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.

The House passed a similar version of Giffords' bill in 2010, but it was not taken up by the Senate. She reintroduced it on Jan. 6, 2011, just two days before she was shot.

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 the legal loophole that gives ultralight plane smugglers lesser penalties than those using other airplanes or cars and add a provision to aviation smuggling law to allow prosecutors to charge people other than the pilot who are involved in aviation smuggling.

It directs the Defense Department and Department of Homeland Security to work together to identify equipment and technology that could be used by customs officials to detect ultralights.

Udall said that hundreds of ultralight aircraft carrying drugs cross the border every year, each capable of carrying hundreds of pounds of narcotics.

"Congresswoman Giffords is committed to taking this crucial step that would help secure the border against drug smugglers," Giffords' chief of staff, Pia Carusone, said in a statement. "That's why she decided this would be the last bill she introduces before she steps down."