EMISAT & 29 microsats - PSLV C45 - March 14, 2019

[input~2]

PSLV C45 should launch EMISAT and 30 piggyback satellites according to ISRO director during a press conference today

https://www.thequint.com/tech-and-auto/tech-news/isro-gaganyaan-women-astronauts-k-sivan-plans

[zubenelgenubi]

Now that the launch campaigns have been revised, and EMIsat will launch on PSLV C45 with 30 microsats...

HySIS is based on the SSB-2 microsatellite bus.  It launched on PSLV C43 with 30 microsats using a PSLV-CA.
https://space.skyrocket.de/doc_sdat/hysis.htm

EMIsat is also built on the SSB-2 s/c bus.
https://space.skyrocket.de/doc_sdat/emisat.htm

Will PSLV C45 also launch using a PSLV-CA?

I see that Gunter has listed the PSLV-CA as the LV version for PSLV C44.

Am I right to deduce that this is because the primary payload, EMIsat, is using the SSB-2 microsatellite bus?  And, even if there are secondary passengers, they would not overfill the PSLV-CA payload mass limits to a LEO?

(SARAL also used this satellite bus and was launched to a low polar orbit (SSO?), with secondary payloads.  SARAL massed only 346 kg.)

EDIT: cross-post/response re: similar question about the LV version for PSLV C43:

Exactly - the small mass of all payloads is a very strong hint, that the CA version will be used.

[zubenelgenubi]

Q1) Will this launch take place from the FLP or the SLP?

Q2) How quickly can the turn-around be between Shriharkota launches?
The shortest duration between launches in recent years, using both LPs, was 15 days.

Launch performed in 2018

November 14 11:38 UTC-  GSLV Mk III D2 (SLP) - GSAT-29
November 29 04:27 UTC - PSLV-C43 - FLP - HySIS & 30 foreign small sats

[vineethgk]

As per this news report it seems EMIsat has been renamed as Anisat (unless the reporter heard it wrong), and C45 carrying it has been delayed to March.

Sivan said, “The next PSLV C45 mission will take place in March. It will carry a DRDO payload *Anisat*.”

[zubenelgenubi]

Cross-post:

PSLV C45/EMIsat mission in March, to be followed by C46/Cartosat-3 and C47/RISAT-2BR 1.

Dates yet to finalized for last two.

Source

[K210]

ISRO might use this launch as a opportunity to test out new QL variant (with four strap-ons). Otherwise i think this will be a CA launch.

[ZachS09]

ISRO might use this launch as a opportunity to test out new QL variant (with four strap-ons). Otherwise i think this will be a CA launch.

How do you know that the PSLV version with four boosters is called PSLV-QL?

[bpd2000]

for PSLV-QL, search page
https://www.reddit.com/r/ISRO/comments/aglwrb/pslvc44_microsatr_mission_updates_and_discussion/

[starbase]

If PSLV XL stands for "X-tra Large" does PSLV DL and QL stand for "Double Large" and "Quad Large"? 🤔

[K210]

ISRO might use this launch as a opportunity to test out new QL variant (with four strap-ons). Otherwise i think this will be a CA launch.

How do you know that the PSLV version with four boosters is called PSLV-QL?

It was mentioned in the post launch speeches after the recent C44 launch.

[ZachS09]

If PSLV XL stands for "X-tra Large" does PSLV DL and QL stand for "Double Large" and "Quad Large"? 🤔

Possibly. The DL refers to two boosters while the QL refers to four boosters.

[K210]

4 of the payloads onboard will be spire global LEMUR's

https://twitter.com/NanoRacks/status/1096125239203909633

[isro-watch]

PSLV-C45 launch on March-14 with EMISAT and 29 other satellites.

https://timesofindia.indiatimes.com/india/isro-set-for-first-three-orbit-mission-of-pslv-c45-on-march-14/articleshow/68016364.cms

[Steven Pietrobon]

And the really interesting bit, this will be the first launch with four boosters or PSLV-QL!

"For the first time, PSLV with four strap-on configuration has been identified for this mission. Till now, ISRO has used either two strap-on or six strap-on configuration for the mission or it was without strap-on, he said."

[ZachS09]

And the really interesting bit, this will be the first launch with four boosters or PSLV-QL!

"For the first time, PSLV with four strap-on configuration has been identified for this mission. Till now, ISRO has used either two strap-on or six strap-on configuration for the mission or it was without strap-on, he said."

For this specific model, how will the boosters be ignited?

Will there be two ground-starts and two air-starts? Or will all four boosters be lit at liftoff?

[Steven Pietrobon]

For this specific model, how will the boosters be ignited?

Will there be two ground-starts and two air-starts? Or will all four boosters be lit at liftoff?

I don't know, but my guess would be two ground lit and two air lit.

[chetan_chpd]

Source: https://timesofindia.indiatimes.com/india/isro-set-for-first-three-orbit-mission-of-pslv-c45-on-march-14/articleshow/68016364.cms

"It will be the first three-orbit mission and the first launch that uses solar panels for the required thrust" (what?)
"PSLV fourth stage (PS4) that uses solar panels"

what does 'required thrust via solar panels' even mean? solar sail?

is below concept is what they are trying for?

[Steven Pietrobon]

"It will be the first three-orbit mission and the first launch that uses solar panels for the required thrust" (what?)
"PSLV fourth stage (PS4) that uses solar panels"

what does 'required thrust via solar panels' even mean? solar sail?

is below concept is what they are trying for?

Yes, but I don't believe its for solar sails. This is the next step in making the PS4 last longer in orbit by adding solar panels. This means PS4 can provide power to attached payloads almost indefinitely. The previously flight used batteries for its attached payload (Kalamsat V2).

[chetan_chpd]

"It will be the first three-orbit mission and the first launch that uses solar panels for the required thrust" (what?)
"PSLV fourth stage (PS4) that uses solar panels"

what does 'required thrust via solar panels' even mean? solar sail?

is below concept is what they are trying for?

Yes, but I don't believe its for solar sails. This is the next step in making the PS4 last longer in orbit by adding solar panels. This means PS4 can provide power to attached payloads almost indefinitely. The previously flight used batteries for its attached payload (Kalamsat V2).

i think mentioning "thrust" is a typo/ confusion by TOI reporter.

[K210]

For the first time, PSLV with four strap-on configuration has been identified for this mission.

This mission is unique as it is the first PSLV fourth stage (PS4) that uses solar panels.

"Upcoming PSLV-C45 mission on March 14 will be a special launch as it will be ISRO’s first three-orbit mission. After launch of the satellite EMISAT into orbit at 780 km, it will inject 29 satellites into orbit at 504 km and the rocket's fourth stage will automatically be reused to establish an orbital platform at 485 km orbit to carry out scientific experiments,” Vikram Sarabhai Space Centre (VSSC) director S Somanath told TOI on Sunday.

New PSLV-QL variant (Four strap-ons instead of six on first stage) will be used for this launch. Overall this will be a 3 orbit mission with EMISAT being launched into a 780 km orbit followed by 29 satellites into 504km orbit and then finally the PS4 stage itself will be put into a 485km orbit.

Source: https://timesofindia.indiatimes.com/india/isro-set-for-first-three-orbit-mission-of-pslv-c45-on-march-14/articleshow/68016364.cms