I'm trying to remember a novel I read (probably in the early 70's) about an inventor that develops an anti-gravity device that looked rather like window blinds. These devices are attached to a small submarine, and it is flown to the Moon—I believe on a rescue mission. The book may have been YA.
Could be Harry Harrison The Daleth Effect.
He fits an experimental Daleth effect unit to a submarine to create a makeshift spacecraft. When it is sent into space to rescue two Soviet cosmonauts who are stranded on the moon, Klein is forced to reveal his secret to the world.
It's escalating use - lab experiment, reducing mass of a ship, converting a submarine into a space vessel, converting a larger ship, then a purpose-built vessel (which is hijacked).
There is an underlying story that once a new discovery is made, it can be replicated even if direct attempts to steal/copy it fail.
This could be H. G. Wells' 1900–1901 novel The First Men in the Moon. In particular, the description of an antigravity device that functioned like window blinds is exactly as it appears in the book. (If the same kind of antigravity device is used in another work, it is probably a deliberate homage to Wells.)
Bedford rents a small countryside house in Lympne, in Kent, where he wants to work in peace. He is bothered every afternoon, however, at precisely the same time, by a passer-by making odd noises. After two weeks Bedford accosts the man, who proves to be a reclusive physicist named Mr. Cavor. Bedford befriends Cavor when he learns he is developing a new material, cavorite, which can negate the force of gravity.
When a sheet of cavorite is prematurely processed, it makes the air above it weightless and shoots off into space. Bedford sees in the commercial production of cavorite a possible source of "wealth enough to work any sort of social revolution we fancied; we might own and order the whole world". Cavor hits upon the idea of a spherical spaceship made of "steel, lined with glass", and with sliding "windows or blinds" made of cavorite by which it can be steered, and persuades a reluctant Bedford to undertake a voyage to the Moon.
There is also a movie based on the book, with special effects by Ray Harryhausen. It is one of lesser known Harryhausen-Schneer films, but it is still quite entertaining.