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LIVE: PSLV C18 Megha-Tropiques October 12, 2011
by
input~2
on 09 Aug, 2011 19:37
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Orbcomm AIS-Sat-1 satellite to be launched on September 25.
(
source)
This would indicate a September 25 launch for PSLV C18.
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#1
by
isro-watch
on 17 Aug, 2011 05:04
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I spoke with some of my sources...even they indicated a Sep-25-28 timeframe.
But, I am afraid that this launch may slip into October as the stacking operations had begun only few days back...First stage stacking is in progress as of 15-Aug-2011.
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#2
by
input~2
on 17 Aug, 2011 13:17
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#3
by
input~2
on 21 Aug, 2011 14:54
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What is the orbit ( Height and Inclination ) for Orbcom AIS-Sat-1 (equatorial) ?
Not exactly the details you want but you may want to check out page 7 of
this Orbcomm presentationThe future 18 Orbcomm-2 satellites, also equipped with AIS, will have an altitude of 750 km
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#4
by
s^3
on 22 Aug, 2011 10:21
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^^^
Thanks input-2
So we may have to wait further announcement to know which specific orbit out of 6 planes.
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#5
by
input~2
on 22 Aug, 2011 19:36
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^^^
So we may have to wait further announcement to know which specific orbit out of 6 planes.
My understanding is that the Orbcomm AIS sat to be launched by PSLV C18 is an AIS-only satellite, not part of the Orbcomm-2 constellation; it is intended for Plane E (equatorial).
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#6
by
Salo
on 24 Aug, 2011 22:01
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#7
by
Salo
on 03 Sep, 2011 05:25
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#8
by
input~2
on 05 Sep, 2011 18:53
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#9
by
input~2
on 07 Sep, 2011 19:57
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#10
by
Salo
on 08 Sep, 2011 04:56
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#11
by
input~2
on 10 Sep, 2011 19:11
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#12
by
Skyrocket
on 13 Sep, 2011 13:07
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the Orbcomm AIS-Sat is named "VesselSat 1"
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#13
by
seshagirib
on 05 Oct, 2011 15:29
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#14
by
Salo
on 09 Oct, 2011 17:05
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#15
by
Shams
on 10 Oct, 2011 10:34
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#16
by
Salo
on 10 Oct, 2011 11:34
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October 10, 2011
Countdown commenced for PSLV-C18 / Megha-Tropiques Mission
The Launch Authorisation Board (LAB) for PSLV-C18/Megha-Tropiques mission, which met on October 9, 2011 at Satish Dhawan Space Centre(SDSC) - SHAR, Sriharikota has cleared the launch of PSLV-C18 at 11:00 hrs (IST) on Wednesday, October 12, 2011.
The 50 hour countdown commenced at 09:00 hours today (October 10, 2011). During the Countdown, propellant-filling operations of the liquid propellant second stage (PS2) and fourth stage (PS4) of the launch vehicle will be carried out. Mandatory checks on the launch vehicle and spacecraft including charging of batteries and pressurisation of propellant tanks will be performed. Readiness of various ground systems such as tracking radar systems and communication networks will also be checked.
PSLV-C18 will inject Megha-Tropiques satellite into an orbit of 867 km altitude at an inclination of 20 deg with respect to equator. PSLV will also inject SRMSat from SRM University, Chennai, JUGNU from Indian Institute of Technology, Kanpur and Vesselsat-1 from Luxembourg.
http://www.isro.org/pressrelease/scripts/pressreleasein.aspx?Oct10_2011Brochure:
http://www.isro.org/pslv-c18/pdf/pslv-c18-brochure.pdfPhoto:
http://www.isro.org/pslv-c18/Imagegallery/launchvehicle.aspxVideo:
http://www.isro.org/pslv-c18-video.aspx
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#17
by
input~2
on 11 Oct, 2011 13:10
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AFAICT, at this time launch is confirmed for to-morrow October 12 at 0530UTC.
Doordarshan News should have live coverage from 0500UTC
http://webcast.gov.in/live/ Live webcasting will start at 10:30 hrs (IST) on Oct 12, 2011
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#18
by
input~2
on 11 Oct, 2011 13:20
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#19
by
input~2
on 11 Oct, 2011 13:33
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#20
by
input~2
on 11 Oct, 2011 13:49
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#21
by
m.prasad
on 11 Oct, 2011 13:49
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Does any one know the max payload capacity of PSLV CA version. Till now I thought, it was around 600 kg into 820 km PSSO (Polar Sun Syncronous orbit). But C18 carries bigger payload - 1047kg into 817 km PSSO orbit. Does ISRO introduce any changes in the vehicle configuration?
Thanks in advance
~Prasad
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#22
by
input~2
on 11 Oct, 2011 14:08
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Does any one know the max payload capacity of PSLV CA version. Till now I thought, it was around 600 kg into 820 km PSSO (Polar Sun Syncronous orbit). But C18 carries bigger payload - 1047kg into 817 km PSSO orbit. Does ISRO introduce any changes in the vehicle configuration?
Thanks in advance
~Prasad
Megha-tropiques will be injected in a low-inclined orbit of 20° (
source) not in PSSO
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#23
by
Skyrocket
on 11 Oct, 2011 15:03
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Does any one know the max payload capacity of PSLV CA version. Till now I thought, it was around 600 kg into 820 km PSSO (Polar Sun Syncronous orbit). But C18 carries bigger payload - 1047kg into 817 km PSSO orbit. Does ISRO introduce any changes in the vehicle configuration?
Thanks in advance
~Prasad
The PSLV-CA has a capacity of about 1100 kg for this orbit, so we are near the upper limit with this launch.
AFAIK, the PSLV-CA version has not received any upgrades since it has been introduced.
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#24
by
input~2
on 11 Oct, 2011 15:21
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The PSLV-CA has a capacity of about 1100 kg for this orbit, so we are near the upper limit with this launch.
"this orbit" meaning, I presume, 20° inclination, not PSSO
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#25
by
Skyrocket
on 11 Oct, 2011 16:12
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The PSLV-CA has a capacity of about 1100 kg for this orbit, so we are near the upper limit with this launch.
"this orbit" meaning, I presume, 20° inclination, not PSSO
Sorry for the confusion: PSLV-CA has a capacity of about 1100 kg for PSSO. For the 20° incl it is higher.
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#26
by
Salo
on 11 Oct, 2011 17:36
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#27
by
Salo
on 11 Oct, 2011 17:41
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#28
by
sanman
on 11 Oct, 2011 19:28
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Hi, I tried using one of these online timezone converters, and I'm not sure if it churned out the correct answer for me.
Oct12 11:00AM Sriharikota time = Oct12 1:30AM Eastern Standard Time
Is that correct? I was just mulling over whether I'd be inclined to stay up to watch the launch.
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#29
by
input~2
on 11 Oct, 2011 20:41
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Oct12 11:00AM Sriharikota time = Oct12 1:30AM Eastern Standard Time
Is that correct?
Seems to be correct: 01:30 am Eastern corresponding to 0530UTC
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#30
by
input~2
on 11 Oct, 2011 20:43
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No-fly zones as per NOTAM
AFAIU, these zones correspond respectively to Stage 1, Fairing, Stage 2 and Stage 3 drop zones
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#31
by
Jason1701
on 12 Oct, 2011 00:45
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How does one pronounce "Megha?"
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#32
by
sanman
on 12 Oct, 2011 03:54
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"May-ghah" would be my closest approximation.
India also has a state called Meghalaya, which means "abode of clouds" in ancient Sanskrit (just like how Himalaya means "abode of snow"):
http://en.wikipedia.org/wiki/Meghalaya
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#33
by
Chris Bergin
on 12 Oct, 2011 04:27
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#34
by
Chris Bergin
on 12 Oct, 2011 04:50
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T-40 mins. No sign of a webcast.
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#35
by
seshagirib
on 12 Oct, 2011 04:56
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#36
by
input~2
on 12 Oct, 2011 04:59
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#37
by
Chris Bergin
on 12 Oct, 2011 05:02
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Ah great, thanks!
Under T-30 mins.
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#38
by
Mapperuo
on 12 Oct, 2011 05:03
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#39
by
seshagirib
on 12 Oct, 2011 05:05
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#40
by
input~2
on 12 Oct, 2011 05:09
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#41
by
Chris Bergin
on 12 Oct, 2011 05:12
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DD is a good quality stream.
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#42
by
Chris Bergin
on 12 Oct, 2011 05:17
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#43
by
Chris Bergin
on 12 Oct, 2011 05:20
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DD simply showing the video from the ISRO site. T-10 mins. Nothing live yet.
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#44
by
seshagirib
on 12 Oct, 2011 05:21
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http://live.indiatimes.com/default.cms?timesnow=1
is live now
This one is showing adverts and news.....including Cricket scandals! 
(Cricket is massive in India)
Hey....they deviated off topic,,,,
right now DD looks like the best bet...though they are playing recorded program so close to T=T0.
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#45
by
Chris Bergin
on 12 Oct, 2011 05:22
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#46
by
seshagirib
on 12 Oct, 2011 05:23
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DD is back to live
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#47
by
input~2
on 12 Oct, 2011 05:23
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#48
by
Chris Bergin
on 12 Oct, 2011 05:23
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#49
by
Chris Bergin
on 12 Oct, 2011 05:24
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#50
by
Chris Bergin
on 12 Oct, 2011 05:26
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#51
by
Chris Bergin
on 12 Oct, 2011 05:28
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#52
by
Rocket Guy
on 12 Oct, 2011 05:29
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#53
by
Chris Bergin
on 12 Oct, 2011 05:30
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#54
by
Chris Bergin
on 12 Oct, 2011 05:30
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T-30 seconds.
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#55
by
Chris Bergin
on 12 Oct, 2011 05:31
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#56
by
input~2
on 12 Oct, 2011 05:32
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#57
by
Chris Bergin
on 12 Oct, 2011 05:32
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#58
by
Chris Bergin
on 12 Oct, 2011 05:33
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#59
by
Chris Bergin
on 12 Oct, 2011 05:33
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Staging. 1-2 Sep.
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#60
by
input~2
on 12 Oct, 2011 05:34
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#61
by
Chris Bergin
on 12 Oct, 2011 05:34
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#62
by
input~2
on 12 Oct, 2011 05:35
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#63
by
Chris Bergin
on 12 Oct, 2011 05:36
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#64
by
input~2
on 12 Oct, 2011 05:37
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#65
by
Chris Bergin
on 12 Oct, 2011 05:38
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#66
by
input~2
on 12 Oct, 2011 05:38
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#67
by
input~2
on 12 Oct, 2011 05:40
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#68
by
Chris Bergin
on 12 Oct, 2011 05:40
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#69
by
input~2
on 12 Oct, 2011 05:42
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#70
by
Chris Bergin
on 12 Oct, 2011 05:43
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Used third stage sep. Still a long way to go with the 778.9 seconds coast.
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#71
by
input~2
on 12 Oct, 2011 05:44
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#72
by
input~2
on 12 Oct, 2011 05:47
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#73
by
input~2
on 12 Oct, 2011 05:48
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#74
by
Chris Bergin
on 12 Oct, 2011 05:49
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Coming to the end of the coast.
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#75
by
Chris Bergin
on 12 Oct, 2011 05:50
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Upper stage (fourth stage) ignition.
154 second burn.
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#76
by
input~2
on 12 Oct, 2011 05:50
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#77
by
input~2
on 12 Oct, 2011 05:51
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#78
by
input~2
on 12 Oct, 2011 05:52
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#79
by
Chris Bergin
on 12 Oct, 2011 05:52
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Orbital velocity. Awaiting sep.
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#80
by
Chris Bergin
on 12 Oct, 2011 05:53
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S/C Sep for MT!
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#81
by
input~2
on 12 Oct, 2011 05:53
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#82
by
input~2
on 12 Oct, 2011 05:54
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SRMsat separated
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#83
by
Chris Bergin
on 12 Oct, 2011 05:54
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SRMSAT S/C Sep!
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#84
by
input~2
on 12 Oct, 2011 05:55
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#85
by
input~2
on 12 Oct, 2011 05:55
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Vesselsat-1 separated
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#86
by
Chris Bergin
on 12 Oct, 2011 05:55
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VesselSat-1 S/C Sep!
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#87
by
input~2
on 12 Oct, 2011 05:56
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#88
by
input~2
on 12 Oct, 2011 05:56
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Jugnu separated
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#89
by
Chris Bergin
on 12 Oct, 2011 05:56
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Jugnu S/C Sep!
Great success for India!
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#90
by
Chris Bergin
on 12 Oct, 2011 05:57
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#91
by
input~2
on 12 Oct, 2011 05:58
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#92
by
input~2
on 12 Oct, 2011 05:59
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#93
by
input~2
on 12 Oct, 2011 06:00
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"Megha-tropiques achieved orbit only 2km from the planned 867km"
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#94
by
Shams
on 12 Oct, 2011 06:01
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Congrats India for the successful launch
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#95
by
Chris Bergin
on 12 Oct, 2011 06:01
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#96
by
input~2
on 12 Oct, 2011 06:05
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Lift-off was at 0531UTC
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#97
by
input~2
on 12 Oct, 2011 06:09
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"Megha-tropiques in good health"
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#98
by
sanman
on 12 Oct, 2011 06:09
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5th speaker said:
deployment of MeghaTropiques antennae successful
deployment of panels successful
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#99
by
input~2
on 12 Oct, 2011 06:10
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CNES representative speaking
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#100
by
Mapperuo
on 12 Oct, 2011 06:13
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PSLV = Perfect Satellite Launch Vehicle so they said.
Congratulations!
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#101
by
sanman
on 12 Oct, 2011 06:19
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ISRO Chief Radhakrishna says:
Next GSLV flight with Cryogenic Upper Stage in Q2 of 2012!
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#102
by
input~2
on 12 Oct, 2011 06:20
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ISRO Chief Radhakrishna says:
Next GSLV flight in Q2 of 2012!
with indigeneous cryo upper stage!
and 2 PSLVs until then: with RISAT and SARAL
(according to ISRO chairman)
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#103
by
seshagirib
on 12 Oct, 2011 09:02
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Is it just me? Or did the 4th stage ignite a little prematurely, also all the stages seemed to slightly over perform.
Anyone else here, noticed these ?
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#104
by
s^3
on 12 Oct, 2011 10:27
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Overperformance .. yes seen.
4th stage ignition time .. did not compare during launch .. may be after someone puts it on youtube we will see. The expected ign time was 1154 seconds after launch time T.
========
Checked with ISRO wesite ( This time they were innovative (!) to include launch video also in their website ). Ignition was announced at around T + 1100 secs. Yes, much earlier than planned. May be because of over-performance of earlier stages.
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#105
by
input~2
on 12 Oct, 2011 11:39
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#106
by
input~2
on 12 Oct, 2011 12:09
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#107
by
seshagirib
on 12 Oct, 2011 13:40
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Overperformance .. yes seen.
4th stage ignition time .. did not compare during launch .. may be after someone puts it on youtube we will see. The expected ign time was 1154 seconds after launch time T.
========
Checked with ISRO wesite ( This time they were innovative (!) to include launch video also in their website ). Ignition was announced at around T + 1100 secs. Yes, much earlier than planned. May be because of over-performance of earlier stages.
Looks like the guidance system decided to go ahead with ignition as soon as altitude was achieved ~832km. The over performance of the earlier stage was compensated by an early ignition and cut off of the 4th stage. The trajectory was back on the pre programmed plot close to s/c sep.
A very mature and versatile guidance system!
Would be interesting to know if the liquid 4th stage is throttle capable and was throttled in this instance.
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#108
by
m.prasad
on 12 Oct, 2011 14:02
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Overperformance .. yes seen.
4th stage ignition time .. did not compare during launch .. may be after someone puts it on youtube we will see. The expected ign time was 1154 seconds after launch time T.
MT sep (T + 1288 s) but planned was T + 1339.8 s. Same for other sats as well. I thought it was a typo in brochure ;-) Thanks for the clarification... Any idean on acheiving 2 km less orbit (even after overperformaning)?
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#109
by
input~2
on 12 Oct, 2011 14:37
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#110
by
input~2
on 12 Oct, 2011 17:02
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#111
by
input~2
on 12 Oct, 2011 17:38
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5 objects have now been catalogued by STRATCOM (no elset yet..)
37838/2011-058A
37839/2011-058B
37840/2011-058C
37841/2011-058D
37842/2011-058E
They should correspond to the 4 satellites plus the PSLV 4th stage.
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#112
by
Shams
on 13 Oct, 2011 05:36
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#113
by
input~2
on 13 Oct, 2011 17:32
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#114
by
sanman
on 14 Oct, 2011 05:00
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I can't wait until GSLV-Mk3 becomes a similarly trusted satellite launcher with a long track record.
I'd also love it if the old PSLV workhorse were spun off to the private sector.
Perhaps to Tata Aerospace or someone similar. They could go over it from top to bottom, and streamline its design and operating costs over time, through iterative incremental improvements.
I would even love to see the PSLV man-rated, and used to send space tourists to orbit.
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#115
by
input~2
on 14 Oct, 2011 05:39
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We now have elsets for the 5 Objects.
Object D has the highest perigee and was in 850.3 x 867.9 km x 19.97° a few hours after launch.
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#116
by
s^3
on 14 Oct, 2011 16:07
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^^^
Surprisingly, all the five objects ( 4 sats + last stage of PSLV ) from PSLV C18 are more or less in the same orbit of about 20 deg inclination.
The brochures for these satellites had not mentioned their inclinations. Even Vesselsat had not indicated about intended inclination.
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#117
by
input~2
on 15 Oct, 2011 16:26
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From
ISRO press release:
It has been confirmed that the Satellite has been placed very precisely into its intended circular orbit, as given below:
| Orbital Parameter at Satellite injection Point | Target | Achieved |
| Perigee (km) | 865.30 + 20 | 864.39 |
| Apogee (km) | 867.15 + 20 | 865.16 |
| Orbital Inclination (degree) | 20.06 + 0.20 | 19.99 |
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#118
by
hop
on 15 Oct, 2011 19:46
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Surprisingly, all the five objects ( 4 sats + last stage of PSLV ) from PSLV C18 are more or less in the same orbit of about 20 deg inclination.
The brochures for these satellites had not mentioned their inclinations. Even Vesselsat had not indicated about intended inclination.
They were all released from the 4th stage after the final burn, so they all have to go the same inclination and pretty much the same orbit. I assume Megha Tropiques has it's own propulsion system, I don't think any of the others do.
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#119
by
input~2
on 16 Oct, 2011 05:25
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Surprisingly, all the five objects ( 4 sats + last stage of PSLV ) from PSLV C18 are more or less in the same orbit of about 20 deg inclination.
The brochures for these satellites had not mentioned their inclinations. Even Vesselsat had not indicated about intended inclination.
The launch brochure did indicate the inclination of the orbit for Megha-tropiques.
With its circular orbit inclined 20 deg to the Equator, the Megha-Tropiques is a unique satellite for climate research...
also the CNES site I quoted
earlier gave Megha-Tropiques inclination.
Concerning Jugnu and SRMsat, a polar orbit was indicated on their respective webpages before launch (see for example
here, before the page is updated
).
These microsats can apparently adjust to any orbit..
Vesselsat-1 was described as an "equatorial AIS"
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#120
by
input~2
on 19 Oct, 2011 19:31
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STRATCOM has now identified former Object B as Megha-Tropiques in the following orbit:
848.9 x 867.4 km x 19.98°
Former Object A becomes Object E (the 4th stage)
Former Object E becomes Object B
Object C and Object D don't change
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#121
by
input~2
on 29 Oct, 2011 06:55
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USSTRATCOM catalog changes:
Jugnu = Object B 37839/2011-058B
Vesselsat-1 = Object C 37840/2011-058C (country catalogued as Norway
)
SRMSAT = Object D 37841/2011-058D
The separation order was SRMSAT then Vesselsat then Jugnu.
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#122
by
jcm
on 29 Oct, 2011 13:20
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USSTRATCOM catalog changes:
Jugnu = Object B 37839/2011-058B
Vesselsat-1 = Object C 37840/2011-058C (country catalogued as Norway )
SRMSAT = Object D 37841/2011-058D
The separation order was SRMSAT then Vesselsat then Jugnu.
Guess they are confusing Vesselsat with AISSAT-1. I have put it as Luxembourg in my database.
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#123
by
input~2
on 29 Oct, 2011 15:08
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Guess they are confusing Vesselsat with AISSAT-1.
Jonathan, I think you are right
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#124
by
input~2
on 06 Nov, 2011 06:26
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USSTRATCOM has now corrected its catalog with Vesselsat-1 allocated to Luxembourg instead of Norway
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#125
by
TheVarun
on 02 Oct, 2020 12:33
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#126
by
vyoma
on 07 Apr, 2022 16:32
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https://timesofindia.indiatimes.com/home/science/after-over-10-years-its-end-of-mission-for-indo-french-sat-megha-tropiques/articleshow/90711253.cmsAfter over 10 years, it’s end of mission for Indo-French sat Megha-Tropiques
BENGALURU: After more than 10 years since it was launched, Megha-Tropiques, the Indo-French joint weather modeling satellite that was studying water cycle and energy exchanges in the tropics has reached what Isro calls the “end of the mission”.
A senior Isro scientist told TOI: “As of date, the satellite still has 120kg of fuel and the end of the mission is also not because of failures in communication, solar panels or any other systems or because we lost communication. All of those are still working.”
The decision to declare the “end of the mission” was taken because the satellite had developed an “attitude problem” which rendered the data unusable.
The problem was first noticed sometime in early or mid-March and given that it is a scientific mission there are minimum requirements. Even if payloads are healthy, the mission won’t continue if data is not usable.
At present, Megha-Tropiques is in an orbit around 870km away from Earth. As is the procedure, Isro will now have to fire the engines again and reduce the altitude through orbit reduction manoeuvres.
Isro and French space agency CNES are now planning another joint mission, Trishna, meant for accurate mapping of land surface temperatures. In his last address, former chairman Sivan K had said “Trishna will be the benchmark for temperature data at best resolution and repeatability globally”.
According to CNES, Trishna — Thermal infraRed Imaging Satellite for High-resolution Natural resource Assessment — will acquire imagery of Earth’s surface in the thermal infrared with a resolution and revisit frequency never seen before.
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#127
by
vyoma
on 25 Jun, 2022 22:04
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From "Joint IMD/ISRO updates since CGMS-50 and report on the medium to long-term future plans" presented at CGMS-50 plenary session (15-17 June 2022) (
here):
• ISRO-CNES joint mission MeghaTropiques was launched into orbit in October 2011. Due to an on-board anomaly in March 2019, the data availability has become low. ISRO- CNES JSC decided to announce the end of mission.
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#128
by
Conexion Espacial
on 07 Mar, 2023 14:43
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Controlled Re-entry Experiment of Megha-Tropiques-1
https://www.isro.gov.in/controlled_re_entry_experiment.html
Mar 05, 2023
ISRO is gearing up for a challenging experiment of controlled re-entry of a decommissioned low Earth orbiting satellite, namely Megha-Tropiques-1 (MT1), on March 7, 2023. MT1 was launched on October 12, 2011, as a joint satellite venture of ISRO and the French space agency, CNES for tropical weather and climate studies. Although the mission life of the satellite originally was to 3 years, the satellite continued to provide valuable data services for more than a decade supporting regional and global climate models till 2021.
UN/IADC space debris mitigation guidelines recommend deorbiting a LEO (Low Earth Orbit) object at its end-of-life, preferably through controlled re-entry to a safe impact zone, or by bringing it to an orbit where the orbital lifetime is less than 25 years.It is also recommended to carry out “passivation” of on-board energy sources to minimise the risk of any post-mission accidental break-up.
The orbital lifetime of MT1, weighing about 1000 kg, would have been more than 100 years in its 20 deg inclined operational orbit of 867 km altitude. About 125 kg on-board fuel remained unutilised at its end-of-mission that could pose risks for accidental break-up. This left-over fuel was estimated to be sufficient to achieve a fully controlled atmospheric re-entry to impact an uninhabited location in the Pacific Ocean. Controlled re-entries involve deorbiting to very low altitudes to ensure impact occurs within a targeted safe zone.Usually, large satellites/rocket bodies which are likely to survive aero-thermal fragmentation upon re-entry are made to undergo controlled re-entry to limit ground casualty risk. However, all such satellites are specifically designed to undergo controlled re-entry at end-of-life. MT1 was not designed for EOL operations through controlled re-entry which made the entire exercise extremely challenging. Furthermore, the on-board constraints of the aged satellite, where several systems had lost redundancy and showed degraded performance, and maintaining subsystems under harsher environmental conditions at much lower than originally designed orbital altitude added to the operational complexities. Innovative workarounds were implemented by the operations team based on the study, deliberations, and exchanges among the mission, operations, flight dynamics, aerodynamics, propulsion, controls, navigation, thermal, and other sub-system design teams across the ISRO centres, who worked in synergy to surmount these challenges.
An uninhabited area in the Pacific Ocean between 5°S to 14°S latitude and 119°W to 100°W longitude was identified as the targeted re-entry zone for MT1.Since Aug 2022, 18 orbit manoeuvres were performed to progressively lower the orbit. In between the de-orbiting, aero-braking studies at different solar panel orientations were also carried out to gain better insights into the physical process of atmospheric drag affecting the orbital decay of the satellite.The final de-boost strategy has been designed after taking into consideration several constraints, including visibility of the re-entry trace over ground stations, ground impact within the targeted zone, and allowable operating conditions of subsystems, especially the maximum deliverable thrust and the maximum firing duration of the thrusters. The final two de-boost burns followed by the ground impact are expected to take place between 16:30 IST to 19:30 IST on March 7, 2023. Aero-thermal simulations show that no large fragments of the satellites are likely to survive the aerothermal heating during the re-entry.
As a responsible space agency committed to safe and sustainable operations in outer space, ISRO proactively takes efforts for better compliance with the UN/IADC space debris mitigation guidelines on post-mission disposal of LEO objects.The re-entry experiment of MT1 has been undertaken as a part of the ongoing efforts as this satellite with sufficient left-over fuel presented a unique opportunity to test the relevant methodologies and understand the associated operational nuances of post mission disposal by direct re-entry into the Earth’s atmosphere.
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#129
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Sam Ho
on 07 Mar, 2023 15:28
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Megha-Trqopiques-1 (MT1) Controlled Re-entry Successful and impacted on the Pacific Ocean
Mar 07, 2023
The controlled re-entry experiment for the decommissioned Megha-Tropiques-1 (MT-1) was carried out successfully on March 7, 2023. The satellite was launched on October 12, 2011, as a collaborative effort between ISRO and the French space agency CNES for carrying out tropical weather and climate studies. Since August 2022, the satellite's perigee was progressively lowered through a series of 20 manoeuvres spending about 120 kg of fuel. Multiple Manoeuvres including the final de-boost strategy were designed after taking into consideration several constraints, including visibility of the re-entry trace over ground stations, ground impact within the targeted zone, and allowable operating conditions of subsystems, especially the maximum deliverable thrust and the maximum firing duration constraint on thrusters. All manoeuvre plans were screened to ensure that there would be no post manoeuvre close approaches with other space objects, especially with the crewed space stations like International Space Stations and the Chinese Space Station.
The final two de-boost burns were executed at 11:02 UTC and 12:51 UTC respectively on 7th March 2023 by firing four 11 Newton thrusters on-board the satellite for about 20 minutes each. The final perigee was estimated to be less than 80 km indicating that the satellite would enter the denser layers of the Earth's atmosphere and subsequently undergo structural disintegration. The re-entry aero-thermal flux analysis confirmed that there would be no surviving large debris fragments.
From the latest telemetry, it is confirmed that the satellite has re-entered the Earth's atmosphere and would have disintegrated over the Pacific Ocean, the final impact region estimated is in the deep Pacific Ocean within the expected latitude & longitude boundaries. The entire sequence of events was carried out from the Mission Operations Complex in ISTRAC.
In recent years, ISRO has taken up proactive measures to improve the compliance level with the internationally accepted guidelines on space debris mitigation. Efforts are underway to build indigenous capabilities for tracking and monitoring space objects to safeguard Indian space assets. ISRO System for Safe and Sustainable Space Operations Management (IS4OM) has been established to spearhead such activities. The controlled re-entry exercise bears yet another testimony to India's continued efforts towards ensuring the long-term sustainability of outer space activities.
https://www.isro.gov.in/mt1-rentry-successful.html
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