[FRIAM] starlink trail
Steven A Smith
sasmyth at swcp.com
Mon May 27 15:11:34 EDT 2019
<another long-winded anecdote>
I was born "under the rising sign of Sputnik" in 1957 (S1 & S2 went up
late that year). I was just about 1 year old when Explorer 1 and then
Vanguard 1 went up in early 1958. Vanguard 1, 2, 3 are still up there,
being in an unusually high orbit for the time. The crowdsource
Moonwatch
<https://www.universetoday.com/100744/citizen-science-old-school-style-the-true-tale-of-operation-moonwatch/>
project was already developing and was used to try to track/find
Vanguard, but the first siting of an artificial satellite was of
Sputnik. Ham radio folks were tracking the radio signals, but visual
siting (telescope or binoculars) was much trickier.
Some here were born early enough to have been young adults at that time
and probably have first-hand memories of these events, and perhaps even
attempting their own observations? My first experience with direct
satellite observation was *probably* when the Echo
<https://en.wikipedia.org/wiki/Project_Echo>"satelloons" were up. At
roughly 100' diameter with a deliberately reflective surface (passive
microwave relays), they were apparently highly visible to the naked eye.
We've come a long way baby! </anecdote>
<speculation> We (humans collectively) now have something approaching
10,000 satellites or fragments in orbit... one man's "trash" is another
man's "treasure" of course. I haven't heard Musk announce a SpaceX
"Salvage Operation" yet, but at some point, that seems like a viable
business, given the expense of launch... the materials in derelict
satellites would seem to be valuable once a method for "recycling" those
materials could be developed. I believe we are still in the early
stages of a "radiation" of design-species in satellites, not having
settled on any specific body plan and functional conceit... some might
eventually depend on a modest amount of "foraging" once in orbit?
Delta-V is clearly the most valuable resource which for all but
solar/mag-sail propulsion depends on reaction mass... which suggests
turning "big ones into little ones" with space junk (grapefruit to
bus-sized objects) into streams of (ionized) particles as small as
individual molecules. Variations on "tether" and "sail" technology
also may be good uses of captured "space junk". A big challenge to all
this is the orbital mechanics sophistication to use less DeltaV matching
orbits to "catch" junk than is gained by capturing it. Oh yeh... and
still do something actually useful besides just wander around eating and
pooping things.
<speculation>
On 5/27/19 10:09 AM, Owen Densmore wrote:
> A TLDR post. It points to a video of the "train" but brings up
> problems with the eventual number of the critters.
>
> -- Owen
>
> Sightings of SpaceX’s Starlink satellites spark awe — and astronomical
> angst (3 minute read)
> <https://tracking.tldrnewsletter.com/CL0/https:%2F%2Fwww.geekwire.com%2F2019%2Fsightings-spacexs-starlink-satellites-spark-awe-astronomical-angst%2F/1/0100016af8bd48bf-94af9903-5a99-4bdc-914c-330937053b7f-000000/1p5yHFi__nt-eWCq_QXyb1VvhqluhaiG5EZV4OIiDqY=90>
>
> SpaceX has launched 60 of its Starlink broadband satellites into the
> sky, creating a chain of satellites that could be observed by
> enthusiasts in a number of locations around the world. Some
> astronomers have expressed concern that the brightness from the
> satellites will interfere with observations of the night sky,
> especially when all 11,000 satellites are deployed. Elon Musk has
> confirmed that the satellites will be dark when the stars are visible.
>
>
> On Mon, May 27, 2019 at 9:57 AM Stephen Guerin
> <redfishgroupllc at gmail.com <mailto:redfishgroupllc at gmail.com>> wrote:
>
> Any idea on how far separated ground cameras would need to to get
> triangulate 3d using a shift in the apparent RA and declination of
> the background start field?
>
> On Mon, May 27, 2019, 8:49 AM Roger Critchlow <rec at elf.org
> <mailto:rec at elf.org>> wrote:
>
> The prediction has shifted to a few minutes earlier tonight,
> appears 20h53, disappears 21h04, track passes close to Vega
> then close to Arcturus.
>
> -- rec --
>
> On Sun, May 26, 2019 at 10:15 PM Roger Critchlow <rec at elf.org
> <mailto:rec at elf.org>> wrote:
>
> They were early, about 21h40m at the meridian, three were
> bright from 45d altitude, others may have flickered into
> visibility or may have been my imagination.
>
> The predicted pass in Santa Fe for Monday the 27th of May
> is from 21h01m10s to 21h12m23s, from SW to NE again,
> passing close to Vega. Give yourself some slack on the
> time, the speed depends on the altitude and the satellites
> are supposed to be boosting higher ever 90 minutes.
>
> -- rec --
>
>
> On Sun, May 26, 2019 at 12:03 PM Roger Critchlow
> <rec at elf.org <mailto:rec at elf.org>> wrote:
>
> According to calsky.com <http://calsky.com> the trail
> of the 60 starlink satellites rises in Santa Fe this
> evening at 21h40m28s in the SW and sets at 21h51m43s
> in the NE. They are 8.5mag at the horizon which is
> too dim to see, but they should reach 4.7mag at the
> meridian at 21h46m17s. Looks like they'll pass close
> to the last star in the big dipper's handle.
>
> -- rec --
>
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