A high-altitude balloon exploded in the early afternoon Tuesday at Spaceport Tucson, a launch site operated south of Tucson International Airport by startup World View Enterprises.
No injuries were caused when a large, tethered test balloon ruptured as crews deconstructed it after a successful ground test to fill the balloon, World View spokesman Andrew Antonio said.
The rupture resulted in a loud sound heard in the area, and a small fire on the balloon, he said.
"We have reached out to reassure our immediate neighbors," Antonio said. "There were no injuries and only superficial facility damage at the site."
World View says it can use either helium or hydrogen gas to fill its stratospheric balloons but has initially been using hydrogen, which company officials have said is safe when handled properly.
Raytheon Missile Systems, which operates its airport plant adjacent to TIA and Spaceport Tucson further south, sent an email message to its employees, explaining that a "substantial explosion" at the World View site had caused some minor damage to Raytheon buildings, such as falling ceiling tiles and dust debris, "as well as a litany of shock sensor alarms being activated."
A Tucson Fire Department unit was present during the blast after being invited to attend the test beforehand by World View, department spokesman Capt. Andy Skaggs said, adding that there would likely be no further investigation by his agency.
World View leases the site from Pima County for high-altitude balloon launches and operates the spaceport under contract to the county.