Men wanted for hazardous journey,
Small wages, bitter cold.
Long months of complete darkness,
Constant danger, safe return doubtful.
Honour and recognition in case of success.

I think the ad that Shackleton put in the paper to recruit crew for his Endurance Journey is a major reason for his sucess.  Any leader that can bring a group of men together and keep them together and survive what they endured is a hero.

Summary of the two year Endurance Voyage: Polar Explorer, Sir Ernest Henry Shackleton has received hero status for his Endurance Voyage, (appropriately named.)   He started the voyage in hopes to make a sea to sea traverse across Antarctica.  However, his ship the Endurance became frozen in ice pack.  Shackleton and his crew survived the extreme conditions on the Antarctic Ice shelf for 497 days (including 4 month of darkness).

The long awaited melting and shifting of the ice did not free their ship...it shredded it to splinters.  Marooned on the melting ice.  Shackleton marched his men toward the open waters where they launched the life boats to reach Elephant Island.  Once there, the crew set up camp where they lived on penguins and seals while Shackleton and 5 other men set out for help.  They boarded the 23 foot James Caird  and rowed it some 800 miles in icy waters for 19 days sustained by rations of hoosh.

Miracoulsly they arrived on South Georgia Island, but the wrong side.  Shackleton and two others decided to traverse the icy cliffs and fields of cravases,  (PS, this is 1915...where the Wool sweaters were the technical gear) to reach the whaling outpost on the other side.  Reaching the outpost Shackleton may have felt relieved to be alive...but he remained determined to rescue his men.   This alone took three different attempts over 3 months.

It is truly amazing that his entire crew survived, one of the most amazing journeys in the history of mankind.