Complex sentence: Atlas 5D (June 6) performed well until booster separation at which point the fuel staging disconnect valve malfunctioned, leading to loss of fuel tank pressure, reversal of the intermediate bulkhead, and missile self-destruction at T +157 seconds.
Split into simpler sentences: Atlas 5D (June 6) performed well until booster separation at which point the fuel staging disconnect valve malfunctioned. Fuel tank pressure was subsequently lost, causing reversal of the intermediate bulkhead and missile self-destruction at T +157 seconds.