"Forty-fifth Space Wing Spokesman Jim Williams informs Florida Today the anomaly happened Saturday in Cape Canaveral Air Force Station while the SpaceX Crew Dragon capsule was experiencing a" static evaluation flame".
According to an internal memo seen by the Orlando Sentinel, the ban refers to workers employed by aerospace company Jacobs under the Test and Operations Support Contract (TOSC).
SpaceX moved the landing offshore after an April 20 test failure at one of its landing pads destroyed a Crew Dragon capsule.
Koenigsmann says SpaceX's engineers have been given "no reason" to believe there is anything amiss with the SuperDraco engines themselves, so it seems likely that some other unforeseen issue cropped up during the launch.
"While it is too early to confirm any cause, whether probable or crude, the initial data indicates that the anomaly occurred during the activation of the SuperDraco system", he added.
SpaceX was supposed to perform an in-flight abort test next with the vehicle that was destroyed, followed by a test with crew to the ISS as early as July with an updated version of Crew Dragon.
In the last minute, the launch was postponed until April 30, which NASA and SpaceX justified by the need for some more checks and tests, and also to wait for better orbital conditions. "It's certainly not great news for the schedule overall, but I hope we can recover".
Koenigsmann said the company is now focused on the investigation into the mishap, and declined to estimate how much of an impact it will have on the schedule of upcoming test flights.
"Here's what we can confirm ... just prior to when we wanted to fire the SuperDraco, there was an anomaly, and the vehicle was destroyed, " Hans Koenigsmann, SpaceX Vice President of Mission Assurance said in a press statement.
Koenigsmann said the company has been in touch with astronauts Doug Hurley and Bob Behnken - who will be on board for the crew Dragon's next test flight to the space station - and that the two have offered encouragement and motivation.
"I don't want to completely preclude the current schedule", he said.
Boeing's launch plan also encountered multiple delays.
SpaceX is launching its 17th cargo resupply mission to the International Space Station (ISS) tonight, onboard the Falcon 9 rocket.
The company still needs to conduct a launch-abort test, before astronauts strap in.