test rocket vs research rocket

test rocket and research rocket both are nouns.

Word	Noun	Adjective	Verb	Adverb
test rocket	Yes	No	No	No
research rocket	Yes	No	No	No

As nouns, test rocket and research rocket are synonyms defined as:

Other synonyms of test rocket include test instrument vehicle.

test rocket (noun)	research rocket (noun)
a rocket fired for test purposes	a rocket fired for test purposes