Leonard Nimoy would have been 87 on Monday and both his children and NASA paid tribute to the late actor with touching social media posts. The Star Trek icon died in 2015. 

"From an immigrant neighborhood in Boston to the outer reaches of the galaxy. Quite the trajectory. Happy Birthday Dad. #LLAP," Adam Nimoy wrote. 

He also shared a black-and-white picture of his father.

"There will never be anyone that could mean the same to me as you. Love you always," Julie Nimoy wrote. She also shared a sweet picture.

"Today we remember @StarTrek actor Leonard Nimoy, who has been, and always shall be, our friend, on his #Birthday," NASA tweeted from its official history account. 

Nimoy, an accomplished actor and director, was also an excellent social media user. His last tweet before his death really resonated with fans: "A life is like a garden. Perfect moments can be had, but not preserved, except in memory. LLAP," he wrote. 

From an immigrant neighborhood in Boston to the outer reaches of the galaxy. Quite the trajectory. Happy Birthday Dad. #LLAP pic.twitter.com/bCZsZnnh8s

— Adam Nimoy (@adam_nimoy) March 26, 2018

Today we remember @StarTrek actor Leonard Nimoy, who has been, and always shall be, our friend, on his #Birthday pic.twitter.com/CN6e2z4FM9

— NASA History Office (@NASAhistory) March 26, 2018

Wishing the first man in my life, my dad @TheRealNimoy, a very Happy Birthday. Missing you today as I do everyday. There will never be anyone that could mean the same to me as you. Love you always. #LLAP #COPD @nimoycopdfilm @StarTrek @WilliamShatner pic.twitter.com/FmABYIxlrG

— Julie Nimoy (@Chefjen21) March 26, 2018

A life is like a garden. Perfect moments can be had, but not preserved, except in memory. LLAP

— Leonard Nimoy (@TheRealNimoy) February 23, 2015