Image Visual SAT-Flare
Tracker 3D

By Simone Corbellini 24 February 2011

Nanosail-D Flares

Starting from the flare captured by Arto Oksanen from Finland on the 24 of February (and reported here) I estimated the sail orientation.

The sail normal, with respect to the satellite frame resulted:

1) tilted toward the ground in the orbital plane of about 55 degrees (with respect the velocity vector)
2) rotated off the orbit plane around the vertical of about 215 degrees (toward the Sun).

The angle between the sail normal and the velocity vector resulted of about 62 degrees (118 between the versors).
(The angle between the sail normal and the Sun resulted of about 47 degrees)

This means that, if the sail has to stabilize along the velocity vector, it is still far from its stable orientation and, therefore, that
other bright flares should be expected for long time.

It is possible to track this flare (generated by the same sail orientation with respect the satellite frame) by using the online program at the following link (
The tracking does not take into account that the sail is rotating, however it can show where the flare should be visible in the case the sail assumes again the same orientation):

Track Nanosail and this flare

Nanosail Flare 24 February 2011
Fig. 1 - 3D representation of the flare: the white blue line represents the ray from the Sun, the dark blue represent the Sail normal and the
green line represents the reflected ray, which has been observed.

Go to the program Home page

Visual SAT-Flare Tracker 3D - By Simone Corbellini -