Possible Clues:

• By the sound of it, hang on bar that's very light
• A rowing team down on Windermere, initially floating
• Not finding our planet attractive?
• Unimportant
• Floating, perhaps
• Promise told to NHS patients is without substance
• Convulsed with glee, saints like astronauts?
• Floating number in UK region without a shilling
• Women's crew with fewer pounds? None at all
• Blow whistles, eg, like people in space station