ISRO General News and Updates

[Indx TechStyle]

Upper stage. Anyone knows if ISRO is working on an upper stage yet?
PAM-G project was dead long back in 2015 AFAIK.

 

[Indx TechStyle]

Like this

Atmospheric entry - Wikipedia

en.m.wikipedia.org

Low-Density Supersonic Decelerator - Wikipedia

en.m.wikipedia.org

This would help minimize damage due to friction with earth's atmosphere and obviously useful to land on planets like Venus and Mars which have an atmosphere.

The brochure itself gives an insight.

 

[Varoon2]

^
This must be a very significant development, for ISRO to have a separate brochure on it. Usually, sounding rocket launches are just reported, sometimes they are not. But they don't have brochures.

 

[Abdus Salem killed]

^
This must be a very significant development, for ISRO to have a separate brochure on it. Usually, sounding rocket launches are just reported, sometimes they are not. But they don't have brochures.

You are essentially reducing the cost by a large amount and reducing complex systems yes it's significant

 

[WarmongerLSK]

I had no idea ISRO was even working on this! This is awesome! We can now think of sending payloads down to Mars, apart from spent stage recovery on Earth.
And its not just this alone that was tested, they tested a new miniature video camera, new SDR, etc:-

View attachment 170336

Spent Stage Recovery meaning something like booster recovery by SpaceX ?

 

[Okabe Rintarou]

Spent Stage Recovery meaning something like booster recovery by SpaceX ?

Yeah, for upper stages. So it won't hoverslam.

 

[WarmongerLSK]

Yeah, for upper stages. So it won't hoverslam.

Found this paper discussing IADs for PSLV1. Looks like its not possible for something as heavy as PSLV rocket.

 

[Vamsi]

Latest ISRO updates from Bengaluru Space Expo 2022 by gareeb scientist...ISRO's next gen launch vehicle (NGLV) will be designed to be reusable from Day 1

Videos – Google Drive

drive.google.com

 

[Vamsi]

 

[FalconSlayers]

Shared by @Karthi on Twitter

 

[Vamsi]

Shared by @Karthi on Twitter
View attachment 171087

I think it's American plan, not ours

 

[Vamsi]

Neeche dekho, now don’t say they’re NRIs hehe.

Yea, didn't see it earlier....

 

[Blademaster]

Shared by @Karthi on Twitter
View attachment 171087

This goes to show why a Mars expedition was never attempted by NASA for the last 50 years. It is incredibly hard to get to Mars and back. You are talking about a period of at least 2.5 to 3 years of living in space and 2-3 weeks living on Mars in a space that is no bigger than your bedroom. Talk about serious cabin fever.

 

[Vamsi]

This goes to show why a Mars expedition was never attempted by NASA for the last 50 years. It is incredibly hard to get to Mars and back. You are talking about a period of at least 2.5 to 3 years of living in space and 2-3 weeks living on Mars in a space that is no bigger than your bedroom. Talk about serious cabin fever.

Yes, all the current proposals for manned Mars mission are extremely costly, even the SpaceX starship will be costly,even though it's reusable. What we need is a radical new kind of propulsion, possibly gas core fission reactors based propulsion.Only then it might be economical.So in my opinion we should work on both Gas Core Fission reactors as well as Fusion reactor technology, before sending our men to mars

 

[Swesh]

@Vamsi @FalconSlayers @Blademaster

 

[Swesh]

@Indx TechStyle

 

[Okabe Rintarou]

Shared by @Karthi on Twitter
View attachment 171087

That still looks like a NASA diagram was used, even if paper is by ISRO people. It just talks about the kind of mission architecture would be needed for a Manned Mars Expedition.
Link to the paper: http://cosmology.com/Mars128.html

Yes, all the current proposals for manned Mars mission are extremely costly, even the SpaceX starship will be costly,even though it's reusable. What we need is a radical new kind of propulsion, possibly gas core fission reactors based propulsion.Only then it might be economical.So in my opinion we should work on both Gas Core Fission reactors as well as Fusion reactor technology, before sending our men to mars

Fission on a rocket is a scary prospect. If you take a fission-based nuclear thermal rocket, you'd need to carry radioactive material up Earth's gravity well and if that fails, you've got a major nuclear and radiological disaster on your hands.

I think we should double down on fusion tech. NASA already has made headway on Direct Fusion Drive (DFD). At least DFD would not be radioactive when its going up to orbit for the first time. Once you reach orbit, you don't need to bring the spaceship back down again. So even if some stray neutron emissions cause radioactive activation of the material of the nozzle and shielding after first use, the spaceship is not going to return to or crash into Earth's atmosphere (keep it in a high enough orbit and use shuttles to transfer crew to and from the ship).

Also, in DFD, they are using Helium 3 and Deuterium as fusion fuel, and this fusion would not produce neutrons, massively cutting down on shielding requirements.

Not to mention the insane specific impulse of the DFD which is 10,000 seconds, compared to 1000 for the best fission rocket and 400 for the best cryogenic engines.

I had no idea that satnav system performance degraded when going off the latitude range they are designed for. I still don't understand completely how this works (something to do with signal attenuation? or satellite orbits and therefore position?). So he says that GPS is tuned to temperate region and GLONASS is tuned to polar region and so NavIC was created for torrid zone? But doesn't that make most Precision Guided Munitions inaccurate in the torrid zone since they mostly rely on either GPS or GLONASS?
.
I have a rudimentary understanding of how satnav works and I do vaguely remember reading how its predecessor systems (like LORAN hyperbolic navigation system) were only accurate upto a couple thousand km. But I thought that was a limitation of ground-based systems and satnav didn't have the same issue. What exactly causes it?
.
Also, I had no idea NavIC = IRNSS + GAGAN to cover torrid and temperate zone in same package! I thought NavIC was just operational name of IRNSS.
.
NavIC as a tracking service is being offered as a sovereign solution to all countries, so instead of the servers being in India, we are offering them the entire equipment in their own country so data resides with that country and not with India, unlike GPS, GLONASS, etc. That could be a USP for NavIC in many cases.
.
After feedback from users, ISRO is planning to add a third signal to NavIC, instead of just the two standard and precision services. Infact, he says that both the existing signals are precision services, which I don't understand.
.
For corporate users, NavIC is already a cheaper solution than GPS and the savings in operational costs are more than 50% (sometimes doubles or triples profits as well) after their company consults on how to leverage NavIC for the job. Examples like Jindal steel, mining , Chennai port, etc.
.
Users abroad are also being offered some demonstrations, trials ongoing in Africa, Indonesia and one study done for Italy as well. In future, they expect their GPS-NavIC integrated solutions to spread in Australia, Middle East and ASEAN. But why Australia though? Isn't that in temperate region?

 

[Vamsi]

That still looks like a NASA diagram was used, even if paper is by ISRO people. It just talks about the kind of mission architecture would be needed for a Manned Mars Expedition.
Link to the paper: http://cosmology.com/Mars128.html


Fission on a rocket is a scary prospect. If you take a fission-based nuclear thermal rocket, you'd need to carry radioactive material up Earth's gravity well and if that fails, you've got a major nuclear and radiological disaster on your hands.

I think we should double down on fusion tech. NASA already has made headway on Direct Fusion Drive (DFD). At least DFD would not be radioactive when its going up to orbit for the first time. Once you reach orbit, you don't need to bring the spaceship back down again. So even if some stray neutron emissions cause radioactive activation of the material of the nozzle and shielding after first use, the spaceship is not going to return to or crash into Earth's atmosphere (keep it in a high enough orbit and use shuttles to transfer crew to and from the ship).

Also, in DFD, they are using Helium 3 and Deuterium as fusion fuel, and this fusion would not produce neutrons, massively cutting down on shielding requirements.

Not to mention the insane specific impulse of the DFD which is 10,000 seconds, compared to 1000 for the best fission rocket and 400 for the best cryogenic engines.


I had no idea that satnav system performance degraded when going off the latitude range they are designed for. I still don't understand completely how this works (something to do with signal attenuation? or satellite orbits and therefore position?). So he says that GPS is tuned to temperate region and GLONASS is tuned to polar region and so NavIC was created for torrid zone? But doesn't that make most Precision Guided Munitions inaccurate in the torrid zone since they mostly rely on either GPS or GLONASS?
.
I have a rudimentary understanding of how satnav works and I do vaguely remember reading how its predecessor systems (like LORAN hyperbolic navigation system) were only accurate upto a couple thousand km. But I thought that was a limitation of ground-based systems and satnav didn't have the same issue. What exactly causes it?
.
Also, I had no idea NavIC = IRNSS + GAGAN to cover torrid and temperate zone in same package! I thought NavIC was just operational name of IRNSS.
.
NavIC as a tracking service is being offered as a sovereign solution to all countries, so instead of the servers being in India, we are offering them the entire equipment in their own country so data resides with that country and not with India, unlike GPS, GLONASS, etc. That could be a USP for NavIC in many cases.
.
After feedback from users, ISRO is planning to add a third signal to NavIC, instead of just the two standard and precision services. Infact, he says that both the existing signals are precision services, which I don't understand.
.
For corporate users, NavIC is already a cheaper solution than GPS and the savings in operational costs are more than 50% (sometimes doubles or triples profits as well) after their company consults on how to leverage NavIC for the job. Examples like Jindal steel, mining , Chennai port, etc.
.
Users abroad are also being offered some demonstrations, trials ongoing in Africa, Indonesia and one study done for Italy as well. In future, they expect their GPS-NavIC integrated solutions to spread in Australia, Middle East and ASEAN. But why Australia though? Isn't that in temperate region?

DFD propulsion has higher specific impulse, but very low thrust (in range of few 100N at Max), but what we need is higher thrust (in range of 100KN) & higher efficiency (like 2000-3000sec ISP) which only a Gas core based fission reactor can give

 

[Okabe Rintarou]

DFD propulsion has higher specific impulse, but very low thrust (in range of few 100N at Max), but what we need is higher thrust (in range of 100KN) & higher efficiency (like 2000-3000sec ISP) which only a Gas core based fission reactor can give

Direct Fusion Drive for a Human Mars Orbital Mission (Conference) | OSTI.GOV

The U.S. Department of Energy's Office of Scientific and Technical Information

www.osti.gov

^ But this study here has a configuration with 6 engines, each producing 11.5 MW which would be almost 700N thrust.
Also, why would you need 100kN range thruster? These rockets won't be going up and down the gravity well all that often. That will still be done by chemical rockets.

 

[Vamsi]

Direct Fusion Drive for a Human Mars Orbital Mission (Conference) | OSTI.GOV

The U.S. Department of Energy's Office of Scientific and Technical Information

www.osti.gov

^ But this study here has a configuration with 6 engines, each producing 11.5 MW which would be almost 700N thrust.
Also, why would you need 100kN range thruster? These rockets won't be going up and down the gravity well all that often. That will still be done by chemical rockets.

The most important which many people ignore is acceleration.700N is very low,thus it will have very very low acceleration.For comparison CY-2's Vikram Lander has five 800N engines. If you want to go to mars in 30 days instead of 6-9 months, you have to use high energy transfer orbits, for which you need both high thrust & high Isp. If you use a 700N engine it will take a very very long time to change orbit.