# Small thrust thrusters

If I have a propeller with a continuous thrust of $$1 \times 10^{-9}$$ Newtons, can I take the satellite from LEO to the moon?

How can I calculate the time it would take for a satellite of a certain mass to reach an orbit knowing the thrust?

The answer is essentially here where the give a figure of 8 km/s for the delta-V needed to get from LEO to LLO (Low Lunar Orbit) as 8 km/s. So, if the mass of your satellite is $$M kg$$ (and it is small enough that light pressure and drag in LEO aren't a concern) your acceleration will be $$a = 10^{-9}/M ms^{-2}$$ so the time required is $$8000/a$$ which is $$8\times 10^{12} M s$$. So a 1 kilo satellite will take about $$200\,000$$ years.
Editing in response to a comment. Light pressure (from sunlight) near earth is about 10 $$\mu Pa$$. Atmospheric drag depends on just how low your LEO is and on "space weather" but it is more than this up to altitudes of 900km or so (because light sails are no use below there). So actually, given that you have constant thrust it isn't small size that makes you vulnerable, but large area. If your probe with the $$1nN$$ engine exposes more than about $$1 cm^2$$ of cross-section, the forces from drag and/or light pressure are likely to exceed the thrust.