After final lunar orbit manoeuvre for Chandrayaan-2, ISRO readies for separation of lander
Bengaluru, Sep 1: ISRO on Sunday said it has successfully performed the fifth and final lunar bound orbit manoeuvre for the Chandrayaan-2 spacecraft and was gearing up for separation of the lander from the orbiter on September 2.
All spacecraft parameters are normal, the Bengaluru headquartered space agency said after Sunday's manoeuvre on the spacecraft, that is currently in the lunar orbit for its rendezvous with the Moon.
"The final and fifth Lunar bound orbit manoeuvre for Chandrayaan-2 spacecraft was performed successfully today (September 01, 2019) beginning at 1821 hrs IST as planned, using the onboard propulsion system.
The duration of the manoeuvre was 52 seconds. The orbit achieved is 119 km x 127 km," the Indian Space Research Organisation said in an update.
It said the next operation is the separation of lander 'Vikram' from Chandrayaan-2 Orbiter, which is scheduled on September 2, 2019, between 1245 hrs and 1345 hrs (IST).
Following this, there would be two deorbit manoeuvres of lander 'Vikram' to prepare for its landing in the south polar region of the moon.
Vikram (with rover 'Pragyan' housed inside) is expected to touch down on the lunar surface on September 7, between 1.30 AM and 2.30 am.
ISRO said that after the lander's separation on Monday, two deorbit manoeuvres are scheduled for September 3 (9:00-10:00) and September 4 (3:00-4:00) respectively, before the powered decent on September 7.
ISRO Chairman K Sivan has said the proposed soft-landing on the Moon would be a "terrifying" moment as it is something ISRO has not done before, whereas the Lunar Orbit Insertion manoeuvre was successfully carried out during the Chandrayaan-1 mission.
In a major milestone for India's second Moon mission, the Chandrayaan-2 spacecraft had successfully entered the lunar orbit on August 20 by performing the LOI maneuver.
Chandrayaan-2 satellite began its journey towards the moon,leaving the earth's orbit in the dark hours on August 14, after a crucial manoeuvre called Trans Lunar Insertion (TLI) carried out by ISRO to place the spacecraft on "Lunar Transfer Trajectory".
India's Geosynchronous Satellite Launch Vehicle, GSLV MkIII-M1 had successfully launched the 3,840-kg Chandrayaan-2 spacecraft into the earth's orbit on July 22.
The spacecraft's health is being continuously monitored from the Mission Operations Complex at ISRO Telemetry,Tracking and Command Network in Bengaluru with support from Indian Deep Space Network antennas at Byalalu, near Bengaluru, the space agency has said.
Following the landing, the rover 'Pragyan' will roll out from lander 'Vikram' between 5:30-6:30 am on September 7 and carry out experiments on the lunar surface for a period of one lunar day, which is equal to 14 earth days.
The mission life of the lander is also one lunar day, while the orbiter will continue its mission for a year.
The orbiter carries eight scientific payloads for mapping the lunar surface and study the exosphere (outer atmosphere) of the Moon while the lander carries three scientific payloads to conduct surface and subsurface science experiments.
The rover carries two payloads to enhance the understanding of the lunar surface.
India's second lunar expedition would shed light on a completely unexplored section of the Moon, its South Polar region.
ISRO has said that the mission objective of Chandrayaan-2 is to develop and demonstrate the key technologies for end-to-end lunar mission capability, including soft-landing and roving on the lunar surface.
On the science front, the mission aims to further expand the knowledge about the moon through a detailed study of its topography, mineralogy, surface chemical composition, thermo-physical characteristics and atmosphere, leading to a better understanding of the origin and evolution of the moon, the space agency had said.
#ISRO
— ISRO (@isro) September 1, 2019
The final and fifth Lunar bound orbit maneuver for Chandrayaan-2 spacecraft was performed successfully today (September 01, 2019) at 1821 hrs IST.
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SC criticizes UP govt services commission for questions with ambiguous set of answers
New Delhi: The Supreme Court has slammed the Uttar Pradesh Subordinate Services Selection Commission (UPSSSC) for having set certain questions with ambiguous choices as answers for the Revenue Lekhpal examination for 2021-2022 and has directed the Commission to re-evaluate the answer sheets.
The bench consisting of Justices Sudhanshu Dhulia and K Vinod Chandran has also said that the ambiguity in the answers has affected the outcome for over 8,000 candidates who had competed for 8,085 vacancies, reports LiveLaw.
The judges further resolved the ambiguities in three major questions from Booklet Series B.
The question on the location from where Mahatma Gandhi started the Salt Satyagraha gave options of Dandi, Surat, Sabarmati and Pawnar. The bench pointed out that the site of violation of the salt law was Dandi from a purely technical point of view. The official position in considering it the right answer was correct. The judges added that the Satyagraha commenced from Sabarmati, and therefore could also be considered as correct although not technically so. They said that the candidates who opt for either of the above answers should be given full marks.
The bench also gave directions related to the longest national highway in Uttar Pradesh, stating that, as the numbers had changed with time, two answers could be considered correct. Thirdly, it referred to the eligibility of farmers to get subsidy under the solar photovoltaic irrigation pump scheme and clarified that two answers were correct due to the changes in the policy implemented by the government.
The judges chastised the UPSSSC for the ambiguous and unclear questions it had set and stressed that the lapses proved to be highly disadvantageous for the candidates. They also directed the Commission to award appropriate marks to the affected candidates while protecting those who had been selected, to avoid disruption in the recruitment process.
