  Residual accelerations due to thermal effects are estimated through a model
of the New Horizons spacecraft and a Monte Carlo simulation. We also discuss
and estimate the thermal effects on the attitude of the spacecraft. The work is
based on a method previously used for the Pioneer and Cassini probes, which
solve the Pioneer anomaly problem. The results indicate that after the
encounter with Pluto there is a residual acceleration of the order of
$10^{-9}~\mathrm{m/s^2}$, and that rotational effects should be difficult,
although not impossible, to detect.
