By 2009 it is estimated that some 85-90% of all 321 IMS stations around the world will have been completed and will be transmitting data to the International Data Centre in Vienna. For some of the remaining 35-40 stations, there are political challenges that will have to be solved before installations can commence. For example, stations intended for India and Pakistan cannot be started until these two countries sign the CTBT.

Environmental challenges
Other stations face environmental challenges. Extreme care must be taken not to disturb the natural habitats and to maintain the fragile ecological balance. The PTS abides by all national regulations, it uses passive technologies, and always restores the area surrounding a station back to its original state.

There is also a new technical “double challenge” to be met. On the one hand, the build-up phase must be followed through to completion. On the other hand, the PTS has to shift gears from build-up to maintenance and sustainment mode.

As the build-up phase is completed, the focus will turn more and more towards sustaining the IMS. System “sustainment” is, in fact, a relatively new word in the IMS vocabulary. Beyond straightforward maintenance of existing equipment, sustainment involves enhancement, improvement, refinement, in some cases even replacement of current equipment with newly evolved technologies.

The build up of the IMS has meant that the PTS has been involved in a globe-spanning construction project for over ten years. Its logistical challenges are daunting. For example, since international organizations are entitled to tax exemptions, legal issues associated with taxation and customs must be addressed in each and every country.