What to know about Mark Kelly, the former NASA astronaut taking on CNN-hater Martha McSally

After Arizona’s Martha McSally, a Republican, called CNN reporter Manu Raju a “liberal hack,” her Democratic opponent, Mark Kelly, tweeted about his history of listening to science.

I spent my entire career at NASA and in the Navy using science, data, and facts to solve difficult problems.

Arizona needs independent leadership in the United States Senate.

If you agree, then join this mission #ForArizona. https://t.co/spjfkQtCrL

— Mark Kelly (@ShuttleCDRKelly) January 16, 2020

Here’s a refresher on who Kelly is:

• Kelly is a former NASA astronaut perhaps best known for his participation in the space agency’s “twins study,” where he remained on Earth while his twin brother, Scott Kelly, spent a year on the International Space Station. The study let scientists compare the two brothers after their year in the drastically different circumstances.
• Prior to that, Kelly himself made multiple voyages to space, including serving as commander of the space shuttles Discovery and Endeavour on some missions.
• Kelly also served in the Navy, including during Desert Storm, and was technically on loan to NASA from the Navy during his time with the space program. (McSally served in the Air Force, where she was the first female pilot to fly in combat and retired as a colonel.)
• Kelly is married to former Rep. Gabby Giffords, who resigned from Congress after sustaining a brain injury when she was shot during a scheduled appearance. Kelly and Giffords have since launched an organization calling for gun safety laws, including universal background checks.
• Kelly and McSally are facing off in a special election to finish out the final years of Republican John McCain’s term. After McCain died in 2018, Governor Doug Ducey appointed Republican Jon Kyl to the seat. Kyl resigned at the end of 2018, and McSally was appointed to the seat. The special election is scheduled for Election Day, November 3.