High-altitude bases offering exceptional aspect from Alps (5,9)
I believe the answer is:
'high-altitude bases' is the definition.
I can't tell whether this definition defines the answer.
'exceptional aspect from alps' is the wordplay.
'exceptional' indicates an anagram (an unusual or exceptional ordering of the letters).
'aspectfromalps' anagrammed gives 'SPACE PLATFORMS'.
'offering' acts as a link.
Can you help me to learn more?