Tag: India

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 successfully launches Earth observation satellite plus 12 cubesats

9:57 pm

India today successfully used its PSLV rocket to launch its own Cartosat-3 Earth observation satellite plus 12 cubesats for the commercial company Planet.

This was India’s fifth launch in 2019.

The leaders in the 2019 launch race remain unchanged:

26 China
18 Russia
11 SpaceX
7 Europe (Arianespace)

China leads the U.S. 26 to 23 in the national rankings.

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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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India targets Nov 2020 for new lunar lander mission

9:24 am

The new colonial movement: Sources inside India’s space agency ISRO yesterday revealed that they are now working to build and fly another lunar lander/rover, dubbed Chandrayaan-3, with a target launch date of November 2020, only one year from now.

Isro has formed multiple committees — an overall panel and three sub-committees — and held at least four high-level meetings since October. The new mission will include only a lander and rover, as the Chandrayaan-2 orbiter is functioning well. On Tuesday, the overview committee met with the agenda of reviewing the configuration of Chandrayaan-3. It also looked into the recommendations of various sub-committees on propulsion, sensors, overall engineering, navigation and guidance.

The Chandrayaan-2 orbiter had provided the propulsion capabilities to get the Vikram lander (with rover) to lunar orbit earlier this year, only to have the lander fail shortly before touchdown. To do this new mission without an orbiter will require adding a propulsion unit to the rover/lander. They are also looking at strengthening the lander’s legs to better resist a high velocity landing.

Kudos to ISRO for moving so quickly. There is no reason a replacement lander/rover should take years to build. They already know what to do, they need only do it again, with upgrades designed to avoid the failure in September.

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Chandrayaan-2 releases more lunar images

9:44 am

3D view of Lindbergh Crater by Chandrayaan-2
Click for full image.

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
Click for full image.

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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LRO’s 2nd attempt to find Vikram comes up empty

9:25 am

In their second attempt to find India’s failed lunar lander Vikram, the science team of Lunar Reconnaissance Orbiter (LRO) were unsuccessful in spotting it.

A project scientist of Nasa’s LRO mission confirmed that the space agency’s second attempt to locate Vikram had come up empty. “The Lunar Reconnaissance Orbiter imaged the area of the targeted Chandrayaan-2 Vikram landing site on October 14 but did not observe any evidence of the lander,” Noah Edward Petro, the project scientist told news agency PTI.

Petro explained that Nasa compared the images shot by the LRO on October 14 with an image of the same area before Vikram’s landing. Nasa used a technique that would help it spot any signs of impact on the lunar surface indicating Vikram’s possible location. However, the images revealed nothing.

“It is possible that Vikram is located in a shadow or outside of the search area. Because of the low latitude, approximately 70 degrees south, the area is never completely free of shadows,” John Keller, deputy project scientist of Nasa’s LRO mission, explained while speaking to news agency PTI.

Based on the data obtained during the landing attempt, it appeared that Vikram should have crashed within a relatively small target area. That they haven’t seen it yet suggests that it landed within a shadowed area that will take time for the Sun to reach, if ever, or that it is farther away that expected, which implies that during landing much more went wrong than presently believed.

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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 scientists release image of Vikram landing site

10:28 am

Overview of Vikram landing area
Click for full image.

The Lunar Reconnaissance Orbiter (LRO) science team yesterday released their high resolution image taken of the area where it is believed India’s lunar lander Vikram crashed.

The image to the right is not that image, but an oblique overview showing where that landing region is, the center of which is indicated by the white cross. Vikram was aiming for this flat region between the Simpelius N and Manzinus C craters.

In releasing the image, the scientists explained what they thought were the reasons they have so far failed to find Vikram.

We note that it was dusk when the landing area was imaged and thus large shadows covered much of the terrain, perhaps the Vikram lander is hiding in a shadow. The lighting will be favorable when LRO passes over the site in October and LROC will attempt to image the lander at that time.

You can explore the actual image at the link. It is quite large, though their viewer there allows you to zoom in and move about, inspecting each grid area very closely. As they note, there are a lot of shadowed areas.

LRO’s high resolution camera can see objects as small as Vikram, even if broke up somewhat on landing. The key for discovery will be timing. LRO will have to pass over at a time when the lander is not in shadow.

UPDATE: Below the fold is a side-by-side comparison of this region, with mid-day on the left and the dusk LRO image on the right, created by Rex Ridenoure of Ecliptic Enterprises.and graciously provided to me.
» Read more

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LRO fails to spot Vikram on Moon

9:32 am

Despite successfully taking high resolution images of the area on the Moon where it is thought India’s Vikram crash-landed two weeks ago, the Lunar Reconnaissance Orbiter (LRO) science team has been unable to identify it in those images.

LRO’s Lunar Reconnaissance Orbiter Camera instrument, or LROC, imaged the intended south pole touchdown site for the lander, which is called Vikram, as planned yesterday (Sept. 17), Aviation Week’s Mark Carreau reported. But “long shadows in the area may be obscuring the silent lunar explorer,” Carreau wrote.

“It was near dusk as the region prepares to transition from a two-week lunar day to an equally long lunar night, so shadows covered much of the region, and Vikram may not be in the LROC’s field of view,” Carreau wrote, citing a NASA statement.

This means that they will simply have to try again during a later orbit. Eventually the lighting conditions will be right, and LRO will photograph Vikram.

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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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