As well as change orbital characteristics (apogee, perigee, inclination) at reasonably low cost, enabling closer observation of specific portions of Earth, or of objects in space.
Burns at closest approach (perigee) have the largest influence on total orbital characteristics. Burns at furthest approach (apogee) can raise the entire orbit if desired.
Burns at perigee can only raise or lower part of the orbit though, right? A burn at perigee lowers or raises the apogee. To lower or raise the perigee, you need to burn at apogee.
It's funny, I remember first learning to use such arcane maneuvers in a game called Children of a Dead Earth, in order to get into a terribly low orbit of Neptune to strike a methane refinery... My poor brain was always used to simple Hohmann transfers in games like KSP!
Could another benefit be the ability to change payloads? If there was a desire to change the orbits and payloads, then could these serve a function as a more responsive version of existing satellites?
The US Space Shuttle could similarly "change payloads", with its modular payload bay capable of carrying either one-time cargoes (often satellites for launch), or reusable modules such as Spacelab, parts of which flew on a total of 35 Shuttle missions.
But modularity is also inherent in conventional rocket-based launches, with cargoes fitting within the fairing bay capable of being deployed or orbited.
Changing payloads in space is a rather different prospect, though the ability to rendezvous with, take on-board, and de-orbit satellites (man-made or artificial, the US's own, or other nations') is another possible capability. The X37's small size gives only limited potential here, and I'm pretty sure that if the US were snatching other nations' satellites we'd have heard about it.
Comments
As well as change orbital characteristics (apogee, perigee, inclination) at reasonably low cost, enabling closer observation of specific portions of Earth, or of objects in space.
Burns at closest approach (perigee) have the largest influence on total orbital characteristics. Burns at furthest approach (apogee) can raise the entire orbit if desired.
(Or so I understand.)
Burns at perigee have best efficiency to make in-plane changes (raise or lower orbit) due to the Oberth effect.
Burns at apogee have best efficiency for out-of-plane maneuvers (change orbital inclination plane) due to lowest velocity of the spacecraft.
Highly elliptical orbits can do both at a few hours' notice.
Burns at perigee can only raise or lower part of the orbit though, right? A burn at perigee lowers or raises the apogee. To lower or raise the perigee, you need to burn at apogee.
Correct.
Burns don't have to happen only at perigee/apogee so there's more flexibility in practice. And counter intuitive stuff like bi-elliptic transfers.
Ahhhh, bi-elliptic transfers!
It's funny, I remember first learning to use such arcane maneuvers in a game called Children of a Dead Earth, in order to get into a terribly low orbit of Neptune to strike a methane refinery... My poor brain was always used to simple Hohmann transfers in games like KSP!
Thanks, I've got only a vague grasp of this.
Could another benefit be the ability to change payloads? If there was a desire to change the orbits and payloads, then could these serve a function as a more responsive version of existing satellites?
I'm not sure what you mean here.
The US Space Shuttle could similarly "change payloads", with its modular payload bay capable of carrying either one-time cargoes (often satellites for launch), or reusable modules such as Spacelab, parts of which flew on a total of 35 Shuttle missions.
<https://en.wikipedia.org/wiki/Spacelab>
But modularity is also inherent in conventional rocket-based launches, with cargoes fitting within the fairing bay capable of being deployed or orbited.
Changing payloads in space is a rather different prospect, though the ability to rendezvous with, take on-board, and de-orbit satellites (man-made or artificial, the US's own, or other nations') is another possible capability. The X37's small size gives only limited potential here, and I'm pretty sure that if the US were snatching other nations' satellites we'd have heard about it.