WASHINGTON – The astronaut husband of wounded US lawmaker Gabrielle Giffords plans to be at the helm of the Space Shuttle Endeavour when it makes its final launch in April, Politico.com reported Friday.

Astronaut Mark Kelly was due to make his announcement at a NASA press conference in Houston, Texas later in the day.

Politico gave no details on Kelly's difficult decision, citing only a source familiar with it.

Kelly, 46, has been at his wife's side since she was shot through the head on January 8 in Tucson, Arizona. He has been on leave since the shooting rampage that killed six people, including a federal judge and a nine-year-old girl.

Giffords is improving every day as she undergoes intensive rehabilitation therapy at a Houston hospital, Kelly said Thursday when he spoke at a national prayer breakfast in Washington.

"Every day, she gets a little bit better and the neurosurgeons and neurologists tell me that's a great sign, the slope of that curve is very important," Kelly said.

NASA had named a backup commander to train with the other five crew members, including Italian Roberto Vittori, an astronaut with the European Space Agency.

The 14-day mission, set to launch April 19 from the Kennedy Space Center in Florida, would mark Kelly's fourth and Endeavour's last.

Kelly's twin brother, Scott, is also an astronaut and is currently commanding the International Space Station.

Endeavour's crew will deliver to the space station a state-of-the-art cosmic ray particle physics detector "designed to examine fundamental issues about matter and the origin and structure of the universe," according to NASA's website.