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PSLV C17 - GSAT-12 - July 15, 2011
by
Salo
on 02 Jun, 2011 15:00
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#1
by
Salo
on 02 Jun, 2011 15:13
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#2
by
input~2
on 03 Jun, 2011 12:39
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The 1,400kg S/C will be first placed in a 284 x 21,000 km orbit
(from the previous reference)
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#3
by
m.prasad
on 07 Jun, 2011 05:47
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GSAT-12 reached Sriharikota (Reported by local news channel). Hope ISRO sticks to the schedule...
~Prasad
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#4
by
input~2
on 18 Jun, 2011 11:57
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#5
by
Salo
on 22 Jun, 2011 04:24
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#6
by
input~2
on 29 Jun, 2011 11:21
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From NOTAMs, launch could occur from July 6 to August 5 in the 1015-1315UTC time slot
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#7
by
input~2
on 30 Jun, 2011 08:27
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Launch is now set for July 15 between 16:48-17:08 Local time (ie 1218-1238 UTC)
(source:
ISRO)
edit : 1118-1138 UTC, India time= GMT+5h30min!
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#8
by
Satori
on 06 Jul, 2011 14:16
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Which launch pad is going to be used?
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#9
by
Salo
on 06 Jul, 2011 21:00
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#10
by
Salo
on 09 Jul, 2011 20:35
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#11
by
Salo
on 13 Jul, 2011 10:43
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#12
by
Salo
on 14 Jul, 2011 14:28
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#13
by
input~2
on 14 Jul, 2011 17:55
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#14
by
tehwkd
on 14 Jul, 2011 19:14
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#15
by
Chris Bergin
on 15 Jul, 2011 05:24
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Going to require a lot of you to keep a look out for the best TV station and see what we can do about collecting as many screenshots from those stations as we can!
Moved for live coverage
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#16
by
tehwkd
on 15 Jul, 2011 10:59
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GREEN for launch at T-20min
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#17
by
Salo
on 15 Jul, 2011 11:04
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#18
by
Chris Bergin
on 15 Jul, 2011 11:08
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GREEN for launch at T-20min
Excellent screenshots. If you could post a couple at a time, that would be a superb help!
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#19
by
Stardust9906
on 15 Jul, 2011 11:11
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#20
by
tehwkd
on 15 Jul, 2011 11:14
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#21
by
Stardust9906
on 15 Jul, 2011 11:14
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#22
by
Chris Bergin
on 15 Jul, 2011 11:15
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T-3 minutes
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#23
by
Chris Bergin
on 15 Jul, 2011 11:17
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T-120 seconds.
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#24
by
Stardust9906
on 15 Jul, 2011 11:18
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#25
by
Chris Bergin
on 15 Jul, 2011 11:18
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#26
by
tehwkd
on 15 Jul, 2011 11:19
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#27
by
Chris Bergin
on 15 Jul, 2011 11:20
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#28
by
Chris Bergin
on 15 Jul, 2011 11:21
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#29
by
Chris Bergin
on 15 Jul, 2011 11:22
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Perfomance nominal at +60 seconds.
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#30
by
Chris Bergin
on 15 Jul, 2011 11:22
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Ground lit strap on boosters sep.
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#31
by
Stardust9906
on 15 Jul, 2011 11:23
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#32
by
Chris Bergin
on 15 Jul, 2011 11:23
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Airlit strap ons seps
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#33
by
Chris Bergin
on 15 Jul, 2011 11:23
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Staging. 1-2 Sep. Second stage ignition.
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#34
by
Chris Bergin
on 15 Jul, 2011 11:24
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Nominal performance on the second stage.
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#35
by
Chris Bergin
on 15 Jul, 2011 11:26
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Fairing ("Heatshield") Sep.
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#36
by
Chris Bergin
on 15 Jul, 2011 11:27
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Staging. 2-3 Sep. Third stage ignition.
Third stage performance nominal.
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#37
by
Chris Bergin
on 15 Jul, 2011 11:31
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T+450 seconds, as much as the webcast is lagging like crazy.
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#38
by
Chris Bergin
on 15 Jul, 2011 11:33
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Staging. 3-4 Sep. Fourth stage coasting before ignition.
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#39
by
Chris Bergin
on 15 Jul, 2011 11:34
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#40
by
Chris Bergin
on 15 Jul, 2011 11:36
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Fourth stage ignition.
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#41
by
Chris Bergin
on 15 Jul, 2011 11:37
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#42
by
input~2
on 15 Jul, 2011 11:40
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#43
by
Chris Bergin
on 15 Jul, 2011 11:40
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300 seconds to go on the fourth stage.
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#44
by
Chris Bergin
on 15 Jul, 2011 11:45
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#45
by
input~2
on 15 Jul, 2011 11:48
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#46
by
Chris Bergin
on 15 Jul, 2011 11:49
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Fourth stage shutdown on target.
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#47
by
input~2
on 15 Jul, 2011 11:49
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#48
by
Chris Bergin
on 15 Jul, 2011 11:51
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S/C Sep! Congrats to ISRO!
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#49
by
Satori
on 15 Jul, 2011 11:51
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Satellite separation. Happy faces there... Congratulations to India!
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#50
by
input~2
on 15 Jul, 2011 11:51
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#51
by
Chris Bergin
on 15 Jul, 2011 11:54
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#52
by
Chris Bergin
on 15 Jul, 2011 11:58
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Doing a General Bolden with huge praise for the President
"When this country needs transponders, we can launch transponders".
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#53
by
Chris Bergin
on 15 Jul, 2011 12:02
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#54
by
input~2
on 15 Jul, 2011 12:02
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According to mission director, the orbit achieved is 282 x 21000 km
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#55
by
tehwkd
on 15 Jul, 2011 12:13
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Videos:
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#56
by
input~2
on 15 Jul, 2011 12:28
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Prayer for successful launch by ISRO chairman prior to launch
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#57
by
Salo
on 15 Jul, 2011 13:24
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#58
by
input~2
on 15 Jul, 2011 17:04
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USSTRATCOM has observed two objects:
Object A in 278 x 21348 km inclined 17.82°
Object B in 275 x 20959 km inclined 17.95°
(My guess would be Object B as GSAT-12, Object A as 4th stage..tbc)
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#59
by
Salo
on 15 Jul, 2011 17:34
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#60
by
seshagirib
on 16 Jul, 2011 07:14
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Why is there a "long" coasting phase between stage-3 Sep. and stage-4 ignition? Don't see any coasting phase for the other stages.
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#61
by
s^3
on 16 Jul, 2011 15:13
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#62
by
s^3
on 16 Jul, 2011 15:21
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Chris, I was really impressed with the interest and pains that you have taken in watching/posting live transmission snapshots in realtime.
Hats off to your enthusiasm.
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#63
by
jcm
on 17 Jul, 2011 03:49
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^^^
There is a small coast between first and second stage ( PS1 seperation and PS2 ignition .. see flight plan http://educationalsalvi.blogspot.com/2011/07/pslv-c17-launch-flight-sequence.html
The long coast is because the 3rd shut stage and the 4th stage have to be physically away from each other. Both are moving at a 7.7kms/sec so physically achieving a separation takes time.
Perhaps, but it's also quite common for there to be a coast before final stage. The profile of many launch vehicles is: bang-bang-bang lower stages, punch out of the atmosphere; then, longish coast to apogee of the Keplerian suborbital ellipse; then, impulse at apogee from final stage to add enough velocity to raise perigee out of the atmosphere. In the usual PSLV scenario of circular polar orbit, the coast lets it reach the desired circular altitude of 800 km or so.
In this case the coast was fairly short, and the long stage 4 burn converts the previous apogee of 250 km or so into the new perigee, and the previous negative perigee into a large (21350 km) apogee.
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#64
by
seshagirib
on 17 Jul, 2011 05:58
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^^^
There is a small coast between first and second stage ( PS1 seperation and PS2 ignition .. see flight plan http://educationalsalvi.blogspot.com/2011/07/pslv-c17-launch-flight-sequence.html
The long coast is because the 3rd shut stage and the 4th stage have to be physically away from each other. Both are moving at a 7.7kms/sec so physically achieving a separation takes time.
Perhaps, but it's also quite common for there to be a coast before final stage. The profile of many launch vehicles is: bang-bang-bang lower stages, punch out of the atmosphere; then, longish coast to apogee of the Keplerian suborbital ellipse; then, impulse at apogee from final stage to add enough velocity to raise perigee out of the atmosphere. In the usual PSLV scenario of circular polar orbit, the coast lets it reach the desired circular altitude of 800 km or so.
In this case the coast was fairly short, and the long stage 4 burn converts the previous apogee of 250 km or so into the new perigee, and the previous negative perigee into a large (21350 km) apogee.
I revisited the launch video:
The (ISRO expert?) commentary seems to indicate ( from 11:58 onwards ) that the long phase for the fourth stage is to decrease the orbital inclination and put the s/c in the equatorial plane orbit.
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#65
by
s^3
on 17 Jul, 2011 10:24
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^^^
The commentary by expert says " ... the longish coast is to ensure an orbit of 284kmsX21000 kms and s/c with 4th sage has travel longer distance so that the 4th stage carries the s/c so that the perigee lies on equator. "
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#66
by
Shams
on 18 Jul, 2011 10:37
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#67
by
s^3
on 19 Jul, 2011 05:38
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^^^
Surprised!
Celestrak is updating the TLEs everyday but it is more or less the same orbit from 16th July.
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#68
by
Shams
on 20 Jul, 2011 07:48
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#69
by
input~2
on 20 Jul, 2011 16:11
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Stratcom is following closely Object 37746 (11034A), the PSLV 4th stage, releasing updated orbital data nearly everyday; on the other hand the orbital data for GSAT-12 (37747/11034B) have not been updated since July 16, before the maneuvers
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#70
by
seshagirib
on 21 Jul, 2011 08:08
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Maybe Stratcom gives higher priority to uncontrolled debris and objects which may reenter atmosphere/impact earth in near future.
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#71
by
s^3
on 21 Jul, 2011 16:24
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^^^
Reason for non updation at Celestrak :
TSKelso (celestrak ) tweet of 19th says
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Six launches & over a dozen new objects since July 8 & none of them yet identified by Space Track.
19 Jul
=====
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#72
by
input~2
on 21 Jul, 2011 19:30
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According to an
ISRO press release published to-day July 21, GSAT-12 is now in 35684 x 35715 km inclined 0.17°.
GSAT-12 is now located at 63 degree East longitude. The Satellite would be moved to reach its designated longitude of 83 degree East within the next 16 days (at the rate of one degree per day).
Let's see if Stratcom catches up with new data for Object 37747/11034B
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#73
by
input~2
on 26 Jul, 2011 15:05
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Well, Stratcom has finally published to-day new data for object 37747/11034B (GSAT-12)
(last data was dated July 16..):
GSAT-12 was observed in 35,686 x 35,717 km inclined 0.17° yesterday July 25 at 1738UTC passing 73.2°E and drifting East with a drift rate of 1.1°/day
(I would then have expected it to be at 68° on July 21 not 63°
)
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#74
by
input~2
on 26 Jul, 2011 19:47
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The Catalog has now been updated:
37746 PSLV R/B 2011-034A
37747 GSAT 12 2011-034B
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#75
by
input~2
on 27 Jul, 2011 16:42
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Now A and B have been switched
37746 GSAT 12 2011-034A
37747 PSLV R/B 2011-034B
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#76
by
seshagirib
on 04 Aug, 2011 08:26
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http://isro.org/pressrelease/scripts/pressreleasein.aspx?Jul21_2011"
GSAT-12 Communication Satellite placed in Geosynchronous OrbitThe GSAT-12 Communication Satellite, launched onboard Polar Satellite Launch Vehicle (PSLV-C17), has been successfully placed in Geosynchronous Orbit with a perigee of 35,684 km, apogee of 35,715 km and an orbital inclination of 0.17 degree with respect to the equatorial plane.
It may be recalled that on July 15, 2011, PSLV-C17 had injected GSAT-12 into an elliptical transfer orbit of 281 km perigee and 21,027 km apogee, and orbital inclination of 17.9 degree. The critical manoeuvres to raise GSAT-12 Satellite into Geosynchronous Orbit were performed by firing the 440 Newton Liquid Apogee Motor of GSAT-12 Satellite for
about 80 minutes in five spells during July 16-20, 2011.
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"
Why was it necessary to fire the LAM so many times(5 times), would 1 or 2 long firings over heat the LAM? Or is there some other reason for so many firings?
Is it not risky to restart the LAM so many times? ( just in case the LAM fails to restart)
!
)