urban viewing, Lacrosses, USA 32, 45, 81
Walter Nissen (dk058@cleveland.Freenet.Edu)
Sun, 9 Jun 1996 18:27:10 -0400
Continuing the discussion from the previous message, in a different
direction.
> I was
> able to find stars and planets it would pass while it was still
> dark and establish various landmarks such as trees and chimneys
> to sight over.
Bingo!
If you regularly observe from an apartment window or backyard observatory,
you should know the alt/az of every obstruction.
Satellite observing in an urban setting offers some advantages over a
mountaintop. Two other advantages are that you don't have to dark adapt
very much (if you take 50,000 IU of Vitamin A every day of the year, like
I do, it becomes pretty much a non-issue) and you always have plenty of
light available to read charts, printouts, watches, etc.
John Pike commented that he doesn't see much in the sky from Capitol Hill.
To which I say, now you understand why I took up satellite observing. 21
years inside the Beltway led me to the conclusion that I would see a lot
more satellites than members of the Coma cluster, because satellites are
relatively bright. From 1992 to 1994, I saw just about 600 different LEO
objects from inside the Beltway. So, John, if I were you, I'd get a pair
of extra-wide angle 7x35 binoculars (I really like the 10 degree field of
view, because it interacts favorably with the skymarks and obstructions
Dave Mullenix mentioned) and have a go at it.
Might give you a start toward an idea about how easy a high school physics
class in Baghdad or Teheran, under the proper tutelage, would find
tracking black objects. You have to factor in darker skies, better
weather, paranoia, etc., etc. When Victor Slabinski teaches his orbital
mechanics classes at GWU (every year or two, I believe), he sometimes uses
black objects when they are well-placed for observation, for the "live"
class projects from downtown DC, during the appropriate part of the
semester. (Warning to newbies: "black" is a euphemism, perhaps more
reflective of the desires of citizens or government functionaries than of
reality; some of these objects, such as Lacrosse, can be bright, maybe not
in the Mir/shuttle class, but pretty bright, around mag 0 or 1; and long
experience suggests that they are both reliably bright and reliably
steady, putting them in the Top 10 visually for those of us who provide
indications of visibility for inexperienced observers). One of his
students, having heard in the class that Space Command is the usual source
of elements and also noting a Lacrosse elset being distributed in the same
class, exclaimed, "You didn't get _these_ elements from the Air Force!"
Very true. A good student. At least two regular participants here can be
pretty confident that they know the actual source. (Newbies: check out
Ted Molczan's file of elsets, or if you happen to be in the DC area, you
can look in Blaine Friedlander's "SkyWatch" column, in the Style Section
of the Wahington Post, on the first Wednesday of every month, for
occasional Lacrosse overflights).
Bruce Watson,
Can you contribute to this discussion, by telling us what your experience
with the Lacrosses as UnIDs is? How frequently you find them? If you
rapidly recognize them, by inclination, speed, brightness, steadiness?
While I have you on the line here, I've been meaning to ask you if you
have ever specifically tried to locate USA 45 within your UnIDs? Perhaps
by constructing elsets for putative objects by modifying the USA 32 elset
from Molczan's file (Newbies: where you will find a discussion of USA 45 =
20220 = 89- 72 A), perhaps by adding various amounts to the RAAN and the
MA. If you constructed a grid of elements every 10 degrees of RAAN and
every 10 degrees of MA, you'd have 1296 elsets, but a single run of QS
would toss all but one or 2 on the scrap heap. USA 32 and its sister
ship, USA 81, might be distinctive enough in flash behavior (pretty wild,
I admit, but at least it's different), speed, inclination and brightness
that you'd have some sense of which of your UnIds would be the most worthy
candidates.
BTW, I don't think I've ever seen any speculation about the nature of
these objects. Can anyone shed some light?
Also, BTW, you would have the purest data for supporting a Top 10 list, in
an opposite(?) sense from Phil's list. If it has made a good impression
on you, it has to be good against the sky.
Here is a very recent elset, chosen with a relatively juicy drag, from
those from OIG, so you won't be late:
Mir
1 16609U 86017A 96158.50040951 .00001299 00000-0 23505-4 0 5386
2 16609 51.6469 177.3678 0005064 49.5093 310.6367 15.58140512588288
And some more:
Lacrosse 1 18.0 4.5 0.0 3.9
1 19671U 88106 B 96146.91977348 .00000020 00000-0 32527-5 0 00
2 19671 56.9790 146.2242 0002000 352.2253 7.7746 14.70748824 03
Lacrosse 2 18.0 4.5 0.0 3.9
1 21147U 91017 A 96146.90695553 .00000059 00000-0 10129-4 0 05
2 21147 67.9910 86.1218 0003000 275.9433 84.0567 14.68596408 02
USA 32 6.0 3.0 0.0 5.4
1 19460U 88078 A 96133.11443661 .00000030 00000-0 11391-4 0 04
2 19460 84.9900 8.0042 0004000 349.0135 10.9864 14.31129821 05
USA 81 6.0 3.0 0.0 5.4
1 21949U 92023 A 96145.07502624 .00000033 00000-0 12971-4 0 05
2 21949 85.0100 274.7935 0001000 258.1430 101.8568 14.29375270 01
Cheers.
Walter Nissen dk058@cleveland.freenet.edu
---
A little extra drag is always a good thing; says the addict.
(too bad "little extra" varies with time)