Ahead of today's second free practice session, the air temperature is 25 degrees C while the track temperature is 38 degrees.

While Sebastian Vettel and Mark Webber led the way this morning, the big news is that Lewis Hamilton crashed round about the halfway mark. The fact that teammate Jenson Button almost suffered a similar fate - at the same corner (Degner) - suggesting that it might have been an issue with the car rather than the driver.

Worryingly, with just a few minutes before the session kicks off, Hamilton is still in his McLaren polo-shirt as opposed to his overalls, suggesting that he won't be going out for some time.

Tyres this weekend are hard (prime) and soft (option) though we didn't see the softer tyre this morning.

When the lights go green once again it is Alguersuari who leads the way. Keen to get back to work, Vettel is one of the first drivers to take to the track.

Just two minutes into the session there are fifteen cars on track with Mark Webber joining his Red Bull teammate.

In no time at all there are fifteen times on the timesheets with Hulkenberg (1:33.800) quickest of the lot.

As Alonso goes quickest in S1, Kubica crosses the line at 33.706 to go quickest overall. Moments later Alonso posts a 33.159, the Spaniard laying down the gauntlet.

As Alonso looks set to raise the benchmark higher, the Red Bull duo are back in the pits neither driver having posted a time. Button goes sixth with a 33.523.

Schumacher goes second with a 33.299, the German a multi-time winner here.

As Massa improves to fifth, 0.216s off his teammate's pace, Webber goes fourth (33.310). Vettel, Glock and Hamilton have yet to post a time.

Next time around Webber goes quickest in all three sectors crossing the line at 32.574. Moments later, on his first flying lap, Vettel goes third with a 33.152.

Next time around Vettel posts 32.501 out-pacing his teammate by 0.073s to take the top spot.

Another lap, another improvement for Vettel, this time the German posts a 32.210.

Twenty-two minutes into the session, Hamilton is finally in his overalls, looking as though he's about to do some work. Teammate Button is currently ninth, 1.313s off the pace.

Kubica goes off into the gravel in the S Curves but is able to continue. Shortly after, Yamamoto makes good use of the massive run-off at Spoon Curve.

Having gone quickest in S2, Webber closes to within 0.203s of his Red Bull teammate.

Petrov, the first driver to switch to the option (soft) tyre, goes quickest in the final sector and third overall, crossing the line at 32.703.

Halfway through the session, it's: Vettel, Webber, Petrov, Alonso, Schumacher, Massa, Kubica, Hulkenberg, Button and Barrichello. Still no sign of Hamilton.

Sutil (options) posts personal bests in all three sectors going fifth overall with a 33.211.

Massa is the first of the big guns to go out on options as Buemi has a big moment in the Toro Rosso. Massa posts a personal best in S1 and again in S2 however, having lost a heap of time in the final sector he can only manage 32.519 which is good enough for third overall.

While Schumacher improves to fifth on the option tyres there is no further improvement for his former teammate Felipe Massa. Seemingly, looking at some of the other drivers who have been out on the softer tyres, they are only good for one lap.

As Alonso improves to fifth (32.785), Webber goes quickest in the first two sectors finally crossing the line at 31.860. Both were on the soft tyres.

Button improves to fourth but remains 0.673s off the pace. 29:13 of the session remaining.