1: Sci-fi pioneer composes Mercury Sources (1.1.,5)
2: Fold suit and undershirt (5)
3: Road without a pole (4)
4: and 15 Novel alternative excised from huge spits (5,12)
5: I renew one TV in a complicated way to get an oral examination (9)
6: A flare-up is getting off 23-across (9)
7: Massive dinosaur hiding in Antigua? No, Donna! (9)
8: 'Naked Gun' actor prepares to be dubbed in (in soundtrack) (7)
14: Government-hater ravaging China star (9)
15: Four runners usually talk about YMCA in the morning (5,4)
16: Spread Dianne's pearls around (9)
18: Free to turn some integral tables (2,5)
21: Wealthiest Rhode Island bureau (7)
24: Cake decoration methods essentially deleted from ancient Chinese book (5)
25: Appreciation without hot water containers (5)
28: Mediterranean leaves unfashionable coins? (3)