McALLEN, Texas (Border Report) — A group of South Texas environmentalists is pressuring the FAA to release data on the potential risks to local border communities and wildlife if SpaceX’s Starship Super Heavy rocket were to fail on launch.

The nonprofit group Save RGV on Thursday released a strongly worded letter sent to the Federal Aviation Administration demanding more information on whether a launch failure study has been conducted on the massive Starship, which is being built to fly to Mars, and its engines are being tested a stone’s throw from Boca Chica Beach, on the U.S.-Mexico border.

“We believe that Starship Super Heavy poses an unacceptable risk of harm to the nearby communities of Port Isabel, Long Island Village, and South Padre Island, as well as to the immediately adjacent national wildlife refuge, state park land, and surrounding fragile tidal wetlands. We do not understand why the FAA is allowing the testing and possible launching of such a massive rocket in this sensitive and populated area,” says the Aug. 30 letter from the group’s board to Brian Rushforth, chief of staff for the FAA Office of Commercial Space Transportation.

For the past year, the FAA has been conducting an Environmental Assessment of SpaceX and its developing Starship Spacecraft and Super Heavy Rocket. SpaceX hopes to carry people to the moon, Mars “and beyond,” on the Starship one day, according to the company’s website.

But environmentalists say that when SpaceX CEO Elon Musk broke ground on the company’s private launch pad in 2014, SpaceX said it was to test and launch the Falcon 9 and Falcon Heavy rocket system — a significantly smaller and less powerful spacecraft. However, the private space company’s mission has since changed and SpaceX now wants to launch the massive Starship from this strip of beach a couple of miles from the Mexican border and where sea turtles nest and rare birds migrate.

“The situation now is different because we’re not talking about Falcon 9 and Falcon Heavy, we’re talking about something that is multiple times that large,” Jim Chapman, a board member for Save LNG told Border Report on Thursday afternoon. “It’s essentially 10 times that powerful. So what’s the worst-case scenario for Port Isabel, South Padre Island and all the communities that are nearby? We’re calling on the FAA to tell us.”

In January, the FAA briefly grounded SpaceX from launching at Boca Chica Beach after the private company launched its SN8 rocket prototype in December, even though the FAA had denied its request. However, the company in February was allowed to begin tests launches again after the FAA determined “that SpaceX complies with all safety and related federal regulations and is authorized to conduct Starship SN9 flight operations in accordance with its launch license,” the FAA said in an email to Border Report.

Several of these prototypes exploded upon liftoff and upon landing and Chapman and other environmentalists are growing increasingly concerned that the FAA is not holding SpaceX as accountable as it should, nor fully alerting the public to the potential dangers.

“We want to know how far the risk area extends,” Chapman said. “How far does the risk zone extend? That’s what the public needs to know.”

“We wrote letter to FAA and we’ve gotten no response. Nothing. So what does that mean? Does that mean they haven’t done the study? Who knows,” said Chapman, who also is president of the nonprofit Friends of the Wildlife Corridor. “If they had responded to our letter there wouldn’t have been a press release. This is a way to put a little more pressure on the FAA to do what they should do.”

Border Report has reached out to the FAA and asked if details of the launch analysis have been released yet, and what it reveals. The agency acknowledged receipt of our questions and this story will be updated if that information is received.