Answer:

ASTRO

AnswerCrossword Clue
ASTRODome or turf starter
ASTROElroy's dog
ASTROIntroduction to physics?
ASTRONolan Ryan, from 1980 to '88
ASTROJetson family pet
ASTROLogical introduction?
ASTROTurf opener
ASTROHouston athlete
ASTROJetsons' pet
ASTROThe Jetsons' dog
ASTRORoger Clemens, in 2004
ASTRODodger opponent
ASTROAthlete in a dome
ASTROPlayer in a dome
ASTRONolan Ryan was one
ASTROHouston player
ASTROThe Jetsons' pooch
ASTROHouston ballplayer
ASTROPebbles : Dino :: Elroy : ..
ASTROJetsons' pooch
ASTROMet foe
ASTROCraig Biggio, as a player
ASTROCraig Biggio, e.g.
ASTROFlintstones : Dino :: Jetsons : ..
ASTRO"The Jetsons" dog
ASTROJetson family member often in the doghouse
ASTROPrefix with physics
ASTROBygone Chevrolet van
ASTROAmerican League player, as of 2013
ASTROMinute Maid Park player
ASTRONational Leaguer since 1965
ASTRORusty Staub, once
ASTROHouston pro
ASTROTexas player
ASTROJeff Bagwell is one
ASTROJetson canine
ASTRONolan Ryan, once
ASTROTexas leaguer?
ASTRORoger Clemens, lately
ASTRORoger Clemens, now