Author Topic: LIVE: Cartosat-2D & 103 S/C - PSLV-XL (C37) - February 15, 2017 (03:58 UTC)  (Read 45678 times)

Offline vineethgk

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An alternate link for onboard footage hosted in Youtube.. ISRO site is still running slow.


Offline vineethgk

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I know those nano satellites were meant to be a 'flock', but I did not think it would be literally so. Were they meant to be deployed so close together? Reminded me of the bumper-to-bumper traffic on Indian roads at peak hours.. Whew! 😓

Online Skyrocket

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I know those nano satellites were meant to be a 'flock', but I did not think it would be literally so. Were they meant to be deployed so close together? Reminded me of the bumper-to-bumper traffic on Indian roads at peak hours.. Whew! 😓

Yes, it was planned so. They space themselves along the orbit by using differential drag control.

Online eeergo

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It's interesting that they (appear to) have a much larger tumbling rate than those launched from ISS, which mostly flew straight out of the canister - here they appear to be imparted a definite torque along the short axis at release, I wonder if to aid in the opening of the telescope door or something else.
-DaviD-

Offline s^3

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Surely they appear to have been purposely tumbled.

Controlling the tumble must be quite energy consuming ..  especially immediately after release before Solar power generation.

BTW are  the Quadpacks also released or they remain attached to the Launch Adapter?  No QP is seen  to have been ejected in the video.
« Last Edit: 02/15/2017 02:55 PM by s^3 »

Offline chota

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This video seem much better. Notice 1:07 mins onwards. Enjoy  :D



« Last Edit: 02/15/2017 03:01 PM by chota »

Offline Rik ISS-fan

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The Quadpacks stay connected to the 4th stage. They are bolted in place, and for each door a cable runs from the Quadpack to one of the five IMDC's (deployment controllers).  Here a link to the ISISpace news article about the launch.

In the video above at around 2:00 I think you can the deployment of several Lemur-2. Those deploy straight, so they are not tumbling.  This leads me to conclude that the rotation of the Doves is caused by the deployment of the lens protector / antenna hinged door. If I'm not mistaken the doves launched from the ISS also tumble when this door unfolds during deployment.

I also expect the video runs at twice or more the normal speed.
« Last Edit: 02/15/2017 05:27 PM by Rik ISS-fan »

Online Chris Bergin

This video seem much better. Notice 1:07 mins onwards. Enjoy  :D





That's so much fun it's freaky! Love the way they all act like their name...flock.

Online FutureSpaceTourist

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Quote
Happy to report that all of the 88 Doves are happy, healthy, and rotating in real-time!

https://twitter.com/planetlabs/status/831996137259180033

Offline zubenelgenubi

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Thank you for this launch coverage thread.  I couldn't watch the live webcast or log into NSF during the launch, so this thread is a great way to see what I missed!
Support your local planetarium!

Offline gwiz

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If I'm not mistaken the doves launched from the ISS also tumble when this door unfolds during deployment.
The ISS Doves are deployed in pairs, with the lid only opening on one of each pair, I think because the second opening could potentially impact the other satellite.  The second lid is opened later.

Offline s^3

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It seems that ISRO data station BHARATI at Antarctic does not have a TTC ( S Band ) capability.

Otherwise that was a better choice to continue launch Telemetry after MAU.

( OR it could be because it has a only store and forward capability ..  and not real time feedback capability )

« Last Edit: 02/17/2017 01:36 PM by s^3 »

Offline Kosmos2001

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Concerning this launch:

(1st Attachemnt) Cartoon appeared in «The New York Times» (28/09/2014).

(2nd Attachment) Some days ago «The Times of India» mocked them (16/02/2017).
« Last Edit: 02/20/2017 11:23 AM by Kosmos2001 »

Offline vineethgk

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« Last Edit: 02/20/2017 09:52 AM by vineethgk »

Offline vyoma

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http://www.isro.gov.in/unique-triumph-of-pslv-c37

Quote
The Unique Triumph of PSLV-C37

On February 15, 2017, PSLV-C37, the 39th mission of the workhorse launch vehicle of ISRO, injected ISRO’s Cartosat-2 Series Satellite weighing 714 kg and two ISRO Nano-satellites namely INS-1A (8.4 kg) & INS-1B (9.7 kg) and 101 Nano-satellites, from six foreign countries into a Sun-Synchronous Orbit (SSO) at an orbit of 506 km above earth, with an inclination of 97.46°. The mass of nano-satellites varied from 1 to 10 kg. The total weight of all the 104 satellites carried on-board PSLV-C37 was 1378 kg.

The large number of satellites in this mission demanded adopting innovative approaches in satellite accommodation and mission design.

Apart from conventional satellite adapters, namely, Payload Adapter (PLA) and Multiple Satellite Adapter (MSA), six numbers of custom made adapters were newly configured and used to house the nano satellites. Some of these adapters allowed multi tier mounting of satellites and few of them were accommodated on the Vehicle Equipment Bay itself. This architecture enabled the optimal utilisation of the payload volume as well as capability.

Next requirement was managing safe separation of these large numbers of satellites within the constraints of limited visibility duration of ground stations and maintaining safe distance between the separated satellites over a longer period of time.

This was managed by designing a unique sequencing and timing for separating the satellites and with complex manoeuvering of PS4 stage to which satellites are attached. The separation sequence, direction and timing were finalised based on extensive study to ensure safe distance among the 105 objects (including PS4 stage) in orbit, which renders 5460 number of pairs.

The next major requirement was to ensure reaching separation command from launcher to respective satellites honoring the predefined sequence, which involves a complex electrical wiring scheme.  Any error in the wiring may result in release of wrong satellite leading to undesirable situation of collision between them.

Another innovative feature in this mission was capturing all the separation events of vehicle stages and 104 satellites using a comprehensive video imaging system onboard.

Meticulous planning was done at launch complex, SDSC SHAR on assembling and handling of all sub systems and satellite preparation. Apart from launching SSO, sub GTO and multi orbit missions, PSLV has established once again as a workhorse vehicle to undertake very complex missions like PSLV-C37.

Offline Steven Pietrobon

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The separation sequence, direction and timing were finalised based on extensive study to ensure safe distance among the 105 objects (including PS4 stage) in orbit, which renders 5460 number of pairs.

Not to be a smarty pants, but the formula for the number of combinations of picking 2 objects from N is C = N*(N-1)/2. Letting N = 105 gives C = 5460, so the article is correct! The general formula for picking M objects out of N is C = N!/((N-M)!*M!) where N! = N*(N-1)*(N-2)*...*3*2*1. That's what we learned in Year 12 mathematics in high school.
« Last Edit: 02/21/2017 07:29 AM by Steven Pietrobon »
Akin's Laws of Spacecraft Design #1:  Engineering is done with numbers.  Analysis without numbers is only an opinion.

First day Images from Cartosat -2D

Why the quality of even the monochrome image is so poor. Is it because of the calibration issue or this is the max the Cartosat can do.

Offline gwiz

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What's poor about resolving cars from space?

What's poor about resolving cars from space?
The Cartosat is supposed to have 25cm resolution

Offline vineethgk

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First day Images from Cartosat -2D

Why the quality of even the monochrome image is so poor. Is it because of the calibration issue or this is the max the Cartosat can do.
Perhaps it was intentionally degraded or down-sized for publication. The satellite, and its similar-speced predecessor the Cartosat-2C, are primarily meant for military reconnaissance tasks. And by the way, with a resolution of 65 cm (PAN), it wouldn't be at par with contemporaries like Worldview-3 in any case.
« Last Edit: 02/25/2017 03:08 PM by vineethgk »

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