Bharat Rakshak

sudarshan

Erratic - down to -143 dB now. Dies occasionally and then comes back.

sudarshan

Quickly goto dsn, goldstone is able to get DL signal from CH2L :) earlier it was Madrid station I see it, seems like two-way communication. Moon must be visible from California now. In Madrid it would be close to setting or already set. Is there any significance to the shape of the wave form? Seems...

sudarshan

Hmm, scratch what I said above about near and far side, I might be guilty of spreading disinformatsiya. It seems, looking at crater maps, that the moon's south pole is on the far side as seen from earth? Will check and get back. But then, like UB said, I fail to see how a radio telescope from earth ...

sudarshan

The landing spot was on the near side of the moon. Yesterday was ashtami (shukla paksha - waxing phase), so one half of the near side of the moon was visible from the earth. Meaning, the other half of the near side was just starting its lunar day, and would continue to have sunlight for fourteen day...

sudarshan

No ji, earlier in the day, I swear, the Madrid CH2L thingy on the site said "Chandrayan 2 Lander." Maybe they switched it to the x-ray observatory now. It seems right now the Goldstone SOHO thingy is trying Chandrayan 2 Lander. Could be that the moon has set in Madrid, maybe?

sudarshan

^ Yeah, you think that's bad? Beat this!

Congress leader Udit Raj: "If only ISRO scientists believed in science instead of breaking coconuts...."

https://www.newsnation.in/india/news/co ... 36918.html

sudarshan

Gagan ji, the stream of Neil Armstrong was black and white. Seeing the doppler shifted data radio spectrum, told the story of wobbling last seconds of flight. The minute oscillation in observed doppler shift corresonding to net delta velocity component (radial to radio receiver); the spatial non-omn...

sudarshan

UB ji, the craft need not have impacted on its head. It could have rolled that way later. We'll see, there's still hope.

sudarshan

Ashokk wrote: On the DSN website right now one of the antennas in Madrid is sending data to the Chandrayaan-2 lander (CH2L) at 11kW

Sending data? You mean it's working?

sudarshan

Sudharshan'ji craft was definitely *not* tumbling during the rough descent phase. That went flawless. I think the cutover from rough descent to smooth landing was not even. What could be the reasons? We need to break down into sequences the smooth landing phase and maybe given public information tr...

sudarshan

Well then now is the chance, right? The "Ghastly Trolls" should now dig up old footage of the Bagla's antics and put it up for all to see how much he has "done for ISRO." That Doppler curve shows steady deceleration during the rough braking phase. If the craft were tumbling then,...

sudarshan

Currently drowning my sorrows (over Vikram succumbing to Vetal) by drinking cold water (hic

) since I don't drink alcohol. Will be back to this thread in a bit.

sudarshan

5. Sudarshan: If you look at the embedded video, the craft dropped rapidly at around 3:00 but look at the altitude drop from 3:06 to 3:13. The 7-second update of altitude showed that it had recoved its poise. The altitude drop is around 150 m to 200m (eyeballed it).So its velocity just before loss ...

sudarshan

I guess the Chinese were under pressure to get it right, if they didn't want to be breaking rocks in Heilongjiang or Inner Mongolia

. Contrast with how Modi treated ISRO with consummate respect even with what happened.

sudarshan

So if I understand right, the first stage of the descent was with four retro-rockets, then it was supposed to go down to two? What is the reason for that? Why not keep the four rockets, and manipulate their thrust? Four rockets is like a quadcopter drone. Easier to manage the turning moments. With t...

sudarshan

^^^ Fair enough. ^^^^ Well if the video is real-time, then the craft was at ~1.8 km height around 2:57, then by 3:06, it was down to ~0.6 km (just by eye-balling). So 1.2 km drop in 9 secs :eek:. 130 m/sec? So the rockets were accelerating it down instead of decelerating - must have turned upside do...

sudarshan

Even assuming that the last communication was at 300m (based on the last point on graph), the concern we have is that the rate of descent from 2.1km to 300m was too fast for the craft to survive. As per ISRO's plan from 500m altitude the decent has to be 1m/sec. Leaving aside the path between 2.1km...

sudarshan

Are you saying it didn't have that much fuel?. How does it waste it when its purpose was getting over in few more minutes? Touch down at 10m/sec?. Are you crazy? Doesn't matter what the gravity is. When we say 10m/sec, we mean 10m/sec. That would be hard crash. Last 10 meters, the actual plan was t...

sudarshan

Used to have a copy of that bassbort abblicashun somewhere. So many good things on Bakistan, so little time. Maybe it can still be downloaded from Baki embassy? Search on google for "passport form pakistan online pdf" and pick the first link. Or alternatively, just click below: http://pak...

sudarshan

Thank you for that article, definitely a more sophisticated view. I think it's pretty irresponsible of people, especially celebrities, to post pictures from years ago (as much as 20 to 30 years ago!) or from a different place and setting altogether, and add on the tag of "Amazon rain-forest is ...

sudarshan

Mort ji, like I said, if the energy density of the battery by weight is one-third of petrol, that might add an additional 3 to 4% to the overall vehicle weight due to the battery alone. There might be savings on the drive train, especially with independently controlled wheels (one motor per wheel) w...

sudarshan

No, conventional battery chemistries aren't there yet. 1Kg of petrol is about 10 KWhr. Aluminum-air is at best 1/3 of that. We're both saying the same thing here. I said on a "volumetric basis," aluminium-air was slightly ahead of petrol. Petrol is around 0.75 g/cc, aluminium is about 2.7...

sudarshan

I don't think time and effort should be wasted on conventional battery chemistries. The energy-to-weight ratio simply isn't there. It would be better to focus on plug-in hybrids and fuel cell technologies. ISRO could be the lead for fuel cell technologies, they've proven their worth in many areas a...

sudarshan

You know they meant 1 gwh (gigawatt hour). That would be about 25,000 batteries per year capacity (40 kwh battery for a range of about 250 kms -- Nissan Leaf). The alternative chemistry to Li-ion they are talking about is probably Aluminum-Air which is several times more energy dense compared to Li...

sudarshan

Indian Oil to build a 1 GW electric vehicle battery plant. What exactly is a "1 GW battery plant"? Is there some DDMitis somewhere here? Do they mean that they will produce enough batteries every second, to store 1 GJ of energy? Or is the plant going to consume 1 GW of power to make the b...

sudarshan

https://www.ndtv.com/world-news/in-viral-video-imran-khan-says-germany-japan-share-a-border-2027149 Imran says Germany and Japan are neighbors. Delegates puzzled. Nothing to be puzzled about. Please read the full context of the speech, it is about how "Germany and Japan were both killing millio...

sudarshan

There were a few posts about measuring distances/velocities .. using radio telescopes ..doppler effect etc.. Apart from ISRO many others (some aam scientists with access to radio-telescope) are watching CY2 too. Sharing some typical activity of this type here. Other eyes are watching CY2 -- From Dw...

sudarshan

Could you elaborate on the bolded and coloured bit? I didn't get that. Emissions (or rather air pollutants including GHG) can be classified under the following: 1. Green-House Gas emissions like CO2, Methane. GHGs broadly comes from transportation, energy (thermal power stations) & agriculture ...

sudarshan

Something that always lurks in my mind is how does evil manifests and lives longer than virtue in Kaliyug. Look at these scumbags, still living strong and holding power with zero achievements. Kapil Sibal - August 8, 1948 (age 71 years) Kamal nath - November 18, 1946 (age 72 years) Jagdish Tytler -...

sudarshan

There are 4 distinct audience here. 1. The Kashmiris 2. The Bakis 3. The rest of the Indians but especially the Muslims 4. The rest of the world that is following up on Kashmir The bakis are very visibly hurt. While Zam Zam HamIED accepts that bakis have been defeated by India and dishing out some ...

sudarshan

disha wrote: Calibrate inputs appropriately and you can have "pollution free" or "zero-emission" or even "negative-emission" internal combustion engines!

Could you elaborate on the bolded and coloured bit? I didn't get that.

sudarshan

BS-VI norms make little difference for petrol vehicles, since petrol cars already have catalytic converters and are relatively clean. The big difference would be in diesel vehicles. Ultra-low-sulphur fuels for diesel vehicles combined with manufacturing changes and exhaust scrubbers would drasticall...

sudarshan

Good grief guys, y'all invited a mod note already :-?? J/K. Jokes apart, this is one view that I found interesting: https://theicct.org/blog/staff/zero-emission-buses-are-worth-reaching-for This is in the context of Brazil. It seems Brazil has P-7 norms (roughly equivalent to Euro-5) and P-8 norms (...

sudarshan

^ True But with continuous R&RR one can determine the variations in X,Y, Z co-ordinates. R&RR sessions last several hours if need be .. but at typically an hour or so. ... Ok, that would work I guess, good old least-squares fitting using some kind of optimization model (heuristic routine), ...

sudarshan

^ If you are moving then do the measurement continuously at equal intervals .. you will get the object receding speed by measuring the distance change in each occasion. That is with audio freq .. if you use RF freq then you can do same measurements more frequently because the RF speed is higher and...

sudarshan

Several Indian states have legislated bans on single-use plastics, especially the <50 micron thickness plastic bags and covers. Maharashtra has made some progress in enforcing the legislation. In TN (from what I read online, don't know how far it is true), people already seem to be moving towards pa...

sudarshan

Primus wrote: Totally OT for this thread though, sorry.

Please post in this thread: Policy Changes in India: Electric Vehicles, Pollution Control, Energy Source Mix, Etc.

This is in the Technology and Economic forum.

Thanks.

sudarshan

I'm starting a new thread on a subject which I expect to become a hot topic in the coming months. There have been a number of policy initiatives and goals in India, relating to environmental concerns, introduction of BS-VI norms for vehicles, push towards electric vehicles, renewable energy sources,...

sudarshan

Let me give it a shot. It is probably more layman than what you considered layman. 1. By measuring the strength of the reflected radar signals, one can accurately determine the position of an object relative to the earth 2. By measuring the rate of change of this strength, one can accurately determ...

sudarshan

At 14:45 onwards the Paki says that if we are not in a position to fight a war with India, then we should have a no war pact with India The above would be taqiya. under the condition that Kashmir be made independent. A porki is imposing condition even when he is powerless. They are born chuityas. :...

Search found 2119 matches