Sierra Space CEO Tom Vice retired on Dec. 31, the company confirmed Monday, with Chairman Fatih Ozmen stepping in as interim CEO. Sierra Space was spun off from Sierra Nevada Corporation in 2021. It's valued at over $5 billion and among the most valuable private U.S. space companies. Delays in launching its reusable Dream Chaser cargo space plane have hindered its efforts to solidify its position in the industry. Dream Chaseris under NASA contracts for seven ISS cargo missions and is now targeting a May launch for its Tenacity space plane. The company continues to eye a potential IPO in 2025.