Ahead of today's opening free practice session, the air temperature is 23 degrees C, while the track temperature is 29 degrees. It is bright and sunny. However, the outlook for the remainder of the weekend is somewhat different with rain expected on both days.

A number of third/test drivers running today, including Romain Grosjean in Vitaly Petrov's Renault - a portent of what might be in 2012 considering the Russian's recent outburst? - while Jan Charouz has The dubious honour of replacing Tonio Liuzzi in the HRT. Nico Hulkenberg is in Adrian Sutil's Force India - another look ahead to next season? - Luiz Razia is in Jarno Trulli's Lotus and Jean-Eric Vergne is in Sebastien Buemi's Toro Rosso.

As he prepares to go out, Charouz is warned of a cross-wind on the back straight that links Turns 3 and 4, which happens to be the DRS zone this weekend.

The lights go green and Kovalainen leads the way, followed by Charouz, Kobayashi, Alguersuari, Vergne, Ricciardo and Razia.

Alonso is the first of the big guns to go out, however, it is Barrichello, possibly about to contest his final Grand Prix, who gets the applause.

Tyre options are medium and soft, with Pirelli two sets (per team) of experimental hard tyres today. A number of updates this weekend, aimed, as it happens, for next season. Among them, Lotus is running a new DRS rear wing.

TV director cuts to a new item, a helmet camera on Sebastian Vettel's car, thereby giving us a proper drivers' eye view of the action.

Eight minutes into the session everyone has been out, Schumacher and Rosberg the only drivers to stay out. Schumacher posts a 1:16.778 while Rosberg pits after posting 21.326.

D'Ambrosio, Charouz and Button are out for a second run, all performing practice starts at the end of the pitlane. Alonso watches from the pit-wall, the Spaniard looking remarkably relaxed.

After a period of almost no activity, the first phase of running gets underway in earnest. Grosjean goes quickest (16.069), ahead of Senna, Schumacher, Ricciardo, Charouz and Rosberg.

Massa goes quickest with a 15.774, the Brazilian really needing a result here this weekend. Despite the fact that he has a contract for next season, his future with the Italian team remains the subject of much speculation. Moments later, former teammate Schumacher goes second (15.914).

On his first flying lap Hamilton goes fourth (16.404) subsequently improving with a 15.078 to go quickest. Massa consolidates second with a 15.473.

Vettel goes tenth before improving to second with a 14.667, the helmet cam inducing a certain amount of sea-sickness. Massa remains third (15.350), ahead of Button, Alguersuari and Schumacher.

Vettel's car looking surprisingly under-steery in the corner that leads into the long uphill run which indeed leads to the start/finish straight.

Vergne, who dominated last week's Young Driver Test, goes twentieth with a 19.512, around 4.1s off Alguersuari's pace. Still, early days.

The times tumble and as the smoke clear - figuratively speaking - it's business as usual with Vettel and Webber atop the timesheets ahead of Hamilton, Massa and Button. All that's missing is Alonso you might say, however, despite completing 9 laps the Spaniard has yet to post a time.

Hulkenberg is sixth, ahead of Alguersuari, Grosjean, Rosberg, Schumacher, Kobayashi, di Resta, Senna, Barrichello, Maldonado, Perez, Vergne, Kovalainen, Razia and Glock.

Once back on track it isn't long before the McLarens turn the tables, Hamilton the first driver to dip into the 1:13s, Button subsequently posting a 13.825.

Grosjean leaps out of the Renault which has ground to a halt at the end of the pitlane. Being where it is, at the bottom of a steep hill, the Frenchman won't be back out again this morning.

As Vettel continues to suffer handling problems, Alonso improves to sixth with a 14.541, slotting in just behind his Ferrari teammate.

A 13.811 sees Webber go quickest, the Australian, running the medium tyre, dearly wanting to end his season with a win. Elsewhere, we're on-board with Vettel as he runs wide.

Glock complains that there is "something wrong" with his car. "Alright mate," comes the weary reply from the pit-wall.