Indian Space Program: News & Discussions

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Gautam said:
This startup founded by IIT alumni wants to become the ‘Jio’ of satellite communication

Bengaluru-based Astrogate is working on technology that will make it easier for small satellites to send more data to earth stations at a faster speed than before. It hopes to change the face of space communication much like Jio changed the face of internet access in India.

Krishna Reddy
7th May 2019

Between now and 2027, the world will launch about 7,000 small satellites – that’s six times as many as we launched in the past decade. Small satellites are in fashion, so to speak, mainly because they are cheaper and faster to launch than their larger counterparts. Many of these are used to enhance internet connectivity in remote areas on Earth or study our planet’s climate.

The main purpose of such satellites is to collect and transmit data for researchers to analyse and work on. The sooner they get the data, the better. But that’s easier said than done. Because the satellites are small, they cannot transmit large amounts of data, and definitely not at high speeds.

The bigger problem, however, is that most ground stations (on Earth) are not equipped with the required hardware to receive large amounts of data sent by small satellites.​

This is where Astrogate, a Bengaluru-based startup set up by IIT alumni Nitish Singh and Aditya Kedlaya comes in. Astrogate works in the area of optical communication and using that technology, has developed a device that helps small satellites send more data to ground stations or communicate better with nearby satellites - a space-to-ground link that functions as a low-cost optical communication solution.

The flight optical terminal device measures just 1U (U is a unit of measurement used, among other things, to measure payloads onboard satellites).

Co-founder and Director Nitish Singh explains,

“You need a faster mode of connection, which can send and receive data in a short span of time among the group of satellites in space (a ‘smallsat constellation’) or from satellites (in orbit) to ground stations. Here, the idea is to use laser as a mode of sending and receiving data with the help of optical communication, rather than using the conventional method.”​

Given its size, the device can be fitted on any small satellite. More importantly, it can receive data at a speed of 150 mbps if fitted at a ground station. This is 10x faster than existing hardware.

When coupled with amateur telescopes used to view planets in space, or when coupled with an optical modem, the transmitter can send data at a speed of 150 mbps.

Nitish further explains,

“In space, small satellites are present in low earth orbit (LEO) and geostationary earth orbit (GEO). Now, satellites are in motion in LEO whereas in GEO, the satellites are stationary or motionless with respect to the Earth. We are developing an (optical communication) device that can be used in both, and measures 1U.”​

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Prototype optical communication terminals by Astrogate

The system works on a simple fundamental, it has two ends, one end sends the message and the other end receives it. Similarly, a satellite has a transmitter (sender) on it and a receiver on the ground station on earth to receive the data it sends.

Roots in space(tech)

The startup traces its origins back to another space-tech company which has been in the news for what was quite literally a ‘moonshot’ endeavour – Team Indus. That startup, founded in 2011, was in the news for being the only Indian company shortlisted for Google’s Lunar XPrize instituted in 2007.

Sadly, the XPrize was scrapped in 2018 when none of the shortlisted teams was deemed ready for the trip to the moon. Since then, Team Indus has become part of an American consortium shortlisted by NASA to fly scientific and commercial cargo to the moon in the next decade or so.

Nitish (28) and Aditya (29) were both a part of Team Indus. Nitish, an aerospace engineering graduate from IIT-Kharagpur, led Mission Planning and Operations team and oversaw systems engineering for the XPrize mission. Aditya, who is an alumnus of IIT-Guwahati, was working on its thermal design and analysis aspects.

It was during this time that Nitish zeroed in on the problems in space communication infrastructure and began thinking about how it could be improved.​

In late 2017, the duo left Team Indus to work on solutions in the space communication sector. To get some guidance and expertise initially, Astrogate participated in the cohort accelerator programme organised by the LightSpeed Innovations in the US that year.

“In 2018, we began working on our prototype, which succeeded as we were able to send and receive data through an optical communication set up on ground. Later, we moved onto low-altitude UAV (unmanned aerial vehicles, aka drones) trials. These tests are more representative of how the satellites in motion will acquire the ground terminal and send data on optical links.”​

A key challenge related to stable pointing. The laser beam, directed from the transmitter, proved to be too small to be detected correctly. It was crucial that this problem be solved because it is the laser that establishes the link between a receiver and a transmitter. Nothing short of pinpoint accuracy would work.

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Nitish (extreme left) with Aditya (second from the right) and his team members

To counter this issue, the duo developed a system to track laser beams sent from the transmitter onboard the satellite.

As Aditya explains,

“We made sure the transmitter and receiver are in place on ground and won’t move even if an earthquake occurs. By the end of 2018, we achieved technological readiness by completing numerous tests and trials to test for link distances and tracking systems.”​

Once the pointing system was perfected, Astrogate received interest for carrying out operational trials for high-speed connectivity in rural and remote areas in India. (The founders said they were not at liberty to disclose who they are working with on this.)

With prototype testing completed, the team of eight at Astrogate has started work on the flight model and qualification plan. The founders believe that their first module will be ready for flight by March 2020.

Next on the anvil is to get satellites to communicate better with each other. But that’s another story.​


This startup founded by IIT alumni wants to become the ‘Jio’ of satellite communication
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Plenty of IIT Kharagpur startup these days, my close friend is also from Aerospace and was on Team Indus, now he started a different startup completely delinked from Aerospace and already a multi-million dollar company. They have a very strong alumni network and connections that can float any startup. Another one from same college same batch is now the owner of Indias most/best rated news app defeating likes of Toi and The Hindu while starting it in the incubator of ToI in Noida itself. Glad to see so much enthusiasm for space in younger ones, taking courageous decisions, one of them will topple Musk someday.
 
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BlackOpsIndia said:
Plenty of IIT Kharagpur startup these days, my close friend is also from Aerospace and was on Team Indus, now he started a different startup completely delinked from Aerospace and already a multi-million dollar company. They have a very strong alumni network and connections that can float any startup. Another one from same college same batch is now the owner of Indias most/best rated news app defeating likes of Toi and The Hindu while starting it in the incubator of ToI in Noida itself. Glad to see so much enthusiasm for space in younger ones, taking courageous decisions, one of them will topple Musk someday.
Click to expand...
Do let me know some of the names of the start-ups. Sounds very interesting.
 
India aims for 1st landing near moon’s south pole

Posted by Paul Scott Anderson in Space | May 10, 2019

The moon’s south pole has never been explored from the ground, but India’s new Chandrayaan-2 mission will attempt a 1st-ever landing there, with a rover, this September.

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Artist’s concept of Chandrayaan-2 approaching the moon. If all goes well, a lander and rover will land near the lunar south pole in September of this year. Image via India Today.

So far, only three countries have successfully landed on the moon – the United States, the former Soviet Union and China – but that might change soon, if all goes according to plan. India is preparing to launch its second lunar mission this summer, and this time the goal is to actually land on the surface, near the moon’s south pole. If successful, India would become the fourth nation to land on the moon and the spacecraft, Chandrayaan-2, would be the first of any country to land in that region.

The Indian Space Research Organization (ISRO) announced the plans via Twitter on May 1, 2019. As of now, the spacecraft is scheduled to launch sometime between July 9 and July 16, 2019, from the ISRO launch facility on Sriharikota, an island off India’s southeastern coast.

https://twitter.com/x/status/1123612384336027650

This new mission is more ambitious than any previous Indian mission to the moon, and will include an orbiter, lander (Vikram) and rover (Pragyan). The landing itself won’t happen until September 6, 2019. As ISRO said in a statement:

All the modules are getting ready for Chandrayaan-2 launch during the window of July 9, to July 26, 2019, with an expected moon landing on September 6, 2019. The orbiter and lander modules will be interfaced mechanically and stacked together as an integrated module and accommodated inside the GSLV MK-III launch vehicle. The rover is housed inside the lander.​
After landing, the rover is designed to operate for at least 14 days on the surface and drive 1,300 feet (396 meters). That may not sound like a lot compared to NASA’s rovers on Mars, which have been able to drive for many years and travel at least several miles (as well as the Apollo rovers on the moon), but it will be a big accomplishment for ISRO if it succeeds, since it will be their first-ever moon rover. As K. Sivan, ISRO chairman, told The Times of India that, once Vikram lands on the lunar surface on September 6, the rover Pragyan will come out of the lander and roll out onto the lunar surface for about 300 to 400 meters (yards). It will spend 14 Earth-days on the moon, carrying out different scientific experiments. Altogether, he told The Times, there will be 13 payloads in the spacecraft: three payloads in rover Pragyan and the other 10 payloads in lander Vikram and orbiter.

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Infographic detailing the lander and rover, as well as the landing site near the moon’s south pole. Image via C. Bickel/Science.

The rover will use three scientific instruments including spectrometers and a camera to analyze the content of the lunar surface and send data and images back to Earth through the orbiter.

The launch of this mission had originally been planned for April 2018, but it was delayed to changes in the spacecraft design. The four-legged Vikram lander (a qualification model) had also suffered a fracture in one of its landing legs during testing earlier this year, contributing to the delay.

The landing near the moon’s south pole will be uncharted territory, where no other spacecraft has landed before. Previous orbiter missions, including India’s Chandrayaan-1, have found evidence for water ice in craters in this region, in locations where there is permanent shadow. With no atmosphere to speak of, temperatures remain exceedingly cold in those areas – about minus 250 degrees Fahrenheit (minus 157 degrees Celsius) – even though they can be boiling hot in sunlit regions. Water ice would be a valuable resource for future crewed missions back to the moon.

This will be India’s second lunar mission. The first, Chandrayaan-1, orbited the moon but did not land. It launched in October 2008 and operated for 312 days, until August 2009. By all measures it was a great success, with the orbiter circling the moon about 3,400 times.

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Artist’s concept of the Chandrayaan-2 rover on the moon, near the south pole. Image via ISRO/YouTube.

moon-south-pole-Clementine-3-31-2012-800x450.jpg

Still frame from animation showing the moon’s south pole as seen by NASA’s Clementine spacecraft in 1994. Image via NASA/Goddard Space Flight Center Scientific Visualization Studio.

On April 11, 2019, Israel’s Beresheet spacecraft attempted that country’s first landing on the moon – and the first landing of a commercial mission – but unfortunately it crashed after a problem with the main engine in the last few moments before landing. A little earlier, however, on January 3, 2019, China’s Chang’e-4 spacecraft did land successfully on the far side of the moon, another first in lunar exploration.

Hopefully this next mission from India will fare better, as a follow-on to the successful first Chandrayaan-1 mission. If so, this will be the first view from the ground near the moon’s south pole that we will have ever had from any spacecraft. Although studied from orbit, this part of the moon is still virtually unexplored, so it is an exciting opportunity to learn more about our nearest neighbor in space.

Bottom line: If all goes according to plan, India will become the first nation to land a spacecraft near the moon’s south in September of this year. Godspeed!

India aims for 1st landing near moon’s south pole | EarthSky.org
 
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Drawing of RISAT 2B from the press kit. Looks like a large deploy-able antenna on top of the vehicle. Mass is 615 kg to 557 km 37° orbit. Radar frequency is X-Band. Applications include agriculture, forestry and disaster management support.
 
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XPoSat - Some Details :

The X-ray Polarimeter (POLIX) is approved to be launched on a dedicated satellite mission of ISRO, XPoSat.

Satellite requirements :

Orbit- Low Inclination equatorial orbit of altitude 500-600km
Spin- Payload spin of 0.5 -5.0 rpm along roll axis

Scientific Objectives :

X-ray polarimetry is an unexplored area in high energy astrophysics. The Crab nebula is the only X-ray source for which a definite polarisation measurement exists.
X-ray polarisation measurements can give valuable insights about:
  1. The strength and the distribution of magnetic field in the sources
  2. Geometric anisotropies in the sources
  3. Their alignment with respect to the line of sight
  4. The nature of the accelerator responsible for energising the electrons taking part in radiation and scattering
This experiment will be suitable for X-ray polarisation measurement of hard X-ray sources like accretion powered pulsars, black hole candidates in low-hard states etc. (Kall-man 2004, Weisskopf et al. 2006). For about 50 brightest X-ray sources a Minimum Detectable

Polarisation of 2–3 % will be achieved with the final configuration.

Will post pics of the Xposat tommorow.
 
Gautam said:
Will post pics of the Xposat tommorow.
Click to expand...
As promised here they are :
This is from a presentation when the XPOSAT was first introduced.
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A closer look :

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A research paper originally published in 2010 about the primary instrument onboard, a Thompson X-ray Polarimeter.

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From the paper :

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Design of the instrument :

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Fabrication begins :

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continued on next post :
 
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