4 ms·

There sort of are some ejection disposals, but they are rarely used due to how specific the orbital parameters need to be in order for that to be the “cheaper”

There sort of are some ejection disposals, but they are rarely used due to how specific the orbital parameters need to be in order for that to be the “cheaper” option. You usually find it’s not exactly the sort of disposals your expecting though. Several space probes have used launch trajectories where their final booster stage will be placed into a heliocentric orbit, with the general trajectory placing it on an uncontrolled gravity assist and then the space probe will use a very small amount of fuel to precisely control the gravity assist it receives in order to get where it needs to be going… and the booster stage will have its already heliocentric orbit further changed by the gravity assist. It’s all about the deltaV … it takes way less to deorbit LEO and even some of the MEO satellites than to perform a lunar orbit raising, and GEO would be too costly to do either when which is why the GEO graveyard orbit belt is quite well defined… as for boosting the ISS up towards the moon to perform a Salyut 7 style long duration equipment survival experiment…. That’s a lot of fuel, and we already have that experience since we’ve been monitoring the entire ISS since we launched it…

westurner 3y ago
Would it be easier to band together the currently-unrecyclable orbital debris and waste and boost bundles of usable material with e.g. solar until it's usable in orbit or on the ground of a planet? Someone probably has the costs to lift n kg of payload into orbit then and today in today dollars. Matter persists in cycler orbits around attractors. Is there a minimum escape velocity for each pending debris object, and then also for a moon gravity-assist solar destination orbit? How much solar energy per kg of orbital mass is necessary to dispose by ejection in some manner? I'm reminded of Wonka's cane and the Loompland river. Can such orbits be simulated with Kerbal Space Program 2?
- techdragon 3y ago
  There’s two fundamental issues with that sort of approach: 1st, is the deltaV difference between useful and desirable orbits that satellite operators want to be in and the selected “disposal orbit band”… with GEO it’s just a small deltaV Hohmann transfer “up” into the geo graveyard “band”… the graveyard starts just 300km further out from earth and the geostationary satellite typically use on the order of 11m/s… which is bugger all. The Manned Manoeuvring Unit “EVA jetpack” had approximately 25m/s. 2nd, is sometimes overlooked, but nonetheless quite important aspect. Any graveyard orbit intended for use by multiple objects should cross the orbits of as few active spacecraft as possible and have as low of a relative velocity between the objects in that graveyard orbit as possible… Geosynchronous satellites are basically above all but a small number of very specific satellites in places like lunar orbit or Lagrange points, and “in a ring” so, performing a gentle boost to the graveyard orbit gets them out of the way of almost everything and they are at least as far as satellites go, not moving particularly fast relative to each other, and they are so high up nothing else is going to regularly cross their obit, so it’s a relatively low risk environment for a satellite on satellite collision… the majority of cycling orbits tend to have a LOT of relative velocity compared to the orbits they cross, tangential crossings leave high relative velocity, and the elongated orbits tend to end up crossing through a lot of space as the orbital precession moves along… on top of that the deltaV to go from most orbits to a cycling orbit tends to be relatively high, not as much as a full transfer to lunar orbit, but it’s basically in the same ballpark as using the moon to kick yourself into a solar orbit, which while potentially doable at considerable extra cost for a GEO satellite, is completely impossible for the sort of smaller LEO and MEO satellites without an entire kick stage, tug or other propulsion which would at least for LEO probably weigh more than the satellite does.
  - westurner 3y ago
    Such graveyarded debris and waste is potentially reusable in orbit, on the Moon, and on Mars. ~space tugs with electric propulsion: https://g.co/bard/share/df6189ac8113 https://g.co/bard/share/df6189ac8113 Is there an effective fulcrum on a lever in space if you attach thrusters at one end; like a space baseball bat? MEU: "Mission Extension Unit" How many kwh of (solar) electricity would be necessary to transfer to and from lunar cycler orbit to earth orbit to stay within the belt? 8, orbit, 8; or 8,8,orbit,8,8 etc?
westurner 3y ago
FWIU there are already-costed launch and refuel mission plans? Launch rocket_2 with fuel for rocket_1 which is already in orbit, attach to object_1, and apply thrust towards an optimal or sufficient gravity-assisted solar trajectory or bundle of space recyclables. Is there any data on space stations in Lunar Cycler orbits? Are there Lunar Cycler orbits that remain within the van Allen radiation belt? What would be the costs and benefits of long-term positioning of a space station or other vessel with international docking adapter(s) in a Lunar cycler orbit?

westurner 3y ago

Would it be easier to band together the currently-unrecyclable orbital debris and waste and boost bundles of usable material with e.g. solar until it's usable in orbit or on the ground of a planet? Someone probably has the costs to lift n kg of payload into orbit then and today in today dollars. Matter persists in cycler orbits around attractors. Is there a minimum escape velocity for each pending debris object, and then also for a moon gravity-assist solar destination orbit? How much solar energy per kg of orbital mass is necessary to dispose by ejection in some manner? I'm reminded of Wonka's cane and the Loompland river. Can such orbits be simulated with Kerbal Space Program 2?

techdragon 3y ago
There’s two fundamental issues with that sort of approach: 1st, is the deltaV difference between useful and desirable orbits that satellite operators want to be in and the selected “disposal orbit band”… with GEO it’s just a small deltaV Hohmann transfer “up” into the geo graveyard “band”… the graveyard starts just 300km further out from earth and the geostationary satellite typically use on the order of 11m/s… which is bugger all. The Manned Manoeuvring Unit “EVA jetpack” had approximately 25m/s. 2nd, is sometimes overlooked, but nonetheless quite important aspect. Any graveyard orbit intended for use by multiple objects should cross the orbits of as few active spacecraft as possible and have as low of a relative velocity between the objects in that graveyard orbit as possible… Geosynchronous satellites are basically above all but a small number of very specific satellites in places like lunar orbit or Lagrange points, and “in a ring” so, performing a gentle boost to the graveyard orbit gets them out of the way of almost everything and they are at least as far as satellites go, not moving particularly fast relative to each other, and they are so high up nothing else is going to regularly cross their obit, so it’s a relatively low risk environment for a satellite on satellite collision… the majority of cycling orbits tend to have a LOT of relative velocity compared to the orbits they cross, tangential crossings leave high relative velocity, and the elongated orbits tend to end up crossing through a lot of space as the orbital precession moves along… on top of that the deltaV to go from most orbits to a cycling orbit tends to be relatively high, not as much as a full transfer to lunar orbit, but it’s basically in the same ballpark as using the moon to kick yourself into a solar orbit, which while potentially doable at considerable extra cost for a GEO satellite, is completely impossible for the sort of smaller LEO and MEO satellites without an entire kick stage, tug or other propulsion which would at least for LEO probably weigh more than the satellite does.
- westurner 3y ago
  Such graveyarded debris and waste is potentially reusable in orbit, on the Moon, and on Mars. ~space tugs with electric propulsion: https://g.co/bard/share/df6189ac8113 https://g.co/bard/share/df6189ac8113 Is there an effective fulcrum on a lever in space if you attach thrusters at one end; like a space baseball bat? MEU: "Mission Extension Unit" How many kwh of (solar) electricity would be necessary to transfer to and from lunar cycler orbit to earth orbit to stay within the belt? 8, orbit, 8; or 8,8,orbit,8,8 etc?

westurner 3y ago

FWIU there are already-costed launch and refuel mission plans? Launch rocket_2 with fuel for rocket_1 which is already in orbit, attach to object_1, and apply thrust towards an optimal or sufficient gravity-assisted solar trajectory or bundle of space recyclables. Is there any data on space stations in Lunar Cycler orbits? Are there Lunar Cycler orbits that remain within the van Allen radiation belt? What would be the costs and benefits of long-term positioning of a space station or other vessel with international docking adapter(s) in a Lunar cycler orbit?