Mr Prescot, 48, and Mr Elson, 45, claimed the world record for a flight by an aircraft without refuelling yesterday as they flew 15,000ft over Bombay, surpassing the previous endurance record of 233 hours and 55 minutes set by Mr Elson last year. Their next target is the long- distance record, currently 10,406 miles.
The pair have little margin for error, because it is feared the Chinese authorities will not tolerate a further violation of their airspace after Richard Branson drifted off an agreed course last December.
The balloon, which has travelled nearly 6,000 miles since taking off from southern Spain, now enters the next "critical" stage of the flight without any heating for the pilots. A fuel pump which feeds a radiator inside the capsule has failed, causing temperatures inside to plummet below freezing and observation domes to ice up as the balloon hits high altitude.
"When they go up higher, it does mean that the windows freeze up and it becomes very cold," said flight director Ian Ashpole.
The pair have already fixed their satellite phone by using a component from the toilet light in their pressurised capsule. Mr Ashpole said: "We managed to do a mock-up of the situation and realised that the capacitor causing the problem could be replaced with one in the toilet light."
The balloon will now track slowly north to catch the right winds to enable it to skirt the Himalayas before heading out over Japan and the Pacific.Reuse content