How many {crew member} are to/by {Story Musgrave} ?
Story Musgrave features how many crew members?
How many crew members are to be by Story Musgrave?
SELECT ( COUNT ( ?j ) AS ?t ) { ?j property:crew_member(s) resource:Story_Musgrave }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1029> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q462132 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P1029 wd:Q462132 }
6