WASHINGTON - A day after Rep. Gabrielle Giffords' emotional departure from Congress, the Senate on Thursday passed and sent to the president the final legislative act sponsored by the Arizona Democrat, who was severely wounded in an assassination attempt a year ago.

The legislation, passed by voice vote, increases penalties for those flying ultralight planes to smuggle drugs into Giffords' home state and other states along the border.

The bill "will not only help to secure our Southwest border, but it also affords us the opportunity to honor an incredible colleague," said Sen. Tom Udall, D-N.M., a sponsor of a Senate counterpart measure.

The House passed the legislation on a 408-0 vote Wednesday, minutes after Giffords formally submitted her resignation surrounded by hundreds of House members gathered to pay tribute to their wounded colleague.

A year ago, the 41-year-old Democrat was shot in the head and severely injured by a would-be assassin who opened fire at a meet-and-greet event outside a Tucson supermarket, killing six and wounding 13. Giffords, who is undergoing speech and physical therapy, said she wanted to devote all her time to her recovery.

Drug smugglers using ultralight planes have been subject to weaker criminal penalties than those flying larger aircraft because the single-seat planes that can fly low enough to evade radar detection have not been classified as aircraft under existing federal law.

The legislation would close that legal loophole.