Vega-5 exploration units are robot/droids designed to be totally automated since the planet Vega-5 stays at aprox: 11 light years , wormhole gates are expensive and still in the testing phase so they can't be easily replaced and even if they could they are way to complicate and hard to manufacture
Vega-5's only objective is to search for life / fossils / water basically anything that can benefit humanity in some way if they come across some new element they will immediately report it trough the main importance channel
Why are they looking for fossils is a easy answer since with our technology we can turn fossils into living beings we can expand our bio-station with new lifeforms never before seen.