It is the place where Elon Musk might one day launch rockets on missions to colonise Mars, though it did not look like much on a drizzly and cold January afternoon.

Two construction sites with a pair of antennae, a few rows of solar panels and a fenced-off hillock. No astronauts, just a handful of workmen, a couple of RVs parked at the beach and birds scavenging through washed-up litter.

Boca Chica was not pulsing with activity and adventure. It was, however, freighted with irony as, 1,800 miles to the north-east, politicians duelled over funding for border security – specifically Donald Trump’s cherished wall, some of the first segments of which are likely to rise here in the Rio Grande Valley.

If Musk’s SpaceX realises its ambitions, the region will one day be a globally famous symbol of soaring human potential and the genius of American private enterprise. Today it is best known as the spot where a government is spending billions of dollars to restrict the movement of people. A location where barriers are installed, not shattered.

Musk is building a spaceport at the border between Mexico and the US in south Texas, where the dividing line between the countries is defined by the sinuous Rio Grande.

The modest delta where the 1,900-mile long river meets the Gulf of Mexico is reached by a two-lane highway that stretches for 20 miles from the suburbs of Brownsville through bleakly beautiful mudflats and ends at grassy dunes and a long strip of deserted beach.

To the north: a port, shipping channel and the sites of several proposed Liquified Natural Gas (LNG) terminals.

To the south: Mexico, as little as 250 metres from the road in places and 2.5 miles from the SpaceX launchpad by the beach.

Texas introduced legislation to allow for the closure of the beach during launches and offered millions of dollars in incentives to woo SpaceX, which took a small step towards Mars when it test-fired its behemoth Falcon Heavy rocket for the first time this month at the Kennedy Space Center in Florida. The company also blasts off from California, the state where it is headquartered.

Rick Perry, then Texas governor, now federal energy secretary, shovelled sand with Musk at the Boca Chica groundbreaking ceremony in 2014.

“It could very well be that the first person that departs for another planet will depart from this location,” Musk said at the time.

After some delays, preliminary operations reportedly could start late this year or in early 2019 and ultimately lead to as many as 12 launches annually, likely of satellites at first. The company did not respond to questions about the site.

‘It’s more a mental barrier’

The spaceport is expected to provide economic, educational and tourism opportunities for Brownsville and other districts in this broad region of 1.4 million people just across the river from the Mexican cities of Reynosa and Matamoros.

Brownsville and its neighbours are regularly cited as among the most economically deprived cities in the US; a third of the 185,000 city residents live in poverty and 37% are without health insurance.

Civic leaders hope the interest in SpaceX will give them the chance to tell positive stories about south Texas: its warm people, hot climate and vital wildlife habitats, a bilingual workforce, low crime rate and room to grow.

“There’s obviously excitement,” said Ramiro Gonzalez, a Brownsville city planner and liaison officer who wonders what the transformation could look like 20 years from now if the most ambitious hopes come to fruition. “Does anybody remember Houston before Nasa?”

But it is not easy to pitch glowing narratives to outsiders when the country is constantly hearing from the president, much of the ruling party and senior Republicans in Texas that the borderlands are an open gateway for Mexican rapists, drug cartel smugglers, would-be benefit scroungers from Honduras and, who knows, folks, maybe Isis terrorists.

The rhetoric hurts. So does the practical reality that existing fencing, let alone the proposed wall, cuts off large parcels of land north of the border and renders them undesirable, while tighter constraints on movement of people and goods through legal ports risks severing family ties and hampering economic progress.

“There’s all this land that is on the other side of the wall that is still in the United States of America,” Gonzalez said. “That presents a challenge. Because there’s thousands upon thousands of acres that have been cut off. Who wants to buy land on the other side of the wall?

“There’s a lot of development potential that could occur that isn’t necessarily going to occur any more because of that. It’s obviously a physical barrier but I think it’s more a mental barrier.”

Maria Cordero is an organiser with the American Civil Liberties Union in Brownsville, where palm trees perk up a downtown dominated by a university, colourful and shabby shops, busy river crossings and imposing border fences.

“We are not the images that the rest of the country has of the border,” she said. “We have dreams and ambitions and hopes for our community that are different from the narratives being painted from other regions.”

Last year, Cordero held a hundred “know your rights” meetings, many at the homes of undocumented families too afraid even to go to community centres or the Mexican consulate, lest they be detained by the immigration agents who saturate the area. She lives a mile from the Rio Grande and often sees law enforcement helicopters flying over her house.

Undocumented people, she said, “already have fear, and then comes a new administration”.

The White House’s redoubled deportation efforts under Trump, coupled with state and federal demands that local police work more closely with immigration authorities, have led to a climate of fear and suspicion, Cordero said, adding: “We are facing a lot of struggles and problems in the community”.

‘You’re trapped’

Celeste De Luna is among the Valley artists who have created works inspired by the surveillance apparatus.

“The general atmosphere just kind of makes people paranoid, the idea that there is so much militarisation,” she said.

“I don’t think a lot of people would like it if they were surrounded by a fence. People think about the border as ‘Oh, it’s our border.’ But they don’t live here. And their children don’t have to live with looking at a border fence and the implications of what that means. It’s an ugly thing.”

Even with the true economic benefits as yet uncertain and noting concerns about the possible impact on the environment and the safety risks of launching rockets, especially if the LNG facilities are built nearby, it seems clear SpaceX could be a significant boost.

For now, though, the main focus is on improving life on this part of the planet. Never mind travelling millions of miles to Mars – interior border patrol checkpoints mean that the Valley’s many undocumented residents are in effect unable to leave the southern tip of Texas.

Even travelling from the SpaceX sites back to Brownsville, all traffic must pass through one such checkpoint.

“That easy back and forth that once existed doesn’t any more, so you’re trapped,” said Michael Seifert, a local activist. “What they’ve done with taking [immigration] and making it red meat for the politicians is made that steep hill we have to climb that much worse.”