The international space station is full of technical wizardry from robot arms to state of the art telecommunication devices. The cost of a pen on the ISS runs into thousands of dollars with decades of research leading to its manufacture.
So which piece of equipment has been deemed the most important on board this multi-billion dollar space craft?
This malleable, reusable, putty-like, pressure-sensitive adhesive is made by Bostik in Australia, and according to astronauts aboard the space-station is the most important piece of equipment up there, despite it's single dollar price tag.
"It's indispensable," said Buzz Aldrin, who recently spent a few weeks aboard the floating tin can. "It's used for everything."
Small leaks in pipe works, ducts or even the shell of the craft can be sealed with a blob of Blu-tack in seconds, instead of the hours using the seventy-thousand dollar puncture repair kit created by NASA. Additionally, any of the crew can do it, instead of the one trained for seven weeks by NASA in using the puncture repair kit. Equipment, parts and even whole experiments can be held in place without messing around with the magnetic clips supplied.
"It forms an air or water tight seal," said Glen Johnson, who - at six months - holds the record for time spent on the ISS. "It doesn't magnetise your screws. When you've finished, you can pull it off and use it later. It's truly fantastic. All the visitors to the station are asked to take a pack up."
With Blu-tack being an insulator it was recently used to repair a circuit board that threatened to take down the ISS life support system.
"You could say it's a life saver," said Johnson. "We also use it to get bits of dust up and to get rid of the vibrations in the air-con unit. That rattling noise had been keeping us awake for weeks."
The quarter of a million dollar air-con unit was repaired with ten cents worth of Blu-tack.
"I also used it to stick photos on the cabin wall next to my bed," said Johnson.
Bostik have said that it will not increase the price of Blu-Tack when selling it to NASA just because they would pay over the odds for it.
"It's what it is," said Shane Shearer, Bostik spokesman.
Other malleable semi-adhesive putty-like substances are available.