Chandrayaan-3 Mission:In-situ Scientific ExperimentsInstrument for the Lunar Seismic Activity (ILSA) payload on Chandrayaan 3 Lander -- the first Micro Electro Mechanical Systems (MEMS) technology-based instrument on the moon -- has recorded the movements of Rover and other payloads. Additionally, it has recorded an event, appearing to be a natural one, on August 26, 2023. The source of this event is under investigation.ILSA payload is designed and realised LEOS, Bangalore. The deployment mechanism is developed by URSC, Bengaluru.https://www.isro.gov.in/Ch3_ILSA_Listens_Landing_Site.html
🎙️ @coastal8049 joined me on the podcast today to talk about @isro’s Chandrayaan-3, @roscosmos’ Luna-25, and @NASA’s Deep Space Network.Such a fun conversation with great insights on Chandrayaan-3, and great questions about Luna-25! Have a listen:
RAMBHA-LP on-board Chandrayaan-3 measures near-surface plasma contentAugust 31, 2023First in-situ measurements of the surface-bound Lunar plasma environment over the south polar region have been carried out by the Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere - Langmuir Probe (RAMBHA-LP) payload onboard Chandrayaan-3 Lander.Langmuir (after Irving Langmuir) probe is a device used for characterising a plasma. It features a 5 cm metallic spherical probe mounted on a 1-meter boom attached to the Chandrayaan-3 Lander's upper deck. The probe is deployed using a hold-release mechanism after the lander's lunar touchdown. The extended boom length ensures that the spherical probe operates within the undisturbed lunar plasma environment, isolated from the lander's body. The system can detect minute return currents, as low as pico-amperes, with a dwell time of 1 millisecond. By applying a sweeping bias potential ranging from -12 to +12 V in increments of 0.1 V to the Langmuir probe, the system can accurately determine ion and electron densities as well as their energies based on the measured return current.The initial assessment indicates that the plasma encompassing the lunar surface is relatively sparse, characterized by a number density ranging from approximately 5 to 30 million electrons per cubic meter. This evaluation specifically pertains to the early stages of the lunar daytime. The Probe operates without interruption, aiming to explore the changes occurring in the near-surface plasma environment throughout the lunar day. These ongoing observations hold significant implications for comprehending the process of charging within the lunar near-surface region, particularly in response to the fluctuations in solar space weather conditions.Development of RAMBHA-LP was led by Space Physics Laboratory (SPL), Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram.
ILSA listens to the movements around the landing siteAugust 31, 2023The Instrument for Lunar Seismic Activity (ILSA) payload on the Chandrayaan 3 Lander is the first instance of a Micro Electro Mechanical Systems (MEMS) technology-based instrument on the moon. It has recorded the vibrations occurring due to the movements of Rover and other payloads.ILSA comprises a cluster of six high-sensitivity accelerometers, which are indigenously fabricated using the Silicon Micromachining process. The core sensing element consists of a spring-mass system with comb-structured electrodes. External vibrations lead to a deflection of the spring, resulting in a change in capacitance which is converted into voltage.ILSA's primary objective is to measure ground vibrations generated by natural quakes, impacts, and artificial events. The vibrations recorded during the rover's navigation on August 25, 2023, are depicted in the figure. Additionally, an event, seemingly natural, recorded on August 26, 2023, is also shown. The source of this event is currently under investigation.The ILSA payload was designed and realised at LEOS, Bangalore, with the support of private industries. The deployment mechanism for placing ILSA on the lunar surface was developed by URSC, Bengaluru.
#Update #Chandrayaan3 #Thread@NASA 's #LRA, India took to #Moon, will start its work once #Vikram & #Pragyan go to sleep. Read on for some exclusive details from the #LRA team... 1/nPS: Also, My #newsletter 'Chethan's Space' is out, subscribe: chethank.substack.comWhile three Indian payloads on #Vikram — #RAMBHA, #ChaSTE & #ILSA — have been turned on by Isro and are sending data, #LRA is an instrument built by NASA Goddard Space Flight Centre. 2/nDavid R Williams, acting head, NASA Space Science Data Coordinated Archive, said: “#LRA is not planned to be used for ranging until after the #Chandrayaan3 mission is complete.” 3/nWhile questions were sent to both Williams and Xiaoli Sun, the principal investigator of LRA, Williams responded to the queries as the designated person to handle the same. 4/nOn why #LRA won’t operate until #Chandrayaan3 mission is complete, Williams, quoting Sun and other LRA team members, said it is to make sure it does not interfere with the operation of the optical equipment (cameras and spectrometers) on the lander. 5/n#LRA is designed to use reflected laser light from orbiting spacecraft laser — typically a laser altimeter or lidar — to precisely determine location of the lander, as a fiducial marker, and the distance to that point on the lunar surface with respect to the orbiter. 6/nThe retroreflectors reflect any light striking them directly back to the source. They can be tracked by an orbiting laser altimeter or lidar from a few hundred kilometres. 7/nAccording to NASA, #LRA on #Vikram consists of 8 circular 1.27-cm diameter corner-cube retroreflectors mounted on a 5.11cm diameter, 1.65cm high hemispherical gold-painted platform. 8/nEach of the retroreflectors points in a slightly different direction, and each has a maximum useful light incidence angle of about +-20 degrees. The Total mass of the LRA is 20 grams, it requires no power. 9/n“#LRA will allow very accurate determination of its position from an orbiting spacecraft. This can be combined with knowledge of orbiting spacecraft’s position for an accurate measurement of LRA-Earth distance, which can help understand Moon’s movement relative to Earth… 10/n…Once a number of LRAs are put on the lunar surface they can serve as fiducial markers and to create a geodetic (geodesy for surveying) network on the surface. This will aid in planning precise landings of future missions,” Williams said. 11/nGiven that the LRA ranging (operations) can only be done through an orbiter equipped with a laser altimeter, Williams said, the only orbiter that can do laser ranging at present is NASA’s Lunar Reconnaissance Orbiter (LRO), “using its laser altimeter, LOLA”. 12/nHe said there was no confirmation on whether the LRO has passed over Vikram as on date. 13/n“LRAs should last a long time, so future missions will be able to use them. The more LRAs you have, the better the (geodetic) network. They are planned for many future missions, but there really isn’t a minimum number they need to have,” Williams added. n/n
Chandrayaan-3 Mission:🏏Pragyan 100*Meanwhile, over the Moon, Pragan Rover has traversed over 100 meters and continuing.
Chandrayaan-3 Mission:The Rover completed its assignments.It is now safely parked and set into Sleep mode.APXS and LIBS payloads are turned off. Data from these payloads is transmitted to the Earth via the Lander.Currently, the battery is fully charged.The solar panel is oriented to receive the light at the next sunrise expected on September 22, 2023.The receiver is kept on. Hoping for a successful awakening for another set of assignments!Else, it will forever stay there as India's lunar ambassador.
#Update #Chandrayaan3 #ThreadOn a day India’s solar sat began its 1.5 mn-km journey, its lunar mission achieved all its objectives, paving the way for @isro to put #Vikram & #Pragyan to sleep on Sunday. Read on for exclusive details from project director P Veeramuthuvel. 1/nSunday, which is the 12th day since India achieved the historic soft-landing on the lunar surface, will see both Vikram and Pragyan retire for the night, Chandrayaan-3 project director P Veeramuthuvel told me. 2/nIsro late on Saturday said: “The rover completed its assignments. It is now safely parked and set into Sleep mode. #APXS & #LIBS payloads are turned off. Data from these payloads is transmitted to the Earth via the Lander.” 3/n“This means the command to put the rover to sleep has been enabled and it will go to sleep only Sunday as there are some tests that need to be done,” Veeramuthuvel explained. 4/nCurrently, the battery is fully charged and the solar panel is oriented to receive the light at the next sunrise expected on September 22, 2023. The receiver is kept on. 5/n“Hoping for a successful awakening for another set of assignments! Else, it will forever stay there as India's lunar ambassador,” Isro added. 6/nOn why an early sleep mode given that the designed life of the lander and rover were 14 Earth days, he said: “We cannot count the first two and last two days. The lunar day began on August 22 and our landing was almost at the end of the second day… 7/n...From there, both Vikram and Pragyan have performed exceptionally to exceed our expectations. All mission objectives have been met and we will enter sleep mode tomorrow (Sunday).” 8/nElaborating on why there cannot be operations on the last two days, Veeramuthuvel said there was a need for a specific angle of the Sun’s elevation to keep systems running. “A full lunar day is from 0° Sun elevation angle to 0° angle… 9/n…But the mission is not designed like that. For landing, the angle requirement was 6-9° elevation and we managed to land when elevation was 8.75°. For operations, we need a minimum of 6° elevation angle because our cameras and other systems are characterised for that… 10/n…It's also for solar panels to remain optimal. Once it goes below 6° elevation, there’s a long shadow,” he said. While there is a grace period for operations to continue, Isro is opting to begin the process of enabling sleep mode earlier than that. 11/n“We want to enable the sleep sequence before this grace period to avoid any last-minute challenges or hurdles. We want the lander and rover to enter the sleep mode as flawlessly as they’ve done everything else so far,” Veeramuthuvel said. 12/nIn its short life on Moon, #Pragyan has completed traversing more than 100 metres as of Saturday, which marked only the 10th day of its deployment, which happened early on August 24, several hours after Vikram’s soft-landing on August 23. 13/nPragyan’s operations are not fully autonomous and require commands to be sent from Earth. In any given mobility plan Pragyan could have only covered 5-metres given the turnaround time. 14/nIt has also had to overcome obstacles — it safely negotiated a small crater whose depth was 10cm and avoided a bigger crater with a 4-metre diametre — which would have consumed a lot of time. 15/n“If we look specifically at the rover, we’ve managed to cover more than 100 metres in just 10 days, while several other missions that have lasted longer, even as long as six months, have only managed 100-120 metres,” Veeramuthuvel said. n/n
When is the sun going to be too low for them to continue? I'm guessing in a day or two?
Quote from: Blackstar on 09/02/2023 12:31 pmWhen is the sun going to be too low for them to continue? I'm guessing in a day or two?Sunset will occur at 2023/09/04, at around 17:35 GMT, according to ]NASA Horizons data(asterisk in second column indicates sun presence in sky, last column is its elevation): 2023-Sep-04 17:35,*,i, 272.323972121, -0.260536978, 2023-Sep-04 17:36,*,i, 272.316044894, -0.263504575, 2023-Sep-04 17:37, ,s, 272.308117669, -0.266472191, 2023-Sep-04 17:38, ,i, 272.300190445, -0.269439825,
Chandrayaan-3 Mission:🇮🇳Vikram soft-landed on 🌖, again!Vikram Lander exceeded its mission objectives. It successfully underwent a hop experiment.On command, it fired the engines, elevated itself by about 40 cm as expected and landed safely at a distance of 30 – 40 cm away.Importance?: This 'kick-start' enthuses future sample return and human missions!All systems performed nominally and are healthy. Deployed Ramp, ChaSTE and ILSA were folded back and redeployed successfully after the experiment.#Chandrayaan_3#Ch3
Quote from: spacexplorer on 09/03/2023 07:02 amQuote from: Blackstar on 09/02/2023 12:31 pmWhen is the sun going to be too low for them to continue? I'm guessing in a day or two?Sunset will occur at 2023/09/04, at around 17:35 GMT, according to ]NASA Horizons data(asterisk in second column indicates sun presence in sky, last column is its elevation): 2023-Sep-04 17:35,*,i, 272.323972121, -0.260536978, 2023-Sep-04 17:36,*,i, 272.316044894, -0.263504575, 2023-Sep-04 17:37, ,s, 272.308117669, -0.266472191, 2023-Sep-04 17:38, ,i, 272.300190445, -0.269439825,That doesn't quite answer Blackstar's question.The omiision of the asterisk implies the total dissapearance of the Sun behing a perfectly level horizonOnce can extrapolate backwards to get that the Sun starts to go below a level horizon around 2023-09-04-14:37, some three hours earlier.Even with vertical solar panels facing west, a critical level would be reached somewher within that interval, although haven't the systems been shut down carefully already?That is less than a half day from this moment, 2023-09-04-03:45, when the sun should be a mere two degrees elevation, having passed the design limit of six degrees a day ago.
On command, it fired the engines, elevated itself by about 40 cm as expected and landed safely at a distance of 30 – 40 cm away.
The #Chandrayaan3 lander is likely been turned off by now in @isro's attempt to prepare it to survive the long lunar night. The Moon is just clearing the trees and we'll see within the hour. Sunset is ~17:00 UTC. 🧵⬇️The #Chandrayaan3 lander was carefully landed on the moon to place the three sides with solar panels facing east, north and west ensuring maximum possible illumination at this high latitude site. This can be seen in the rover tracking plot @isro shared a few days ago. ⬇️twitter.com/isro/status/1697881823391711684Further @isro released this image around noon at the Shiv Shirta Point further confirming how the lander was orientated on the moon. The rover ramp deployed south to ensure the three power generating surfaces were best orientated for power generation. ⬇️So @isro has demonstrated not only softly landing on the moon but the ability to land at the exact orientation they desired to maximize power generation. Sweet dreams #VikramLander!🛑
QuoteChandrayaan-3 Mission:🇮🇳Vikram soft-landed on 🌖, again!Vikram Lander exceeded its mission objectives. It successfully underwent a hop experiment.On command, it fired the engines, elevated itself by about 40 cm as expected and landed safely at a distance of 30 – 40 cm away.Importance?: This 'kick-start' enthuses future sample return and human missions!All systems performed nominally and are healthy. Deployed Ramp, ChaSTE and ILSA were folded back and redeployed successfully after the experiment.#Chandrayaan_3#Ch3
Chandrayaan-3 Mission:Vikram Lander is set into sleep mode around 08:00 Hrs. IST today. Prior to that, in-situ experiments by ChaSTE, RAMBHA-LP and ILSA payloads are performed at the new location. The data collected is received at the Earth. Payloads are now switched off. Lander receivers are kept ON. Vikram will fall asleep next to Pragyan once the solar power is depleted and the battery is drained. Hoping for their awakening, around September 22, 2023. Here are the images before and after the hop. #Chandrayaan_3#Ch3
That doesn't quite answer Blackstar's question.
