You really only need enough independent energy to get up to rendezvous, not enough independent energy to get back to earth. That saves on the amount of fuel you need to lift to have enough fuel to lift the fuel that you need to have to lift the fuel that you etc. etc. I’m assuming that getting an independent vehicle to Mars’ surface for sample return with enough energy to make the trip home is the issue. An Aldrin Cycler (thank you) means you don’t need to independently pack that fuel anymore.
If you’re meeting the cycler in its orbit, you’re already on a free return trajectory back to Earth by definition. You need another burn if you want to stop at Mars and another burn after that to leave and get back on a trajectory to Earth. In any event, you need to bring all of that propellant one way or another through some combination of independent launches. I’m still not seeing what a rendezvous with the cycler craft is doing for an unmanned mission. Any delta-v you take from the cycler has to be put back via refueling or reboosting at some point or another.
You really only need enough independent energy to get up to rendezvous, not enough independent energy to get back to earth. That saves on the amount of fuel you need to lift to have enough fuel to lift the fuel that you need to have to lift the fuel that you etc. etc. I’m assuming that getting an independent vehicle to Mars’ surface for sample return with enough energy to make the trip home is the issue. An Aldrin Cycler (thank you) means you don’t need to independently pack that fuel anymore.
If you’re meeting the cycler in its orbit, you’re already on a free return trajectory back to Earth by definition. You need another burn if you want to stop at Mars and another burn after that to leave and get back on a trajectory to Earth. In any event, you need to bring all of that propellant one way or another through some combination of independent launches. I’m still not seeing what a rendezvous with the cycler craft is doing for an unmanned mission. Any delta-v you take from the cycler has to be put back via refueling or reboosting at some point or another.