Yep, it's all about vectors. My own take on it was based on my intuition and I admit I could be wrong, but it's your concept so I'd leave it to you to show me more detailed numbers. You'd need to do that to get a grant proposal anyhow...
For simplicity, let's imagine two satellites, each in idealized circular, equatorial orbits. I'll steal an example from Wikipedia: "... for a circular orbit of 200 km (120 mi) the orbital velocity is 7.79 km/s (4.84 mi/s), but for a higher 1,500 km (930 mi) orbit the velocity is reduced to 7.12 km/s (4.42 mi/s). The launch vehicle's delta-v needed to achieve low Earth orbit starts around 9.4 km/s (5.8 mi/s)"
There's your starting point (or anyone else's) for this exercise. Plug in any masses you want for the catapult device and for the target in the lower orbit. Calculate how much force the pusher needs to apply to de-orbit the first target, and if the catapult can get enough boost from that to reach the higher one, eventually.-- a1, Jun 05 2024 New idea (Not really practical, just a thought experiment):
1- Cable on a fishing pole on catapult satellite.
2- Reel it out 1,000 feet or so contacting target satellite.
3- Reel it in very fast
4- Catch it so it's spinning around the catapult ship.
5- At the appropriate time, release the target satellite like a hammer thrower in the Olympics.
Again, these are moring coffee thought experiments, nothing to see here folks.-- doctorremulac3, Jun 05 2024 That would look nifty - and may work just as well as the original pusher concept. Stil need to address all of the same considerations of how much force you can apply through the reel and the comparative masses of the catapult vs target satellite.
You earlier description and illustration still reminds me of a giant pool cue though. Maybe I should have used Minnesota Fats and Fast Eddie Felson instead of Stan and Ollie in my earlier example.
Pool cues, fishing poles? Could be a whole line of sports & leisure inspired satellite capture systems. Maybe a cesta as used in jai alai would work.-- a1, Jun 05 2024 The other idea is to have a hoop shaped affair with two main units on either end. The cable or cables extends from these, attaches to the target, then pulls the cable. Not sort of like a slingshot, exactly like a slingshot.
Now with this lightweight cable if you're careful you could really get a lot of pull for less weight and you don't get all that mass slamming the slingshot ship in the wrong direction that you get with that plunger.
Only downside is you are pulling the two ships together and collision would need to be avoided, but I don't think that would be hard. Make the hoop wide enough probably be pretty hard for the crafts to collide.
Gonna draw this one next. (link)
Probably only have two cables, to extend them out think I'd pump them with compressed gas to make them rigid that would be reused after the target was grabbed.-- doctorremulac3, Jun 05 2024 Left something out, the way the system resets. At the outer limits of its particular mission cycle, it grabs a target satellite and shoots it away from the Earth and out of orbit or at least into an orbit that will eventually return to Earth.-- doctorremulac3, Jun 05 2024 random, halfbakery