Team science dominates scientific knowledge production, but what makes academic teams successful? Using temporal data on 25.2 million publications and 31.8 million authors, we propose a novel network-driven approach to identify and study the success of persistent teams. Challenging the idea that persistence alone drives success, we find that team freshness - new collaborations built on prior experience - is key to success. High impact research tends to emerge early in a team's lifespan. Analyzing complex team overlap, we find that teams open to new collaborative ties consistently produce better science. Specifically, team re-combinations that introduce new freshness impulses sustain success, while persistence impulses from experienced teams are linked to earlier impact. Together, freshness and persistence shape team success across collaboration stages.