Prince Harry has joined 12 wounded servicemen and women as they leave the UK to take part in a gruelling - and rather chilly - race across Antarctica.
The three teams competing in the 200-mile Walking With the Wounded charity trek were seen off by friends and family ahead of flying from Heathrow Airport.
The Virgin Money South Pole Allied Challenge 2013, of which Harry is patron, will see them race across three degrees to the South Pole.
Speaking at Heathrow before they boarded a flight to Novo Base in Antarctica, via Cape Town, Ibrar Ali, whose right arm was amputated after he was caught up in a roadside bomb explosion in Afghanistan in 2007, said he felt both nervous and excited about the challenge ahead.
"A bit like pre-tour when you're just about sat at Brize Norton when you're just about to go out to Iraq or Afghanistan," he added.
Speaking of Harry's involvement, he said: "As we've said throughout, he's a great team member and just fits in really well so no different to anyone else."
Once acclimatised to the freezing temperatures and altitude the teams hope to begin the race on November 29.
All 12 injured service personnel from Britain, America, Canada and Australia have overcome life-changing injuries and undertaken challenging training programmes to prepare themselves for the conditions they will face in Antarctica.
Duncan Slater, who lost both his legs following after an IED (improvised explosive device) blew up in his vehicle in 2009, was waved off by his family including his three-year-old daughter Lily, who had dressed up as a princess for the occasion.
"I think today more than any other day we sort of realise how it's going to be," he said.
"It's going to be a bit intense now.
"Once those doors close and we get on that plane that's it now, it's game on.
"We're only going down there to do one thing and that's work hard.
"I'm really excited, I can't wait to get down there and get going on it."
Trekking around 15km to 20km per day, the teams will endure temperatures as low as minus 45C and 50mph winds as they pull their 70kg sleds, known as pulks, towards the southernmost point on the globe.
They hope to reach the geographic South Pole by December 16.
The UK Team Glenfiddich will be joined by Harry, Team Soldier On from the Commonwealth will include actor Dominic West, while the US Team Noom Coach will line up alongside actor Alexander Skarsgard.
Each team also has a mentor and a polar guide.
Walking With The Wounded co-founder Ed Parker said the send-off at the airport had been emotional.
"Isolation is around the corner for us all," he said.
"We won't be speaking to our families for over five weeks and so it's an emotional time but it's lovely to have them here to see us off."
He said the charity had been a "rollercoaster" since he formed it in 2010.
"For us this is comfortably the biggest expedition we've ever done," he added.
"And the aim remains with the expeditions to raise awareness so we can continue to do the work we're doing supporting our wounded back to work."
Each team will represent and raise funds for military charities from the constituent nations: Soldier On from Canada, Soldier On from Australia, Soldiers to Summits from the US and Walking With The Wounded from the UK.