Doctors are set to replace a piece of US politician Gabrielle Giffords's skull with a plastic implant, another encouraging step in the congresswoman's recovery from a gunshot to the head more than four months ago.
The surgery comes just days after Ms Giffords travelled to Florida to watch her astronaut husband launch into space on the Space Shuttle Endeavour.
Doctors removed a piece of Ms Giffords's skull to allow room for brain swelling shortly after a would-be assassin shot her in the head on January 8, critically wounding her, killing six people and injuring 12 others at a political event in her hometown of Tucson, Arizona.
The three-term Democratic congresswoman has been wearing a helmet adorned with an Arizona state flag.
Doctors said when she arrived in Houston in late January they hoped to do the cranial surgery in May.
Dr Richard Riggs, chair of physical medicine and rehabilitation at Cedars-Sinai Medical Centre in Los Angeles, said the surgery to place the plastic implant is relatively simple.
Recovery is short - a day or two at the most - and is mostly from the effects of anaesthesia, he said.
"This gives her quality of life because she won't have to worry about the helmet and protection when moving around," said Dr Riggs, who is not involved in Ms Giffords's care.
The implant is placed under the scalp, allowing hair to grow on top so it is not visible.
Ms Giffords returned to Houston and rehab late on Monday from Florida, where she watched her astronaut husband Mark Kelly rocket into space.