Allow into International Space Station’s land masses (6)
I believe the answer is:
islets
'land masses' is the definition.
The definition and answer can be both natural objects as well as being plural nouns.
Maybe there's an association between them I don't understand?
'allow into international space station's' is the wordplay.
'allow' becomes 'let' (synonyms).
'into' indicates putting letters inside.
'international space station' becomes 'iss'.
'let' inserted within 'iss' is 'ISLETS'.
Can you help me to learn more?
(Another definition for islets that I've seen is " small keys".)