NASA on Friday scrubbed the launching of space shuttle Endeavour's final mission due to an electrical issue. President Barack Obama and his family were among hundreds of thousands of people expected to be on their way to witness the shuttle program's second-to-last flight when the postponement was issued. 

A second launch attempt from Kennedy Space Center in Florida will not occur earlier than Monday, the agency said.

The Obamas hadn't arrived in Florida yet when the delay was announced--less than four hours before the scheduled 12:47 p.m. PDT launch--but they visited and toured Kennedy on Friday anyway as scheduled. There the president spoke to Endeavour's six-member crew as well as Arizona Rep. Gabrielle Giffords. The congresswoman, who was injured from an assassination attempt in January and has been recovering in Houston, arrived in Florida on Wednesday to see her husband Mark Kelly, mission commander, fly on the shuttle. It is unclear whether Obama and Giffords will return to watch Endeavour again.

The 14-day mission will deliver spare parts, critical supplies and experiments to the International Space Station, including a $2 billion particle physics detector called the Alpha Magnetic Spectrometer-2 to help researchers study the formation of the universe.