posted on Jul, 15 2009 @ 09:40 AM
Originally posted by stratsys-sws
Ermmm Jim, I think your tone is extremely condescending, and totally incorrect! Are you trying to suggest that when a rocket engine fires in space
that there is no flame??? Just because you're in a vacuum does not mean that with a supply of oxygen and a fuel you wouldn't get a flame! Don't
worry s.one.z, most of us here understood what you meant.
Actually, yes -- thruster plumes in space generally are invisible except when there's a momentary mismatch in the propellant mixture ratio, and the
brief flash you see is super-heated unburned propellant. Some out-of-tune thrusters do produce more continuous visible plumes, and there are videos of
this on youtube -- but it's not the general rule.
Mission Control is always interested in outside 'stuff' because it could be a clue to a vehicle malfunction -- past, present, or future. Thruster
leaks are the most common. Some of the objects have been identified as structural elements breaking loose. Sadly, the one potential visual clue that
was missed was on Columbia's last flight, when the hunk of stove-in RCC panel (from the ascent impact) drifted free the day after reaching orbit. Had
the crew moticed it, Mission Control might have paid more attention to the potential for breakage of the thermal shield.
So the visual apparitions are by no means all nonsense or all unimportant.
There also remains the possibility, however small, that there is evidence for unexpected activity of any type -- you certainly wouldn't want to
overlook that by dismissing it all without trying to understand it. But if you ring up too many 'false positives' (as the UFO buffs do), you
certainly discourage the serious investigators from getting involved to the extent that they really should.
When I did this for a living, I often made these points -- here's a July 23, 1993 report I presented, "The Problem of Spacecraft-Generated Debris
in Orbit", 3 meg,
filed here for access: