SpaceX the Alan Notes

BOSTON, Mass. — SpaceX engineers still aren't exactly sure what caused the company's Falcon 9 rocket to disintegrate minutes after it launched on an uncrewed mission to the International Space Station on June 28, Elon Musk, the company's founder, said Tuesday.

This failure marks Falcon 9's first major accident in 19 total launches. This disintegration has caused some people to question SpaceX's ability to accomplish some of the hugely ambitious goals — like creating a — that are integral to the company's long-term plans to make spaceflight more affordable.

SpaceX's Falcon 9 rocket exploded just after launch on June 28, 2015.

"We take these missions incredibly seriously."

People involved with SpaceX's investigation of the accident are continuing to pore over data collected during the rocket failure, but that information is not easy to interpret. The root cause of the failure is not an easy to diagnose problem, Musk said, and some of the data is conflicting.

"There's still no clear theory that fits with all the data, " Musk said, adding that, in spite of this, SpaceX is starting to get a sense of what likely happened.

The Falcon 9 rocket broke apart above Florida a little more than two minutes after it left the launchpad. The rocket was taking SpaceX's Dragon capsule loaded down with about 4, 000 lbs of food and supplies to orbit on the system's seventh cargo run to the Space Station under a contract with NASA.

Eventually, SpaceX plans to launch crewed missions aboard the Falcon 9 and its Dragon capsule.

The rocket failure also halted the company's plan to land this Falcon 9 on a drone ship in the Atlantic Ocean to demonstrate its reusable rocket technology. According to Musk, this reusable rocket test would have been SpaceX's best shot to land the rocket on the floating platform yet, following on the heels of three unsuccessful tests.

Oh, and the Falcon 9 failure also happened to occur on Musk's birthday.

"It was a real downer, " Musk said, getting a big laugh from the crowd. Musk also mentioned that SpaceX plans to try another rocket landing later this year, though he didn't specify when.

The Falcon 9 failure also dealt a blow to the International Space Station. The Falcon 9 accident marks the third cargo mission failure in eight months.

In October 2014, Orbital Sciences' Antares rocket exploded just after liftoff and in April, Russia's Progress resupply vehicle didn't make it to the ISS due to damage it sustained when flying to orbit.