Mark Kelly and his twin brother Scott were both NASA astronauts. Scott is scheduled to embark on a year-long mission to the International Space Station later this month.
Mark retired from NASA to spend more time with his wife, Arizona congresswoman Gabrielle Giffords who was shot at a public appearance in 2011.
Mark now writes children's books. His latest, "Astrotwins: Project Blastoff" centers around a pair of twins who spend their summer building a rocket to orbit the earth.
As Mark tells Here & Now's Jeremy Hobson, the book is "about encouraging kids to dream big, to be interested in engineering and science and rockets" and to get some of them more interested in studying math and science.
Book Excerpt: 'Astrotwins: Project Blastoff'
by Mark Kelly
JULY 18, 1975
This time the twins were determined. Nothing would go wrong.
Scott had stationed Major Nelson, the family’s big, brown, friendly mutt, at the back door to bark if Mom came home early.
Mark had laid newspapers on Dad’s basement workbench.
They had assembled their tools.
And they were absolutely going to follow the advice Grandpa Joe gave them for anytime you took something apart: Lay the parts down in order so when you put the pieces back together, you can simply reverse the process.
“It’s like Grandpa Joe always says: Learn from your mistakes,” Mark said.
“Yeah, and since we’ve made so many, we ought to be geniuses by now,” Scott agreed.
Mark laughed. “Okay, so go ahead. I’ll keep everything organized.”
With a screwdriver made for repairing eyeglasses, Scott removed two screws, which Mark placed in the top left corner of the newspaper.
Then—the best part—Scott removed the plastic backplate and the boys got their first look inside Dad’s calculator.
“Cool!” they chorused.
Exposed, the insides resembled staples, pushpins, and grains of rice, all of them tiny and arrayed around a white plastic rectangle. The biggest piece was the battery, which was easy to recognize and easy to remove. After that, there were six more screws.
Mark duly put each in its place on the newspaper.
“Should we take out the CPU?” Scott asked.
- Mark Kelly, former astronaut and children's book author. He tweets @ShuttleCDRKelly.
This segment aired on March 18, 2015.