It is not necessary to acquire a Portable Star Lab to complete the Principle Of Pyrotechnics. The principles merely require you to request a lab, and to watch 7 stars launch from a lab. The Portable Star Lab is only useful for unlocking new stars at a University.
After registering at a Portable Star Lab, watchers may observe randomly generated stars. The owner of the lab may select the best star of the set -- a purely subjective opinion -- for submission to the University scientists.
When a sufficient number of Portable Star Labs have been returned to the University, a new star will be unlocked for public use.
More information is available under the Star Rack entry.