Welcome back to ESPNF1's coverage of Friday practice from Spa-Francorchamps. FP2 is just over 20 minutes away, and the track is still damp...

While we wait for 2pm local time to come around, why don't you check out this video of a car on a track? It's not any car, it's a Red Bull, and it's not any driver, it's Tom Cruise.

Two drivers who will also be eager for more track time this afternoon are Bruno Senna and Paul di Resta. They both had offs at turn nine - Senna sustaining more damage by breaking his rear wing and suspension - and neither managed double figures in terms of laps completed.

Mercedes (OfficialMGP) on Twitter: "10 minutes to FP2. Not raining at the moment. It might by the the time this tweet is out!"

There was a little gap there while I watched the Tom Cruise video myself. He has a tough life...

Laurence has been with Lewis Hamilton today, and he's been talking about McLaren's development, saying that Red Bull is strong because it has evloved its 2009 cars over the past three seasons. He also wants McLaren to be less dependent on the downforce created from its exhausts, which of course has to change in 2012.

A bit of a strange one, but there's a driver change for FP2 today. Nico Hulkenberg is in the Force India in place of Adrian Sutil, as Force India thought FP1 would see the best weather.

The session is underway. Nick Heidfeld has just been talking to BBC 5 Live and he confirms there is a hearing on September 19th to see if he can have his seat back. He says there's no problem between him and Bruno Senna, nor any of the team mechanics with who he has a good relationship.

The installation laps are taking place on intermediate tyres.

Michael Schumacher is back on track having set the fastest time of the morning. If the track doesn't dry up enough then he may end up with the fastest time of the day.

The first timed laps come in even slower than this morning, Kobayashi with a 2:16.279, Alguersuari a 2:16.590 and Maldonado a 2:17.192

Michael Schumacher locks his right front and cuts the first part of Les Combes

Webber goes quickest with a 2:11.652 as the sun tries to break through.

Webber improves next time round to a 2:10.524

Alonso jumps up to second with a 2:10.839. We haven't had installation laps from Vettel, Hamilton and di Resta.

The sun is out, so the track should continue to dry and allow quicker lap times as Buemi runs wide at Les Combes

Of course, if you want to get in touch with us here you can do using the link above or via Twitter @ESPNF1_live. Laurence will try to answer any questions he can in between dodging showers in the Spa paddock.

Webber improves once again to a 2:09.094.

Senna is up in third, within 0.1s of Alonso as he makes up for lost time this morning.

At the top Webber just keeps lowering that mark (no pun intended), as he improves to a 2:08.351. Senna now second on a 2:09.558

Bruno Senna goes quickest on a 2:08.293, before Vettel comes through and beats it by 1.9s

Lachlan1116 on Twitter asks: "How much time does a Spa specific aero package give a driver per lap?"

It's difficult to put a time difference on it as we don't usually see teams run a non-Spa specification on the track. But the packages are designed to reduce drag, so teams will be looking for an extra 5 or so mph on the long straights. Obviously that is detrimental to cornering speeds, so it won't be a huge gain in time, just makes the car better suited to the circuit characteristics.

Rakesh emails in to say: "The late, great Ayrton Senna had said that "If you think Im fast, wait till you see my nephew Bruno!!". That most definitely was not going to be just a void statement, as it came from the great man himself."

That may be true Rakesh, but Senna is now down to seventh as the track dries further. Button now quickest with a 2:02.206, and Alonso second on a 2:03.953

The sun is shining, and we should see drivers venturing out on slicks soon as there's a dry line visible now. Schumacher has gone second quickest, 1.3s away from Button.

Rosberg rejoins the track on intermediates. Ferrari says its radar is showing no rain for 30 minutes, but some is headed in from the south.

And then Toro Rosso tells Buemi it will rain in 10 or 15 minutes. No-one knows anything when it comes to weather at Spa...

Kovalainen carries too much speed in to the chicane and spins trying to make the apex

Now Webber goes quickest with a 2:01.015

Oddly, Hamilton and di Resta are yet to go out on track...

Rosberg is going quickly, as Webber drops to a 2:00.964

Rosberg has backed off after I said that. Little under an hour to go in this session

Vinay emails in to ask: "Is there severe damage to Di Resta's Force India? Having lost much time in the first session, why hasn't he come out yet?"

We believe that di Resta's car wasn't heavily damaged, although he may have had a mechanical problem as he couldn't pull away after his accident.

Alonso is the first man on to slick tyres. He's fine through the dampest turn one and half a second up in sector one

This will be easily the quickest lap, as you would expect...

And there it is, a 1:56.292. That's about 2 seconds off Schumacher's pace of this morning.

A rush of cars out on track on slick tyres now. Schumacher sets the fastest first sector by some 0.8s

Hamilton radios in to tell McLaren he has some vibrations under braking, while sparks fly from his car as he tackles Eau Rouge

Schumacher goes fastest with a 1:55.186, but that is beaten by Alonso on a 1:53.942

Big differences between lap times now as drivers build up confidence on the slick tyres

Hamilton third quickest, 2.1s slower than Alonso. Schumacher is going quicker again - the Mercedes seems very fast in sector one.

Schumacher goes fastest with a 1:52.102. Alonso is second, half a second slower

Rosberg now quickest by 0.135s

Hamilton now fourth, 0.2s slower than Alonso. Sergio Perez just did a run on soft tyres but could only go fifth quickest.

EdmondsonESPNF1 on Twitter: "As he told the media yesterday, Hamilton is shutting his DRS in Blanchimont. He has to do that manually as it's not a braking zone. Hope he doesn't forget..."

Rain expected in about 15 minutes according to the radar, so we have a lot of cars looking to get lap times in on slicks. Only Alonso, Massa, Button and Senna not on track

Vettel just took Blanchimont with his DRS wide open. Shows how much more downforce that Red Bull has

And Vettel's gone quickest with a 1:51.794

Red Bull radio to Webber: "Mark the rain's coming in pretty quick, I think we should pit for softs. Box box box"

Hamilton flying in sector two, but he pits

Rosberg is quick in the first two sectors...he two disables his DRS in Blanchimont but still comes through to go quickest with a 1:51.242

Alonso now fastest after a run on soft tyres: a 1:50.461

Webber goes fastest with a 1:50.430 as the radar shows the rain closing in

Everyone but Petrov on track right now

Button has gone third, and now it's started raining...

Kovalainen goes off at Les Combes but rejoins. Everyone driving very carefully back to the pits

The pit lane is very busy as everyone comes back in.

Still 35 minutes to go in the session, but this rain is forecast to last for the rest of practice

Nobody on track now, so a quick mention to those further down the field. Hulkenberg is eighth quickest and di Resta is ninth, just 0.26s slower having only completed 6 laps. Senna is down in 17th now, 3.5s slower than Webber's time, while Petrov is last having not done a run on slicks.

It's very quiet as the drivers sit in the cars and look at the lap times. Now is the perfect time to get in touch with us...

And Jenson has done just that: "What is wrong with Petrov? It would have been good to see him do some laps and compare with Senna's times."

Petrov went out on soft tyres Jenson, but didn't set a time before pitting. Not too sure on the reasons why but could easily have been a case of traffic causing him to back off before the rain came.

Just under 25 minutes to go in the session, and rain still falling.

Jarno Trulli sat in his Lotus looks ready for a nap.

Rob emails in to ask: "What's wrong with Schumacher that he suddenly is so far down the pecking order? Did he set all his times too early and not hit the track at the optimal time? I want to see him do well this weekend. But looks like it might be the same story as ever. Nico just pips him at the final hurdle? Your opinion...?"

My opinion Rob is that Schumacher isn't that far down at all - he's 11th at present and just 0.2s slower than Vettel. The track conditions were ever changing and some drivers managed to get in a run on soft tyres before the rain came. It's just a case of when he set his last lap time, and this morning was obviously a very false position. Schumacher said yesterday that seventh or eighth was the aim.

Alex says: "Why did Renault put senna in the car when klien beat him in qualifying in singapore last year by over a second? Senna was coming with excuses even before he hit the track! I'm no fan of the ever complacent heidfeld but surely there were better options. Senna is way over rated and I reckon that ide bloke from super aguri would beat him on outright pace, super license or not!"

Senna is the Renault test driver Alex, so the natural replacement as he knows the team and has worked on this car so far this season. With no testing in-season allowed, that's crucial. He also should bring a lot of sponsorship money, which will help Renault if the speculation about its financial state is true. I fear a few people may disagree with your comment about Ide!

Timo Glock heads out on track with just over 15 minutes to go. He's on intermediate tyres. Kamui Kobayashi joins him

The sound of more engines being fired up...

Renault (OfficialLRGP) on Twitter: "Tyres being put on @BSenna 's car... What could this mean?"

Cesar asks: "What is Ferrari's plan behind the head to head match between Bianchi and Perez they organizes this September? We all know Massa is pretty much at the end of his career in Ferrari, but I cant imagine any of these rookies in Ferrari, not after the huge pressure the team is suffering from the lack of expected results so far this season..."

Ferrari does like to have a clear number one and number two driver, especially with Alonso in the team now. A young Ferrari prodigy is the usual move, and despite a less than convincing season from Bianchi so far in GP2 he will still get his chance in the F1 car as he is a product of the Ferrari driver academy. It's more a measure of gauging progress.

Glock spins at high speed in Pouhon, but avoids any damage and continues.

Webber and Senna join the track

Webber is on intermediate tyres but the track is properly wet now. His second sector time is some 15 seconds off the pace

A 2:17.615 for Webber shows just how wet it is now

The weather forecast is for a damp qualifying tomorrow, so drivers are trying to get a feel for all kinds of track conditions.

The rain is still falling and Bruno Senna carries too much speed in to the chicane and runs straight on before pitting

Senna was on full wets too, as is Alguersuari.

Three minutes to go and the track is relatively quiet. Alguersuari and Senna both drive through the pits and continue.

McLaren won't be going out again to do any practice starts.

Senna carries out a practice pit stop and rejoins the track. Suddenly it's a lot busier...

14 cars on track as the session ends, as they will all be able to carry out practice starts.

Alonso still looking quick through Eau Rouge after his practice start. He finishes the session secon quickest, 0.140s slower than Webber's 1:50.321. Button is third on a 1:50.770, just 0.060s ahead of Hamilton, with Massa and Rosberg both within a second of Webber.

Vaideesh asks: "Very often we see the 3rd driver of teams such as Force India & Lotus taking part in one of the friday sessions? Why is it that these teams do it, while you never see such a thing with the top teams?"

The main reason is money Vaideesh. A sponsored driver in the midfield teams will bring money as long as he's getting exposure with track time. They also don't get any other opportunity to test the cars and help with development, whereas the top teams don't need that income and have more sophisticated simulators which are driven by their test drivers.

So, after a predictably unpredictable day weather-wise at Spa, it's Mark Webber who ends Friday on top. Thanks for all of your questions and comments, make sure you keep an eye on the website for all of the reaction to the two sessions, and join us again for FP3 tomorrow. Bye for now.