The spacecraft looked like a toy gyroscope. I think it had a cylinder that stuck up out of the top when it wanted to go use "Meson Power."
I think I remember it being at the bottom of an aquarium, but I may be confusing it with Diver Dan.
This must surely be Space Patrol, a puppet show written and produced by Roberta Leigh, and originally broadcast in 1963. She had previously worked with Gerry Anderson on puppet shows like The Adventures of Twizzle and Torchy the Battery Boy, which accounts for the similarity in look between Space Patrol and Anderson's works - for example, Fireball XL5.
From the wikipedia summary:
The series is set in the year 2100, by which time the indigenous and autonomous civilizations on Earth, Mars and Venus have banded together to form the United Galactic Organization (UGO). Space Patrol is the UGO's military wing, and the series follows the actions of this interplanetary force, focusing on the missions of a tiny unit led by the heroic, bearded Captain Larry Dart...
The Galasphere [their spaceship] had a top speed of about 800,000 mph, using "meson power"
The spaceship indeed looked rather like a toy gyroscope.