By Ollie BarstowFollow @OllieBarstow on Twitter

It's probably difficult to remember exactly what goes through your mind when you're pointing skywards in a car... one moment you're facing down the Mulsanne Straight, the next you're 'high-fiving' the birds.

That said, since Mark Webber was in the midst of his second such airborne accident at the 1999 Le Mans 24 Hours in almost as many days 'not again' is likely to have come up.

Those crashes - or more specifically the identically frightening 'flip' that would go on to befall team-mate Peter Dumbreck's CLR in the race - may have gone down in folklore as some of motorsport's luckiest escapes, but the impact for Mercedes and Webber would go beyond a literal bump back to earth.

A promotional disaster for the three-pointed star, Mercedes withdrew from sportscar racing immediately to re-evaluate its motorsport involvement, leaving its youngest prot?g? with an abruptly uncertain future.

This was 17 years ago and of course Mark would go on to establish an immensely successful tenure in Formula 1 and most recently as a World Endurance Champion, but it's easy to forget his career path could have meandered an entirely different route away from F1 had that infamously flawed Mercedes CLR not had a penchant for making like an aircraft.

Mark Webber's career almost followed a very different route after securing Mercedes factory support aged 21

Following the well-trodden path from Australia to the UK to forge his burgeoning opportunities, though Mark hit the ground running in British Formula 3 in 1997, the all-too-familiar mantra of dwindling funds loomed large, threatening to scupper his dreams before they had begun.

And then a phone call.

"I was doing Formula 3 at the time with Alan Docking and Norbert Haug (Mercedes Motorsport boss) rang me up around the British Grand Prix time and said Gerhard Berger is ill. I'm like, 'OK, that's got nothing to do with me. How the hell is that going to change me a little?"

Strictly speaking, it didn't change much at all initially. Haug had been keenly watching Mark's progress in F3 and liked what he had seen, so much so that he would make the offer Mark the unprecedented chance to partner Bernd Schneider in its Mercedes CLK-GTR in the FIA GT Championship, replacing Alex Wurz, who had gone on to assume Berger's Benetton F1 seat. An extraordinary offer to have been tabled for someone so inexperienced, it was for this reason that Mark would turn the chance down.

"He [Norbert] said we've got a seat with Bernd Schneider," he continues. "I said 'OK, that's at Nurburgring for the next race'. This is a car with 900hp which is very quick compared to what I'd driven in the past. I was only racing Formula Ford six months before that, so I wasn't overly excited to go straight into a race to be honest."

Haug remained keen to get his man though and instead organised a test for Mark at the A1 Ring in an effort to tempt him. The test went well and a full-time Mercedes factory deal was now on offer.

Even then, Mark admits he had his doubts, his long-held desire for pursuing a single-seater route to F1 questioning what appeared to be a logical decision to slip under the safety of a works-backed umbrella. He accepted - reasoning it was a 'say yes or go home' situation -, Mercedes funding the remainder of his British F3 season before preparing him for a career in sportscars.

"We organised a test and it went very, very well. I started a contract with Mercedes - a long term contract - and they paid for the rest of my Formula 3 season and I started working for them in 98 as a driver of sports cars.

"Obviously, I didn't have the stress for having to look for sponsorship anymore which was a huge relief. It was probably a go home factor for me - I was only a month away from going home, so it was a huge saviour for me

Though Mark says his contract with Mercedes was a 'loyal' one, he admits he signed on the dotted line still with F1 on his mind despite the manufacturer's relatively tenuous influence as an engine supplier only.

"I think I was still looking still for an angle into Formula 1 from sportscars, with McLaren or something along those lines because it was an opportunity to work with an incredible manufacturer. It was in my interest to show that loyalty and continue with them for as long as possible."

Mark benefited from Mercedes FIA GT dominance in 1998 to win five races en route to the runners-up spot alongside Bernd Schneider

Admitting the sensations of driving a car with a roof, immense power and vast grip levels was initially startling, though 'virgin driver' Mark admits he was 'a little bit out of his depth, the benefit of driving alongside hugely experienced Mercedes ambassador - and five-time DTM champion - Schneider helped the then-21 year old find his feet.

"It was just a big car too - very wide compared to a little nimble Formula 3 car, it was very different. So, I had a lot to take in. I was fast, but I was also a bit rough round the edges, there's no question about it.

"I think that when you've got Klaus Ludwig and Bernd Schneider and even Ricardo Zonta as team-mates, I could only benefit.

"I didn't know the tracks. I was definitely the weakest driver in terms of experience. The cars were really 'honest' - difficult to drive, no torque is on them. I was at times, certainly a little bit out of my depth and learning along the way. But with Bernd, I had a sensational team-mate and he was helping as much as he could."

Almost a world champion by the time he was 22, Webber and Schneider finished runner-up to Ricardo Zonta and Klaus Ludwig in the 1998 FIA GT Championship, notching up five wins as Mercedes trounced the opposition.

Such was Mercedes' dominance that the opposition fled and GT1 was discontinued to make the FIA GT Championship a GT2-spec series only. As a result, Mercedes switched its attentions to a Le Mans 24 Hours return, bringing its GT quartet with it as part of a three-car, nine driver line up.

With the FIA GT Championship axing the GT1 class, Mercedes turned its attentions to winning the 1999 Le Mans 24 Hours with the notorious CLR

Despite the allure of competing at Le Mans, Mark admits the prospect of spending much of the 1999 season on the sidelines in preparation for one race and a handful of exhibition events didn't sit well with him.

"There was a very small programme that year which was a concern for the momentum of my career. There were only two races I was aiming to do that year With Nurburgring and Norisring, as well as Le Mans."

Nevertheless, a strong performance at Le Mans - in a remarkably strong year that would see BMW, Toyota, Audi and Nissan also vie for overall glory - had the potential to propel Mark into the motorsport limelight and solidify his sportscar career.

Instead, a crucial issue in the design of the magnificent but flawed CLR would see him hit the headlines for the wrong reasons during that dramatic weekend, with two spectacular airborne accidents - including one in morning warm-up - forcing him out of the race altogether, only to watch on as a third flip for Dumbreck in the race finally prompted Mercedes to halt its participation.

Mark suffers his second identical crash on the Mulsanne Straight during morning warm-up, ruling him out of the race

"I remember everything and of course you have hesitations," he says, discussing the thought-process of getting in the car for a second time after such an incident. "When you're in a life threatening situation you have to deal with that and come back on it. That was a tough moment. You have to dig deep, and press on and get back on the horse."

However, there was no 'horse' to get back onto, Mercedes canning its sportscar programme immediately as it re-evaluated its participation in motorsport.

While the more experienced members of the team would have the security to hold firm in readiness for Mercedes' next move (several joined the manufacturer's revived DTM programme), Mark didn't want to wait to placed somewhere he didn't want to go.

Hampered further by the limited sportscar opportunities as the 'golden era' of GT1 ended with most manufacturers withdrawing - thus paving the way for the largely unchallenged Audi domination that would come for the next decade - Mark recognised this as his opportunity to return to single-seaters, even if Mercedes were reluctant to let him exit his contract so easily.

"It wasn't that straightforward initially to get out of the contract, but they saw that there was no real goal for me within their programme as there was effectively not racing happening, which was a problem."

A legal battle followed but while Mark successfully freed himself from Mercedes, it cast him adrift in the motorsport wilderness, an initial offer to drive in IndyCar/CART turned down because of Greg Moore's death in 1999.

It took an approach to Eddie Jordan for Mark to get his career back on track, the team owner pointing him in the direction of fellow Australian Paul Stoddart, who became his investor and ultimately set him back on a path towards F1 (via F3000), where he made his famous point-scoring debut for Minardi in 2002 before stints at Jaguar, Williams and Red Bull.

Mark returned to sportscars in 2014 with Porsche and has since gone on to become world champion at last

Fast forward 12 years, Mark's career has come full circle, his successful tenure in F1 leading to his current vocation back in sportscar racing, this time heading up Porsche's World Endurance Championship and Le Mans 24 Hours effort.

Finally a world champion 17 years after coming so close back in 1998, Mark says it was never his intention to bookend his career in such a way.

"When I was in F1, I was obviously focused on that, and then towards the end of my career, I was pretty tired and not overly motivated to maybe do something else. But in the end, the desire and ambition to race for me to race for Porsche was too strong, and I'm so happy I made that decision because the first year out of F1 is probably the hardest year in terms of you probably want to have a bit of a break.

Indeed, though Mark admits he has wondered how his career may have panned out had he remained within the Mercedes fold, he says he is getting a lot of pleasure from his racing now.

"I was happy I got through 2014 really well and then now enjoying my racing a lot and having that timing with the phone call from Porsche was sensational.

"I'm very lucky to have got that seamless, the timing was right, personally, professionally, it worked was mega. Now I get to drive these weapons of cars and that's great!"

This year celebrates the 20th anniversary of Mobil 1's technology partnership with Porsche and sees the winning team return to Le Mans where Mark Webber is preparing to drive the Porsche 919 Hybrid, defending their 2015 1-2 title