Like everyone else on board the Shuttle Endeavour and the ISS, ESA astronaut Umberto Guidoni has a busy schedule. But he has managed to find time for one activity that isn't strictly mission-critical: answering emails from Earth-bound space enthusiasts.
The emails - hundreds have been sent so far - come from all ages and scores of nations, although Guidoni's native Italy heads the list. Guidoni could not possibly respond to so many well-wishers, of course. ESA staff have been selecting the best or most typical emails each day to send on to him.
They have also been filtering out the inevitable weirdos that the Internet has always attracted - so Guidoni will not be pestered by threats from self-proclaimed space aliens or libidinous suggestions from would-be astronaut groupies. Even the weirdest of the weirdos, though, usually sends best wishes for the mission's success - as do all the normal people.
The favourite request from Guidoni's electronic penpals - especially children - is for descriptions of the view from space. One emailer wants to know if it is possible to eat spaghetti in space, and another asks Guidoni whether the Italian astronaut had any chance of a trip to Mars. Perhaps the most touching is from a young girl who wonders whether she could see her much-loved great-grandmother, "now in heaven" from space.
You can read the emails that were selected to be forwarded to the ISS and Umberto's replies at: 'Guidoni answers' on our special STS100 page.
Some of the other general questions on the mission have been answered in our discussion forum - where you can continue to post your queries. But no more marriage proposals, please; and if you are the Grand Warlord of Arcturus IV, just keep your ideas to yourself.