What happens to objects that enter a Stargate from the wrong side?
Can a person/object pass through a stargate and go back again without having to shutdown the gate's wormhole, and without dialing again?
Because, when they sent a UAV to the volcanic planet, they control it in realtime and sending them back signals and video.
That being said, why can't they open a stargate from Earth and let the other side pass it. No DHD needed then, this is from the episode where the DHD fell to the ocean. Ok... the SGC does not know they cannot dial back, also the power might be cut off, but if ever they felt that their team is missing from sometime, can't they send a drone to see if everyone's OK, then they can report that they cannot use DHD somehow and ask the Earth team to open it to their side.