Centauri Spaceworks has made advances in resuppply the planetary bases on BLU and PUR. Previously these bases were supplied with with a cargo bay on LK Lander Legs. After the tanks and batteries were empty, they were discarded. Launching the supplies back to orbit to be recharged was cost prohibitive since the LK Core and LM Ascent stage can only hold three cargo. This uses fuel and leaves the discarded lander legs on the surface.
The new approach documented below allows the expended tanks and batteries to be retrieved from the surface and recharged in an orbital station. The resupply does take several minutes to complete, however it only uses a small amount of fuel, and does not require a launch of supplies from HOM. This makes it much more environmentally friendly and cost effective.
For this proof of concept effort, Centauri Spaceworks launched a very small station consisting of an oxygen garden and an ATV. The station was located in geosynchronous orbit above the base on BLU. It was just above orbital velocity. Below is the procedure for the cargo transfer and recharge.
Step 1: Pre-separation
- Secure cargo
- Close hatch
- Check that fuel switch is closed
Note: If your station is relying on the ATV for power, at least one battery needs to remain in the ATV to power the station.
Step 2: Separation
- Check velocity to insure it is still above orbital velocity
- Add velocity with thruster burn if required
The transfer won't work if the ATV is docked to something else. The separation will push the ATV into a lower orbit above the tops of the ground modules. If the station is set up at the correct altitude this will position the ATV for the transfer without using any fuel.
Step 3: Transfer Cargo
- Switch to cargo mode and prepare for transfer
- Transfer cargo
- Switch back to fly mode to prepare for re-docking
When the ATV passes overhead of the modules, you can transfer cargo between them. This has a limited range so the ATV has to be in a low orbit and nearly overhead to the ground modules. At this point the ATV will be moving faster than the ground modules so there is a limited time to transfer cargo. It may take several orbits around to transfer all the cargo between the surface and the ATV.
Step 4: Re-dock
This part requires some piloting skill. You will need to use the main engines on the ATV to boost it to a higher orbit. Despite the ATV and station having similar velocities, this is not a straight dock. They have different ground speeds because of the difference in altitude. The station makes a bigger circle so it takes a longer time to make a complete orbit compared to the ATV. You will need to time the ATV's burn so that it reaches the station altitude at the same moment the ATV passes beneath the station.
Step 5: Recharge
- Connect ATV and oxygen garden power
- Recharge tanks in the oxygen garden
- Recharge batteries in the ATV