A $1.5 billion cosmic ray telescope may meet up with the International Space Station after years of delay.

The Alpha Magnetic Spectrometer was mothballed after agency officials realised there weren't enough shuttle missions left to take the experiment to the space station. That's because the shuttles are due to be retired in 2010, and most of the remaining flights are needed to carry up parts to finish building the orbital outpost.

If launched, the telescope, which still awaits final assembly,...