Chandra (tckb) Profile picture
🇩🇪 | 🇮🇳 Bharat ; I'm a hobbyist researcher, nerd with a deep interest and passion for Planetary science, Remote Sensing. (check my highlights for my works)
Feb 28 • 6 tweets • 2 min read
I've done 3d reconstruction of the landing site of #IM1 @Int_Machines - this gives a sharp idea of what kind of terrain #odysseus landed the data shows the IM1 landed at a slope about 12 deg this is quite evident from the 3d terrain
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Here's another look at the crater circle that #IM1 landed from the view overlooking the crater
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Feb 27 • 7 tweets • 3 min read
More discussions on how #IM1 @Int_Machines approached its landing site. Although, its likely due to the adjustments in the final approach the path might be different but, an existing trajectory shows IM1 approached NE / NNE I'll do more approach related analysis here 🧵 Image Interestingly, @Int_Machines said these pictures are just above 30m - this is the time when #IM1 is HDA or prepares to start VD - so by that these images should've been taken while approaching landing site or close to it- this would be ~2-3 mins before landing with a 3m/s at VDA. Perhaps this helps in tracking -

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Feb 26 • 6 tweets • 2 min read
Interesting #IM1 location is way off than my study region - as you can see is close to the "red" region. More studies will follow (-80.13 ,1.44 )
Image rest is here:
Feb 26 • 15 tweets • 4 min read
#GoodAfterMoon #SLIM woke up today as announced by @SLIM_JAXA and the its not all over yet. If you haven't following it here's all my* analysis so - far on SLIM from transfer to landing - #JAXA #slim月着陸ライブ (roughly chronological) 🧵/ 🧵 I didn't do the trajectory for #SLIM but @tony873004 has put together this one - shows how impressive this trajectory is from Earth to the moon

Feb 23 • 7 tweets • 2 min read
#Update #IM1 @Int_Machines approximate location when the image was taken.
Image @Int_Machines Some background here:

Feb 23 • 4 tweets • 2 min read
Heres more evidence that indeed that there was some of kind of deviations from the planned and actual orbits of #IM1 @Int_Machines I can't tell exactly how bad it is @coastal8049 this is what I can give you - how does these look like ?

on-board:
Semi-Major axis: 1837.46
Eccentricity: 0.000685
Inclination: 77.110418
Argument of Periapsis: 299.675054
Longitude of Ascending Node: 195.130291
True Anomaly: 287.423759

expected/gold:
Semi-Major axie: 1837.13
Eccentricity: 0.000209
Inclination: 77.153517
Argument of Periapsis: 71.045785
Longitude of Ascending Node: 195.173850
True Anomaly: 156.029370

deviation:

Semi-Major Axis: 0.33 km
Eccentricity: 0.000476
Inclination: 0.0431 degrees
Argument of Periapsis: 228.6293 degrees (wow!)
Longitude of Ascending Node: 0.0436 degrees
True Anomaly: 131.3944 degrees

thank you @stim3on
@DJSnM any thoughts on this? ----

Data is from the DDL shared @Int_Machines and simulation is from @tony873004

Feb 21 • 11 tweets • 4 min read
Now that LOI is finished: I've done full and final landing simulation of @Int_Machines #IM1 that will occur tomorrow ~ 22.02.2024 22.48 UTC . Here are the major events (pay close attention to change velocity vector at the end!) 1/n
The Descent Orbit Insertion DOI of #IM1 begins at around ~22.02 21.43 UTC to start reducing the altitude from ~92Km to 10Km near by the landing site on the far side of the moon. You can see that change in altitude on the opp. side of the arrow pointing towards the earth

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Feb 17 • 9 tweets • 3 min read
I did more precise terrain analysis on the landing site of @Int_Machines #IM1 based on pre-launch trajectory @coastal8049 suggested a possible location and this location has a general agreement with what @LRO_NASA has previously shared (1/n) This landing location is in the general vicinity of (-80.158515, 1) which is flat, very flat. The location has a slope that is <4 degrees and the dark green areas almost 0 degree with an elevation around 2700m in this region. Because of this feature - this location makes an ideal landing locationImage
Feb 14 • 13 tweets • 4 min read
I did some initial terrain and landing site analysis of @Int_Machines #IM1 . Nova-C is set to launch today to Malapert-A a satellite crater, this area is within the Lunar South polar region ~80S lat and approx 300Km from Lunar South Pole ⬇️ Image If successful IM-1 would be the first ever to reach the polar region. This terrain is not only hard to reach and land, but also tough to survive, with little illumination and also comes as hard for communication with earth because of the high skew angle at the poles.

To compare, #Chandrayaan3 only landed close to the polar region - about 69SImage
Feb 9 • 12 tweets • 3 min read
Why the whole rush to goto Shackleton de Gerlache Ridge (SDR)? @NASAArtemis @lupex_jaxa @Int_Machines
and perhaps the next #Chandrayaan, and many other missions are planning to go there but why goto such a dissolute place so close to pole?

Credits: NASA/GSFC/ASU/C.Tungathurthi Shackleton de Gerlache Ridge (SDR), an ancient ridge between the famous Shackleton crater and de Gerlache crater is been in the news for a while now. This has been particular of interest because of the proximity to permanently shadowed regions (PSRs) like Shackleton crater or even, micro PSR.

Credits: NASA/GSFC/ASU/C.TungathurthiImage
Feb 7 • 13 tweets • 6 min read
On Aug 23rd, 2023 @ 12:33 UTC India made a significant achievement of landing near Lunar South Pole. Before landing Dr.S Somanath, chairman of @isro said #Chandrayaan3 was designed with 6-sigma bounds - with a "Salvage mode" - "It will land no matter what" But how?! Lets find out For folks, who remember just before landing ~150m above the surface, Vikram state changed to "pre/LHDAC" and then went into "LHDAC Hover" - this is when Vikram started inspecting the surface and started the "RE-TARGET" to move to another location that was safe to land.

What is this retarget and why was it landing away from the intended location? and, how does it work exactly?Image
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Feb 4 • 13 tweets • 5 min read
What if I tell you there are boulders inside Shackleton crater that casts "shadows" where there is no sun light! How is this possible? and what does it mean for #Artemis, what about Polar water Ice ? Significant conclusion at the end 👇

Credits: NASA/KARI/ASU/C.Tungathurthi Image In Aug'22, #ShadowCam was launched aboard the Korea Pathfinder Lunar Orbiter (KPLO). It was designed by ASU and NASA to specifically target and study the Moons PSR (Permanently shadowed region). It aims to detect water ice and other lunar resources.

- It is equipped with ultra-sensitive sensors, a sensitivity 200x greater than the traditional @LRO_NASA, enabling it to capture detailed images of PSRs.
- It enhances our understanding of the lunar surface's composition and supports future exploration and potential resource utilization.
- A primilimary investigation of Shackelton crater, reveals new details about Shackleton that was not revealed before:Image
Image of the Earth and Moon from 1.24 million km away acquired by the KPLO LUTI camera. Image courtesy of KPLO LUTI/KARI.
Saturated image of the Earth (right) and Moon (left) taken by ShadowCam on 29 August 2022 from over 1.2 million km away from Earth. The image has been rotated 90 degrees for display purposes. ShadowCam image E002095321S [NASA/KARI/ASU]
Jan 28 • 9 tweets • 3 min read
Part2/n🚨 Despite critical failure @SLIM_JAXA managed to do high-precise landing. But how did they do that? I'll explain their Visual Based Navigation Algorithm - In this post an overview 👇
#SLIM #月着陸 #JAXA #たのしむーん Credits: JAXA Before the powered descent phase visual based navigation kicked-in 3 times to correct the spacecraft location and then twice during to correct its planned trejectory and then twice during the actual vertical descent to finally place it within 50m. In total 7 crucial corrections Image
Jan 19 • 16 tweets • 5 min read
🚨 In few hours @SLIM_JAXA will attempt to make a pin-point landing near Shioli - In this part 1 of the series I'll explain why it so difficult and makes it one of the most challenging missions so-far! Read and learn👇
#SLIM #月着陸 #JAXA #たのしむーん #月着陸カウントダウンImage
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The landing site is close to Shioli crater, near by the so-called Sea of Nectar - this site is chosen because its one of the regions that has rocks with Olivines (its a kind of mineral also in Earths Mantle) derived from the Lunar Mantle. One of the 'extra 'goals is in-situ analysis of the composition of them. Hence a precision landing was needed.
Dec 15, 2023 • 25 tweets • 8 min read
🚨*Big Breaking*🚨 We finally have our own Indian ChatGPT rival now @Krutrim #KrutrimAI by Ola @bhash - This is our #IndianAI trained on Indian languages, with our context. First Indian AI chip by 2025. First Indian AI early access by 2024
Mega thread- all you have to know 👇
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According the company head Bhavesh - the vision of the company is not only to build a large language model like chatGPT but to build a strong AI ecosystem to build future applications starting from silicon - the AI chip manufacturing to building end user facing application. Image
Nov 9, 2023 • 5 tweets • 1 min read
a few days ago @IIABengaluru observed something strange - an #aurora activity but there was something different about it. This was red, "an intense red coloured aurora" instead of the well known green - but why? Auroras usually form at higher altitudes but this one was observed at IAO at Hanle and Merak which at a high altitude of 4,500m. This Red-tinted aurora is called "Stable Auroral Arc" a typical Aurora observed at the polar regions