Category Astronomy

What is the role of ISRO in space technology?

The ISRO works to develop and apply space technology in various sectors of our economy.

The Indian Space Research Organisation (ISRO) and the Indian Navy continue to conduct important trials for the Gaganyaan mission. However, do you know what ISRO is?

Organisation

 The ISRO is India's space agency that was established on August 15, 1969.

Previously known as the Indian National Committee for Space Research (INCOSPAR), it was envisioned by Vikram Sarabhai, who helped develop nuclear power in India and is considered one of the founding fathers of Indian space programme. ISRO is a major constituent of the Department of Space (DOS), Government of India.

The department executes the Indian Space Programme primarily through various centres or units within the ISRO.

Works

The ISRO works to develop and apply space technology in various sectors of our economy. It has established major space systems for communication, television broadcasting, and meteorological services.

ISRO's first satellite, Aryabhata, was launched by the Soviet Union on April 19, 1975. Meanwhile, Rohini, the first satellite to be placed in orbit by an Indian-made launch vehicle, was launched on July 18, 1980. It has developed satellite launch vehicles, PSLV (Polar Satellite Launch Vehicle) and GSLV (Geosynchronous Satellite Launch Vehicle), to place the satellites in the required orbits.

These rockets have launched communications satellites and Earth-observation satellites as well as missions to the Moon and Mars – Chandrayaan-1, 2008; Chandrayaan-2, 2019; and Mars Orbiter Mission (MOM), also called Mangalyaan, 2013.

ISRO has launched several space systems, including the Indian National Satellite (INSAT) system for telecommunication, television broadcasting, meteorology, and disaster warning and the Indian Remote Sensing (IRS) satellites for resource monitoring and management. The first INSAT and IRS satellites were launched in 1988.

While ISRO's headquarters is in Bengaluru, the launch vehicles are built at the Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram. Launches take place at the Satish Dhawan Space Centre on Sriharikota Island, near Chennai.

ISRO's chief executive is a chairman, who is also chairman of the Indian government's Space Commission and the secretary of the Department of Space. Its current Chairman is S. Somnath.

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A test flight with a number of firsts

The 1960s were a rather exciting time if you were part of NASA. After U.S. President John F. Kennedy stated his goal of landing humans on the moon and returning them safely home before the end of the decade of the 1960s, work at NASA progressed at breakneck speed given the enormity of the task ahead of them.

There were a lot of successes along the way, and setbacks too that proved to be equally important in terms of the overall learning. The Apollo-Saturn (AS) 201 mission in the mid 1960s was one such test flight that had a number of firsts, but also experienced malfunctions.

"All-up" philosophy

Coming at the height of Project Gemini, the AS-201 served as a crucial milestone in our march towards the moon. It used the "all-up" philosophy, according to which all components of a system were tested in a single first flight.

A suborbital test flight, its goals included demonstrating the Saturn IB's capabilities, the operation of Apollo Service Module's (SM) main engine, and determining the effectiveness of the Command Module's (CM) heat shield. The Saturn IB rocket, which was built on the 10 successful launches of Saturn 1 rocket, was the most powerful rocket up to that time.

Construction of the AS-201 spacecraft began in 1963 at the North American Aviation (NAA) plant in California. Assembly for the mission began in 1965 with the Saturn IB first stage arriving at the Cape Kennedy Air Force Station (CKAFS), now the Cape Canaveral Space Force Station, on August 14.

Extensively tested

The CM and SM of the spacecraft arrived within two days of each other in October. After successful mating of the two modules and extensive testing, they were trucked to the launch pad and stacked on top of the rocket by December. By January 1966, the final pieces were in place, and the rocket and spacecraft were declared ready for its mission after a flight readiness review and a countdown demonstration.

On February 26, 1966, the AS-201 mission lifted off after a number of launch delays. With flight director Glynn S. Lunney at the helm, a team of engineers kept an eye on all aspects of the mission.

Both stages of the Saturn IB rocket performed well and the Apollo Command and Service Module (CSM) was placed in its suborbital trajectory, with a peak altitude of 488 km. A camera mounted inside the first stage was later recovered at sea, and it had captured some key moments, including the fiery stage separation.

Helium ingestion in propellant lines, however, resulted in lower thrust than predicted during the first burn and the same problem also affected a second burn to test the engine's restart capability. The Service Propulsion System engine also underperformed, meaning the CM entered the atmosphere at a velocity slower than that planned.

Additionally, the capsule rolled during reentry as an electrical fault in the CM led to a loss of steering. The heat shield performed its duties without any flaws despite all these setbacks and the spacecraft splashed down in the Atlantic Ocean, 75 km from the intended target.

On museum display

The largely successful 37-minute test flight travelled 8,472 km overall. The CM was retrieved by swimmers from the prime recovery ship and it was then sent to the NAA plant for postflight inspections. After using it for land impact tests, NASA donated the capsule, which is now on loan and is displayed at the Strategic Air Command and Aerospace Museum.

The Saturn IB is now largely forgotten as its efforts pale in comparison with the Saturn V rocket, one of the largest and most powerful rockets built and which successfully sent people to the moon. But the Saturn IB rocket and the AS-201 mission were all part of the small stepping stones that made the giant leap possible.

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Who was Maria Mitchell?

The astronomer is best known for her discovery of a comet, which later came to be known as ‘Miss Mitchell’s Comet.

Maria Mitchell was the first professional female astronomer in the United States. She is best known for her discovery of a comet, which later came to be known as ‘Miss Mitchell’s Comet

Maria Mitchell was born in 1818 in Nantucket, Massachusetts. Her father was a school principal and an amateur astronomer who helped her develop interest in science and astronomy at an early age. Maria would spend hours observing the night sky through a telescope and help her father in such calculations as predicting annual eclipses. Through her jobs as a teacher and later as a librarian, Maria Mitchell kept her passion for astronomy alive. Her success in establishing the orbit of a new comet in 1847 gained her international repute. She received a gold medal from the King of Denmark for this discovery.

Later, she took up a job as professor of astronomy at Vassar College in New York. Mitchell and her students continuously tracked and photographed sunspots. She was the first to find that sunspots were whirling vertical cavities and not clouds, as had been earlier believed. In 1882, she documented Venus traversing the sun-one of the rarest planetary alignments known to man.

Maria Mitchell was also a well-known proponent of equal rights-she fought relentlessly for women as well as for blacks. The school that she started admitted black children at a time when segregation was common in the US. At Vassar College, she demanded and got equal pay when she realised that her junior male colleagues were paid more.

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When was the third human landing on the moon?

On February 5, 1971, Apollo 14 made a successful landing on the lunar surface, thereby becoming the third human landing on the moon after Apollo 11 and Apollo 12.

When we talk about the Apollo programme, it is often hard to look beyond the Apollo 11 mission, which achieved the distinction of landing the first humans on the moon. Even though the Apollo programme is best remembered for this, it should also be noted that it provided for innumerable demonstrations of ingenuity and problem solving and increased NASA’s expertise by leaps and bounds.

Following the success of Apollo 11 in July 1969, Apollo 12 landed humans on the moon in November 1969. Apollo 13, however, had to be aborted following an oxygen tank explosion in the service module.

This meant that the Fra Mauro Formation, originally planned to be the lunar landing site for Apollo 13, served as the landing site for Apollo 14, once NASA had completed an accident investigation and upgraded the spacecraft.

Shepard, Mitchell, and Roosa

Launched on January 31, 1971, Apollo 14 had a three-member crew that included commander Alan Shepard, lunar module pilot Edgar Mitchell, and command module pilot Stuart Rossa. Even though there was a potential short circuit in an abort switch on the lunar module and the landing radar came on very late during the landing sequence, Shepard and Mitchell successfully landed on the lunar surface on February 5. In fact, it was the most precise landing until then, as they landed less than 100 feet from the targeted point.

Shepard and Mitchell spent over 33 hours on the moon, including two extra vehicular activities (EVAS) that spanned nine hours and 23 minutes. Even though the first of the two EVAS began an hour later than scheduled due to communications systems problems, it turned out to be a success.

Modular Equipment Transporter

The first EVA was mainly to deploy a number of experiments and some of these sent back data to Earth until September 1977. While a seismometer detected thousands of moonquakes and helped find out the moon’s internal structure, other instruments looked at the composition of solar wind and the moon’s atmosphere.

Apart from the safety upgrades that were done for Apollo 14, there was also the addition of the Modular Equipment Transporter (MET). While Apollo 11 astronauts carried their tools by hand and Apollo 12 astronauts used a hand tool carrier, Shepard and Mitchell could employ the MET like a wheelbarrow, stowing away their scientific equipment, tools, camera, and sample collections.

During the duo’s second EVA dedicated to explore the Cone Crater, the MET came in handy as they were able to pick up a football-sized rock, designated 14321, but better known by its nickname “Big Bertha”. Using the MET, the astronauts were able to transport this sample back to the lunar module. As recently as 2019, studies suggested that a two-cm sliver of the Big Bertha might have originally come from the Earth’s crust, and not the moon.

42 kg of samples

Even though the crew never saw the interior of the crater, post-mission comparisons showed that Shepard and Mitchell were within 50-75 m from the crater rim. The round trip lasted four hours and 35 minutes in which the duo traversed nearly 3 km, including samples from the first EVA, the duo had collected 42 kg of lunar samples.

While Shepard and Mitchell were busy on the lunar surface, Roosa, who was in the command module, clicked many pictures in high resolution. These photographs of the moon’s Descartes region played a pivotal role in certifying the area’s safety as a landing site and even helped plan rover traverses for the Apollo 16 mission.

Liftoff from the lunar surface took place exactly on schedule, while rendezvous and docking with the command module was just two minutes off schedule. After spending 2.8 days in lunar orbit, during which time the command module had circled the moon 34 times, the Apollo 14 crew members headed back to Earth. They splashed down safely in the Pacific Ocean on February 9, exactly nine days and two minutes after launch.

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What was the Mercury space capsule project?

On June 11, 1963, the Mercury space capsule was patented and assigned to NASA. The patent was received less than a month after the last flight of Project Mercury had been carried out.

Receiving a patent generally signals a major milestone. As an exclusive right granted for an invention, be it a product or a process, it usually denotes a new way of doing something, thereby becoming important. In the case of the Mercury space capsule, however, the patent came closer to the end.

Project Mercury was conceived as a NASA programme to put the first American astronauts in space. Named after a Roman god who was very fast, the project notched up many successes. At the centre of this success was the Mercury space capsule.

“Space capsule”

The principal designer of the Mercury spacecraft was Maxime Faget, a mechanical engineer who also contributed to the designs of the Gemini and Apollo spacecraft. Faget, along with Andre Meyer, Robert Chilton, Willard Blanchard Jr., Alan Kehlet, Jerome Hammack and Caldwell Johnson filed for a patent titled “Space capsule” on October 16, 1959.

In this patent application, they described their invention relating to space vehicles as a “manned capsule configuration capable of being launched into orbital flight and returned to the Earth’s surface.”

Additionally, it was capable of providing “protection for its occupant from the deleterious effects of large pressure differentials, high temperatures, micrometeorite collisions, high level acoustical noise, and severe inertial and impact loads.”

Not cosy

It did all that, but the capsule was a rather small one, with room for just one astronaut. What’s more, this astronaut had to stay seated throughout the flight. While there was very little room for even the single seated astronaut to make any movements, it was argued that not much was required as the pilot would only need to move his arms and head, and was to never leave the spacecraft during flight.

Following uncrewed flights and those with primates as part of Project Mercury, the first crewed flight took place on May 5, 1961. Alan Shepard made the first crewed Mercury flight in a capsule that he named Freedom 7. The 15-minute flight that went into space and came back down made him the first American in space.

Between 1961 and 1963, there were six successful flights as part of Project Mercury that showed that Americans could fly in space. While two of these flights were suborbital flights (reached space and came right back down), the other four made it into orbit and circled our Earth.

Every time the Mercury spacecraft re-entered the Earth’s atmosphere, the blunt end came in first to not only slow down the spacecraft, but also shed the heat caused by friction with the air during the descent. With layers of heat resistant ablative resins coating the curved heat shield, it charred away to minimise structural heating, preventing damage to the spacecraft, and of course, protecting the crewman.

The last of the six successful crewed Mercury Project spaceflight took place on May 15, 1963. Each of these flights lasted from 15 minutes to 34 hours, with most lasting less than nine hours.

Just a formality

This meant that by the time the patent for the Mercury capsule was awarded on June 11, 1963, it had already been put to use multiple times successfully, with each of the successes celebrated by an entire country. The patent, which was assigned to NASA, was merely a formality.

In fact, NASA retired the Mercury capsule in the same week in which the patent was awarded. The first manned space vehicle of the U.S. was retired with honours of course, having been central to a project that came at the height of the space race between the U.S. and the Soviet Union.

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When was the last human expedition to the moon?

On December 11, 1972, Apollo 17 achieved lunar landing. The sixth mission in the Apollo program to explore the lunar surface, Apollo 17, for now, is the last human expedition to the moon.

Apollo 11 will forever be remembered as the mission which enabled human beings to set foot on the moon, our natural satellite, for the first time. While the first will always remain the the same cannot be said for what is the last such mission, as future missions might take that place. But for the time being, Apollo 17 remains the last human expedition to the moon.

After the success of Apollo 11 in 1969, there were six more Apollo missions to the moon, five of which were successful. As U.S. President John F. Kennedy’s objective of landing humans on the moon had been achieved, NASA faced funding cuts. Technology and research-based missions weren’t seen as important as the landing itself, forcing NASA to cancel some of the planned missions in 1970. As a result, the Apollo 17 mission of 1972 became the last manned mission to the moon.

Firsts and records

Apollo 17 was a 12-day mission that spanned from December 7-19. Apart from the distinction of being the last human expedition to the moon for now, Apollo 17 also achieved a number of firsts and broke some records. It had the then longest space walk and enabled the collection of the largest lunar samples brought back to Earth. It was the first Apollo mission to be launched at night and allowed a scientist to walk on the moon for the first time.

The scientist in question was Harrison H. Schmitt, a geologist who had been part of the backup crew for Apollo 15. Schmitt was originally scheduled to go on Apollo 18, which was cancelled. The scientific community lobbied for Schmitt’s inclusion in Apollo 17. While Schmitt served as the pilot of the lunar module “Challenger”, Eugene A. Cernan was commander and Ronald E. Evans was the pilot of “America”, the command module.

Following a successful night launch on 7, Apollo 17 achieved lunar orbit insertion on December 10. Then, with Evans orbiting the moon, Cernan and Schmitt flew Challenger and landed on the moon’s surface on December 11, touching down within 200 m of the targeted landing point.

Two primary objectives

Apollo 17’s two primary objectives were to obtain a specific sample and to explore geologically recent, explosive volcanism. The former was achieved as they retrieved the oldest known unshocked (unaltered by meteoric impact) rock from the moon. This sample, called Troctolite 76535, is believed to be at least 4.2 billion years old.

The second objective was met as Schmitt discovered orange soil near Shorty crater. This colour was the result of orange and black volcanic glass that had formed in the type of volcanic eruption that is referred to as “fire fountain” on Earth.

Cernan and Schmitt were on the lunar surface for 75 hours, the longest till now. They clocked 22 hours of extravehicular activity (EVA) with the help of their rover and travelled about 36 km. They went as far as 7.4 km away from the Challenger, close to the limit of what was considered the walk-back distance possible, should the rover have failed. Apart from conducting various experiments, they took over 2,000 photographs and collected 110 kg worth of soil and rock samples from 22 different sites.

Last man on the moon

Following the third and final EVA, the duo televised the unveiling of a plaque with a message, which they left on the moon. On December 14, Cernan took humankind’s final step, to date, off the moon.

After lifting off from the moon, the Challenger was docked with America on December 15. Four days later, on December 19, the Apollo 17 capsule splashed down in the Pacific Ocean at a distance of 6.5 km from the recovery ship, after a mission elapsed time of 301 hours.

For 50 years, Cernan has often been referred to as the last man on the moon. With NASA’s Artemis program aiming to return to the moon and even set up a sustained human presence, it might not be long before the next human being sets foot on the moon.

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