Tag: engineering

Vikram takes movie of Pragyan rover as it roves

9:30 am

Pragyan as seen by Vikram
Click for movie.

Using one of Vikram’s lander cameras, engineers have produced a short movie of India’s Pragyan rover as it rotated to avoid a small crater about ten feet ahead.

The picture to the right is from that 16-second movie, near its end. It appears that the engineers operating Pragyan were unhappy with almost any route ahead from its present position, as they rotated Pragyan almost 360 degrees, and even attempted forward motion at one point and then resumed rotation.

It is not clear if any of the craters visible in this picture are the crater that caused the detour. The movie however does provide a sense of scale. Pragyan is small, but it is able to maneuver easily using its six wheels.

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China’s Long March 2D launches 3 satellites

8:55 am

China today successfully placed three “remote sensing” satellites into orbit, using its Long March 2D rocket lifting off from its Xichang spaceport in south China.

The state-run press provided no other information, including whether the rocket’s lower stages crashed near habitable areas. According to the flight path, the crash zones were near major population centers, including one city with a population of nine million.

SpaceX meanwhile scrubbed a Falcon 9 launch this morning at Vandenberg due to an issue with one first stage engine, but it is still scheduled to launch 22 Starlink satellites this afternoon from Cape Canaveral. The live stream is here.

The leaders in the 2023 launch race:

59 SpaceX
38 China
12 Russia
7 Rocket Lab

In the national rankings, American private enterprise still leads China in successful launches 68 to 38. It also leads the entire world combined, 68 to 61, while SpaceX by itself now trails the rest of the world (excluding American companies) 59 to 61 in successful launches.

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Buried ridges at the bottom of a Martian abyss

11:03 am

Buried ridges in a Martian abyss
Click for full image.

Today’s cool image could be labeled a “What the heck?!” photo, as the origin of its most distinct feature is utterly baffling. The picture to the right, cropped, reduced, and sharpened to post here, was taken on June 18, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what look like a collection of meandering ridges peeking out from a terrain covered by thick dust.

The scientists label this dust-covered ground, as well as the ripple dunes to the south in the full image, “sand sheets.” Without question, the ground here seems to resemble a Sahara-like terrain. It is utterly featureless, other than the few bedrock features that poke up out of that sand. In the full image some peaks stick out, but it the meandering ridges in this section that are most intriguing. They are reminiscent of rimstone dams in caves, but what formed them remains baffling, since cave rimstone dams are formed by the interaction of limestone and water, and there is absolutely no evidence of any near surface ice at this location in the dry equatorial regions of Mars.

All the ridges signify is a buried terrain formed in some inexplicable way.
» Read more

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Scientists believe they have recovered the first known interstellar meteorite

8:52 am

A scientific expedition in the Pacific off the coast of Papua New Guinea has found what it thinks are spherules from the first known interstellar meteorite that hit the Earth on January 8, 2014 and dubbed IM1. From their preprint paper [pdf]:

On 8 January 2014 US government satellite sensors detected three atmospheric detonations in rapid succession about 84 km north of Manus Island, outside the territorial waters of Papua New Guinea (20 km). Analysis of the trajectory suggested an interstellar origin of the causative object CNEOS 2014-01-08: an arrival velocity relative to Earth in excess of ∼ 45 km s−1, and a vector tracked back to outside the plane of the ecliptic. The object’s speed relative to the Local Standard of Rest of the Milky-Way galaxy, ∼ 60 km s−1, was higher than 95% of the stars in the Sun’s vicinity.

In 2022 the US Space Command issued a formal letter to NASA certifying a 99.999% likelihood that the object was interstellar in origin.

Using a “magnetic sled” that they dragged across the seafloor, the scientists collected about 700 spherules thought to come from the meteorite, of which 57 have been analyzed and found to have properties that confirm their interstellar origin. As they note in their paper, “The spherules with enrichment of beryllium (Be), lanthanum (La) and uranium (U), labeled “BeLaU”, appear to have an exotic composition different from other solar system materials.”

The “BeLaU” elemental abundance pattern does not match terrestrial alloys, fallout from nuclear explosions, magma ocean abundances of Earth, its Moon or Mars or other natural meteorites in the solar system. This supports the interstellar origin of IM1 independently of the measurement of its high speed, as reported in the CNEOS catalog and confirmed by the US Space Command.

Based on the sparse data, the scientists speculate that these spherules could have come from the crust of an exoplanet, the core collapse of a supernova, the merger of two neutron stars, and even possibly “an extraterrestrial technological origin.” They have no idea, but all these are among the possibilities.

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Starlink makes deal with Japanese cell phone company

8:33 am

SpaceX has now partnered with the Japanese cell phone company KDDI to provide satellite-to-cellular service in remote areas of Japan that do not have good cell tower service.

The companies plan to start with SMS text services as early as 2024 and will eventually provide voice and data services. Almost all existing smartphones on KDDI network will be compatible with this new service as it employs the device’s existing radio services.

Since Starlink now has more than 5,000 satellites in orbit, it can offer its services to a wider ranger of customers worldwide, and has been slowly signing them up, from country to country.

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Pragyan snaps first pictures of Vikram sitting on the Moon

8:28 am

Vikram as seen by Pragyan
Click for original image.

India’s space agency ISRO has released the first two pictures from the Pragyan rover showing the Vikram lander that bought both to the Moon safely.

The picture to the right is the close-up image, which shows two of Vikram’s science instruments. CHASTE is a probe that has been measuring the temperature of the Moon’s regolith at this spot, while ILSA is a seismometer for measuring the seismicity around the landing site.

Both spacecraft have been on the lunar surface now for one week, which means they are both halfway through their nominal two-week mission that lasts until lunar sunset, occurring on September 4th. Neither were designed to survive the 14-day-long lunar night, though engineers will attempt to kept both alive.

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The prevailing winds in Mars’ volcano country

12:35 pm

The prevailing winds in Mars' volcano country
Click for original image.

Today’s cool image is actual one new picture and four past images, which taken together reveal something about the larger wind patterns on Mars. The picture to the right, cropped, reduced, and sharpened to post here, was taken on June 27, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and shows a tiny wind-swept section of the giant volcanic ash field dubbed the Medusae Fossae Formation, about the size of the subcontinent of India and thought to be source of most of the dust on Mars.

The innumerable parallel thin ridges here all suggest that the prevailing winds blow from the southeast to the northwest. As they blow, the scour the surface ash out, and sometimes reveal the underlying bedrock, which here shows up as those small peaks and a handful of northeast-to-southwest trending larger ridges. Note too that the picture shown is only a small section of the full image, which shows that this landscape continues for a considerable distance in all directions.
» Read more

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InSight team releases a global map of Mars’ seismic zones

10:03 am

Global map of quakes on Mars
Click for original image.

In a new paper that reviewed the entire archive of Mars quakes detected by the seismometer on InSight during its four years of operation on the Martian surface from 2018 to 2022, scientists have now released an updated global map showing the regions on Mars where seismic activity is most common. From the abstract:

Seismicity on Mars occurs mostly along or north of the boundary between the southern highlands and northern lowlands. Valles Marineris is seismically more active than previous catalogs of located events imply. Further, we show evidence that two events likely originate from the Olympus Mons region.

The map to the right is figure 6 from the paper, and shows clearly the sum total of InSight’s data. The yellow triangle marks InSight’s landing spot. The red line delineates the distant quakes from the nearby quakes detected by InSight. The green line is what the scientists identify as the border between the northern lowland plains and the southern cratered highlands. The data suggests that transition point could be linked geologically in some manner to the quakes themselves.

Though the majority of the detected quakes were in the Cerberus Fossae region, the data also suggests two other seismic active regions, one under the giant canyon Valles Marineris and the other south of Mars’ largest volcano, Olympus Mons.

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Boom begins taxi tests of a one-third scale prototype of its proposed supersonic passenger plane

9:35 am

Three years after it first unveiled the XB-1 prototype of its proposed supersonic passenger plane, Boom Supersonic is finally about to begin taxi tests.

At the Mojave Air & Space Port in Mojave in California, Boom has been conducting ground tests of its one-third scale XB-1 prototype supersonic jet as part of its project to develop its Overture supersonic airliner. The latest round has included taxi tests in the run up to its maiden flight.

In addition to the tests, the FAA has granted the XB-1 an experimental airworthiness certificate that will allow the test aircraft to make its first flight with Chief Test Pilot Bill “Doc” Shoemaker and Test Pilot Tristan “Gepetto” Brandenburg at the controls. Along with simulator work, the pilots are practicing with a T-38 trainer that will also act as a chase plane during the flight tests.

When the prototype was first unveiled in 2020 — after several years delay — the company said it planned to begin flight tests in 2021, with the full scale jet flying by 2024. The project has clearly been delayed since then. At the same time, the company has already gotten contracts and financial support from a number of major airlines, including United and Japan Airlines.

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Residue ice in southern mid-latitude Martian crater?

11:16 am

Residue ice in the southern mid-latitudes of Mars?
Click for original image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on April 10, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows an unnamed 1.2-mile-wide crater at about 35 degrees south latitude with what appears to be residual glacial ice hugging its north interior wall.

As this is in the southern hemisphere, the ground immediately below the south-facing interior wall of the crater is going to be in shadow the most, and thus it will also be the place where any surface or near-surface ice will survive the longest. In this case it appears that from the bumpy nature of that residual ice it has also been sublimating away. Within it however remains the faint hint of multiple layers, suggesting about a dozen past climate cycles with each new cycle producing a new but smaller layer with less ice.

The material in the southern half of the crater floor appears to be dust formed into ripple dunes.
» Read more

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Vikram finds temperatures of lunar soil varies significantly, depending on depth

9:17 am

Temperature range of soil at Vikram landing site

Based on data from one of the instruments on India’s lunar lander Vikram, scientists have found that the temperatures of the lunar soil at the landing site vary significantly, depending on depth. The temperature dropped from 55 degrees Celsuis to -10 degrees Celsuis when going from about 10 millimeters above the surface to about 82 millimeters below the surface, as shown in the graph to the right.

That’s equivalent from going from a summer day in Death Valley of 131 degrees Fahrenheit to a winter day in Minnesota of 14 degrees Fahrenheit, in a distance of only about 3.5 inches. While it was expected that there would a temperature drop, it appears the quick temperature drop just below the surface was faster than expected.

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JAXA scrubs launch of X-Ray telescope & SLIM lunar lander due to high winds

8:57 am

SLIM's landing zone
Click for interactive map.

Because of high winds, Japan’s space agency JAXA yesterday scrubbed the last launch of its H2A rocket, carrying the XRISM X-Ray telescope and the SLIM lunar lander.

A nice description of both payloads can be found here. XRISM is a simplified reflight of the Hitomi X-Ray telescope that failed immediately after launch in 2016.

Though SLIM carries a camera and two secondary payloads, both designed to hop along on the surface and obtain some data, its main mission is engineering, testing whether a robotic spacecraft can achieve a precision landing with a target zone of 100 meters, or 310 feet. The map to the right shows SLIM’s landing site, with the white dot in the close-up inset a rough approximation of that entire target zone. If successful this technology will make it possible to put unmanned planetary probes in places previously thought too dangerous or rough.

All three craft are designed to operate for only about fourteen days, during the daylight hours of the 28-Earth-day-long lunar day.

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