It was this really old show I used to watch in the early eighties that looked like it was made as early as the 70s.  It has combining tanks etc. that form a mega soldier like Voltron, only the show isn't a cartoon--it's a like that old show Thunderbirds where they use "marionettes/puppets" for the main characters.  There may be another show with a similar description where they had a base like on earth and these laser type weapons that were attached to their their wrists.  I believe the enemies bled green blood, and their combiners linked up in space.  
			
			
				
		
			