Fuzzy satellites

In the July 2002 issue of Astronomy magazine, James Oberg describes some observations of artificial satellites that release water or fuel during flight. These satellite dumps produce fuzzy clouds or plumes around the satellite as it moves across the sky. Some satellite watchers have even caught such phenomena on film.

On October 15, 1997, NASA’s Cassini spacecraft launched from Cape Canaveral, Florida, strapped atop a U.S. Air Force Titan IVB/Centaur launch vehicle. About twenty minutes after launch (and after Cassini and the Centaur upper stage had separated from the Titan IV main stages), the Centaur booster launched Cassini out of Earth orbit and onto its trajectory toward Venus, which provided its first planetary gravity assist toward Saturn.

On October 15, 1997, NASA’s Cassini spacecraft launched from Cape Canaveral, Florida, strapped atop a U.S. Air Force Titan IVB/Centaur launch vehicle. About twenty minutes after launch (and after Cassini and the Centaur upper stage had separated from the Titan IV main stages), the Centaur booster launched Cassini out of Earth orbit and onto its trajectory toward Venus, which provided its first planetary gravity assist toward Saturn.

Gordon Garradd of Loomberah in New South Wales, Australia, used a telescope to catch this view of Cassini and its separated Centaur stage on launch day. The fuzzy cloud surrounding the Centaur stage at right is believed to be unused hydrogen or oxygen that vented from the booster after separation. The 8.8-magnitude star PPM 204332 is also pointed out for reference.

Many observers have also witnessed waste water dumps from the space shuttle. During shuttle flights, waste water and excess water produced by onboard fuel cells gets vented into space. After it is forced out of a small nozzle, the water rapidly freezes into a cloud of ice crystals, which can look somewhat like a cometary tail to ground observers.

As Space Shuttle Discovery flew over Houston, Texas, on December 25, 1999, satellite enthusiast Paul Maley recorded a water dump during the Hubble servicing mission STS-103. After being vented, the water fell into a lower orbit, causing the coma-like tail to curve forward as the particles accelerated. The bright point to the lower right of the shuttle is the Hubble Space Telescope. Other points are stars.