flytandem
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A discussion in another thread ( http://www.orbiter-forum.com/showthread.php?p=339056&postcount=10 ) brings up the idea of a lunar cycler. I found it a fun challenge and have set up a scenario for you to try.
The idea is simple but you might need the graphics from the report to understand it. A docked pair of craft head to the moon Apollo style. But instead of both inserting into lunar orbit, they separate a few hours before arriving at Pe and only the landing craft inserts and ultimately lands.
In the mean time, the other craft (the comfy more massive service module) slings off the moon into Earth orbit, but in an identical orbit as that of the moon going around the Earth, however inclined relative to the moon. This means that like tracing the edges of a skin of a wedge of cantaloupe the service module returns to the moon 14 days (1/2 orbit) later. The paper refers to this as a "backflip", cute name. It then slings in reverse of the first sling and heads back to Earth. In effect it's a free return but uses 2 passes at the moon to do it. During this second sling, the landing craft ejects and rendezvous with the service module. This is a fun and challenging maneuver.
A hint, what I did was to save after the lander was in low lunar orbit. I then did a trial run of the backflip craft to see what orbit inclination and LAN it would have when it returned to the moon. And then I placed a surrogate in low orbit at the moon to trace out the target orbit. Knowing that the moon would be rotating slowly under this orbit, I estimated a spot that would be about 9 or 10 days before it rotated to be under the surrogate. I landed there and when the positioned was under the surrogate I launched to the same orbit, which had me in good position for a clean rendezvous with the backflip craft when it came by a couple days later.
Here's the scenario. You have to set up the entire plan yourself. Fuel is low intentionally but it's not desperately low. There should be 400 to 500 or more extra deltaV in each ship that they actually need.
The idea is simple but you might need the graphics from the report to understand it. A docked pair of craft head to the moon Apollo style. But instead of both inserting into lunar orbit, they separate a few hours before arriving at Pe and only the landing craft inserts and ultimately lands.
In the mean time, the other craft (the comfy more massive service module) slings off the moon into Earth orbit, but in an identical orbit as that of the moon going around the Earth, however inclined relative to the moon. This means that like tracing the edges of a skin of a wedge of cantaloupe the service module returns to the moon 14 days (1/2 orbit) later. The paper refers to this as a "backflip", cute name. It then slings in reverse of the first sling and heads back to Earth. In effect it's a free return but uses 2 passes at the moon to do it. During this second sling, the landing craft ejects and rendezvous with the service module. This is a fun and challenging maneuver.
A hint, what I did was to save after the lander was in low lunar orbit. I then did a trial run of the backflip craft to see what orbit inclination and LAN it would have when it returned to the moon. And then I placed a surrogate in low orbit at the moon to trace out the target orbit. Knowing that the moon would be rotating slowly under this orbit, I estimated a spot that would be about 9 or 10 days before it rotated to be under the surrogate. I landed there and when the positioned was under the surrogate I launched to the same orbit, which had me in good position for a clean rendezvous with the backflip craft when it came by a couple days later.
Here's the scenario. You have to set up the entire plan yourself. Fuel is low intentionally but it's not desperately low. There should be 400 to 500 or more extra deltaV in each ship that they actually need.
Code:
BEGIN_DESC
2 deltagliders ("backflip" and "lander") docked at the ISS. Undock from ISS and connect them together. Use "backflip" to eject the pair to the
moon on a trajectory for a sling of moon to moon to Earth, doing a backflip (hint:set sling inclination angle to around -120). During the 14 day
flip which is just a half orbit of the Earth, land the "lander" deltaglider anywhere on the moon. Then launch it again and when "backflip" is
returning, rendezvous with it. This is to simulate a modified apollo-style CSM LEM team where the LEM in this type of maneuver has additional
deltaV and the CSM has less with overall fuel savings from the original Apollo missions due to the backflip strategy.
END_DESC
BEGIN_ENVIRONMENT
System Sol
Date MJD 55979.6092465784
END_ENVIRONMENT
BEGIN_FOCUS
Ship backflip
END_FOCUS
BEGIN_CAMERA
TARGET backflip
MODE Extern
POS 17.34 122.13 137.57
TRACKMODE TargetRelative
FOV 31.79
END_CAMERA
BEGIN_HUD
TYPE Docking
REF ISS
END_HUD
BEGIN_MFD Right
TYPE Docking
VIS
END_MFD
BEGIN_SHIPS
ISS:ProjectAlpha_ISS
STATUS Orbiting Earth
RPOS -2361546.09 5075683.05 -3736848.23
RVEL 5990.380 4337.598 2115.014
AROT 111.46 -16.04 80.01
AFCMODE 7
PRPLEVEL 0:1.000000
DOCKINFO 0:0,lander 3:0,backflip
IDS 0:588 100 1:586 100 2:584 100 3:582 100 4:580 100
NAVFREQ 0 0
XPDR 466
END
lander:DeltaGlider
STATUS Orbiting Earth
RPOS -5718393.32 -1994972.78 -2937133.46
RVEL -666.394 6875.684 -3383.406
AROT -73.98 11.66 105.92
RCSMODE 2
AFCMODE 7
PRPLEVEL 0:0.1480 1:0.1700
DOCKINFO 0:0,backflip
NAVFREQ 0 0
XPDR 0
NOSECONE 1 1.0000
AAP 0:0 0:0 0:0
END
backflip:DeltaGlider
STATUS Orbiting Earth
RPOS -2361560.20 5075697.47 -3736850.53
RVEL 5990.380 4337.598 2115.014
AROT -101.05 -71.17 -58.90
RCSMODE 2
AFCMODE 7
PRPLEVEL 0:0.160000 1:0.170000
DOCKINFO 0:3,ISS
NAVFREQ 0 0 0 0
XPDR 0
NOSECONE 1 1.0000
AAP 0:0 0:0 0:0
END
END_SHIPS
BEGIN_VistaBoost
END
