On a historic and important day for Formula One, the air temperature is 12 degrees C, while the track temperature is 17 degrees. It's unseasonably cool, cold even, but bright.

We say historic and important because, after numerous botched attempts, the sport finally appears to have found a home in the country that is essentially the home of the motor car, the United States.

While it doesn't have the glitz on Monaco, the sparkle of Singapore or the opulence of Abu Dhabi, already there is a feeling that for once the sport has made the right turn, for once substance takes precedence over style.

There is only one test/reserve driver on duty today and that's Ma Qing Hua who will drive Narain Karthikeyan's car in this session, a move borne of financial needs rather than anything else.

Tyre options are hard (prime) and medium (option), the teams being given an extra set of the prime tyres today. Many believe that Pirelli might have been a little conservative this weekend.

Historic or not the timing system fails as the first drivers head down the pitlane, Kimi Raikkonen leading the way.

Unsurprisingly, the track is very green, as proven by Glock and Kobayashi, two of several cars to run wide. "It's very slippery," advises Massa, "very slippery". "It's worse than rain," adds Hulkenberg.

Massive wheelspin for Webber as he performs a practice start leaving the pits while, moments later, Vettel loses the back end as he enters the pits.

It might be the penultimate race but the teams continue to bring updates, even those no longer involved in the title fight, and new parts mean lots of flo-vis.

In the Mercedes garage mechanics are working on Schumacher's car, the German having returned to the pits with smoke and flames pouring from the back of the car. The German is running a new exhaust while Rosberg sticks with the old one.

Fifteen minutes into the session, Kobayashi is the first driver out for a second run. He remains on track and begins the first ever flying lap here. The car is sliding around and locking up (T12) the Japanese crossing the line at 1:54.846.

As Senna posts 56.291, Kobayashi improves with a 51.228. Moments later, Abu Dhabi winner Raikkonen splits them with a 54.902.

As more drivers pour onto the track Kobayashi gets down to 48.517 ahead of Raikkonen, Senna and Perez, however, a 49.870 sees Webber go second.

As Webber improves to 48.182, the cameras pick up a big excursion for Kobayashi at T17 and Vergne getting all crossed up at T13.

On his first flying lap, Vettel goes sixth (45.735), while Kobayashi raises the bar with a 45.866.

A 44.839 sees Webber take the top spot as Rosberg goes sixth and Schumacher eleventh. Di Resta is straight on the pace, the Scot going third with a 45.474.

Vettel runs wide at T19, the world champion now up to fourth (46.240), ahead of Perez, Senna and Vergne.

A 44.233 sees Vettel make it a Red Bull 1-2, the German 0.561s off his teammate's pace. Moments later however, the two are deposed when Hamilton bangs in a 42.603, over a second quicker than Webber's best.

Like Hamilton, Alonso wastes no time in making his mark, the Spaniard going quickest with a 42.538. Elsewhere a spin for Hulkenberg at T1.

As the drivers familiarise themselves with the track which is slowly becoming grippier, the times continue to tumble. Hamilton goes quickest again (40.918) ahead of Alonso, Rosberg, Vettel, Button, Massa, Webber, Grosjean, Schumacher and Hulkenberg.

As Hulkenberg has another spin, this time at T13/T14, Hamilton complains that the sun is making is impossible to see the warning lights.

Finally, at half-time, we have some live timing.

Alonso retakes the top spot with a 40.603 as Button improves to third, still no sign of de la Rosa.

Every lap sees an improvement throughout the timesheet, Hamilton and Button giving McLaren a 1-2 as the benchmark slips to 40.175.