Complex sentence: Dommett initially specialised in aerodynamic heating and supersonic flows, he worked on the re-entry vehicle design for Blue Streak, and was more deeply involved in the design and analysis of the Black Knight re-entry requirements.
Split into simpler sentences: Dommett initially specialised in aerodynamic heating and supersonic flows. He worked on the re-entry vehicle design for Blue Streak, and was more deeply involved in the design and analysis of the Black Knight re-entry requirements.