Sir Bob Geldof said his friend Billy Connolly is "as strong as an ox" and backed the comedian not to be deterred by the initial stages of Parkinson's disease and his surgery for prostate cancer.
Sir Bob told Channel 5 News: "Pam [his wife] and Bill are great mates. He’s as strong as an ox mentally from everything he’s been through as a kid. So I don’t think this will deter him from being that individual that we know.”
Bob Geldof is set to blast off into space as a passenger on a commercial flight.
The singer was offered the trip after his band, the Boomtown Rats, agreed to play a concert at a charity ball at the Natural History Museum, London, where seats on the flight will be auctioned off for good causes.
He said: "Being the first Irishman in space is not only a fantastic honour but pretty mind-blowing...The First Rock Astronaut - Space Rat! Elvis may have left the building but Bob Geldof will have left the planet! Wild!"
The flights, which will take place in 2015, will be auctioned at the high-society event next month along with a diamond-encrusted watch and a car ride with former Formula One drivers.
He also talked about the concept of "food security" which is something the Obama government are set to make a number of pledges on during the G8 meeting next week. Food security is a term used to describe both the availability and access to food for the world's poorest.
Food security across the continent of Africa is being threatened by the continuing rise of food prices.