27/03/2015
NEWS STORY
Ahead of today's opening session, the air temperature is 29 degrees C, while the track temperature is 37 degrees.
Tyres available this weekend are the hard (prime) and medium (option). There are two DRS zones, one on the start/finish straight and the other on the final straight.
The big talking point this weekend is the return of Fernando Alonso, whose comments during yesterday's press conference posed more questions than answers in reference to his crash during pre-season testing.
This weekend also sees the return of Valtteri Bottas following his back problem in Melbourne and, hopefully, Manor following its no-show down under.
Having achieved a 1-2 here last year, and again two weeks ago, Mercedes is the red hot favourite here, however, Ferrari is confident than it can match its Melbourne pace here, this being a 'traditional' circuit.
While Sauber is looking to build on its Melbourne performance, and Williams keen to benefit from having both cars in action, all eyes are on Red Bull as its relationship with Renault worsens.
The only reserve driver on duty today is at Sauber where Raffaele Marciello replaces Melbourne star Felipe Nasr.
The lights go green and Ericsson leads the way, followed by a whole host of others including Vettel and Massa. Stevens, in the Manor, is another early riser as is Alonso.
Within the first five minutes all but Merhi and Bottas have made an appearance.
As he begins a run of four timed laps, Hamilton is told that he has no telemetry. He returns to the pits.
Sensors abound, some teams running the 'garden fence' variety witnessed pre-season.
Merhi is last out but immediately runs into problems, the car slowing and crawling its way back to the pits. He first reports problems with braking before adding he has lost power also.
Ericsson posts the first time of the weekend, the Swede stopping the clock at 1:44.483. Elsewhere, Bottas heads down the pitlane.
Verstappen posts a 42.725 and Massa 43.029 as Rosberg runs wide at T9.
Despite running wide, Bottas raises the bar with a 42.533 only to be beaten by Raikkonen and then Grosjean (42.202).
Oh dear, Rosberg gets serious with a 40.973, 1.229s quicker than Grosjean's best.
As Ricciardo goes third (42.226), Verstappen is told that he has a puncture and must abandon his run and head to the pits.
A big lock up for Raikkonen in T15 who subsequently runs wide. Rosberg improves to 40.561.
Approaching the end of the opening half-hour, all but Vettel, Stevens, Hamilton and Merhi have posted times. Indeed, Hamilton has stopped on track at T9 and is pushed to safety by the marshals. He climbs from the car.
As the circuit falls quiet, and the teams hand back one set of prime tyres, it's: Rosberg, Sainz, Raikkonen, Grosjean, Ricciardo, Massa, Ericsson, Kvyat, Bottas and Maldonado.
Hamilton says he could have got back to the pits but his team instructed him to stop on track.
There follows more than ten minutes of total inactivity. Some of it, admittedly, while Hamilton's car is rescued, but much of it with an eye on the four power unit rule and the need to save components.
Finally an engine fires up, and moments later Stevens heads down the pitlane. As he begins his first flying lap, the red and white car doesn't appear to bear a single sponsor logo, not even (team owner's company) Ovo Energy.
His first flying lap sees Stevens post 51.091, over 10s off the pace. Next time around he improves to 47.734s.
As Button seeks to improve on 44.395, Alonso prepares to go out in the second McLaren.
Stevens now up to 46.686, 6.125s off the pace.
A mistake by Alonso in T1 as he locks-up and misses the apex. He subsequently crosses the line at 55.313.
Grosjean improves to second with a 41.543, with Rosberg raising the bar ever higher moments later with a 40.124.
Verstappen improves (41.803) to make it a Toro Rosso 3 - 4.
Vettel goes sixth (42.137) but is subsequently demoted when Kvyat posts 42.055).
A 41.016 sees Raikkonen go second, the Finn much, much happier with the 2015 Ferrari.
Kvyat reports an issue with his brakes and then reports a loss of power, his team inform him that they were unable to recover sufficient energy on his previous lap. Still unhappy with his brakes, which he claims are "pushing him", Kvyat is told to pit.
Vettel improves to third (41.707) to make it a Ferrari 2 - 3.
Lots of work going on in the Mercedes garage on Hamilton's car, the gearbox having been removed.
Alonso is up to thirteenth (42.885) compare to Button's 43.100.
Merhi finally posts a time - leaving Hamilton the only driver yet to do so - the Spaniard stopping the clock at 48.937.
Mercedes reports that it is investigating an engine problem for Hamilton, "not the ideal way to start but we're working hard to analyse," it admits
Perez runs wide in T9, a corner which has caught a few drivers out this morning.
Merhi improves to 47.683, both Manors over 6.5s off the pace.
Into the final stages of the session, drivers are now on longer runs with an eye on Sunday afternoon.
A big slide for Bottas in T11, the Finn currently eighth, over 1.7s off the pace.
Maldonado runs very, very wide in T1 after locking-up, the result of carrying too much speed into the corner. Problems also for Alonso, the Spaniard experiencing massive understeer.
Now Massa has a back issue, the Brazilian revealing that the tube from his drink bottle is cutting into his back.
Problems clearly for Ricciardo also, the Australian's Red Bull absolutely covered in mechanics in the Red Bull garage.
A late charge by Raikkonen sees the Ferrari driver close to within 0.373s of pace-setter Rosberg, the Finn making a clear point as Mercedes works to get Hamilton's car fixed in time for FP2.
Rosberg is quickest therefore, ahead of Raikkonen, Vettel, Grosjean, Sainz, Ricciardo, Verstappen, Bottas, Kvyat, Ericsson Massa, Maldonado, Marciello, Alonso, Hulkenberg, Perez, Button, Stevens and Merhi.
Check out our Friday gallery, here.