Newtonium is very useful to create Antigravitation and therefore has been named after the great physicist Sir Isaac Newton (1642-1726), who formulated the laws of motion and universal gravitation (and the one who came up with the name "Newtonium" was probably was a little joker).
Basically it works like a Peltier element for gravity. If you set the metal under electric voltage, one side emits antigravitational waves and the opposite side produces gravitational waves.
The ships’s bottom side is made of Newtonium which lets you levitate or land on planets. On the opposite side inside the ship, an artificial field of gravity is created which is about 1g like on Earth. The power of (anti)gravitation can be set by controlling the amount of energy.
This gravitation is even independent of the ships rotation or acceleration and a very useful invention. There is one disadvantage: if your main energy source fails you will have serious problems as your crew will float weightless through the ship.
The inhabitants of the Moon Base celebrated for days as the first anti-gravity unit has been installed in residential areas in 2178. Now they no longer felt from their beds at night due to the low gravity on the moon which is only 1/6 the gravity on earth.
This resulted in an increase in productivity of fabulous 298%, which would have made every business consultant envious (if there would be still some left).
Newtonium is not used up like fuel but the antigravitational effect weakens over time and after a certain amount of time it needs to be replaced.
If your ship has to be serviced, the antigravitation units are exchanged and the mechanics will need Newtonium for that. Without a working antigravitation unit system, the ship can’t start again.
And if you don’t have any Newtonium left in the stock, you need to mine some on the Moon surface first, like a beginner.