Mainland scientists have discovered a "super material" that is as light as a balloon yet as strong as metal, which could be developed by the mainland's military into armour that protects troops ...

However, the photos reveal the piles of balloon material were able to be pulled aboard by hand. The US military has also deployed unmanned underwater vehicles as part of the search effort.

Art Thompson:There's a series of nylon strings that run through that balloon material to be able to carry the weight. 801:01:26:02 01:01:31:20Narrator:As the balloon climbs, the helium expands ...