husband Mark Kelly's space shuttle launch

Arizona congresswoman

travel for the first time since flown from Tucson to Houston more than three months ago

doctors gave permission to travel to Cape Canaveral, Fla. for launch of Endeavour

scheduled for 3:47 p.m.

Kelly is commander

met with doctors, neurosurgeon

President Obama and first family

shot in head on Jan. 8, killed six people and injured 12 others

married in 2007, went to Kelly's last launch in 2008, when he commanded space shuttle Discovery

Obama writes in Time magazine's list os 100 most influential people that "she's got the prayers of a nation rooting for her," is a "needed voice that cannot return soon enough

Kelly returned to training for shuttle launch in February after taking time off to be at wife's hospital bedside

two-week trip will be last for that shuttle and next-to-last shuttle mission

Kelly and five crewmates will deliver a $2 billion physics experiment to International Space Station as well as critical spare parts