President Obama, former President George Bush and Hillary Clinton join thousands in South Africa for Nelson Mandela's memorial

Aboard Air Force One, President Barack Obama and First Lady Michelle Obama were joined by former President George W. Bush and former First Lady Laura Bush, as well as former Secretary of State Hillary Clinton, on the journey to Johannesburg, South Africa to mourn the loss of Nelson Mandela, and honor the great leader at his memorial.

"The President and the First Lady have been able to spend time with the Bushes and with Secretary Clinton. And so I think it's a unique experience obviously," Ben Rhodes, who is the deputy national security adviser for strategic communications, told reporters also on the flight, according to CNN.

He added that the President and others had been reflecting on their interactions, and the times they spent with the former South African President.

"He is a leader that intersected with so many different American political leaders of both parties over the years, and so each of them has their own experience with Mandela," Rhodes said.

CNN also mentions that, Attorney General Eric Holder, National Security Adviser Susan Rice and Obama senior adviser Valerie Jarrett were also in attendance on the plane Monday heading to South Africa.

The high-profile figures mostly congregated in the plane's conference room, White House press secretary Jay Carney said. The group would separate and carry on doing their own activites. When not in the conference room, the Obama's stayed in the President's cabin while the Bushes sat in the medical office located behind the Obama cabin. Clinton sat in the senior staff cabin behind the medical office, according to the White House pool report.

"It's a very I think enjoyable experience certainly for the President and First Lady. And they're both grateful to be able to have (the) former President and First Lady, former Secretary of State on board," Carney added.

Former President Bill Clinton and daughter Chelsea, as well as former President Jimmy Carter, are also expected to attend Mandela's memorial, but they're traveling separately from the rest of the group. Former President George H.W. Bush, who is 89, was not on the trip to South Africa, and will be at home.

The seven-hour memorial of Nelson Mandela will be held, Tuesday at the 95,000-capacity FNB stadium in Soweto. The stadium was the scene of Mandela's last public appearance, during the World Cup in 2010, and previously 20 years earlier it was filled to overflowing as Mandela addressed a huge crowd two days after his release from jail.