Indian Space Program: News & Discussion

[Cyrano]

I think it implies redundancy in several systems and increased testing to have as many critical components, systems and processes etc certified as fail safe.

[ramana]

Folks How do Chinese and Russian space probes communicate with Earth?

Do they also use NASA DSN?

As Imdia is launching more deep space satellites should they invest in.own DSN as backup and added redundancy ?

Can it be ship based ?

[sanman]

What does it mean to have a rocket that is human rated?

I know there must be an escape mechanism for astronauts at the launch pad and low altitudes of flight, but what else? More 9s in resiliency?

Its performance reliability and safety margins must be high enough that we're willing to risk humans flying on it.

[sanman]

Folks How do Chinese and Russian space probes communicate with Earth?

Do they also use NASA DSN?

As Imdia is launching more deep space satellites should they invest in.own DSN as backup and added redundancy ?

Can it be ship based ?

https://en.wikipedia.org/wiki/Indian_Deep_Space_Network


India does already have its own DSN, starting with 2 or 3 large dishes at Byalalu in Karnataka.
This is run by ISTRAC (ISRO Telemetry Tracking & Command Network)

India also has agreements with other countries to use their ground stations, and likewise to provide support for their missions.

India also has seagoing ships fitted with communications antennae that have already been used for these beyond-Earth space missions.

ISRO also plans to launch its own IDRSS (Indian Data Relay Satellite System) which will amount to a bunch of orbital satellite relays for high-bandwidth communications, so that it won't need to rely on ground stations.

[ramana]

Oh great. Let me know about IDRSS.

I thought DSN needs to be separated by distance to ensure coverage.

[ramana]

Yojana Special issue on Space

https://www.isro.gov.in/media_isro/pdf/ ... e_Tech.pdf

[Haridas]

https://en.wikipedia.org/wiki/Indian_Deep_Space_Network

India does already have its own DSN, starting with 2 or 3 large dishes at Byalalu in Karnataka.
This is run by ISTRAC (ISRO Telemetry Tracking & Command Network)

India also has agreements with other countries to use their ground stations, and likewise to provide support for their missions.

India also has seagoing ships fitted with communications antennae that have already been used for these beyond-Earth space missions.

ISRO also plans to launch its own IDRSS (Indian Data Relay Satellite System) which will amount to a bunch of orbital satellite relays for high-bandwidth communications, so that it won't need to rely on ground stations.

@Ramana
Imho DSN are two types. For near earth and interplanetary communication. They use S and X band.

Ship based antenna size OK for near earth dsn as well as low latency data download from LeO sats (mil application)

The interplanetary DSN need very high antenna gain thus are huge (70m diameter) putting them on ship will be challenging bcoz of
1. Very heavy antenna mass. Payload apart that moves ship CG very high thus stability issue. Sea surface ship stabilization is no mean task wrt power and force, given that pointing accuracy need is also high.
2. needing super huge radome that cant use metal structure and size means more weight and more CG issue.

AESA would be more tempting for ship based DSN but handicapped by rather limited +/- 60 deg electronic beam steering.

Me think India first take land based hi gain DSN. Apart from Bharatvarsh take unoccupied island to setup dsn in pacific and south Atlantic.

[drnayar]

Worth considering that NASAs DSN consists of 70 m antennae

"The DSN consists of three facilities spaced equidistant from each other – approximately 120 degrees apart in longitude – around the world. These sites are at Goldstone, near Barstow, California; near Madrid, Spain; and near Canberra, Australia. The strategic placement of these sites permits constant communication with spacecraft as our planet rotates – before a distant spacecraft sinks below the horizon at one DSN site, another site can pick up the signal and carry on communicating."

larger size extrapolates to longer tracking distance.

ISRO DSN network is appxly 3 in number, 32 m 18m and 11m in byalalu.

IDRSS does not replace the need for antennae on the ground !

https://en.wikipedia.org/wiki/Indian_Da ... ite_System

"It will facilitate relay of information between various Indian spacecraft, in-flight launch vehicle monitoring and assist Indian Human Spaceflight Programme"

India will need bigger DSN ground stations in the future

[AdityaM]

Russian experience should caution us that international DSN cooperation can be suddenly revoked.

Do we have to pay a fat fee for their services?

[drnayar]

Russian experience should caution us that international DSN cooperation can be suddenly revoked.

Do we have to pay a fat fee for their services?

the current arrangement seems reciprocal., Indian DSN stations will support NASA and ESA in their missions as well

the NASA DSN seems adequate for nearly half the solar system beyond which tracking is still available but significantly degraded i presume., maybe gurus can answer this as to "How big" do we need

DSNs can be ship based , there is no reason to think otherwise., but how big and what expense ?!.. ground based ones would be more practical

[Amber G.]

Folks How do Chinese and Russian space probes communicate with Earth?

Do they also use NASA DSN?

As Imdia is launching more deep space satellites should they invest in.own DSN as backup and added redundancy ?

Can it be ship based ?

FWIW: Some General information:
Chinese and Russian space probes communicate with Earth using their own ground-based tracking and communication networks, similar to how NASA uses the Deep Space Network (DSN). Both have developed their own ground stations and satellite communication infrastructure to support their space missions.


China has established the Chinese Deep Space Network (CDSN). The CDSN includes several ground stations equipped with large antennas to communicate with deep space probes. One of the most prominent stations in the network is the Xi'an Satellite Control Center, which plays a crucial role in communicating with China's lunar missions..

Russia operates a network of ground-based space communication centers, collectively known as the Russian Space Communications (RSC) network. These centers are equipped with tracking and communication equipment to support various space missions, including deep space probes. The Russian Academy of Sciences' Space Research Institute (IKI) also operates ground stations for communication with space missions.

While Both China and Russia have their own communication networks, they also use international cooperative agreements for tracking and communication some times.

As for India's space program, having its own deep space communication capabilities can provide added redundancy and flexibility ,, India currently relies on ground stations like the Indian Deep Space Network (IDSN) for its deep space missions.

Setting up ship-based communication systems is possible, but it comes with technical and operational challenges. Ships would need to be equipped with large, stable antennas to maintain communication ... and they would need to navigate to strategic locations to maintain line-of-sight communication.. ( Russia, from what I know have one deep sea tracking ship called the 'Marshal Krylov' which was in the Pacific Ocean providing coverage for Luna -25)
(Did a google, here is an image:)

[sanman]

After reaching the Moon, India now aims for the Sun

Mission Aditya-L1 will be launching in first week of September:

[bala]

The Movie Rocketry (on Dr. Nambi Narayanan - of Vikas liquid engine fame) won a National award. 'Rocketry: The Nambi Effect' won the National Award for Best Feature Film at the 69th National Awards today.

Check out: https://www.youtube.com/watch?v=Nes3hl7Ycd8

Great coming on the heels of Chandrayaan-3 success.

[sanman]

[sanman]

https://twitter.com/PMOIndia/status/1695269172534501592

Now onwards, every year, 23rd August will be celebrated as the National Space Day.

[sanman]

Is India participating in some kind of joint BRICS space initiative?

I find these ideas to be stupid. We already have space ties with Russia, and the others aren't worth bothering with for space (China won't help us, and others can't help us - ie. we'd be carrying them)

[sanman]

[sanman]

AdityaL1 solar observation mission to Earth-Sun LaGrange Point is coming up in couple of weeks:

[rrao]

Indian electronic component industry is on terrible Shae.very few make jss grade components in India and that too limited to PTFE wires and mechanical switches.
Importing even for commercial use also being questioned with enduse certificate...earlier ecil and Bel used to make some components..it's time electronic components industry is revived on war footing...micron has come forward to make memory chip in Hyderabad....but it's only packaging...GATEC,SCL they are ornamental only...

[sanman]

While I am an atheist, I am immediately impressed by this man




I hope he has a long tenure at ISRO, and in public service

[chetak]

some things never change


the venom of the commies and urban naxals....

[nitzter]

Minister of space - Ahead of the human spaceflight, scheduled for the second half of 2024, top scientists are working on an unmanned mission in September this year and later a mission mimicking humans through a robot early next year. The female robot has been named Vyomamitra.

Links - https://www.tribuneindia.com/news/natio ... ept-537076

https://www.livemint.com/news/india/jit ... 09044.html

Other platforms also reporting launch and recovery trial in October 1st/2nd week!!

[nitzter]

some things never change

the venom of the commies and urban naxals....

Let's not give any footage to these sort of individuals. They only crave attention with such remarks...

[sanjaykumar]

^^ interesting. The man does not say that his god is bigger than all and he works for his glory. He states that he comes to a temple to explore.

What a refreshing contrast between the frank idiocy of revealed religions and this. But in India one has to apologise for this paganism lest it offend your all powerful god and he has another apoplectic rage.


At any rate I’m not sure why his religious views are the media’s business. It will only invite accusations of saffron science.

[nitzter]

^^ interesting. The man does not say that his god is bigger than all and he works for his glory. He states that he comes to a temple to explore.

What a refreshing contrast between the frank idiocy of revealed religions and this. But in India one has to apologise for this paganism lest it offend your all powerful god and he has another apoplectic rage.


At any rate I’m not sure why his religious views are the media’s business. It will only invite accusations of saffron science.

Not afraid of any accusation - Hindu tan-mann, hindu jeevan; rag rag hindu mera parichay!

Exploring the truths and challenging the depths is the core of sanatani identity...

[sanman]

[sanman]

This must be a newer channel, as I've only recently discovered it:



While I do like General Shankar's channel, I regret I must mention some caveats here, regarding lunar Helium-3 as a source of energy. I first read articles put out by IDSA (Institute of Defence Studies Analysis) over 20 years ago, which began talking about lunar Helium-3 as an energy source. This was in concert with a lot of other science publications around the world who were also making similar assertions at the time.

But the reality is that Helium-3 is only present in the lunar surface regolith in very faint trace amounts of parts-per-billion. Therefore harvesting significant quantities of lunar Helium-3 would require processing very large quantities of the lunar surface regolith. Some people ciaim this could still be done relatively easily through solar heating of said topsoil, but it's not clear how efficient this would be as an extraction method.
More abundant sources of Helium-3 might be found in the upper atmospheric layers of gas giants Jupiter and Saturn. This would require skimming through the upper atmospheres of these planets, which have huge gravity wells.

The advantage of Helium-3 is that it can be used for Aneutronic Fusion, whose energy is much more easily/efficiently harvested from the fusion reaction process, because the energetic fusion products are entirely in the form of charged particles and gamma-rays.
However, with nobody having achieved energy breakeven from fusion of hydrogen, nobody's going to bet on Helium-3 with its higher nuclear charge repulsion barrier.

Furthermore, there's another Aneutronic Fusion reaction (p+B11) that is possible with Hydrogen and Boron, which are much more abundant and available materials here on Earth. No need to go to the Moon to get them. However, that reaction is also quite hard to achieve, given its even higher nuclear charge repulsion barrier.

[RCase]

some things never change
the venom of the commies and urban naxals....

For this commie bimbo 'farmer' at Smell of the Earth, let her go celebrate her egotistical self by constantly sniffing manure laden soil and methane farts from bovines. Hey you never know, the sh*t that she has been constantly inhaling has probably found its way to her brain.

[sanman]

He's fearless with his words - after everything he's been through, I don't think they can do much worse to him:

[Ashokk]

https://twitter.com/isro/status/1696097793616793910

PSLV-C57/Aditya-L1 Mission:
The launch of Aditya-L1,
the first space-based Indian observatory to study the Sun, is scheduled for
September 2, 2023, at
11:50 Hrs. IST from Sriharikota.

[bala]

Sanman ji, On that interview of Dr. Nambi Narayanan, the shameless reporter talks about objections to BJP, when the question is rather moot and irrelevant. During Nambi Narayanan's time, the dreaded Kangress were in power, Narasimha Rao was PM. The PM Rao, being controlled by Kangress, did not nip in the bud the false accusation hoisted on Dr. Nambi by the insidious commie oriented Kerala operatives. The entire story is so ridiculous, but we now know that powerful entities (read this as the US) against India resorted to unfair means to thwart the Indian progress on rocket engines. Had Dr. Nambi been in charge at ISRO the rocket engine could have advanced (semi-cryogenic kerosene engine) and India would be in a position to hoist larger payloads into space. Instead via US President Clinton the Chinese openly stole US rocket technology and advanced to such a level that they now threaten the US. India and US are in the Quad.

[sanman]

Even though India's Mars Orbiter stopped functioning last year, past data is still being combed through, with interesting footage turning up:

[nitzter]

Any reference on how AdityaL1 will communicate with Earth , considering that the big Noisy Sun disc is always behind the satellite?

(Apart from great distance there is a constant big noisy Sun behind .)
Aditya or any spacecraft at the (L1) position face unique communication challenges due to the presence of the Sun and its associated noise, as well as the long distance from Earth. Engineers have developed techniques to ensure effective communication .. Few points;

- Antenna Design and Placement: ... specialized communication systems--- high-gain antennas -- to focus their signals toward Earth and reduce sensitivity to signals coming from other directions

Engineers schedule communication sessions during times when the spacecraft is not in direct line of sight with the Sun, minimizing the effects of solar noise.

Signal focusing and directioning is truly key followed by amplification at ground bases, especially for long distance and deep space missions...

However, a doubt - Do we really need to worry that much about solar noise? Having a large major axis for Aditya's orbit would bring the signal angles farther away from the sun...
What are the orbit details for Aditya?
Is there an impact on station keeping for larger orbits?


PS - Bringing non-CY3 related conversation back to this thread.

[Amber G.]

(Apart from great distance there is a constant big noisy Sun behind .)
Aditya or any spacecraft at the (L1) position face unique communication challenges due to the presence of the Sun and its associated noise, as well as the long distance from Earth. Engineers have developed techniques to ensure effective communication .. Few points;

- Antenna Design and Placement: ... specialized communication systems--- high-gain antennas -- to focus their signals toward Earth and reduce sensitivity to signals coming from other directions

Engineers schedule communication sessions during times when the spacecraft is not in direct line of sight with the Sun, minimizing the effects of solar noise.

Signal focusing and directioning is truly key followed by amplification at ground bases, especially for long distance and deep space missions...

However, a doubt - Do we really need to worry that much about solar noise? Having a large major axis for Aditya's orbit would bring the signal angles farther away from the sun...
What are the orbit details for Aditya?
Is there an impact on station keeping for larger orbits?


PS - Bringing non-CY3 related conversation back to this thread.

Once Aditya is at (near) L1, it is *always* between sun and earth. (L1 is a point which remains fixed with respect to sun and earth in the reference system of rotating earth around the sun).


(Lagrange points in the Sun–Earth system (not to scale) – a small object at any one of the five points will hold its relative position).

Since L1 is not stable -- Both L1 and L2 points are unstable on a time scale of approximately 23 days, which requires satellites orbiting these positions to undergo regular course and attitude corrections --(Halo orbits)... but aditya-1 is never far away from line joining earth and real adtiya (sun).



(This is not to the scale, the actual planned orbit around L1 has a very small angular radius as seen from earth)

For more details see for example <this> or <this>

[nitzter]

Low angular radius and monthly station keeping - thanks Amber ji.

While I have a basic understanding of the Lagrange points, there is almost no information out there about the final orbit of the observatory.

[Amber G.]

Some general information about L1 point and orbits around it - Basic physics..
Way I explain is using rotating frame of reference -- dealing with fictions forces like centrifugal along with gravity -- makes math a little simpler

Lagrange points are specific locations in space where the gravitational forces of two large bodies, such as the Earth and the Sun, balance the centrifugal force felt by a smaller object. There are five Lagrange points in the Earth-Sun system: L1, L2, L3, L4, and L5.


The L1 Lagrange point lies on the line connecting the two large bodies, closer to the smaller body (in this case, Earth). At the L1 point, the gravitational pull from the Earth is balanced by the centrifugal force due to the combined gravity of the Earth and the Sun. This creates a point where an object can effectively "hover" relative to the Earth's position.


A halo orbit around the L1 point is a type of three-dimensional, unstable periodic orbit. It's called a "halo" orbit because if you were to view the path from a distance, it would resemble a ring or a halo around the L1 point. These orbits are highly complex and result from the gravitational interactions between the Earth, the Sun, and the spacecraft.

From a general physics standpoint, halo orbits are a fascinating result of the interplay between gravitational forces and centripetal (centrifugal) forces. Imagine a spacecraft situated at the L1 point. If it drifts slightly in any direction, the gravitational forces from the Earth and the Sun will attempt to pull it back to the equilibrium point at L1. However, due to the unstable nature of this equilibrium, the spacecraft can't remain exactly at L1 but instead traces a path around it.

Think of it like balancing a pencil on the tip of your finger – any slight displacement will cause the pencil to oscillate around the balanced position. Similarly, the spacecraft in a halo orbit experiences oscillations around the L1 point, creating a dynamic and complex trajectory.

The Aditya-L1 mission aims to study the Sun, its outermost layer (corona), and the solar wind. Placing a spacecraft in a halo orbit around the L1 point allows for a relatively stable position with an uninterrupted view of the Sun, as the spacecraft moves in sync with Earth's orbit around the Sun.

In summary -- halo orbits around the L1 Lagrange point are a result of gravitational and centrifugal forces acting in equilibrium, creating a dynamic yet relatively stable orbital path. This concept is crucial for missions like Aditya-L1, enabling prolonged and unobstructed observations of the Sun from this specific vantage point.

[SSSalvi]

AdityaL1 Launch Kit doc is out!!!!

Now SRF should start new thread.

https://www.isro.gov.in/media_isro/pdf/ ... ochure.pdf

[nitzter]

AdityaL1 Launch Kit doc is out!!!!

Now SRF should start new thread.

https://www.isro.gov.in/media_isro/pdf/ ... ochure.pdf

Very interesting PS4 burn sequences 15 and 42 minutes after PS3 cutoff... With a lighter payload, it is behaving like a propulsion module.

[Amber G.]

AdityaL1 Launch Kit doc is out!!!!

Now SRF should start new thread.

https://www.isro.gov.in/media_isro/pdf/ ... ochure.pdf

Starting a new thread ... please continue here for Aditya-L1 specific topics:
viewtopic.php?t=7930

[sanman]

"India’s accomplishments in space are getting more impressive"

https://arstechnica.com/space/2023/08/w ... al-powers/