Lewis, five-time US Grand Prix winner, three-time F1 world champion, US Grand Prix always a big one for your, personally and for the team, no doubt many commitments in the run-up to the event, but I just wondered how much you enjoyed your hours spent at NASA yesterday?

Lewis Hamilton: Good morning everyone, super happy to be here of course and had an incredible day yesterday, having a bit of a comedown today. I was just buzzed all day yesterday because it's always been something I've wanted to do. It's always something I've been fascinated about, space and space travel particularly. So to actually go there... and I had a million questions. I'm sure the guy got fed up with me. I asked a lot of questions and I got to see a lot of great things, some of the new technology they are working on and yeah, I want to go back.

You stand on the threshold of your fourth Driver's world championship this weekend, but does a part of you regret that the fight has sort of gone out of it now with all the misfortunes that Vettel and Ferrari suffered on the Asian leg in Singapore, Malaysia and Japan?
LH: No I don't feel any type of way about it.

But obviously you've got such a massive margin now. There was such a tension throughout the season up to September but there's much less tension now from your point of view, approaching the races?
LH: Nothing has changed for me, man. Everything is exactly the same as it was going into the last race, going into the second half of the season; it's exactly the same mentally for me. Maybe it's changed from your perspective, but for me it hasn't.

Fair enough. Thanks for that. Marcus, the seats are filling up now for 2018. Are you comfortable with the position you are in and do you have any guarantees about next season?
Marcus Ericsson: I think in Formula One when you don't have a contract signed you can never be comfortable, so it's important for me to push hard now in the last few races to show that I should be on the grid for next year.

You've never been outqualified I believe by a team-mate here at Austin, what do you like particularly about this track?
ME: I didn't know that but that's good. I enjoy this track. I think it's the best one of the new tracks on the calendar. It has a good mix of very fast corners. The first sector is really good fun to drive and really challenging and I look forward to driving it with these new cars as well. I think it's going to be quite impressive. It's a good mix of corners on this track and it's enjoyable to driver.

Turning to Brendon Hartley, 2017 Le Mans 24 Hours winner, welcome to your grand prix debut. Tell us, who called who, what part did Porsche play in it all and where is it all leading?
Brendon Hartley: Good questions. Actually, when it was announced that Porsche would stop endurance racing in LMP1 for next year, I called Helmut Marko and I said: 'Look, I'm a different driver than I was 10 years ago, I've learned a lot, and if there is ever and opportunity I am ready.” He didn't say much, he just said he got the message, and three months later he made the call. This happened very quickly. I didn't know about it much sooner than the press did. It's been quite a whirlwind of a couple of weeks to arrive here. Yeah, I'm pretty relaxed at the moment, all things considered. Really looking forward to getting out on track. Obviously I've had quite a bit of time to chat to the engineers, to go through some data, a little bit of time on the sim. But I'm looking forward to free practice one and see how comfortable I feel and working towards the race start on Sunday, which is a big moment for me, so yeah, really excited.

When you say you are a different driver from 10 years ago, what was wrong with you as a driver 10 years ago that made it go wrong with Helmut and how have you changed?
BH: I guess I wasn't ready. I had some success in the early days, I won the Formula Renault championship, I became the reserve driver, had my first F1 test at 18 years old and I guess I just didn't deal with the pressure. I stopped enjoying it, I wasn't happy; I was pretty young and away from home. When the Formula One dream, so to speak, stopped in 2010, I picked myself up, I found endurance racing and yeah, I have learned a lot from that experience. Being in the LMP1 programme, a high-profile category, where there is a lot of pressure, probably not that dissimilar to Formula One in some ways, in that respect, in development of the race car, and working with team-mates has been great. I'm a lot stronger than I was back then, basically. I wasn't ready at 18 years old. I like to think I'm ready now. I'm not very prepared for this weekend, I haven't the car, I haven't driven a single-seater since 2012, but I like to think that Porsche LMP1 has hopefully prepared me well.

Excellent. Thank you very much for that. Carlos, splendid in yellow. You've made your move to Renault this weekend. Why? Why is it important to do four races at the end of this season, to get your head around the new team ahead of next year? In what ways will you benefit from this?
Carlos Sainz: First of all, I think that 2018 cars will be an evolution of this year's cars. So every input I can have regarding this year's car, every feeling I can get from every single area of the car, I'm sure it will help me for next year. On top of that, it's always better to meet engineers, PR people, team bosses... start working along together with all of them four races earlier that gives us a bit of an advantage for 2018 rather than going straight into winter testing in 2018.

So I think the thing we all want to know is how close can you expect to be to Hulkenberg's pace in qualifying, your new team-mate this weekend, given the amount of time you will have with an unfamiliar car on Friday and Saturday in practice? What's your goal?
CS: Let's wait and see, no? I think my main target has to be to go session by session. I'm the first one who wants to be on the pace straight away, but I cannot get too excited about that. I need to cover all the procedures, all the steps that I want to take, little by little, to get to know the car. I need to adapt myself to the car and I need to adapt the car to myself at the same time. That takes a bit of time and I'm going to go step by step and hopefully get there as soon as possible.

Questions From The Floor

(Frederic Ferret - L'Equipe) Lewis, do you have any explanation of your strengths in qualifying, even when your car is not as good as you would like?
LH: I think it's just about know the car and knowing where you can push at those areas. Of course there are weaknesses but still you can find a way to exploit those weaknesses and just about get by. It's been a fun car to drive because it's not been perfect. So it's then relied on a lot of your ability to balance it in uncomfortable scenarios or situations, which is something that I've always loved doing. It's how I started in life, with not such a great go-kart when I was young, so that's about it really.

(Joey Barnes - Motorsports Tribune) Lewis, the fun exchange with Takuma Sato on the podium got a lot of buzz here in the States. Talk about your interest, potentially, in the Indy 500 after getting a chance to have that exchange with him?
LH: Honestly, it hasn't inspired me to do the Indy 500. I've always respected it and appreciated it and I got to watch part of it when Fernando did it, which was super exciting. I love the idea of drivers being able to do more than one series. Just the other day I happened to get to drive a Formula One car on an oval, which was interesting. I have a huge amount of respect for those drivers; it's quite scary when you approach those banks at the speed that they do. But I personally don't have any particular desire to... maybe one day I'll day I'll have some fun and go out. Obviously I get lots of opportunities to do those things but I have no plans to go there and do anything serious.

(Chris Medland - Racer) Brendon, what have the team have said to you about their expectations for this weekend and longer term what may come after this weekend?
BH: Actually, there have been no expectations set. To be honest, some of the team members I'm just meeting for the first time today, and yesterday during the seat fit. I made the seat yesterday. Nothing has really been said yet. Obviously I want to do the best that I can. I'm trying not to put to many expectations on it. In some ways I'm underprepared but obviously I want to do the best job I can. Nothing has been said by the team, and also, going forward nothing has been said yet.

(Andrew Benson - BBC Sport) Lewis, you've talked about being on another level since the summer break. I was just wondering, what's changed for you within the team, and maybe for you personally, over that break and into these races that's allowed you to operate on that higher level of consistency?
LH: I think it's really just been that confidence of understanding the car a lot better this year, particularly in the second half of the season; knowing it's strengths and weaknesses. Then, I would say that we are constantly evolving the process in which we work together, myself and my engineers. So we'd often hit the ground running with a balance I'm more comfortable with, which then naturally helps you easily step forward throughout the weekend in the right direction. And otherwise, just on my driving side, I don't know, I think there are a lot of positive things happening in my life. There are a lot of interesting things forecast over these next 18 months, so I guess that's an exciting and uplifting thing. So I'm arriving at these races, generally, with an abundance of positivity; it helps keeps your mind in the right place. Obviously, Toto and the team, Mercedes, have been incredibly supportive of all the different things that I'm into and the things I do and the way I move, which enable me to be in that position, and which are much appreciated.

Check out our Thursday gallery from Austin, here.