SpaceX said it is still trying to figuring out what caused its rocket to break apart during liftoff nine days ago, but it's getting close.
The unmanned Falcon 9 had just lifted off from Cape Canaveral on June 28, carrying cargo for the International Space Station, when the accident occurred.
More than 5,200 pounds of Space Station cargo was on board, including the first docking port designed for future commercial crew capsules, a new spacesuit and a water filtration system.
Speaking Tuesday at a conference in Boston, SpaceX founder and chief executive Elon Musk said the trouble appeared to be in the upper stage, with an overpressurization of the liquid oxygen tank.
The company is putting together what he called a "super-detailed" timeline, millisecond by millisecond.
So far, he said nothing seems to fit "all the dots." But he hopes to have something definitive to say by week's end.
Musk said the accident was "a huge blow" to the private space firm's program.