GSLV at a glance
Apparently, the strapons carry the core stage for 48 seconds after the core burns out.
GSLV at a glance
Apparently, the strapons carry the core stage for 48 seconds after the core burns out.
Normal for GSLV
I presume the 4 L40 stages remain attached to the core solid booster for pitch and yaw control (using gimbal controls on L40).
S139 in GSLV does seem to have SITVC control but is more for a backup if gimbal control on L40 fails. The L40 also has fins for aero dynamic stability.
I think its better to see the 4 L40 + S139 as a "one single" clustered engine for propulsion.
Of the 48 seconds difference between S139 burnout and first stage separation, you need to subtract 4 sec as L40 is lit at T-4 seconds before liftoff.
ISRO might have felt that adding a jettison system on each of the 4 L40 might add to weight penalty and complexity. So it remains attached to the S139 stage for pitch and yaw control probably to handle the open loop first stage guidance and incorporates the day-of-launch wind biasing algorithm .
I suspect also that the dip in propulsion power when S139 burnsout while L40 is still burning will in a small way help in the subsequent first stage separation where the stage 2 gases are vented out through the inter-stage thus avoiding the need for additional retro motors as in the case of PSLV
What if S139 become may be S140 and burn-out of S139 and L40 timing are synced?
I think its better to see the 4 L40 + S139 as a "one single" clustered engine for propulsion.
Yes, ISRO considers 4 liquid boosters and the solid stage as a single first stage.
On the launch pad.
(Attached large version of the same pic)
In the VAB prior to MLP rollout ...
Nice shot of the payload air-conditioning duct. I assume all these white wire-ties(?) are to hold this duct in place, during tanking, and cryo-filling etc?
Transporting the cryo stage into the VAB (horizontally) for stacking and integration..
I'm asking again... but could somebody explain why the coldest stage is painted black? Sure, it may not be paint, and it may just be the colour of the insulation material, but what good insulators are coloured black?
It is not a black paint but I guess its a "Multilayer Insulation blanket" wrapped manually. It came in all colors.
For the first 4 GSLV flights, it was light grey in color. For the fifth flight, it was white in color and the last 2 and the current took the current black color.
Doordarshan telecast and ISRO webcast start from 3:52 PM IST, Jan 5.
Live Telecast of the GSLV D5 launch on Doordarshan and Webcast through http://www.isro.gov.in/ will be available from 3:52 PM (IST) onwards on Sunday afternoon.
We will keep you posted on this page and also on our official twitter handle https://twitter.com/isroofficial
edit by mod: i.e. from 1022UTC
I presume the 4 L40 stages remain attached to the core solid booster for pitch and yaw control (using gimbal controls on L40).
The 4 L40 boosters remain attached to the core to provide thrust for the entire stack after the core burns out. For some reason, ISRO decided on a system where the core burns out 40 seconds before the strap-on boosters.
I presume the 4 L40 stages remain attached to the core solid booster for pitch and yaw control (using gimbal controls on L40).
The 4 L40 boosters remain attached to the core to provide thrust for the entire stack after the core burns out. For some reason, ISRO decided on a system where the core burns out 40 seconds before the strap-on boosters.
Isn't that a bad thing ? the 4 strap on boosters propelling an entire rocket with an emptied 20,000 kg first stage.
I think GSLV is a flawed design and was basically build to test the Russian Cryogenic engine.
I presume the 4 L40 stages remain attached to the core solid booster for pitch and yaw control (using gimbal controls on L40).
The 4 L40 boosters remain attached to the core to provide thrust for the entire stack after the core burns out. For some reason, ISRO decided on a system where the core burns out 40 seconds before the strap-on boosters.
I understand that the reason is to reuse the PSLV first stage. The GSLV MkI/II was a short term solution for GTO until the MkIII was ready. Thus, they based it off the PSLV, and tried to do the minimum additions to get the desired performance. Thus, the rocket is not exactly very efficient, but it was done that way due to budget and schedule restrictions. Now, given all the failures, were attributed to the new elements, it was not a bad idea to use already developed parts with minimum mods.
I presume the 4 L40 stages remain attached to the core solid booster for pitch and yaw control (using gimbal controls on L40).
The 4 L40 boosters remain attached to the core to provide thrust for the entire stack after the core burns out. For some reason, ISRO decided on a system where the core burns out 40 seconds before the strap-on boosters.
Can we consider this opportunity as more a test for Indigenous Cryogenic Engine than the complete rocket itself? If Cryogenic Engine Succeeds then this can be incorporated into other rockets under development with minimal changes to suit the new rocket design. Might be ISRO thought to make utmost utilization of efforts and technology by adopting re usability where ever applicable keeping the budget and schedule constraints in mind. If this is the case then we can see progressive elaboration through incremental developments in rocket technology.
Can anyone here confirms that all the photos and videos currently on the ISRO website are from the second launch attempt and not from the one last August? Thanks!
Dr. Radhakrishnan said: We got a new S139 solid first stage. Its four liquid strap-on stages have a lot of avionics, so we refurbished them at Mahendragiri and Hindustan Aeronautics Ltd. We also made a new second stage. When the launch was called off in August, the liquid stage had to be drained of fuel and washed with much water. This might have affected the electronics systems, so we replaced them, too.
More importantly, the fuel tank material has been changed, fully phasing out the traditional but corrosion-prone aluminium-zinc combine, called AFNOR 7020. The new alternative, aluminium-copper alloy called AA2219, is now the material for all PSLV and GSLV tanks.
http://www.thehindu.com/news/national/will-2014-place-isro-in-cryo-club/article5527391.ece
So let me get it straight - everything on the boosters, the first and second stages are completely new with respect to the rocket on the pad last August?
The core and second stage are new. The boosters were refurbished.