1 ISRO launches PSLV-C55 with two Singapore satellites

Successful take off: PSLV-C55 lifts off from the Satish Dhawan Space Centre, Sriharikota, on Saturday.

The Indian Space Research Organisation’s Polar Satellite Launch Vehicle (PSLV-C55) carrying two Singapore satellites, TeLEOS-2 as primary satellite and Lumelite-4 as co-passenger, took off from the Satish Dhawan Space Centre, Sriharikota, at 2.19 p.m. on Saturday.

According to details provided by ISRO, PSLV-C55 was a “dedicated commercial PSLV mission of NewSpace India Limited (NSIL), for an international satellite customer from Singapore”. TeLEOS-2 carries a Synthetic Aperture Radar payload while Lumelite-4 is a technology demonstration nano-satellite. This is the 57th flight of PSLV and 16th mission using the PSLV Core Alone configuration (PSLV-CA).

After the lift-off, ISRO Chairman S. Somanath said the PSLV-C55/TeLEOS-2 mission was accomplished successfully and placed both satellites in the intended orbit.

The TeLEOS-2 was developed under a partnership between DSTA (representing the Government of Singapore) and ST Engineering, a Singapore firm. Once deployed and operational, it will be used to support the satellite imagery requirements of various agencies of Singapore. TeLEOS-2 will be able to provide all-weather day-and-night coverage, and capable of imaging at 1-metre full-polarimetric resolution, the ISRO said.

Lumelite-4 was co-developed by the Institute for Infocomm Research (I2R) of Agency for Science, Technology and Research (A*STAR) and Satellite Technology and Research Centre (STAR) of the National University of Singapore. It is an advanced 12U satellite developed for the technological demonstration of the High-Performance Space-borne VHF Data Exchange System (VDES). Using the VDES communication payload developed by I2R and STAR’s scalable satellite bus platform, it aims to augment Singapore’s e-navigation maritime safety and benefit the global shipping community.

Incidentally, PSLV-C55 mission will carry out in-orbit scientific experiments by using the spent PS4 stage as an orbital platform. This is the third time that PS4 will be used after satellite separations as a platform for experiments. There will be non-separable payloads mounted on MSA (multi satellite adapter). Payloads will be “powered on” by a command after all satellites are separated. The platform will have solar panels mounted around the PS4 tank which will be deployed after confirmation of the stage achieving stabilisation. The deployment of the solar panels will be through a ground command. The platform will ensure that the deployed solar panel points towards the sun optimally using appropriate sun-pointing mode, which will increase the power generation capability of the platform. The power will be provided to payloads and avionic packages based on their requirements, the ISRO said.

2. Pushkaralu festival returns to the Ganga after a gap of 12 years

Holy dip: People gather to take a bath in the Ganga during the Ganga Pushkaralu Kumbh in Varanasi on Saturday.

The 12-day Pushkaralu festival celebrated by Telugus started in Varanasi on Saturday with the Uttar Pradesh government expecting more than one lakh pligrims to visit the city as part of the event till May 3.

The festival, during which pilgrims worship the Ganga and their ancestors, is being organised in Varanasi after a gap of 12 years.

It is the second event, after the Kashi-Tamil Sangamam, being organised in Varanasi which will witness a large number of South Indians visiting the city.

Many groups of pilgrims arrived on Saturday with special trains scheduled for the festival.

The Varanasi district administration has made arrangements for crowd regulation as well as for facilitating visitors in completing their rituals at the ghats along the Ganga and for offering prayers at the Kashi Vishwanath temple.

“We have done all the necessary arrangements such as drinking water supply, toilets and changing rooms and deployed rescue teams, including divers, a medical team and the police, for crowd regulation. Dedicated teams of sanitary staff will take care of cleanliness works at the ghats between Assi and Dashashwamedh,” said S. Rajalingam, the District Magistrate of Varanasi.

The U.P. government is expecting more than one lakh pilgrims to visit the city for the event

3. Reviving a ‘dead’ river: a cultural event to celebrate legacy of Yamuna

On edge: The Central Pollution Control Board declared the river ‘almost dead’ in 2015. 

IGNCA has been tasked with conducting the festival as a pilot

for a bigger project

The Yamuna, a river that environmentalists consider ecologically dead in Delhi, will now be the focus of a cultural push to renew India’s civilisational and socio-religious connect with its waterbodies.

Come September, the Indira Gandhi National Centre for the Arts (IGNCA) will host a cultural programme on the banks of the river in Delhi, under its special project — Riverine Cultures of India — that began in 2018.

The highlight of the event will be a short festival of films on waterbodies, shot by children from across the country.

The programmes will include a photo exhibition comparing the Yamuna of today with what the river was like 50 years ago; symposia on various aspects such as ecology and conservation of India’s rivers and their importance in the country’s heritage; and an exhibition themed on 15 ghats across the country in Sanjhi or paper stencil art.

The larger project is focusing on six rivers right now: Ganga, Yamuna, and Sindhu in the north; and Krishna, Godavari, and Cauvery in the south. Dates of similar events on the other rivers are not known. The project envisages festivals celebrating rivers in different cities, a study on these rivers in their contemporary context, and workshops along the banks involving environmentalists, cultural historians, anthropologists and folklorists. They hope to develop a major study on riverine cultures, along with one on the mythical river Saraswati to “understand its importance in the evolution of human cultures”.

As of now, festivals have been organised on the banks of the Ganga in Munger (Bihar), Godavari in Nashik (Maharashtra), Krishna in Vijayawada (Andhra Pradesh), and Hooghly in Kolkata (West Bengal).

An effort to reconnect

Sachchidanand Joshi, Member Secretary, IGNCA, said, “We in Indian culture look at rivers very differently. We have an emotional bond with them. In many places rivers are worshipped; there is a regular connect with society. A river influences the socio-cultural life of the entire region, whether it is cropping pattern, festivals, or religious rituals.” He also feels that India is “losing that connect very fast” and this project is an effort to reconnect with rivers.

Sources in the Ministry of Culture said that the government has tasked the IGNCA to conduct the cultural festival as a pilot for a bigger project on the Yamuna.

The Yamuna’s confluence with the Ganga and the mythical Saraswati at Triveni Sangam in Prayagraj is one of the country’s most important pilgrimage spots for Hindus.

However, the river had been declared “almost dead” by the Central Pollution Control Board (CPCB) in 2015 citing untreated waste flowing into it from several cities along its banks.

The definition of a river is that it must have life, which is measured by its capacity to dissolve oxygen. The dissolved oxygen content in the Yamuna as it passes through Delhi is zero.

Environmentalists feel that before recreating a cultural connect, the government needs to take measures to bring the river back to life. “The Yamuna in Delhi is in such a state that letting children do anything on its banks might harm their health,” says Vikrant Tongad, founder, Social Action for Forest and Environment (SAFE), who has worked extensively towards the conservation of the river. He added that the government needs to think of protecting the river’s flood plains before planning any kind of major event there.

4. Microbes at the top of the world

Researchers collected microbial communities in sediment samples left by human climbers on Mt. Everest

An article, Genetic analysis of the frozen microbiome at 7,900 metres above sea level on the South Col of Sagarmatha (Mount Everest), by Dr. N.B. Dragone and others in journalArctic, Antarctic, and Alpine Researchexamines the human microbiota on the inhospitable slopes of Mount Everest.

They were able to collect microbial communities in sediment samples left by human climbers on the South Col of Mount Everest, 7,900 metres above sea level (msl).

The South Col is the ridge which separates Mt. Everest from Lhotse — the fourth highest mountain on earth. The two peaks are only three kilometres apart. At 7,900 msl, the South Col is rather inhospitable — a heat wave in July 2022 led to a record high temperature of minus 1.4 degree Celsius.

Barring humans, visible signs of life have been left behind. The last visible residents are seen at 6,700 msl — a few species of moss and a jumping spider that feeds on frozen insects carried by the wind.

At high altitudes, there is low oxygen (7.8% against 20.9% at sea level), strong winds, temperature usually below minus 15 degree Celsius, and high levels of UV radiation. All these make life processes difficult. And as there is an interdependence among species of all sizes in all ecosystems, even microbes cannot sustain themselves.

Wind and humans

But microbes keep arriving, carried by either birds, animals, or winds. Up to about 6,000 msl, dust particles, less than 20 micrometre in diameter, are blown in by the winds. Some of this dust originates in the Sahara Desert, which explains why a wide range of microflora are found at these altitudes. Above 7,000 msl, it is mostly winds and humans that act as carriers.

Using sophisticated methods such as 16S and 18S rRNA sequencing, the microbe hunters were able to identify the bacteria and other microorganisms found on the South Col.A cosmopolitan human signature is seen in the microbes collected here. Also found aremodestobacter altitudinisand the fungus,naganishia, which are known to be UV-resistant survivors.

Who gave the name ‘sagarmatha’ to Mt. Everest? Nepal’s eminent historian, late Baburam Acharya, gave it the Nepali name, sagarmatha, in the 1960s.

Kangchenjunga peak

In 1847,Andrew Waugh, British Surveyor Generalof India, found a peak in the eastern end of the Himalayas which was higher than the Kangchenjunga — considered as the highest peak in the world at that time. His predecessor, Sir George Everest, was interested in high-altitude hills and had deputed Waugh to take charge. In true colonial spirit, Waugh called it the Mount Everest.

The Indian mathematician and surveyor, Radhanath Sikdar, was an able mathematician. He was the first person to show that Mount Everest (then known as peak XV) was the world’s highest peak.

George Everest had appointed Sikdar to the post of ‘Computer’ in the Survey of India in 1831.

In 1852, Sikdar, with the help of a special device, recorded the height of ‘Peak 15’ at 8,839 metres. However, it was officially announced in March 1856.

5. Seven worst years for polar ice melting in past decade: study

Scientists report that the seven worst years for polar ice sheets melting and losing ice have occurred during the past decade, with 2019 being the worst year on record.

Combining 50 satellite surveys of Antarctica and Greenland taken between 1992 and 2020, the international team of researchers have found that the melting ice sheets now account for a quarter of all sea level rise, a fivefold increase since the 1990s.

The findings of the team, led by the Northumbria University’s Centre for Polar Observations and Modelling, U.K., were published in the journal, Earth System Science Data.

In their study, the researchers found that earth’s polar ice sheets lost 7,560 billion tonnes of ice between 1992 and 2020, which is equivalent to an ice cube that would be 20 km in height.

They also found that the polar ice sheets have together lost ice in every year of the satellite record, and the seven highest melting years have occurred in the past decade.

Melting year

The satellite records showed that 2019 was the record melting year when the ice sheets lost a staggering 612 billion tonnes of ice.

They said that the loss, driven by an Arctic summer heatwave, led to record melting from Greenland peaking at 444 billion tonnes that year.

Antarctica was found to have lost 168 billion tonnes of ice, the sixth highest on record, due to the continued speedup of glaciers in West Antarctica and record melting from the Antarctic Peninsula.

The East Antarctic ice sheet was found to remain close to a state of balance, as it had throughout the satellite era.

Melting of the polar ice sheets has found to cause a rise of 21 millimetre (mm) in global sea level since 1992, almost two thirds, or 13.5 mm, of which has originated from Greenland and one third, or 7.4 mm, from Antarctica.

Fivefold increase

The researchers say that there has been a fivefold increase in melting since the early 1990s. While ice sheet melting accounted for only a small fraction (5.6% of sea level rise), they are now responsible for more than a quarter (25.6% of all sea level rise).

“After a decade of work, we are finally at the stage where we can continuously update our assessments of ice sheet mass balance as there are enough satellites in space monitoring them,” said Andrew Shepherd, head of the Department of Geography and Environmental Sciences, Northumbria University.