Balloon bursts at Tucson's World View plant

A balloon being tested on the launch pad at World View, the high-altitude balloon company, ruptured Tuesday afternoon, alarming many who heard what they thought was an explosion on Tucson's South Side.

The balloon burst as it was being deflated following a "successful test fill" at the facility near Tucson International Airport, company officials said.

The resulting boom was heard across much of Tucson, and workers in nearby offices reported that the shaking caused by the bursting balloon knocked down ceiling tiles. Some Facebook posts reported broken windows up to a mile away.

No serious injuries were reported, World View said Tuesday afternoon:

Following the completion of a successful fill test on the launch pad, during the process of backing out of the full fill configuration, a significant balloon rupture occurred which was reportedly heard in the local area. We have reached out to reassure our immediate neighbors. There were no injuries and only superficial facility damage at the site. The flight system itself was unaffected.

Early Wednesday morning, the company said that two employees reported ringing in their ears after the incident and were sent to an urgent care for evaluation.

TucsonSentinel.com asked the company for further details about the incident, but World View declined to answer most of our questions.

The balloon ruptured at 12:48 p.m., said company spokesman Andrew Antonio, who said he couldn't respond to questions about why the balloon failed, what gas mixture was being used, and what the nature of the test was.

"The test was conducted for a confidential commercial customer, so we’re unfortunately unable to disclose many of the details you’re requesting," he said Tuesday afternoon. "Confidentiality is key to our customers and is very normal in the aerospace business. So I can just reassure you that safety procedures and protocols were followed meticulously, (and) that everyone is OK."

"Some damage has been reported by a few residents and businesses in the area in addition to superficial facility damage at the site," Antonio said in the statement released overnight. "We will be proactively coordinating with the parties affected."

"We sincerely apologize for the inconvenience this incident may have caused our local neighbors. We are working to fully understand the cause of the incident to ensure that it cannot and will not happen again," he said.

A spokesman for the Federal Aviation Administration said Wednesday that he wasn't aware that the agency was investigating the incident at this time.

Spaceport Tucson, the 700-foot-wide pad near TIA, is operated by World View under a temporary waiver from the FAA.

But the company "does not have a commercial space license from the FAA, so the operation was not being conducted under the auspices of an FAA-issued license. Furthermore, the balloon was on the ground, not in the air, when the incident occurred, so there is not an air traffic component to the incident," said Ian Gregor of the FAA.

Because the balloon carried no passengers, the National Transportation Safety Board is not investigating the incident, an agency spokesman said.

World View's year-old plant was built for the company by Pima County, which is leasing the facility to the manufacturer for 20 years.

That deal, which prompted a lawsuit, was recently upheld by the Arizona Court of Appeals.

The startup plans to offer top-dollar balloon rides to the stratosphere as a marquee attraction for what will at base be an operation carrying scientific instruments and communications gear to high altitudes. Company representatives have said that World View has lined up government and corporate contracts to loft the instruments, including military and NASA applications. The deal with the county calls for World View to eventually employ 400 workers at the site.

World View founders Jane Poynter and Taber MacCallum, who were crew members of the Biosphere 2 experiment and also partners in local tech firm Paragon before leaving in 2014 to pursue investors for the new company, refused to make public many financial details of the company during the 2016 meeting in which the deal was OKed by the supervisors,

In addition to space tourism flights that are projected to cost $75,000 per passenger on what Poynter described as "very high-tech, high-altitude ballons," World View fill focus on carrying scientific instruments and communications gear nearly to the edge of space.

World View agreed to pay rent on the facility for 20 years, totaling about $23.6 million. The cost to taxpayers, after interest is included, will be about $20 million.

County officials said in early 2016 that the project should have total economic impact of $3.5 billion over 20 years, with the company having a $25.3 million annual payroll by 2020.