Tim Peake's message for Limavady boy with autism
It's not everyday you get a message from a real live astronaut, but that's what happened to seven-year-old Hayden Geraghty.
As the astronaut was being launched into space in 2015, Hayden began to count down to the rocket's take-off.
Since then, the little boy's speech has improved dramatically.
On Wednesday, Major Tim, who became the first British astronaut to blast off to the International Space Station, tweeted to say he was "delighted" that Hayden was making such great progress.
His mum Caroline said he is unrecognisable to the boy he was a year ago: "He was a very withdrawn little boy".
"He didn't make much eye contact and he was with very into himself," she said.
"We used to worry - are we ever going to find out what Hayden's all about?
"As the countdown began, he joined in. It totally transformed him and was the first proper sentence we'd had from him.
"He's been talking about space ever since".
Hayden is now the youngest member of the Astronomy Ireland club and even met his hero last year when Major Tim Peake visited Belfast in October 2016.