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Smooth countdown for ISRO launch of six Singapore satellites

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ISRO's satellites

Chennai: The countdown for the launch of six Singaporean satellites using an Indian rocket Polar Satellite Launch Vehicle (PSLV) is progressing smoothly at the rocket port in Sriharikota in Andhra Pradesh, a senior Indian space agency official said.

“The countdown is progressing smoothly without any hitch. The rocket is slated to blast off at 6 p.m. today (Wednesday) with six Singaporean satellites,” a senior official of Indian Space Research Organisation (ISRO) told IANS. Sriharikota is around 80 km from here.

Apart from launching the six foreign satellites, ISRO will also be testing the rocket’s fourth stage/engine’s ability to restart after it is cut-off around 17 minutes into the flight.

Technically speaking, India will be testing a multiple burn fuel stage/rocket engine for the first time.

“The restart and shut off of the fourth stage engine is done as a first step towards launching multiple satellites but in different orbits,” a senior ISRO official, speaking on the condition of anonymity, told IANS.

Launching of multiple satellites with a single rocket is nothing new for ISRO and it has been doing that for several years. The challenge is, however, to launch several satellites at different orbits with one rocket.

This is what ISRO will be testing after PSLV ejects out six Singaporean satellites on Wednesday.

The PSLV rocket is a four stage/engine rocket powered by solid and liquid fuel alternatively.

“Restarting a rocket engine soon after it is shut off is a critical technology that has to be mastered. Once a rocket engine is activated, then the heat generated is very high. The trick is to cool it down in space and to restart it at a short gap,” an industry expert told IANS.

“This is entirely different from switching on and off the communication satellite’s engines in space. The interval between two restarts of a communication satellite engine will be in days. But in the case of restarting a rocket engine, the time gap will be in hours,” the expert added.

“By that time, the rocket’s engine has to be cooled down. This part of the experiment is very critical,” he explained.

The PSLV’s fourth stage/engine will be restarted just over 67 minutes into the flight or 50 minutes after the engine was cut-off.

At the time of restart, the fourth stage will be in a lower altitude of 523.9 km while the satellites were ejected at 550 km altitude.

The engine will be operated for four seconds and is planned to go up to an altitude of 524 km before the stage will be cut-off again.

On December 16, ISRO will be flying the ‘core alone’ variant of the PSLV rocket. The rocket will not have the strap on boosters, its standard feature.

The successful launch of the six Singaporean satellites will take ISRO’s total flights of foreign satellites to 57.

Out of the six satellites, the 400 kg earth observation satellite called TeLEOS-1 is the main passenger for the PSLV rocket and hence the mission is called TeLEOS mission by ISRO.

TeLEOS-1 is Singapore’s first commercial earth observation satellite designed and developed by ST Electronics.

The other five co-passenger satellites are VELOX-C1 (123 kg), VELOX-II (13 kg), Kent Ridge-1 (78 kg), Galassia (3.4 kg) and Athenoxat-1.

The December 16 mission will be the last rocket launch mission for ISRO in 2015.

So far in 2015, ISRO has launched 14 satellites (three Indian and 11 foreign) from its rocket port in Sriharikota. Thirteen satellites were launched with PSLV rocket and one communication satellite – GSAT-6-with geosynchronous satellite launch vehicle (GSLV).

Last month India also launched its communication satellite GSAT-15 using the Ariane rocket of the European space agency which takes the total number of satellite launches in 2015 to 21 (17 foreign, four Indian).(IANS)

Next Story

Vikram Lander Spotted On Moon

The Vikram moonlander was sent by the Indian Space Research Organisation (ISRO) aboard the Chandraayan 2 that orbited the moon

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India’s Vikram lunar lander
India’s Vikram lunar lander, which crashed on its final approach to the Moon’s surface in September, has been found. Pixabay

BY ARUL LOUIS 

Shanmuga Subramanian, the eagle-eyed citizen space scientist who found Vikram moonlander said on Tuesday that he took spotting it as a challenge when NASA couldn’t.

He said in an email interview to IANS: “It was something challenging as even NASA can’t find out so why can’t we try out? And that’s the thought that led me to search for Vikram lander.”

Subramanian, who works as an information technology architect, in his spare time looked through the images taken by NASA’s Lunar Reconnaissance Orbiter (LRO) camera on September 17 and spotted a debris from Vikram.

Those images were taken when the light during moon’s dusk was very harsh at the place where the moonlander crashed and the long shadows made the hunt for Vikram difficult, NASA and LRO said at that time.

LRO Project Scientist Noah Petro, to whom Subramanian emailed his finding, told IANS: “The story of this really amazing individual (who) found it, helped us find it, is really awesome.”

The Vikram moonlander was sent by the Indian Space Research Organisation (ISRO) aboard the Chandraayan 2 that orbited the moon.

Vikram was launched from Chandrayaan on September 6 in hopes of making a safelanding and exploring the moon’s surface. However, it lost contact with ISRO minutes before the scheduled landing and crashed.

Vikram Moon Lander
A Moon landing is the arrival of a spacecraft on the surface of the Moon. Pixabay

Petro said: “This is the wonderful thing about our data. We released it for the world and anyone can use and he used it to make this discovery.”

Subramanian suggested a crowd-sourced citizen scientist movement to help space organisations.

“LRO’s data is a treasure trove. I would suggest students and others to help out NASA, ISRO and other space organisations by building a good database of LRO images with features like comparison etc.,” Subramanian told IANS.

“Currently we have to compare it manually (and I) wish someone can do more on that, with NASA’s scientists time crunched for their Moon missions,” he added.

Asked how he got interested, Subramanian said: “Space exploration is nothing new for me as I have been interested in space right from the scratch and watched ISRO’s rocket launches closely even managed to capture some of it on my YouTube channel.

“I don’t think Vikram lander would have made a such impact on the minds of the Indian public if it had landed successfully (but) since it was lost there was a lot of discussion in public forums as well as on my Facebook regarding what malfunctioned etc.

“The crash landing of Vikram made more people interested in it and it also got eventually hooked me, which lead to me searching NASA’s pic for nearly some 4-5 hours every night.”

Subramanian spoke of the social media world of space enthusiasts where intense discussions were taking place about the mystery of Vikram and which helped his quest.

“Initially there was lot of false positives I got (that were) corrected by Twitterati and one of the tweets led to me a Reddit forum where they had the exact intended landing location and the path of Vikram,” he said.

Vikram on moon
The Moon is an astronomical body that orbits the Earth as its only permanent natural satellite. Pixabay

On being able to narrow down the area for his search, he said: “Though there was no data available about the path of Vikram lander, I eventually concluded it would have come from North Pole as one of the tweets from ‘cgbassa’ said Vikram has crossed the North Pole of the moon. And from ISRO’s live images, I made out it would have stopped short of around 1 km from the landing spot so it eventually led to me searching around 2 sq km around the landing area.”

That tweet was from CG Bassa, an astronomer with Astron, the Dutch radio astronomy institute.

ALSO READ: Nations and their Moon Missions

After better pictures came from the LRO’s pass over the area in October and on November 11, when the light conditions improved, the LRO camera team scoured the area surrounding the spot where Subramanian had spotted a debris and found the impact spot of Vikram’s crash and other debris, the ASU said.

The impact site is located at 70.8810AoS, 22.7840AoE, at an elevation of 834 metres, it added. (IANS)

2 responses to “Vikram Lander Spotted On Moon”

  1. Before the launch of the Chandrayana 2 mission, I read that the lunar orbiter has the best moon orbiting camera. Form the very beginning of the moon landing failure, I was wondering, why there are no images received from the ISRO lunar module orbiting. All we learned over next many days was about the images taken by NASA orbitor. Just now, statement of ISRO says, ISRO orbitor has located and photographed the failed lander. But most of the news feeds show the photograph of ISRO chief K. Sivan, and not of lunar surface where the lander is found ! Is this science reporting standard of ISRO ?

  2. So what? The lander crashed at the end of the day or night or whatever… Grow up people we have grown out of these cock and bull stories; haven’t we?!