Conversation so far:
What are some world record attempts Richard Branson has made?
Branson made several world record-breaking attempts after 1985, when in the spirit of the Blue Riband he attempted the fastest Atlantic Ocean crossing.
What is some information about the boat Richard Branson used when he attempted the fastest Atlantic Ocean crossing?
Branson's first attempt on the record, in 65 ft twin-hull Virgin Atlantic Challenger, departed New York in June 1985.
Are there any other notable record attempts Richard Branson made after the fastest Atlantic Ocean crossing attempt?
In January 1991, Branson crossed the Pacific from Japan to Arctic Canada, 6,700 miles (10,800 km), in a balloon of 2,600,000 cubic feet (74,000 m3).
How long did it take Richard Branson to the cross the Pacific from Japan to Arctic Canada in a balloon?
46 hr 15 min
Did Richard Branson fail any attempts at a world record?
In September 2008, Branson and his children made an unsuccessful attempt

Question: What was this unsuccessful attempt?
Self-contained rewrite: What was the unsuccessful attempt by Richard Branson and his children in September 2008?