NEZAHUALCOYOTL: Estrella Salazar, a 17-year-old science whiz from a working-class town near Mexico City, was inspired by her sister to develop an app to help deaf and hard-of-hearing Mexicans communicate more easily.

Salazar's older sister, Perla, was born with a rare disorder that affects mobility and hearing, called MERRF syndrome. The 25-year-old has undergone close to a dozen surgeries followed by years of physical therapy, and was told by one sign language school that she would be unable to learn to sign due to her condition.

Salazar, whose academic prowess allowed her to graduate three years early from high school, said that, after seeing the discrimination Perla faced, she asked herself: "What am I doing to help my sister?"

Last year, she started developing an application to connect Mexican Sign Language (MSL) speakers with hearing users - allowing people to shift from sign language to text or voice, and vice versa.

An estimated 4.6 million Mexicans are deaf or hard-of-hearing, according to Mexico's statistics agency. There is a chronic shortage of certified MSL interpreters, though many Mexicans act as unofficial interpreters for deaf or hard-of-hearing family members.

Estrella formed a community of nearly 90 participants - including native speakers and interpreters - to develop the app, called Hands with Voice, which she hopes to launch this year. In recent months, the family has started to learn sign as Perla's mobility has improved.

"I'm proud of my sister," said Perla. "And I've liked finding a community along the way."

In addition to juggling the app development and university studies in biotechnology engineering, Salazar gives science classes near her home in Nezahualcoyotl, 5 km (3 miles) northeast of Mexico City.

"I think it's time to change the way people think," Salazar told Reuters: "to be able to create a culture where, in the future, there will be lots of children working on scientific and technological projects."

Salazar's mother, Leticia Calderon, said she would take a young Estrella to her sister's therapy sessions and noticed how quickly she caught on. To practice Perla's speech, Calderon would ask her daughter questions about what she was learning in school.

"I would put (Estrella) in the highchair, and from there she would tell her sister the answers to her exams," Calderon said.

Salazar's appetite for learning quickly outpaced what teachers in Nezahualcoyotl could offer, she said. By the time she was 15, Salazar passed her high school exams and was keen to start to apply her knowledge.

Salazar was one of 60 young people chosen to attend the International Air and Space Program, a five-day camp this spring run by a NASA contractor in Huntsville, Alabama, home to the Marshall Space Flight Center.

To cover the cost of the $3,500 camp, Salazar launched a crowd-funding campaign on her Instagram account. With weeks left to reach her goal, she says she's 75% there.

Now, Salazar said, she's on the hunt for a U.S. university that will allow her to continue her investigation on the neurological impacts of COVID-19, both during active infection and after illness.

"I know young people, children, who have a way of thinking that says: 'It doesn't matter where I come from, what matters is what I'm going to do,'" Salazar said.

"I'm really proud to be from here, from Nezahualcoyotl, and to see kids learning and giving it their all to accomplish what they want to do."