Explorer 38 - was Re: UNID in France

Philip Chien (kc4yer@amsat.org)
Wed, 4 Jun 1997 14:06:02 -0400

>Alphonse Pouplier wrote:
>"On 05-30-1997 at 22:05 UT several (over 20 in different places) observers of
>the region of Bordeaux Lat. +44d50m Lon. near zero
>saw a satellite near the zenith MOVING FROM EAST TO WEST
>3 sec VERY BRIGHT flash then 7 sec not visible and so on.
>They say that during the flashes it was MUCH BRIGHTER than MIR.
>What could it be?"

Bruno Tilgner <Bruno_Tilgner@compuserve.com> replied:

>Another object which moved from northeast to southwest and reached
>an elevation of 85 degrees at 22:05 UT on 30 May 97, i.e. fits the
>observation very well, is Explorer 38 (68055A). However, it is a
>slow-moving object and its distance near the zenith was 5 845 km.
>This large distance pretty much rules it out. However, it was a radio
>astronomy satellite. The RAE Table of Earth Satellites lists it as
>a tubular cross of 190 kg mass, and the column "Size" has the entry
>"Arms of cross 229 m". This sounds hardly credible, but if it were
>true, the good match of the observation with the analysis could be
>more than a coincidence.

Explorer 38 was large in terms of _maximum_ dimensions, but not in terms of
physical size.  From what I recall it was basically a cylinder with very
very long extendable antennas.  If memory serves it was listed in the
Guiness Book of World records as the world's 'largest' spacecraft due to
those antennas.  At least until tether satellites started flying.

In any case I highly doubt the antennas would be very visible.  Basically
you'd be looking for the main body of the spacecraft which is fairly small.

Philip Chien [M1959.05.31/31.145//KC4YER@amsat.org]