The journey is going to be gruelling and packing space is at a premium but six descendants of Sir Ernest Shackleton and his team who hope to complete his failed polar mission have found room for whisky and cigars to celebrate if they reach the South Pole.

Three of the group will set off this month hoping to mark the centenary of Shackleton's expedition by finishing his journey.

At 10am on October 29, team leader Army Lieutenant Colonel Henry Worsley, from Hereford, and two fellow adventurers will set off from the Ross Ice Shelf to make the 900-mile, 80-day journey to the South Pole.

Lt Col Worsley's ancestor, Frank Worsley, was not on the attempt on the South Pole in 1908 but went on to become Shackleton's skipper on the Endurance, which became icebound in the second polar expedition of 1914.

He and Shackleton made a perilous journey to seek help by negotiating Drakes Passage in a lifeboat – a feat that has not been repeated to this day.

The adventurers have had to pack already because their equipment is being shipped to Punta Arenas in Chile on Friday.

Lt Col Worsley said: "I have been an obsessive student of Shackleton since I was a child and I am particularly admiring of leadership skills and his triumph over adversity.

"The decision to turn around only 97 miles away was astounding. To be part of this same journey will be a great thrill."

The trio will be joined in January by the other three descendants and a seventh team member who is fighting for a place in a gruelling open selection process.

They hope, with modern navigational aids and other new developments, to cover those final 97 miles – the point where Shackleton and his men were forced to turn back 100 years ago by howling blizzards and dwindling rations.

The team of British adventurers has been training for four years for this expedition.

Although they will have the benefits of modern equipment, the 21st-century explorers will be without the ponies and dogs that helped their forebears.

This means they will have to haul 300lb sledges laden with their supplies, ranging from food to ice axes, for up to 10 hours a day.

And while they will get plenty of sun – it will be 24-hour daylight at the Pole – temperatures will drop as low as minus 35C and headwinds could reach 50mph.

There are six members of the team but only city worker Will Gow and shipping lawyer Henry Adams will join Lt Col Worsley on the entire 900-mile journey to the South Pole.

Mr Gow, 35, from Ashford, Kent, is related to Shackleton by marriage, and Mr Adams, 33, from Snape, Suffolk, is a great-grandson of Jameson Boyd-Adams, Shackleton's number two on the unsuccessful expedition.

The further three descendants will join them at the point Shackleton was forced to give up and all six will aim to complete the final 97 miles.

They are: Patrick Bergel, 36, from London, Shackleton's great-grandson, who works in advertising; Tim Fright, 24, from Billingshurst, West Sussex, great-great-nephew of Frank Wild; and David Cornell, 38, from Andover, Hampshire, a City fund manager and another great-grandson of Boyd-Adams.

The final member will be chosen soon.