There are three such footballs in existence. The first travels with the President, a spare is kept at the White House, and the third is with the Vice President. Anyways, the missiles would still be launched by the commander of National Military Command Center and multiple airborne command posts .
The Secretary of the Defense must agree with the POTUS top release nuclear weapons. Its called the “two man rule”. Secondly there are numerous classified airborne posts around the world to carry out the order for nuclear release. There is NORAD command and other posts to carry out the order. Its called rednudancy.