Author Topic: FAILURE: IRNSS-1H, PSLV C39, SLP, August 31, 2017 (13:30 UTC)  (Read 67917 times)

Offline eeergo

Webcast abruptly cut?
-DaviD-

Offline K210

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Re: LIVE: IRNSS-1H, PSLV C39, SLP, August 31, 2017 (13:30 UTC)
« Reply #101 on: 08/31/2017 01:54 PM »
Looks like a failure or at least a partial failure. This is not good.

Offline AJA

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Re: LIVE: IRNSS-1H, PSLV C39, SLP, August 31, 2017 (13:30 UTC)
« Reply #102 on: 08/31/2017 01:55 PM »
Webcast abruptly cut?

The YouTube chat had a comment from the hosting channel saying that they'd be stopping the telecast. (It was hosted by the Press Trust of India). Little disheartening for sure.


Also, attached a desktop video capture showing (maybe pareidolia and all that) the satellite separating from its launch adapter, and floating around, while still enclosed in the fairing.


As regards troubleshooting... what can they do?
1. Can't communicate with the satellite directly (presumably)
2. Is the satelllite cavity inside the fairing hermetically sealed? Can they build enough positive pressure inside the fairing by firing attitude control thrusters - to perhaps pry (don't want to use the 'e' word) the PLF open? This would need 1 to be false, obviously.
3. Limited battery life of the satellite, and telecommand ability (orbital position window) - if the facility exists at all..
« Last Edit: 08/31/2017 02:01 PM by AJA »

Offline soltasto

Looks like failure and total loss of payload. The payload fairing (heatshield) did not separate, so it caused underperformance (do to more mass to carry on) and then the satellite separated inside the fairing hitting it after cutoff.

Bad day for ISRO today :(
« Last Edit: 08/31/2017 01:57 PM by soltasto »

Online Steven Pietrobon

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Re: LIVE: IRNSS-1H, PSLV C39, SLP, August 31, 2017 (13:30 UTC)
« Reply #104 on: 08/31/2017 01:57 PM »
Webcast has ended. I didn't hear the heat shield separation event which explains the low delta-V and altitude. There might be a very slim chance they might be able to command the heat shield to open, since the payload is in orbit. We'll have to see what ISRO says.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline Chris Bergin

Like Sea Launch.... if it fails, kill the webcast.

Offline worldtimedate

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Re: LIVE: IRNSS-1H, PSLV C39, SLP, August 31, 2017 (13:30 UTC)
« Reply #106 on: 08/31/2017 01:58 PM »
PSLV appears to have failed in its 38th mission. Bringing in the industry to do satellite manufacturing and assembly don't appear to have paid off. Indian industry let down ISRO.

Offline K210

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Re: LIVE: IRNSS-1H, PSLV C39, SLP, August 31, 2017 (13:30 UTC)
« Reply #107 on: 08/31/2017 02:00 PM »
PSLV appears to have failed in its 38th mission. Bringing in the industry to do satellite manufacturing and assembly don't appear to have paid off. Indian industry let down ISRO.

Maybe. At this point in time it looks like a software error that failed to command heatshield seperation.

Offline Chris Bergin

Remember the Orbital launch that suffered a fairing sep failure with OCO?

Online maint1234

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Re: LIVE: IRNSS-1H, PSLV C39, SLP, August 31, 2017 (13:30 UTC)
« Reply #109 on: 08/31/2017 02:02 PM »
The ISRO chairman announced on podium that due to heat shield seperation failure , mission unsuccessful on DD national tv.

Online Galactic Penguin SST

Remember the Orbital launch that suffered a fairing sep failure with OCO?

.....and Glory 2 years later.  :-X
Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Offline eeergo

PSLV appears to have failed in its 38th mission. Bringing in the industry to do satellite manufacturing and assembly don't appear to have paid off. Indian industry let down ISRO.

What does industry doing *satellite* manufacturing and assembly have to do with the LV's payload fairing failing to separate?
-DaviD-

Offline soltasto

Does anyone know if they use pyros or pushers (like SpaceX) for the fairing separation?

Online Steven Pietrobon

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Re: LIVE: IRNSS-1H, PSLV C39, SLP, August 31, 2017 (13:30 UTC)
« Reply #113 on: 08/31/2017 02:08 PM »
Here's the internal video camera of the payload at T+14:00, T+18:14 and T+18:44. You can clearly see the heat shield has not separated. Payload separation was supposed to occur at T+19:25.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline Mapperuo

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Re: LIVE: IRNSS-1H, PSLV C39, SLP, August 31, 2017 (13:30 UTC)
« Reply #114 on: 08/31/2017 02:10 PM »
If the satellite was moving around could the fairings have been jammed by that? So this may actually be a payload mount failure vs a fairing sep failure.
- Aaron

Offline SmallKing

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Re: LIVE: IRNSS-1H, PSLV C39, SLP, August 31, 2017 (13:30 UTC)
« Reply #115 on: 08/31/2017 02:11 PM »
Does anyone know if they use pyros or pushers (like SpaceX) for the fairing separation?
Pyro Systems
Some are bound for happiness, some are bound to glory, some are bound to live with less, who can tell your story?

Offline Chris Bergin

Anyway, let's keep this going for further updates on the situation.

Many thanks to Steven again for the coverage and all who joined in.

William's article updated to what we currently know:
https://www.nasaspaceflight.com/2017/08/indian-pslv-irnss-replacement-launch/

Online Steven Pietrobon

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Here's the camera view at T+5 minutes,
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

Offline eeergo

Does anyone know if they use pyros or pushers (like SpaceX) for the fairing separation?

Pyrobolts and/or zipcords, Merman bands and spring pushers.
« Last Edit: 08/31/2017 02:18 PM by eeergo »
-DaviD-

Offline soltasto

Does anyone know if they use pyros or pushers (like SpaceX) for the fairing separation?
Pyro Systems

Which unfortunately can't be tested :|

Guessing what could have happened, the pyros could have not been ignited due to a bad electrical connection or multiple pyrotechnic separation mechanisms could have failed (As they are usually designed so that if only one fails, the force of the others make it break).

It could also be a software error, but I doubt it since it's not their first mission

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