Hoping to rebound from their road loss to the Buccaneers, the Titans flew to Reliant Stadium for a Week 7 AFC South showdown with the Houston Texans. With Vince Young recovering from a quad injury, back-up QB Kerry Collins was given the start. In the first quarter, Tennessee drew first blood with kicker Rob Bironas getting a 52-yard field goal. The Texans would respond with LB DeMeco Ryans returning a fumble 26 yards for a touchdown. Afterwards, the Titans answered with Bironas kicking a 25-yard field goal. In the second quarter, Tennessee began to pound away as Bironas got a 21-yard field goal, while RB LenDale White got a 1-yard TD run. Afterwards, Bironas would end the half with a 30-yard and a 28-yard field goal. In the third quarter, the Titans continued its domination with Bironas kicking a 43-yard field goal, while rookie RB Chris Henry got a 4-yard TD run. However, in the fourth quarter, Houston began to rally as QB Sage Rosenfels completed a 7-yard TD pass to WR David Anderson and a 6-yard TD pass to WR Kevin Walter. Afterwards, Tennessee managed to reply. With Bironas' 29-yard field goal, he became the 5th kicker in NFL history to get 7 field goals in one game. However, the Texans managed to retake the lead with Rosenfels completing a 7-yard TD pass to TE Jeb Putzier and a 53-yard TD pass to WR Andr&#233; Davis. Fortunately, the Titans managed to get a historic last-second field goal. With his 29-yard field goal, not only did it seal the win for Tennessee, but it made Rob Bironas the first kicker in NFL history to get 8 field goals in one game.
Question: How many yards was the shortest field goal of the first half?
Answer: 21