Planet detection through microlensing is usually limited by a well-known degeneracy in the Einstein timescale t _ { E } , which prevents mass and distance of the lens to be univocally determined .
It has been shown that a satellite in geosynchronous orbit could provide masses and distances for most standard planetary events ( t _ { E } \approx 20 days ) via a microlens parallax measurement .
This paper extends the analysis to shorter Einstein timescales , t _ { E } \approx 1 day , when dealing with the case of Jupiter-mass lenses .
We then study the capabilities of a low Earth orbit satellite on even shorter timescales , t _ { E } \approx 0.1 days .
A Fisher matrix analysis is employed to predict how the 1- \sigma error on parallax depends on t _ { E } and the peak magnification of the microlensing event .
It is shown that a geosynchronous satellite could detect parallaxes for Jupiter-mass free floaters and discover planetary systems around very low-mass brown dwarfs .
Moreover , a low Earth orbit satellite could lead to the discovery of Earth-mass free-floating planets .
Limitations to these results can be the strong requirements on the photometry , the effects of blending , and in the case of the low orbit , the Earth ’ s umbra .