Author Topic: PSLV-XL C30 - ASTROSAT, LAPAN-A2, NLS-14, 4xLEMUR - Sept 28, 2015 (04:30 UTC)  (Read 59345 times)


Offline K210

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Re: PSLV-XL C30 - ASTROSAT - September 28, 2015 (04:30 UTC)
« Reply #41 on: 09/27/2015 02:58 PM »
Any live coverage?

Online Skyrocket

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Re: PSLV-XL C30 - ASTROSAT - September 28, 2015 (04:30 UTC)
« Reply #42 on: 09/27/2015 03:03 PM »
BTW, the four Lemur satellites are named this way:

LEMUR-2-JOEL
LEMUR-2-PETER
LEMUR-2-JEROEN
LEMUR-2-CHRIS


Offline vyoma

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Re: PSLV-XL C30 - ASTROSAT - September 28, 2015 (04:30 UTC)
« Reply #43 on: 09/27/2015 03:06 PM »
From http://isro.gov.in/media :

Quote
Sep 27, 2015
PSLV-C30 / ASTROSAT MISSION UPDATE: Countdown activities are progressing normally.


PSLV-C30 / ASTROSAT MISSION UPDATE: Mobile Service Tower (MST) withdrawal to 50 m distance is completed by 15:00 hr IST. Propellant filling operation of Second Stage (PS2) is in progress.
« Last Edit: 09/27/2015 03:09 PM by vyoma »

Offline vyoma

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Re: PSLV-XL C30 - ASTROSAT - September 28, 2015 (04:30 UTC)
« Reply #44 on: 09/27/2015 03:17 PM »
Any live coverage?

DD News will have a live webcast:
http://webcast.gov.in/live/

ISRO webcast:
http://www.isro.gov.in/pslv-c30-astrosat-mission/pslv-c30-astrosat-launch-live-webcast

DD National live (starts at 9:30 AM IST):
« Last Edit: 09/28/2015 04:09 AM by vyoma »

Offline Galactic Penguin SST

Seeing that 3 Asian nations are going to put up new short wavelength astronomical observatories over the next few months (Astrosat, JAXA's ASTRO-H and China's HXMT), I've asked high-energy specialized astronomer and spacecraft expert Jonathan McDowell to explain their differences between them:


Cosmic Penguin @Cosmic_Penguin
@planet4589 Can you compare the abilities of the trio of new short-lambda observatories from Asia, ASTRO-H, Astrosat and China's HXMT?

Jonathan McDowell ‏@planet4589
@Cosmic_Penguin ASTRO-H is a world class mission - not a Chandra, but more than a Swift or NuStar.  (1/3)

@Cosmic_Penguin Astrosat will be very useful in certain science domains, esp. quasar studies. Broad energy range but poor spatial res.

@Cosmic_Penguin HXMT will be interesting as 1st hard-x-ray sky survey, but maybe a bit more limited in science return (3/3)

@Cosmic_Penguin all of them doing good science; ASTRO-H cutting edge, the other two with targeted niches missed by US/Europe

@Cosmic_Penguin so Astrosat looking at specific known targets that need the broad energy range; HXMT mapping at 100 keV to see what's there
Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Offline Ohsin

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Re: PSLV-XL C30 - ASTROSAT - September 28, 2015 (04:30 UTC)
« Reply #46 on: 09/27/2015 04:24 PM »
Any live coverage?

http://24framesdigital.com/isro/webcast/280915/video.html

Network Stream
http://24framesdigital.com/isro/webcast/280915/live.asx

If these are not working you might need windows media player plugin.
https://support.mozilla.org/en-US/kb/play-windows-media-files-in-firefox

DD News should cover it.
DD news

Isro might tweet a link for DD National.

Edit:

DD just tweeted they'll live broadcast it. Starting half hour before launch

DD national on Youtube

Edit: fixed links to YT channels
« Last Edit: 09/28/2015 03:32 AM by Ohsin »
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Offline zubenelgenubi

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Seeing that 3 Asian nations are going to put up new short wavelength astronomical observatories over the next few months (Astrosat, JAXA's ASTRO-H and China's HXMT), I've asked high-energy specialized astronomer and spacecraft expert Jonathan McDowell to explain their differences between them:


Cosmic Penguin @Cosmic_Penguin
@planet4589 Can you compare the abilities of the trio of new short-lambda observatories from Asia, ASTRO-H, Astrosat and China's HXMT?

Jonathan McDowell ‏@planet4589
@Cosmic_Penguin ASTRO-H is a world class mission - not a Chandra, but more than a Swift or NuStar.  (1/3)

@Cosmic_Penguin Astrosat will be very useful in certain science domains, esp. quasar studies. Broad energy range but poor spatial res.

@Cosmic_Penguin HXMT will be interesting as 1st hard-x-ray sky survey, but maybe a bit more limited in science return (3/3)

@Cosmic_Penguin all of them doing good science; ASTRO-H cutting edge, the other two with targeted niches missed by US/Europe

@Cosmic_Penguin so Astrosat looking at specific known targets that need the broad energy range; HXMT mapping at 100 keV to see what's there

Thank you, Jonathan AND GP!  This is a concise summary, on a timely subject.  I was wondering myself where these 3 observatories fit into the short EM wavelength astronomy "big picture."
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Offline isro-watch

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The weight of Astrosat is mentioned as 1470 Kg in the article. The weight as per the brochure is 1513 Kg

Offline northenarc

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The weight of Astrosat is mentioned as 1470 Kg in the article. The weight as per the brochure is 1513 Kg
  From the article
 "The 1,470-kilogram (3,241 lb) AstroSat spacecraft carries 43 kilograms (95 lb) of fuel for a total launch mass of 1,513 kilograms (3,336 lb)."

Offline savuporo

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Stream is live
Orion - the first and only manned not-too-deep-space craft

Offline Steven Pietrobon

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Some nice classical music while we wait.
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.


Offline savuporo

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Running overview of payloads
Orion - the first and only manned not-too-deep-space craft



Offline jcm

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Seeing that 3 Asian nations are going to put up new short wavelength astronomical observatories over the next few months (Astrosat, JAXA's ASTRO-H and China's HXMT), I've asked high-energy specialized astronomer and spacecraft expert Jonathan McDowell to explain their differences between them:


Cosmic Penguin @Cosmic_Penguin
@planet4589 Can you compare the abilities of the trio of new short-lambda observatories from Asia, ASTRO-H, Astrosat and China's HXMT?

Jonathan McDowell ‏@planet4589
@Cosmic_Penguin ASTRO-H is a world class mission - not a Chandra, but more than a Swift or NuStar.  (1/3)

@Cosmic_Penguin Astrosat will be very useful in certain science domains, esp. quasar studies. Broad energy range but poor spatial res.

@Cosmic_Penguin HXMT will be interesting as 1st hard-x-ray sky survey, but maybe a bit more limited in science return (3/3)

@Cosmic_Penguin all of them doing good science; ASTRO-H cutting edge, the other two with targeted niches missed by US/Europe

@Cosmic_Penguin so Astrosat looking at specific known targets that need the broad energy range; HXMT mapping at 100 keV to see what's there

Thank you, Jonathan AND GP!  This is a concise summary, on a timely subject.  I was wondering myself where these 3 observatories fit into the short EM wavelength astronomy "big picture."

So excited for all the teams on ASTROSAT and ASTRO-H (I don't know any of the HXMT folks personally)

For ASTROSAT, I don't know so much about the UV payload. XMM-Newton had a UV/optical monitor too, but it
doesn't get used that much. These things are hard to calibrate and subject to problems with contamination on the coatings, so I suspect we won't know how good it is until a while after launch.

 The interesting X-ray payload is the LAXPC which
has a big 'effective area' so it can get many, many photons per second compared to say Chandra. But it only has
a vague idea where in the sky those photons are coming from, so it's no good for faint sources - there will be hundreds of faint sources within one 'beam' (field of view). It'll give you GREAT data on the bright sources though. You need a few hundred photons to get an idea of the energy spectrum (color, temperature, state of the black hole accretion disk, whatever), so the more photons you get per second the more often you can slice up the data into a new spectrum, seeing more rapid changes. And the simultaneous UV gives you an anchor for the shape of the spectrum, a more reliable fit
for your model accretion disk for example.   

The LAXPC doesn't have a focussing telescope, it's just one step up from waving a geiger counter at the sky and seeing which constellation it clicks more in. The SXT telescope is a real telescope but it's more a technology test for futre ones,
it has comparable count rates to Chandra but with 500 times worse spatial resolution - so I don't expect much
new science to come out of this, but it's an excellent technology achievement, 1 keV-band X-ray focussing telescopes are hard.

The CZTI coded mask telescope is like having hundreds of pinhole cameras. It works in the harder X-ray range of 10 - 100 keV, where doing a focussing telescope is much harder (only NuSTAR so far can do that).  This was first done by SIGMA-GRANAT (French-Soviet) in the 1980s. I am not sure about the details here but I gather they are running the detector
cool to get better energy resolution than the bigger detector on the SWIFT satellite. So less sensitivity but better energy res, in a less well explored waveband, might get some interesting results.

SSM - lots of X-ray satellites have carried all-sky monitors to spot bursts and novae and so on; MAXI on ISS does this, but in the years while Astrosat was delayed SWIFT has pretty much cornered the market on this niche. So, a useful addition but not ground breaking.

-----------------------------

Jonathan McDowell
http://planet4589.org


Offline vyoma

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Satellite Director authorizes mission.
« Last Edit: 09/28/2015 04:15 AM by vyoma »

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