Ahead of today's opening free practice session, the air temperature is 28 degrees C, while the track temperature is 33 degrees. It is warm, bright and sunny, the rain of Britain and Germany a distant memory.

Jules Bianchi stands in for Nico Hulkenberg today, while Valtteri Bottas is in for Bruno Senna and Dani Clos for Narain Karthikeyan.

Tyre this weekend are medium (prime) and soft (option) rubber here, as in Australia, China, Bahrain, Valencia and Germany.

The lights go green and Vergne heads the eager beavers as they get to work.

The big talking point this weekend is engine mapping, as it was last Sunday. The FIA has moved to close the loophole but rival teams are wondering what other tricks Adrian Newey and Red Bull have up their sleeves. The Austrian team insists that it has done nothing wrong and that the closing of said loophole with not impact performance. Time will tell.

As Massa heads down the pitlane, Ferrari reveals that it has a lot of aerodynamic work to do today. Then again, ahead of the five week break, which includes a two week compulsory total shutdown, lots of testing of the non-stop updates needs to be carried out.

Five minutes into the session everyone has been out, a handful of drivers having completed two installation laps.

As the Lotus crews gathers at the front of the team garage, shielding prying eyes and camera lenses out, it is clear that the Enstone team is continuing with the mysterious DRS gizmo it introduced in Germany last Friday. This week however, it is on Grosjean's car.

Alone on track carrying out a series of single lap runs for aero testing purposes, concentrating on the front wing, Massa is joined by Bianchi and Kovalainen.

As Webber works out at the back of the Red Bull garage, Kovalainen posts the first time of the day, the Finn crossing the line at 1:29.977. Next time around the Caterham driver improves with a 28.508.

When Massa returns to the Ferrari garage, the most amazing array of sensor equipment is removed from the Brazilian's car… frighteningly complex.

No sooner has Kovalainen posts a 27.345 than Raikkonen crosses the line at 25.117. Next time around, despite going quickest in S3, the Lotus driver fails to improve.

"We have engine cooling problems," Raikkonen is told, "so as long a gear as you can please." The Finn returns to base.

Webber goes second (25.673) before being leapfrogged by Vergne (25.559), while Kobayashi goes fifth and Ricciardo sixth. After thirty minutes there are just six names on the timesheets.

Hamilton's first flying lap sees Hamilton go second (25.289), as Schumacher, Button and Grosjean leave the pits.

Button posts 26.500 but immediately goes quickest in S2 of his next lap, going on to post a 24.137 and go quickest. Moments late however, his teammate crosses the line at 23.941.

As the McLaren duo raise the benchmark, Hamilton posting 23.522, Schumacher goes third ahead of Raikkonen and Ricciardo.

Forty minutes into the session, as the McLaren drivers trade fastest times, Bianchi, Massa, de la Rosa, Vettel, Alonso and Perez are the only drivers still to post a time.

Schumacher, whilst complaining of understeer, runs wide, a week after a similar lapse in concentration saw him crash out of the opening session in Germany.

As Rosberg goes fourth (24.178), and Webber fifth, the Australian having completed 14 laps, the McLaren duo head back to the pits, Hamilton having set the benchmark time of 22.821.

Replay shows Perez suffering from oversteer in the final corner, while di Resta locks-up in Turn 1.

Alonso is on track, the Spaniard and Bianchi the only drivers yet to post a time. The world championship leaders posts 28.403 to go twenty-third.

At half-time, it's: Hamilton, Button, Schumacher, Rosberg, Perez, Massa, Webber, Bottas, Maldonado and Vettel.