Known for his career as a NASA Astronaut. In July 2014, he served as an aquanaut during the NEEMO 18 underwater exploration mission on board the Aquarius underwater lab. He was submerged for a total of 9 days.
He obtained his Bachelor of Arts degree in physics from St. John's University in 1989. Upon his graduation, he was commissioned a 2nd Lieutenant in the US Army after successfully completing St. John's ROTC program.
He began his career in the US Army as a combat Engineer. He obtained his master's degree in applied physics in 1999 from Stanford University. In 2015, NASA announced his selection as an Astronaut for ISS Expedition 51/52 in 2017.
He was born in Falls Church, Virgina. He subsequently grew up in Minnesota.
He served aboard the Aquarius for the NEEMO 18 underwater exploration mission alongside Thomas Pesquet.