Charging the Gateway
The Gateway requires a certain amount of power to be transferred for a small amount of time, so make sure you bring a strong enough generator or a small/medium battery. If you are using your rover to charge, remember to bring an extender or a platform through which to transfer the power.
Once the Gateway is charged, you can interact with the object in the center to open up the gateway interface, allowing you to teleport between the unlocked gateways. Remember that oxygen cannot travel through a gateway, so make sure both have a tethered connection.