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#160
by
edkyle99
on 22 Sep, 2010 01:21
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@ edkyle99, kevin-rf,
I suspect that one of the reasons why ULA's broadcast was cut off before BECO/MEI was so that it would be that much harder to guesstimate final trajectory from the footage. Is Centaur powerful enough for a plane change manoeuvre after insert to parking orbit?
Yes, but it depends, as always, on payload mass and orbital altitude. 501 might be able to lift 6 tonnes to a 700 km sun synchronous orbit from Vandenberg AFB, but only 5 to 5.3 tonnes to a 120 deg-ish orbit at the same height. Add 500 kg of payload for a 200 km orbit. Subtract 500 kg for a 1,200 km orbit. Etc. Note that two Centaur burns are needed for altitudes greater than about 500 km.
- Ed Kyle
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#161
by
TitanFan
on 22 Sep, 2010 03:19
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Here's my home video of the launch (skip to 45 seconds if you want to just see liftoff). This was filmed through a telescope from Harris Grade Road.
Where were you at on the Grade taking that video? That is phenomenal! I was going to head up there if the pad was still fogged in, but the fog lifted in time so I headed out to a (rather creepy when you are alone) backwoods area my grandpa showed me many years ago on base.
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#162
by
jcm
on 22 Sep, 2010 04:21
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and 24 hours after launch, Ted has reported on SeeSat an orbit based by observations this evening by Bob and Brad... these guys are just darn impressive.
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#163
by
kevin-rf
on 22 Sep, 2010 12:25
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and 24 hours after launch, Ted has reported on SeeSat an orbit based by observations this evening by Bob and Brad... these guys are just darn impressive.
...and the Orbit is?
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#164
by
edkyle99
on 22 Sep, 2010 14:07
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and 24 hours after launch, Ted has reported on SeeSat an orbit based by observations this evening by Bob and Brad... these guys are just darn impressive.
...and the Orbit is?
Jonathan ("jcm") has reported a 1057 x 1072 km x 123.0 deg orbit at his long-lived, authoritative, hyper-vital web site. You can find the latest info at:
http://planet4589.org/space/jsr/latest.htmlThe "amateur" (more like "semi-professional", IMO, though without pay
) tracking effort is described at the Seesat-L discussion board at
http://www.satobs.org/seesat/Sep-2010/index.htmlThere, Ted Molczan has listed (a semipro educated guess) the payload as "FIA Radar 1".
- Ed Kyle
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#165
by
kevin-rf
on 22 Sep, 2010 14:13
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Ed, thanks...
Interesting quote:
"That costs extra fuel since you are fighting the Earth's
rotation instead of gaining from it. The altitude is also rather higher
than earlier surveillance satellites."
Add that to the use of an Atlas 501, probable deorbit of the Centaur and one wonders how light was that bird under the 5 meter fairing?
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#166
by
toddbronco2
on 22 Sep, 2010 15:04
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Here's my home video of the launch (skip to 45 seconds if you want to just see liftoff). This was filmed through a telescope from Harris Grade Road.
Where were you at on the Grade taking that video? That is phenomenal! I was going to head up there if the pad was still fogged in, but the fog lifted in time so I headed out to a (rather creepy when you are alone) backwoods area my grandpa showed me many years ago on base.
I was at the first major pull-off on Harris Grade Road (34 43 41.91 N, 120 26 36.24 W) where there were probably another 30-40 cars by the time of the launch. I'd like to find somewhere closer for Atlas V and Delta IV launches that still has a good view, but I don't know the area well enough to know which areas are closed by the Air Force during launches
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#167
by
edkyle99
on 22 Sep, 2010 15:04
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Ed, thanks...
Interesting quote:
"That costs extra fuel since you are fighting the Earth's
rotation instead of gaining from it. The altitude is also rather higher
than earlier surveillance satellites."
Add that to the use of an Atlas 501, probable deorbit of the Centaur and one wonders how light was that bird under the 5 meter fairing?
I would guess 4 tonnes or less, emphasis on the "less". Obviously this is much lighter than the 14-ish tonne Lacrosse radarsats. But then again Lacrosse is a probably a dinosaur by comparison with modern radar imagers like Germany's X-band Sar Lupe, which only weighs 0.8 tonnes but reportedly has 50 cm resolution. It is also possible that whatever this is, it is not performing a super-detailed reconnaissance mission like Lacrosse.
- Ed Kyle
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#168
by
eeergo
on 22 Sep, 2010 15:48
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Reading through the SatObs discussions, the bird's low magnitude (6.5 at best conditions) drew my attention. It seems to me to be low for such a "big volume" satellite as this is estimated to be, being at around 1000 km altitude, but I'm not really sure what the typical magnitudes are for these orbits.
Of course, I realize not many observations have been made and better lightning conditions may increase magnitude, and also any big reflector it may have probably hasn't been deployed yet, but just wondering if there may be other factors at play.
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#169
by
Ben the Space Brit
on 22 Sep, 2010 17:42
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Reading through the SatObs discussions, the bird's low magnitude (6.5 at best conditions) drew my attention.
It's logical that a military satellite would have a low-observable coating of some kind to make it difficult to track optically. A lot depends on the angle of the solar arrays to the sun too.
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#170
by
hop
on 22 Sep, 2010 21:59
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It's logical that a military satellite would have a low-observable coating of some kind to make it difficult to track optically.
That would only be logical if it was sufficiently low-observable to affect potential adversaries ability to track it. If the "pro-amateurs" on Seesat-L can reliably track it, this is unlikely.
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#171
by
Ben the Space Brit
on 23 Sep, 2010 07:13
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It's logical that a military satellite would have a low-observable coating of some kind to make it difficult to track optically.
That would only be logical if it was sufficiently low-observable to affect potential adversaries ability to track it. If the "pro-amateurs" on Seesat-L can reliably track it, this is unlikely.
I dunno, sometimes I think that these 'enthusiastic amateurs' are actually better (and more creative in counter-measures) than the 'official' intelligence agencies. Certainly the guys who located X-37 had the NRO pulling their hair out.
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#172
by
Ronsmytheiii
on 23 Sep, 2010 14:57
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#173
by
TitanFan
on 24 Sep, 2010 03:49
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I was at the first major pull-off on Harris Grade Road (34 43 41.91 N, 120 26 36.24 W) where there were probably another 30-40 cars by the time of the launch. I'd like to find somewhere closer for Atlas V and Delta IV launches that still has a good view, but I don't know the area well enough to know which areas are closed by the Air Force during launches
Where you were at is actually less than 5 minutes from my house. I was going to try to go up there and get a time-lapse streak shot of it, but I can see SLC-3 off in the distance from the end of my street, so when I left my house to go watch, and I saw the pad was fairly clear, I couldn't pass up the base. I didn't want to chance taking pictures out there on base, even though at my viewing location out there, about the only folks who would've been aware of my picture taking would've been myself and the coyotes...LOL.
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#174
by
yinzer
on 24 Sep, 2010 04:13
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It's logical that a military satellite would have a low-observable coating of some kind to make it difficult to track optically.
That would only be logical if it was sufficiently low-observable to affect potential adversaries ability to track it. If the "pro-amateurs" on Seesat-L can reliably track it, this is unlikely.
I dunno, sometimes I think that these 'enthusiastic amateurs' are actually better (and more creative in counter-measures) than the 'official' intelligence agencies. Certainly the guys who located X-37 had the NRO pulling their hair out.
The amateurs are good at finding satellites because hiding satellites is hard (as far as we know). But I think most of the amateurs would admit that having more money would make their job easier, so it's reasonable to suppose that interested state actors can track satellites at least as well as the amateurs.
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#175
by
DaveJes1979
on 29 Sep, 2010 21:58
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I can confirm that viewing Atlas V launches from Ocean Avenue does indeed make for an excellent show. Fog wasn't really a problem, so I don't know why so many folks were way back at Harris Grade. It was quite easy to get within 2.5 miles of the pad, where many spectators had parked. It was FANTASTICALLY loud, even without any solid boosters. It was much louder than my experiences viewing Delta II's (5 miles away) or the Space Shuttle (6.5 miles away). Yes, the rocket is partially obscured while on the pad, but from certainly locations along the road you could make out most of it.
The lack of boosters on this Atlas made for an interesting show. The RP-1 and LOX do not burn nearly as bright as solid motors do. However, the fact that the Atlas' ascent was so much slower really increased the dramatic impact to viewers on the ground. Launchers with solids just leap off the pad and the show simply does not last very long.
) tracking effort is described at the Seesat-L discussion board at