Tag: Chandrayaan-2

Crash site of Vikram found

4:09 pm

Vikram impact point
Click for full image.

Using a mosaic of Lunar Reconnaissance Orbiter (LRO) images, citizen scientist Shanmuga Subramanian located on the Moon the debris and impact point for India’s Vikram lander that crashed there in September, an identification that has since been confirmed by LRO scientists.

The image on the right, reduced to post here, has been modified by the scientists to bring out the features that changed before and after the impact.

After receiving this tip the LROC team confirmed the identification by comparing before and after images. When the images for the first mosaic were acquired the impact point was poorly illuminated and thus not easily identifiable. Two subsequent image sequences were acquired on 14, 15 October and 11 November. The LROC team scoured the surrounding area in these new mosaics and found the impact site (70.8810°S, 22.7840°E, 834 m elevation) and associated debris field. The November mosaic had the best pixel scale (0.7 meter) and lighting conditions (72° incidence angle).

The debris first located by Shanmuga is about 750 meters northwest of the main crash site and was a single bright pixel identification in that first mosaic (1.3 meter pixels, 84° incidence angle). The November mosaic shows best the impact crater, ray and extensive debris field. The three largest pieces of debris are each about 2×2 pixels and cast a one pixel shadow.

No word yet on what this new information reveals about Vikram’s failure.

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India confirms details of Vikram’s crash on Moon

8:52 am

India’s government has finally officially admitted that its Vikram lunar lander crashed in September.

In a written answer to a question posed to the Department of Space in Lok Sabha, Minister of State in the Prime Minister’s Office (PMO) Jitendra Singh said the “reduction in velocity” of the Vikram lander during the final phase of its descent on the moon’s surface “was more than the designed value”. As a result, Vikram “hard-landed” on the moon “within 500 metres of the designated landing site”, he said.

…“The first phase of descent was performed nominally from an altitude of 30 km to 7.4 km above the moon surface. The velocity was reduced from 1,683 m/s to 146 m/s. During the second phase of descent, the reduction in velocity was more than the designed value. Due to this deviation, the initial conditions at the start of the fine braking phase (final phase below 7.4 km altitude) were beyond the designed parameters. As a result, Vikram hard-landed within 500 m of the designated landing site,” the minister said in a written answer in the Lok Sabha.

Except for the detail that they think Vikram landed within 500 meters of its planned landing site, this answer really doesn’t tell us much new. It was very obvious during the landing that the spacecraft was traveling too fast as it began its final braking phase, and that it then descended much too fast thereafter.

In fact, the couched language and the unwillingness so far of ISRO, India’s space agency, to provide a detailed report on the failure does not reflect well on them. This kind of cutting edge engineering requires a hard kind of intellectual honesty. They have so far not shown that kind of honesty in their response to this failure.

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Chandrayaan-2 releases more lunar images

9:44 am

3D view of Lindbergh Crater by Chandrayaan-2
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The Chandrayaan-2 science team today released several new images from the spacecraft, while also showcasing their ability to use those images to produce 3D oblique simulations, as shown to the right. This oblique view of Lindbergh Crater was created from an overhead view using computer software that estimated the elevations from the image.

The spacecraft’s high resolution camera can resolve objects as small as sixteen feet across, which is the best resolution yet for any lunar orbiter.

No word yet on whether they have been able to find and image their failed Vikram lander.

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India releases first radar images from Chandrayaan-2

12:45 pm

Radar image from Chandrayaan-2
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India yesterday released the first radar images produced by its lunar orbiter, Chandrayaan-2, the best such images yet produced by any spacecraft. As their press release notes:

Synthetic Aperture Radar (SAR) is a powerful remote sensing instrument for studying planetary surfaces and subsurface due to the ability of the radar signal to penetrate the surface. It is also sensitive to the roughness, structure and composition of the surface material and the buried terrain.

Previous lunar-orbiting SAR systems such as the S-band hybrid-polarimetric SAR on ISRO’s Chandrayaan-1 and the S & X-band hybrid-polarimetric SAR on NASA’s LRO [Lunar Reconnaissance Orbiter], provided valuable data on the scattering characterisation of ejecta materials of lunar impact craters. However, L & S band SAR on Chandraayan-2 is designed to produce greater details about the morphology and ejecta materials of impact craters due to its ability of imaging with higher resolution (2 – 75m slant range) and full-polarimetric modes in standalone as well as joint modes in S and L-band with wide range of incidence angle coverage (9.5° – 35°). In addition, the greater depth of penetration of L-band (3-5 meters) enables probing the buried terrain at greater depths. The L & S band SAR payload helps in unambiguously identifying and quantitatively estimating the lunar polar water-ice in permanently shadowed regions.

The image on the right, cropped and reduced to post here, is from one of the two images released. The brighter areas indicate rougher terrain as well as the location of ejecta from the crater, some of which is below the surface and is not obvious in optical images.

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First images from Chandrayaan-2

8:45 am

One of Chandrayaan-2's first hi-res images
Click for the full image.

India has released the first image from the high resolution camera on its Chandrayaan-2 lunar orbiter.

The image on the right, cropped to post here, is from that image and shows objects as small as 10 inches across, which is better than the 20 inch resolution obtained by the U.S.’s Lunar Reconnaissance Orbiter (LRO). Depending on orbit, they should therefore eventually be able to image their crashed Vikram lander with more detail. It also means they can supplement and improve on data from LRO, a significant achievement for India.

Additionally they report that all instruments on board are functioning normally.

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LRO to image Vikram landing site next week

10:16 am

The Lunar Reconnaissance Orbiter (LRO) science team plans to take high resolution images of the Vikram landing site when the orbiter flies over that site on September 17, thus allowing them to release before and after images.

Noah Petro, LRO’s project scientist at NASA’s Goddard Space Flight Center, said that the orbiter is due to fly over the Vikram landing site Tuesday, Sept. 17. “Per NASA policy, all LRO data are publicly available,” Petro wrote in an email. “NASA will share any before and after flyover imagery of the area around the targeted Chandrayaan 2 Vikram lander landing site to support analysis by the Indian Space Research Organization.”

Officials with India’s space agency ISRO have said they have photographed Vikram with their orbiter, Chandrayaan-2, but they have not released these images as yet. Their have also been reports from India stating that their images suggest the lander is still in one piece, but these reports are not confirmed.

LRO’s images should clarify the situation. The images should also help tell us what exactly happened after Indian engineers lost contact with Vikram shortly before landing.

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Chandrayaan-2 locates Vikram

8:28 am

According to K. Sivan, the head of ISRO, India’s space agency, their Chandrayaan-2 orbiter has captured a thermal image of Vikram on the lunar surface, pinpointing the lander’s location.

They have not released the image. According to reports today, they do not yet know the lander’s condition, and have not regained communications. Reports late yesterday had quoted K.Sivan as saying “It must have been a hard-landing.” That quote is not in today’s reports.

In watching the landing and the subsequent reports out of India, it appears that India is having trouble dealing with this failure. To give the worst example, I watched a television anchor fantasize, twenty minutes after contact had been lost, that the lander must merely be hovering above the surface looking for a nice place to land. Most of the reports are not as bad, but all seem to want to minimize the failure, to an extreme extent.

Their grief is understandable, because their hopes were so high. At the same time, you can’t succeed in this kind of challenging endeavor without an uncompromising intellectual honesty, which means you admit failure as quickly as possible, look hard at the failure to figure out why it happened, and then fix the problem. If India can get to that place it will be a sign that they are maturing as a nation. At the moment it appears they are not quite there.

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Vikram fails to land on Moon

1:26 pm

Vikram, India’s first attempt to soft land on the Moon, apparently has failed, with something apparently going wrong in the very last seconds before landing.

As I write this they have not officially announced anything, but the live feed shows a room of very unhappy people.

It is possible the lander made it and has not yet sent back word, but such a confirmation should not take this long.

India’s prime minister, Narendra Modi, was given a very short briefing by K. Sivan, head of ISRO, and then apparently left without comment. This I found an interesting contrast to the actions of Israel’s prime minister Benjamin Netanyahu when its lunar lander Beresheet failed in landing earlier this year. Netanyahu came out to comfort the workers in mission control, congratulating them for getting as far as they had. Modi apparently simply left. UPDATE: Modi has reappeared to talk to the children who had won a contest to see the landing as well as people in mission control. After making a public statement he has now left.

They are now confirming that communications was lost at 2.1 kilometers altitude, which was just before landing. They are analyzing the data right now to figure out what went wrong.

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Watch Vikram landing on Moon

10:55 am

Vikram's primary landing site

The new colonial movement: I have embedded below the live stream of India’s attempt today to land its Vikram lander on the Moon, broadcast by one of their national television networks.

The landing window is from 4:30 to 5:30 pm Eastern. This live stream is set to begin about 3 pm Eastern.

If you want to watch ISRO’s official live stream you can access it here.

Some interesting details: Vikram is named after Vikram A. Sarabhai, who many consider the founder of India’s space program. The lunar rover that will roll off of Vikram once landing is achieved is dubbed Pragyan, which means “wisdom” in Sanskrit. Both are designed to operate on the Moon for one lunar day.

The landing site will be about 375 miles from the south pole.

That spot is a highland that rises between two craters dubbed Manzinus C and Simpelius N. On a grid of the moon’s surface, it would fall at 70.9 degrees south latitude and 22.7 degrees east longitude.

The white cross on the image to the right is where I think this site is. The secondary landing site is indicated by the red cross.

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Vikram makes second and last lunar orbital change

9:40 am

The new colonial movement: India’s Vikram lunar lander today made its second and last orbital change, preparing itself for landing on the Moon on September 7.

The orbit of Vikram Lander is 35 km x 101 km. Chandrayaan-2 Orbiter continues to orbit the Moon in an orbit of 96 km x 125 km and both the Orbiter and Lander are healthy.

With this maneuver the required orbit for the Vikram Lander to commence it descent towards the surface of the Moon is achieved. The Lander is scheduled to powered descent between 0100 – 0200 hrs IST on September 07, 2019, which is then followed by touch down of Lander between 0130 – 0230 hrs IST

They plan to roll the rover Pragyan off of Vikram about two hours after landing.

This article provides a nice overview of the mission.

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Vikram completes first de-orbit burn

9:45 pm

The new colonial movement: India’s Vikram lunar lander has successfully completed its first de-orbit engine burn, lasting 4 seconds, adjusting its orbit slightly in preparation for landing on the Moon on September 7.

They will do a second burn tomorrow, further adjusting the orbit.

Note that the update says that this burn was by Chandrayaan-2, but this must be a mistake. The Vikram lander separated from the Chandrayaan-2 orbiter yesterday, and it is Vikram that is doing the orbital changes and will land on the Moon.

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Vikram has successfully separated from Chandrayaan-2

9:11 am

The new colonial movement: India’s lunar lander, Vikram, has successfully separated from Chandrayaan-2, and is functioning nominally in lunar orbit.

The update describing this is the second update at the link, with the first detailing the arrangements for the press to cover the landing on September 7.

The lander carries the rover, dubbed Pragyan, which will roll off Vikram only a few hours after landing.

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Chandrayaan-2 now in proper lunar orbit for release of lander/rover

7:45 pm

India’s Chandrayaan-2 spacecraft today completed its fifth engine burn in lunar orbit, placing it in the correct orbit for releasing its lander/rover.

The next operation is the separation of Vikram Lander from Chandrayaan-2 Orbiter, which is scheduled on September 02, 2019, between 1245 – 1345 hrs (IST). Following this, there will be two deorbit maneuvers of Vikram Lander to prepare for its landing in the south polar region of the moon.

The landing itself is scheduled for September 7.

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More images from Chandrayaan-2

9:13 am

Moon image from Chandrayaan-2
Click for full image.

The Chandrayaan-2 engineering team has released more lunar images from Chandrayaan-2, this time from its higher resolution Terrain Mapping Camera 2.

One example is to the right, reduced to post here. It was taken from about 2,700 miles altitude, and shows a section of the northern hemisphere on the Moon’s heavily cratered far side. There are other images at the link.

The goal of these images is to demonstrate that the camera and spacecraft pointing systems are working. It appears they have done so successfully.

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ISRO releases Chandrayaan-2’s first Moon image from lunar orbit

9:22 am

The Moon as seen by Chandrayaan-2

India’s space agency ISRO has released the first image taken by Chandrayaan-2 after entering orbit around the Moon.

That image is to the right, reduced to post here. It was taken from about 1,600 miles elevation, and shows mostly the far side of the Moon. The dark mare in the upper right is the Sea of Moscow, which is the only large mare on the far side.

This image once again proves the camera and the spacecraft’s ability to point it accurately are both functioning.

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Chandrayaan-2 successfully enters lunar orbit

8:42 am

The head of ISRO today announced that, after completed a 29 minute engine burn, India’s Chandrayaan-2 orbiter/lander/rover has successfully entered the correct orbit around the Moon.

In his briefing, Dr. Sivan announced that “The LOI maneuver was performed successfully today morning using the onboard propulsion system for a firing duration of about 29 minutes. This maneuver precisely injected Chandrayaan-2 into an orbit around the Moon.” He emphasised the unique requirement of 90 degree orbital inclination of Chandrayaan-2 and said that it was achieved by the precise execution of both the Trans Lunar Injection (performed on August 14, 2019) and today’s LOI maneuver.

“The satellite is currently located in a lunar orbit with a distance of about 114 km at perilune (nearest point to the Moon) and 18,072 km at apolune (farthest point to the Moon)”, he added.

Over the next four lunar orbits they will execute four more engine burns to lower the spacecraft to the orbit needed to send the lander/rover to the surface on September 7 in the south polar region of the Moon between the craters Manzinus C and Simpelius N at about 71 degrees latitude.

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Chandrayaan-2 successfully puts itself in route to the Moon

8:46 am

Chandrayaan-2 today successfully completed its last Earth perigee burn, raising its orbital apogee so that it will enter the Moon’s gravitational sphere of influence on August 20th.

Chandrayaan-2 will approach Moon on August 20, 2019 and the spacecraft’s liquid engine will be fired again to insert the spacecraft into a lunar orbit. Following this, there will be further four orbit maneuvers to make the spacecraft enter into its final orbit passing over the lunar poles at a distance of about 100 km from the Moon’s surface.

…Subsequently, Vikram lander will separate from the orbiter on September 02, 2019. Two orbit maneuvers will be performed on the lander before the initiation of powered descent to make a soft landing on the lunar surface on September 07, 2019.

Vikram will be doing the hardest part, the landing.

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First images from Chandrayaan-2

8:29 am

Earth from Chandrayaan-2

India yesterday released the first images taken by its lunar orbiter/lander/rover Chandrayaan-2, taken from Earth orbit of the Earth.

The image on the right is one example, and was taken mostly for engineering purposes. All the images (available here) demonstrates that the spacecraft’s camera is working properly, and it can orient itself accurately.

They now hope to put the spacecraft into lunar orbit on August 20th, with the landing attempt set for September 7th, after they have lowered that lunar orbit sufficiently.

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Chandrayaan-2 successfully completes 4th orbit burn

9:23 am

The new colonial movement: India’s lunar orbiter/lander/rover Chandrayaan-2 today successfully completed its fourth engine burn, this time raising its orbital apogee to 89,472 kilometers (55,595 miles).

The next burn is scheduled for August 6, when the spacecraft’s orbit brings it back down to its perigee.

By September they expect to raise that apogee high enough so that it is within the Moon’s gravitational sphere of influence, when they will be able to put it the spacecraft into lunar orbit.

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Chandrayaan-2 completes third orbit maneuver

9:14 am

Chandrayaan-2 has completed its third engine burn to raise the apogee of its orbit to 71K.

The next burn is set for August 2, when the spacecraft returns to its orbital low point, the perigee. As it raises its orbit each time the time between burns gets extended because the orbit gets longer. By September however the apogee will put the spacecraft in the Moon’s gravitational field of influence, and when Chandrayaan-2 reaches that apogee engineers will then fire its engines again to slow it down and enter lunar orbit.

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Chandayaan-2 completes first orbit burn

8:18 am

India’s lunar orbiter/lander/rover Chandrayaan-2 yesterday completed its first orbital engine burn, raising its apogee, the high point in its orbit, 6,000 kilometers to about 51,000.

This boost meant that Isro scientists have to perform one less manoeuvre in the Earth orbit than what was planned earlier. According to the path chalked out for Chandrayaan-2 before the launch, the on-board propulsion systems were to be fired six times in Earth orbit – five times to raise the apogee and once to raise the perigee. Now, only four more “burns”, or firing of the propulsion system, will be needed on July 26 and 29, and August 2 and 6, to reach the final orbit of 233.2 x 143,953km.

…With a final boost on On August 14, Chandrayaan-2 will escape Earth’s orbit and begin its seven-day journey towards the moon. The spacecraft is scheduled to reach the moon orbit on August 20.

Once in lunar orbit they plan four more burns to lower the spacecraft to a 100 kilometer circular orbit, where the lander/rover will release and begin their own lowering process aimed for a September 7 landing.

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India successfully launches Chandrayaan-2

8:24 am

The new colonial movement: India yesterday successfully launched its lunar orbiter/lander/rover Chandrayaan-2 into orbit.

India’s Geosynchronous Satellite Launch Vehicle GSLV MkIII-M1, successfully launched the 3840 kg Chandrayaan-2 spacecraft into an earth orbit today (July 22, 2019). The spacecraft is now revolving round the earth with a perigee (nearest point to Earth) of 169.7 km and an apogee (farthest point to Earth) of 45,475 km. Today’s flight marks the first operational flight of the GSLV Mk III.

They will slowly raise the spacecraft’s apogee over the next two months to bring it into the Moon’s gravitational sphere of influence, when they will begin lowering the orbit leading to a separation of the lander/rover for a September 7 landing near the Moon’s south pole.

This was the third launch of the upgraded GSLV Mark III. With this launch India now has an operational rocket it can use to launch its astronauts into space in 2022.

The leaders in the 2019 launch race:

9 China
9 Russia
8 SpaceX
5 Europe (Arianespace)
4 India

The U.S. continues to lead in the national rankings, 14 to 9.

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India reschedules Chandrayaan-2 launch

8:36 am

The new colonial movement: India’s space agency ISRO have rescheduled the launch of Chandrayaan-2 lunar orbiter/lander/rover now for July 22, 2019.

The new launch date apparently requires a very short launch window.

July 15 had offered the most comfortable launch window of 10 minutes for the Mission. But Isro has managed to successfully launch several satellites within one-minute windows in the past. However, delaying beyond July 31 could have potentially reduced the Orbiter’s life around the Moon.

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Chandrayaan-2 launch scrub caused by leak in helium bottle

8:50 am

Engineers today announced that the July 14 scrub of India’s Chandrayaan-2 lunar orbiter/lander/rover was caused by a leak in a helium bottle in the GSLV rocket.

“The good news is that we can fix the leak without dismantling the rocket, since there is an access door to the gas bottle which is atop the oxygen tank,” a senior scientist told TOI. “The bad news is that unless we ascertain the reason for the leak, there is a probability of the problem recurring.” Not having to dismantle means Chandrayaan-2 may be able to fly before the end of the July launch window, but a final failure analysis will be available only in a day or two.

Sources told TOI that the leak wasn’t serious enough to impair the flight, but Isro decided to apply “abundant caution,” given the importance of the Rs 978-crore project that would make India only the fourth country – after the US, Russia and China – to land a craft on the lunar surface.

I am willing to bet that if their investigation does not pinpoint the cause of the leak in the next few days, they will stand down from the July launch window. This mission, as well as proving the reliability of their GSLV rocket, are both too important to risk on an unknown and unsolved engineering issue.

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