Revision as of 21:19, 22 October 2018

Chandrayaan 1

Decision making process of Chandrayaan- I
From: Chethan Kumar, India’s tryst with Moon: 10 years and two missions, October 21, 2018: The Times of India

See graphic:

Decision making process of Chandrayaan- I

'Lost' in 2009; NASA finds it orbiting Moon in 2017

Srinivas Laxman, Chandrayaan-1 found by Nasa after 8 years, March 11, 2017: The Times of India

Eight years after it was considered “lost“, India's first lunar spacecraft, Chandrayaan-1, has been “re-discovered“ by Nasa's ground-based radars, the American space agency announced.

Chandrayaan-1, launched on October 22, 2008, was credited with the first discovery of water on the moon on November 14. After that, it suddenly lost communication with Isro ground stations on August 29, 2009 due to a technical problem. Speculation was rife at Isro then that it had crashed on the moon.

But nine years since its launch, a new radar technology pioneered by scientists at Nasa's Jet Propulsion Laboratory (JPL) was put into place to trace Nasa's Lunar Reconnaissance Orbiter and Chandraya an-1. “This technique could assist planners of future moon missions,“ Nasa said.

JPL's orbital calculations indicated that Chandrayaan-1 was still circling 200km above the lunar surface. The father of India's moon mission, Krishnaswamy Kasturirangan, told TOI, “To be declared lost and then found after eight years is a great accomplishment.“ Chandrayaan-1 was our first interplanetary mission, and I am delighted that it has been found,“ Kasturirangan said.

According to Nasa, the main challenge in detecting Chandrayaan-1 was on account of its size; the spacecraft is very small, a cube of about 1.5 metres on each side -about half the size of a smart car. It has not been transmitting signals.

According to Nasa, to find the spacecraft 3.80 lakh km away , the Jet Propulsion Laboratory (JPL) team used its 70-metre antenna at the Goldstone Deep Space Communications Complex in California.

A powerful beam of microwaves was directed towards the moon. The radar echoes then bounced back from the lunar orbit, which were received by the 100-metre Green Bank telescope in West Virginia in the US, Nasa said.

The radar team utilised the fact that Chandrayaan-1 is in polar orbit around the moon. So, it would always cross above the lunar poles on each orbit. On July 2, 2016, the team pointed Goldstone and Green Bank at a location 160km above the moon's north pole and waited to see if Chan drayaan-1 crossed the radar beam. Chandrayaan-1 was predicted to complete one orbit around the moon every two hours and eight minutes. Nasa said that the timing of the detections matched the time it would take for Chandrayaan-1 to complete one orbit and return to the same position above the moon's pole.

Help in creation of first global map of water in Moon's soil

India's Chandrayaan-1 helps scientists map water on Moon, Sep 14, 2017: The Times of India

HIGHLIGHTS

The water concentration reaches a maximum average of around 500 to 750 parts per million in the higher latitudes

NASA's Moon Mineralogy Mapper flew aboard India's Chandrayaan-1 spacecraft

Although the bulk of the water mapped in this study could be attributed to solar wind, there were exceptions

NEW YORK: Using newly-calibrated data taken from NASA's Moon Mineralogy Mapper, which flew aboard India's Chandrayaan-1 spacecraft, scientists have created the first global map of water in the Moon's soil.

The study, published in the journal Science Advances, builds on the initial discovery in 2009 of water and a related molecule - hydroxyl, which consists of one atom each of hydrogen and oxygen - in lunar soil.

"The signature of water is present nearly everywhere on the lunar surface, not limited to the polar regions as previously reported," said the study's lead author Shuai Li, who performed the work while a PhD student at Brown University in Providence, Rhode Island, US.

"The amount of water increases toward the poles and does not show significant difference among distinct compositional terrains," Li, now a postdoctoral researcher at University of Hawaii, added.

The water concentration reaches a maximum average of around 500 to 750 parts per million in the higher latitudes. That is not a lot - less than is found in the sands of Earth's driest deserts - but it is also not nothing.

"This is a roadmap to where water exists on the surface of the Moon," study co-author Ralph Milliken, Associate Professor at Brown University said.

"Now that we have these quantitative maps showing where the water is and in what amounts, we can start thinking about whether or not it could be worthwhile to extract, either as drinking water for astronauts or to produce fuel," Milliken said.

The way the water is distributed across the Moon gives clues about its source, the researchers said. The distribution is largely uniform rather than splotchy, with concentrations gradually decreasing toward the equator, the study said. That pattern is consistent with implantation via solar wind - the constant bombardment of protons from the Sun, which can form hydroxyl and molecular water once emplaced.

Although the bulk of the water mapped in this study could be attributed to solar wind, there were exceptions. For example, the researchers found higher-than-average concentrations of water in lunar volcanic deposits near the Moon's equator, where background water in the soil is scarce.

Rather than coming from solar wind, the water in those localised deposits likely comes from deep within the Moon's mantle and erupted to the surface in lunar magma. The study also found that the concentration of water changes over the course of the lunar day at latitudes lower than 60 degrees, going from wetter in the early morning and evening to nearly bone dry around lunar noon.

The fluctuation can be as much as 200 parts per million. As useful as the new maps may be, they still leave plenty of unanswered questions about lunar water. The Moon Mineralogy Mapper, which supplied the data for the research, measures light reflected off of the lunar surface. That means that it can't look for water in places that are permanently shadowed from the sun's rays.

Many scientists think these permanently shadowed regions, such as the floors on impact craters in the Moon's polar regions, could hold large deposits or water ice. "Those ice deposits may indeed be there, but because they are in shadowed areas it's not something we can easily confirm using these data," Milliken said.

Nasa probe finds water distributed across lunar surface

Srinivas Laxman, Water distributed across lunar surface: Nasa probe on Chandrayaan-1, February 26, 2018: The Times of India

An analysis of data from India’s first mission to the moon, Chandrayaan-1, and Nasa’s Lunar Reconnaissance Orbiter (LRO) has found evidence that the moon’s water is distributed across the lunar surface and not confined to a particular region or type of terrain as stated earlier.

The water appears to be present day and night, though it’s not necessarily easily accessible, said Nasa in a statement. The space agency added that they derived the conclusion after obtaining data from a diviner instrument on the LRO. Nasa has stated that the new data was obtained from the diviner instrument on LRO. “The team applied this temperature model to data gathered earlier by the moon mineralogy mapper, a visible and infrared spectrometer that NASA’s Jet Propulsion Laboratory in Pasadena, California, provided for India’s Chandrayaan-1 orbiter,” it has stated.

“The findings could help researchers understand the origin of the moon’s water and how easy it would be to use as a resource. If the moon has enough water, and if it’s reasonably convenient to access, future explorers might be able to use it as drinking water or convert it into hydrogen and oxygen for rocket fuel or oxygen to breathe,” reads the statement.

The results contradict some earlier studies, which had suggested that more water was detected at the moon’s polar latitudes and that the strength of the water signal waxes and wanes according to the lunar day (29.5 Earth days). “We find that it doesn’t matter what time of the day or which latitude we look at, the signal indicating water always seems to be present,” said Joshua Bandfield, a senior research scientist with the Space Science Institute in Boulder, Colorado, and lead author of the new study published in Nature GeoScience.

Chandrayaan-1 device finds ice on moon surface

Chandrayaan-1 device found ice on moon surface: Nasa, August 22, 2018: The Times of India

Scientists have confirmed the presence of frozen water deposits in the darkest and coldest parts of the moon’s polar regions using data from the Chandrayaan-1 spacecraft, which was launched by India 10 years ago, Nasa said on Tuesday.

With enough ice within the top few millimetres of the surface, water would possibly be accessible as a resource for future expeditions to explore and even stay on the moon, and potentially easier to access than water detected beneath the surface. The ice deposits are patchily distributed and could be ancient, according to a study published in the journal PNAS.

The scientists used data from Nasa’s moon mineralogy mapper, an instrument carried on Chandrayaan-1, to identify three specific signatures that definitively prove the presence of ice. Learning more about it will be a key focus for Nasa and its commercial partners.

Chandrayaan 2

History

Chethan Kumar, India’s tryst with Moon: 10 years and two missions, October 21, 2018: The Times of India

At 6.22am on October 22, 2008, the PSLV carrying Chandrayaan-1 roared into the sky paving the way for the future of India’s endeavours for planetary exploration. And, on November 8 that year, Chandrayaan-1 reached the polar orbit around the Moon.

M Annadurai, called the Moon-man of India recollects: “On November 14, in the presence of then Indian President APJ Abdul Kalam, we commanded a tiny Moon Impact Probe (MIP) to detach from the mother craft targeting to touch down the moon after 27 minutes of flight into the atmosphere of the moon. While climbing down to the lunar surface one of the science equipment onboard the MIP, namely CHACE— a mass spectrometer—started indicating the presence of water (vapour) in the moon’s atmosphere.”

The signal then got more pronounced when the probe was going nearer to moon’s surface. The presence of water near moon was considered to be sourced from the lunar surface. So remaining instruments on board Chandrayaan-1 mother craft were programmed to look for presence of water on the Lunar surface. Untitled design (96)

The search was for the entire surface of the moon. Accordingly Chandrayaan-1 paved the way for deriving Lunar Map with water resources (see pic). “Discovery of ice on the poles of the moon is also credited to the Chandrayaan-1. When another set of International Scientists used Chandrayaan-1 data for their research again the claim was once again got confirmed,” Annadurai said.

Chandrayaan-1 received three international awards , one each for Discovery of water on the moon, Spacecraft Design and compact accommodation of 11 Science instruments and the very high level of international co-operation that paved the way for new wave in planetary exploration.