Complex sentence: On Mars, Benny has gained access to the STS system, but the controlling influence weakens the further away from the tunnels she gets and she recovers enough to send Zamina to the Doctor for help.
Split into simpler sentences: On Mars, Benny has gained access to the STS system, but the controlling influence weakens as she gets further from the tunnels. She recovers enough to send Zamina to the Doctor for help.