Answers emerge as SpaceX investigates April accident

• The first crewed SpaceX flight was expected to occur before the end of 2019, but the accident — which didn't cause any injuries — is likely to set those plans back.

Details: A SpaceX and NASA investigation team found that a leaky valve in the Crew Dragon's propulsion system was to blame for the explosion, which took place about 100 milliseconds before the company lit up the capsule's SuperDraco thrusters for a test firing.

• SpaceX says they've finished about 80% of the investigation and are switching out the problematic valves, among other fixes.

What to watch: NASA has yet to put out an updated expected timeframe for SpaceX's first crewed flight to the station.

• "I hope it's this year, but we're going to fly when it's the right time and when we know that we're going to be flying our crew safely." NASA Commercial Crew program manager Kathy Lueders said during a press call.
• Boeing is also working toward building its Starliner spacecraft under a contract with NASA to fly astronauts to the space station as well.