How Long Would This Experiment Take?
An important consideration (since you need the answer fairly quickly in
order to answer the challenge question first!) before you actually launch
the probe is just how long it would take to complete this experiment and
get the measurement you need.
The light signal from the probe travels at the speed of light, which is the
ultimate speed limit. The probe must travel much slower, so the time for a
light signal to travel to Cyg X1 and back is a measure of the absolute
minimum time this experiment could take. It is an easy matter to calculate
this minimum time, once you know the distance to Cyg X1.
The total distance traveled would be twice the distance to Cyg X1.
 The distance to Cyg X1 is 2.5 kiloparsecs.
 A kiloparsec is a thousand parsecs.
 A parsec is equal to
3.0857 x 10^{16}m.
 The speed of
light in a vacuum is 3 x 10^{8} m/sec
