Ahead of today's opening free practice session, the air temperature is 34 degrees C, while the track temperature is 45 degrees. It is bright and sunny.

The lights go green and it is Brazil GP winner Mark Webber who is first out, followed by Heidfeld, Buemi, Sutil and Liuzzi. Within three minutes of the start of the session all but Barrichello have been out.

Vettel advises his team that the track is "dusty" and "slippery", which is hardly a surprise.

Tyre options this weekend are medium (prime) and soft (option), the same combination used in Belgium and Italy.

Nine minutes into the session Barrichello finally makes an appearance, the Brazilian widely thought to be making his last appearance for Brawn this weekend.

Alguersuari is the first driver out for a second run, the Spaniard likely to post the first ever (F1) lap time here. Sure enough, fifteen minutes into the session, the Toro Rosso driver crosses the line at 1:55.624.

Hamilton heads down the pitlane, however, after another installation lap he heads back to the pits.

As he gets used to the track, not to mention the dust, Alguersuari gets down to 49.545. Elsewhere, Buemi and Grosjean get to work.

As Alguersuari raises the benchmark with a 49.388, Buemi posts 50.961 to go second.

Rosberg and Fisichella leave the pits as Buemi goes quickest with a 48.373. Shortly afterwards, watched by Michael Schumacher and Felipe Massa, Raikkonen gets to work.

On his second flying lap Rosberg goes second (49.138), as Buemi goes quickest in all three sectors finally crossing the line at 47.207.

Buemi and Rosberg both improve as Kobayashi goes fourth (48.081), ahead of Raikkonen. Webber improves from tenth to sixth with a 48.123.

A 46.117 sees Rosberg go quickest, as Kobayashi goes third ahead of Webber, Fisichella, Nakajima and Raikkonen.

The painted run offs are somewhat reminiscent of Paul Ricard, however, of more concern is that that as is becoming the norm these days, drivers are able to run very wide, making full use of the run offs, without punishment.

A 45.649 sees Webber go quickest, as Rosberg goes second (46.093), ahead of Rosberg and Nakajima, both Williams drivers making their final appearances for the Grove outfit.

It's a Red Bull 1-2 as Vettel secures the top spot with a 45.372. All but Sutil, Liuzzi and Button have posted times.

As Barrichello looks set to improve on sixteenth, Hamilton goes quickest in the middle sector, the McLaren star finally crossing the line at 465.619 to go tenth.

Kovalainen splits the Red Bulls with a 45.484 as Hamilton once again goes quickest in the middle sector, this time crossing the line at 45.713 to go fifth.

At half-time, it's: Vettel, Kovalainen, Kubica, Webber, Trulli, Hamilton, Nakajima, Alonso, Rosberg and Button. All but Sutil have posted a time, the Force India driver understood to be suffering a brake problem.

Despite appearing to lose time behind one of the Brawns, and not going quickest in any sectors, Hamilton goes quickest overall with a 44.908.

The Brawns are currently tenth (Button) and fifteenth (Barrichello), though the Brackley duo have only completed 17 laps in total.

Webber goes quickest in the first sector, finally crossing the line at 45.437 to go third. Kubica posts 44.988 to go second. Next time around Webber improves with a 44.805 to take the top spot.

Kovalainen goes quickest in the second sector, consolidating fourth place with a 45.236.

Heidfeld goes quickest in the first sector, however, Button is also on a strong lap. The new World Champion goes quickest with a 44.524 as a poor final sector means Heidfeld remains eighth.