ISRO successfully carries out controlled re-entry experiment of aged satellite
Bengaluru (PTI): The Indian Space Research Organisation said it successfully carried out an "extremely challenging" controlled re-entry experiment of the decommissioned orbiting Megha-Tropiques-1 (MT-1) satellite.
"The satellite re-entered the Earth's atmosphere and would have disintegrated over the Pacific Ocean", the Bengaluru-headquartered national space agency said on Twitter on Tuesday.
The final impact region estimated is in the deep Pacific Ocean within the expected latitude and longitude boundaries, an ISRO statement said.
The low Earth satellite was launched on October 12, 2011, as a joint satellite venture of ISRO and the French space agency, CNES for tropical weather and climate studies.
Since August 2022, the satellite's perigee was progressively lowered through a series of 20 manoeuvres, spending about 120 kg of fuel.
Multiple manoeuvres including the final de-boost strategy were designed after taking into consideration several constraints, including visibility of the re-entry trace over ground stations, ground impact within the targeted zone, and allowable operating conditions of subsystems, especially the maximum deliverable thrust and the maximum firing duration constraint on thrusters.
All manoeuvre plans were screened to ensure that there would be no post manoeuvre close approaches with other space objects, especially with the crewed space stations like International Space Stations and the Chinese Space Station, ISRO said.
The final two de-boost burns were executed at 11:02 UTC and 12:51 UTC respectively on March 7 by firing four 11 Newton thrusters on-board the satellite for about 20 minutes each, it said.
The final perigee was estimated to be less than 80 km, indicating that the satellite would enter the denser layers of the Earth's atmosphere and subsequently undergo structural disintegration. The re-entry aero-thermal flux analysis confirmed that there would be no surviving large debris fragments.
The entire sequence of events was carried out from the Mission Operations Complex in ISTRAC (ISRO Telemetry, Tracking and Command Network), Bengaluru.
An uninhabited area in the Pacific Ocean between 5 S to 14 S latitude and 119 W to 100 W longitude was identified as the targeted re-entry zone for MT1, weighing about 1000 kg, ISRO said earlier this week.
About 125 kg on-board fuel remained unutilised at its end-of-mission that could pose risks for accidental break-up, an ISRO statement had noted.
This left-over fuel was estimated to be sufficient to achieve a fully controlled atmospheric re-entry to impact the uninhabited location in the Pacific Ocean, ISRO had said.
Controlled re-entries involve de-orbiting to very low altitudes to ensure impact occurs within a targeted safe zone.
Usually, large satellites/ rocket bodies, which are likely to survive aero-thermal fragmentation upon re-entry, are made to undergo controlled re-entry to limit ground casualty risk.
However, all such satellites are specifically designed to undergo controlled re-entry at end-of-life (EOL).
"MT-1 was not designed for EOL operations through controlled re-entry which made the entire exercise extremely challenging," ISRO said.
Furthermore, the on-board constraints of the aged satellite, where several systems had lost redundancy and showed degraded performance, and maintaining sub-systems under harsher environmental conditions at much lower than originally designed orbital altitude added to the operational complexities, it said.
Innovative workarounds were implemented by the operations team based on the study, deliberations, and exchanges among the mission, operations, flight dynamics, aerodynamics, propulsion, controls, navigation, thermal, and other sub-system design teams across the ISRO centres, who worked in synergy to surmount these challenges, it said.
Although the mission life of the satellite originally was three years, it continued to provide valuable data services for more than a decade supporting regional and global climate models till 2021, ISRO said.
UN/IADC (Inter-Agency Space Debris Coordination Committee) space debris mitigation guidelines recommend de-orbiting a LEO (Low Earth Orbit) object at its EOL, preferably through controlled re-entry to a safe impact zone, or by bringing it to an orbit where the orbital lifetime is less than 25 years, according to ISRO.
It is also recommended to carry out "passivation' of on-board energy sources to minimise the risk of any post-mission accidental break-up, ISRO said.
The orbital lifetime of MT-1 would have been more than 100 years in its 20 deg inclined operational orbit of 867 km altitude, it said.
"As a responsible space agency committed to safe and sustainable operations in outer space, ISRO proactively takes efforts for better compliance with the UN/IADC space debris mitigation guidelines on post-mission disposal of LEO objects", the ISRO statement said.
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Karnataka Milk Federation enters Delhi-NCR, offers competitive pricing on Nandini products
New Delhi, Nov 21: Karnataka Chief Minister Siddaramaiah on Thursday launched the Karnataka Milk Federation's (KMF) Nandini brand milk products in the Delhi-NCR market, pricing them marginally lower than competitors to gain a foothold in the region.
The cooperative will retail four cow milk variants, curd, and buttermilk from Friday, with competitive pricing that undercuts established players like Mother Dairy and Amul.
Cow milk will be sold at Rs 56 per litre, full Cream Milk at Rs 67 per litre, Standardised Milk at Rs 61 per litre, Toned Milk at Rs 55 per litre, and curd at Rs 74 per kg.
"We have surplus milk in the state. KMF along with Mandya Milk Union will market surplus milk of 3-4 lakh litres per day in Delhi-NCR," Siddaramaiah told reporters after launching the products.
The federation currently collects 100 lakh litres of milk daily, with local consumption at 60 lakh litres, leaving a surplus of 40 lakh litres for expansion into new markets.
However, the Chief Minister acknowledged the challenges of transporting milk over 2,500 km, which takes 50-54 hours.
There is a need to find new markets for surplus milk and gradually the KMF should be able to sell 5-6 lakh litres per day in Delhi-NCR, he added.
KMF Chairman LBP Bheemanaik assured that milk quality would be maintained during transit.
The federation has already partnered with 40 dealers in the Delhi-NCR region to facilitate sales, he added.
With a robust infrastructure of 26.76 lakh milk producers, 15,737 dairy cooperative societies, and 15 district milk unions, KMF has a turnover of Rs 25,000 crore and exports dairy products to over 25 countries.
State Animal Husbandry Minister K Venkatesh and Agriculture Minister N Cheluvarayaswamy were present at the product launch.
ದೇಶದ ಹಾಲು ಉತ್ಪಾದನೆಯಲ್ಲಿ ಗುಜರಾತ್ ಮೊದಲ ಸ್ಥಾನದಲ್ಲಿದ್ದರೆ, ಕರ್ನಾಟಕ ಎರಡನೇ ಸ್ಥಾನದಲ್ಲಿದೆ.
— Siddaramaiah (@siddaramaiah) November 21, 2024
ದೆಹಲಿ ನಗರದಲ್ಲಿ ಕೆ.ಎಂ.ಎಫ್ ಮತ್ತು ಮಂಡ್ಯ ಹಾಲು ಒಕ್ಕೂಟಗಳು ಸೇರಿಕೊಂಡು ವಿವಿಧ ಶ್ರೇಣಿಯ ಹಾಲನ್ನು ಮಾರುಕಟ್ಟೆಗೆ ಬಿಡುಗಡೆ ಮಾಡಿವೆ. ದೆಹಲಿಯ ನಿವಾಸಿಗಳಿಂದ ನಂದಿನಿ ಉತ್ಪನ್ನಗಳಿಗೆ ಅತ್ಯುತ್ತಮ ಸ್ಪಂದನೆ ದೊರೆಯಲಿದೆ ಎಂಬ ವಿಶ್ವಾಸ ನನಗಿದೆ.… pic.twitter.com/yUmTQknGzD
