Tag: engineering

Astronomers discover twelve more Jupiter moons

9:21 am

In reviewing ground-based data from 2021 and 2022, astronomers have discovered another twelve Jupiter moons, bringing that planet’s total moon population to 92.

All of the newly discovered moons are small and far out, taking more than 340 days to orbit Jupiter. Nine of the 12 are among the 71 outermost Jovian moons, whose orbits are more than 550 days. Jupiter probably captured these moons, as evidenced by their retrograde orbits, opposite in direction to the inner moons. Only five of all the retrograde moons are larger than 8 kilometers (5 miles); Sheppard says the smaller moons probably formed when collisions fragmented larger objects.

One newly discovered moon, dubbed Valetudo, is about 3,000 feet across and orbits in a retrograde orbit that crosses the orbits of several other moons that orbit in the opposite direction. As the article notes, “This highly unstable situation is likely to lead to head-on collisions that would shatter one or both objects.”

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Webb instrument back in operation

9:13 am

Engineers have returned NIRISS, the near infrared spectrograph instrument on the Webb Space Telescope, to full operation after rebooting its software and determining the cause of the problem.

On Jan. 15, NASA’s James Webb Space Telescope’s Near Infrared Imager and Slitless Spectrograph (NIRISS) experienced a communications delay within the science instrument, causing its flight software to time out. Following a full investigation by NASA and Canadian Space Agency (CSA) teams, the cause was determined to likely be a galactic cosmic ray, a form of high-energy radiation from outside our solar system that can sometimes disrupt electrical systems. Encountering cosmic rays is a normal and expected part of operating any spacecraft. This cosmic ray event affected logic in the solid-state circuitry of NIRISS electronics known as the Field Programmable Gate Array. Webb engineers determined that rebooting the instrument would bring it back to full functionality.

After completing the reboot, NIRISS telemetry data demonstrated normal timing, and to fully confirm, the team scheduled a test observation. On Jan. 28, the Webb team sent commands to the instrument to perform the observation, and the results confirmed on Jan. 30 NIRISS is back to full scientific operations.

Engineers actually have a name for such cosmic ray incidents that effect software. They call it a bitflip.

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Developments at the Houston Spaceport industry park

7:44 pm

Link here. The article gives a detailed review of the various space-related businesses (Axiom, Intuitive Machines, Collins Aerospace) that have set up operations at this industry park focused on attracting space companies to the Houston area.

The park in a sense in misnamed, as it isn’t a launch facility. However, it is now building a taxiway that will connect the park directly to Ellington Airport, which for these businesses will help facilitate the transport of large space station modules and lunar landers.

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That ain’t snow on Mars

12:29 pm

That ain't snow on Mars
Click for original image.

Today’s cool image proves once again that you must never too quickly jump to any conclusions when you first look at a picture from space. The photo to the right, cropped, reduced, and sharpened to post here, was taken on November 24, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

At first glance it appears that those ridges are topped with patches of snow or frost. Not. What appears white in this black and white photo is immediately revealed to be light-colored dust in the color image.

According the label assigned to this image by the science team, these ridges represent layers, likely tilted steeply so that when exposed they form the layered cliff edges where that light dust has now gathered.

The overview map below provides further evidence that the white patches are dust, not snow.
» Read more

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Perseverance completes placement of first ten samples for later pick up

9:36 am

Overview map
Click for interactive map.

On January 29, 2023 the Perseverance science team completed the placement of the first ten core samples on the floor of Jezero Crater.

On the overview map to the right, the green outline indicates the location of this sample depot. The blue dot marks Perseverance’s present location, while the green dot marks Ingenuity. The red dotted line shows the planned route up onto the delta, which is Perseverance’s next goal.

The titanium tubes were deposited on the surface in an intricate zigzag pattern, with each sample about 15 to 50 feet (5 to 15 meters) apart from one another to ensure they could be safely recovered. Adding time to the depot-creation process, the team needed to precisely map the location of each 7-inch-long (18.6-centimeter-long) tube and glove (adapter) combination so that the samples could be found even if covered with dust. The depot is on flat ground near the base of the raised, fan-shaped ancient river delta that formed long ago when a river flowed into a lake there.

This mapping will be used by a future Mars helicopter to precisely land by each sample, grab it, and then take it to the ascent vehicle for return to Earth.

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Juno’s camera experiences temperature problem

8:57 am

Because of an unexpected rise in its temperature, Juno’s camera was unable to take its full schedule of planned images during its January 22, 2023 close approach of Jupiter.

The JunoCam imager aboard NASA’s Juno spacecraft did not acquire all planned images during the orbiter’s most recent flyby of Jupiter on Jan. 22. Data received from the spacecraft indicates that the camera experienced an issue similar to one that occurred on its previous close pass of the gas giant last month, when the team saw an anomalous temperature rise after the camera was powered on in preparation for the flyby.

However, on this new occasion the issue persisted for a longer period of time (23 hours compared to 36 minutes during the December close pass), leaving the first 214 JunoCam images planned for the flyby unusable. As with the previous occurrence, once the anomaly that caused the temperature rise cleared, the camera returned to normal operation and the remaining 44 images were of good quality and usable.

Engineers are analyzing the issue to try to determine its cause, as well as a fix. The camera at this moment appears to be operating properly, with the next close fly-by occurring on March 1, 2023.

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Curiosity looking back

9:22 am

Panorama by Curiosity, looking back
Click for full image.

Overview map
Click for interactive map.

Curiosity is now about halfway across the flat marker band terrain it faced last week, and as part of its routine, used its right navigation camera on January 28, 2023 to create a 360 degree panorama mosaic of the Mount Sharp foothills that now surround it. The panorama above, cropped, reduced, and sharpened to post here, focuses on the part of that mosaic looking behind Curiosity.

You can see the rover’s recent tracks as it crossed this part of the marker band. In the far distance can be seen in the haze the rim of Gale Crater, approximately 20 to 40 miles away. The yellow lines in the overview map to the right show the approximate area covered by this section of the panorama. It is possible the peak of Navarro Mountain is peeking up in the center of this panorama, but more likely it is no longer visible, blocked by the smaller but closer hills.

As Curiosity is now inside the foothills of Mount Sharp, the floor of Gale Crater is no longer easily seen. The rover needs to be at a high lookout point, something that will likely not occur in its travels for many months if not years to come.

The Curiosity pictures I am featuring this morning are cool, and they are also the only real news in the space field at this moment. As is usual on Monday, it takes few hours for the news at the beginning of the week to make itself known.

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A cloud on Mars

8:46 am

A cloud on Mars
Click for original image.

Cool image time! The photo to the right, reduced and sharpened to post here, was taken on January 27, 2023 by Curiosity’s high resolution camera (dubbed Mastcam) as part of its periodic survey of the sky, looking for clouds. Most of the time the sky is either hazy or clear. This time the camera picked up this cloud, which resembles a cirrus cloud on Earth.

In March 2021 I posted another example of clouds found above Gale Crater by Curiosity. Two months later the science team released a press release about those clouds, which might help explain the cloud above.

The fine, rippling structures of these clouds are easier to see with images from Curiosity’s black-and-white navigation cameras. But it’s the color images from the rover’s Mast Camera, or Mastcam, that really shine – literally. Viewed just after sunset, their ice crystals catch the fading light, causing them to appear to glow against the darkening sky. These twilight clouds, also known as “noctilucent” (Latin for “night shining”) clouds, grow brighter as they fill with crystals, then darken after the Sun’s position in the sky drops below their altitude. This is just one useful clue scientists use to determine how high they are.

Even more stunning are iridescent, or “mother of pearl” clouds. “If you see a cloud with a shimmery pastel set of colors in it, that’s because the cloud particles are all nearly identical in size,” said Mark Lemmon, an atmospheric scientist with the Space Science Institute in Boulder, Colorado. “That’s usually happening just after the clouds have formed and have all grown at the same rate.”

Though usually formed from water-ice, there is a chance this cloud is formed from crystals of dry ice. More analysis will of course be necessary to make that determination.

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Glaciers or taffy on Mars?

10:11 am

Glaciers of taffy on Mars?
Click for full image.

Cool image time! The photo to the right, rotated, cropped, reduced, and sharpened to post here, was taken on November 28, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It was released on January 4, 2023 as a captioned image, with this caption by Alfred McEwen of the Lunar & Planetary Laboratory in Arizona:

The floor of the Hellas impact basin, the lowest elevation on Mars, remains poorly explored because haze often blocks it from view. However, we recently got a clear image, revealing the strange banded terrain. These bands may be layers or flow bands or both.

At first glance, these bands reminded me of the many glaciers found on Mars. McEwen however is being properly vague about the nature of these features, for a number of reasons illustrated by the overview map below.
» Read more

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The twin asteroid Janus probes, stranded by Psyche delay, might go to Apophis

9:20 am

Apophis' path past the Earth in 2029
A cartoon showing Apophis’s path in 2029

The science team that built the twin Janus spacecraft, designed to fly past an asteroid but stranded when its launch got canceled, are now considering the potentially dangerous asteroid Apophis as a new target.

If the Janus spacecraft can find a ride by early 2028, scientists could use one or both of the spacecraft to scout out the large asteroid Apophis before its super-close approach to Earth in April 2029. (If only one spacecraft visits Apophis, scientists would see only about half of the asteroid but could send the second spacecraft elsewhere; if both spacecraft fly past the same object they can be arranged to reveal the whole surface.)

Initially the entire Janus mission had been designed on the assumption it would launch as a secondary payload when the Psyche mission to the asteroid Psyche launched last fall. When that launch had to be canceled because Psyche was not ready, Janus lost its mission. The science team has since been struggling to find a replacement, handicapped by the fact that it must go as a secondary payload.

There is a serious issue however with arriving ahead of Apophis’s close approach in 2029. The science community has discouraged such missions, because they fear a spacecraft arriving then could shift Apophis’s trajectory and actually increase the chance it will hit the Earth during a later close approach. Instead, all planetary probes presently going to Apophis in 2029 are planning to arrive after the flyby.

The risk is extremely small, but it must be considered before sending Janus to Apophis.

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A Martian bear!

10:24 am

A Martian bear!
Click for original image. Full image here.

Silly image time! Today the science team for the high resolution camera on Mars Reconnaissance Orbiter posted the photo to the right, which I have cropped, reduced, and annotated to post here. It was taken on December 12, 2022, and was rotated so that north is to the right in order to make its resemblance to a bear’s face obvious. As noted in the caption by Alfred McEwen of the Lunar & Planetary Laboratory in Arizona:

There’s a hill with a V-shaped collapse structure (the nose), two craters (the eyes), and a circular fracture pattern (the head). The circular fracture pattern might be due to the settling of a deposit over a buried impact crater. Maybe the nose is a volcanic or mud vent and the deposit could be lava or mud flows?

Maybe just grin and bear it.

If you have red-green glasses you can see a 3D anaglyph of this image here. The feature itself is located in the southern cratered highlands of Mars at 41 degrees south latitude, so the presence of near surface ice that would cause a mud volcano is definitely possible.

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NASA and Russian engineers meeting to discuss status of leaks on ISS’s Zvezda module

9:40 am

According to Russia’s state-run press, NASA and Russian engineers have been reviewing the status of the repairs on the cracks in the Zvezda module on ISS.

Repairs to the various cracks in Zvezda’s hull, done by Russian astronauts in ’20 and ’21, have reduced the leakage from 1,140 grams per day to 300 grams per day. Normally ISS is expected to lose 325 grams per day, across the entire station, so the Zvezda leak doubled this loss, even after the repair. Thus, the hatch to Zvezda is kept closed in order to maintain the atmosphere of ISS at its normal levels, and opened only when there is need to enter it. In addition, its port is no longer used for dockings.

The engineering review is also looking into the cause of the cracks, which are believed to be stress fractures caused by the age of Zvezda (ISS’s second oldest module) combined with the many dockings that had occurred at its port. The review is also discussing ways to reduce the problem, until ISS’s retirement in 2030.

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German rocket startup Isar Aerospace gets first American customer

9:28 am

The German rocket startup Isar Aerospace, which hopes to complete the first launch of its Spectrum rocket this year, has signed its first launch contract with an American company, the satellite broker and space tug company Spaceflight.

U.S.-based launch services provider Spaceflight said Jan. 25 it has booked a dedicated launch in 2026 from Isar Aerospace, the German rocket developer aiming to perform the first test flight of its Spectrum vehicle this year. The mission is slated to lift off from Isar’s launchpad in Andøya, Norway, to sun-synchronous orbit (SSO).

Their agreement also includes an option for an additional dedicated launch in 2025, which Isar chief commercial officer Stella Guillen told SpaceNews could also use a launchpad it is developing at the Guiana Space Center near Kourou, French Guiana.

Spaceflight has been scrambling to find rockets for its tugs, since SpaceX announced in March 2022 it would no longer carry them. It signed a deal with Arianespace to fly on its Vega rocket, but launch failures have delayed its launch.

Isar is one of three German rocket startups vying for business. The race to be the first to launch remains very tight.

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Lucy team adds 10th asteroid to the spacecraft’s tour

9:17 am

Lucy's route through the solar system
Lucy’s route through the solar system

The Lucy science team has now added a tenth asteroid to the spacecraft’s tour of the solar system, planning its route so that it will pass within 280 miles on November 1, 2023.

The Lucy mission is already breaking records by planning to visit nine asteroids during its 12-year tour of the Jupiter Trojan asteroids, which orbit the Sun at the same distance as Jupiter. Originally, Lucy was not scheduled to get a close-up view of any asteroids until 2025, when it will fly by the main belt asteroid (52246) Donaldjohanson. However, the Lucy team identified a small, as-yet unnamed asteroid in the inner main belt, designated (152830) 1999 VD57, as a potential new and useful target for the Lucy spacecraft.

The asteroid is about 2,300 feet wide. The primary goal of this visit however will be engineering, testing Lucy’s new method of tracking an object as the spacecraft flies past. On the map to the right the dots along Lucy’s path indicate the asteroids to be visited.

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SpaceX successfully launches a record 56 Starlink satellites

8:54 am

SpaceX early today successfully launched a record 56 Starlink satellites on a single Falcon 9 rocket, which also carried a record mass for the rocket.

The first stage successfully landed on a drone ship in the Atlantic, completing its 9th flight. The fairing halves completed the 6th and 7th flights.

The 2023 launch race:

6 SpaceX
5 China
1 Rocket Lab
1 Japan

American private enterprise now leads China 7 to 5 in the national ranks, and the entire world combined 7 to 6.

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Japan’s H2A rocket successfully launches radar surveillance satellite

8:16 pm

Japan’s space agency JAXA today successfully launched a radar surveillance satellite using its H2A rocket, built by Mitsubishi.

This was Japan’s first launch since December 2021, a gap of more than a year, with no launches in 2022. JAXA hopes to finally launch its unimaginatively named H3 rocket, the replacement for the H2A, on February 12, 2023, after a two year delay because of cracks found in the engines.

The 2023 launch race:

5 China
5 SpaceX
1 Rocket Lab
1 Japan

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A dry lakebed on Mars?

12:37 pm

Evidence of a past lake in a crater on Mars
Click for original image.

Today’s cool image illustrates in some ways the uncertainty of science. The photo to the right, rotated, cropped, reduced, and sharpened to post here, was taken on December 1, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The science team intriguingly labeled it “Small Candidate Lake Deposit Downstream of Alluvial Fan.” I am not sure what they consider that lake deposit in the full image, so I have focused on the area of stucco-like ground, which resembles bedrock that has been corroded by some water process.

This area is just to the east of the central peaks of an unnamed 25-mile-wide crater in the southern cratered highlands. Many of the craters in this region are believed by scientists to have once harbored lakes formed by run-off from the glaciers that once existed on the craters’ inner rim. In this case it appears this stucco area is the head of an alluvial fan, coming down from the crater’s central peaks. You can see its beginning in this MRO high resolution image of the central peaks, taken in November 2016. As defined geologically,

An aluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to semiarid climates, but are also found in more humid environments subject to intense rainfall and in areas of modern glaciation.

In this case the terrain is now arid, but shows evidence it once was icy wet.
» Read more

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ISRO about to test land a prototype of India’s own version of the X-37B

9:46 am

ISRO's own X-37B copy

According to S. Somanth, the head of India’s space agency ISRO, it will attempt the first flight on January 28, 2023 of a prototype reusable launch vehicle, similar to the Space Force’s X-37B.

According to ISRO’s website, Saturday’s landing demonstration will involve a “landing experiment (LEX)” in which the RLV will be carried using a helicopter to an altitude of 3-5 km and released at approximately 4-5 km from the runway with a horizontal velocity.

After the release, the RLV glides and navigates toward the runway, and carries out a conventional autonomous landing. This is planned in a defence airfield near Chitradurga in Karnataka.

The graphic to the right shows the flight profile of earlier tests that landed in the ocean. If this runway test is successful, it appears ISRO will next attempt an orbital flight and return.

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Arianespace’s chief condemns the idea of independent private European rocket companies

9:31 am

Stéphane Israël, the head of Arianespace, the European Space Agency’s (ESA) commercial rocket division, yesterday strongly condemned the idea of allowing independent private European rocket companies to develop and compete with his government operation.

“It is not possible to copy-paste the US model,” he said. “It is not possible. The level of space spending in the United States is five times higher than in Europe, and the private capital is not the same. So if the answer is to say let’s do what the US has done, I think we will not manage to do it.”

Moreover, Israël said the European Space Agency must resist supporting microlaunchers to the point where these companies might compete with the existing capabilities.

“A huge mistake would be that this focus on microlaunchers destabilizes Ariane 6 and Vega C—it would be a historic mistake,” he said. “Microlaunchers can be of support to boost innovation. But we should not make any confusion. This launcher will never give autonomous access to space to Europe. They’re on a niche market representing maybe 10 percent of the market, and less than that when it comes to European needs.”

He said this in Brussels at the 15th European Space Conference, where it appears he was trying to convince the ESA to block any competition with Arianespace.

Israël might say this, but not only has his track record in predicting the success of commercial space in the U.S. been bad, other European governments are not taking his advice. Both Germany and the United Kingdom have several rocket startups gearing up for their first launches this year, with others in Spain and France not far behind. Moreover, Israël doesn’t have much to offer in competition. Arianespace’s Vega rocket, intended to be a low cost option, has failed on three of its last eight launches. The Ariane 6 rocket is years behind schedule, and has not yet launched. And both are overpriced and cannot compete, not only with the American rocket startups but with India’s government rockets.

Moreover, those European governments have in recent years been taking control and power away from Israël and Arianespace. Unlike earlier rockets, the Ariane 6 rocket is not controlled or owned by Arianespace. Instead, it belongs to ArianeGroup, the partnership of Airbus and Safran that is building it. Arianespace’s role in operating it will be greatly limited, once it begins flying.

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Roscosmos predicts Russia’s new space station will launch by 2027

9:14 am

Wanna bet? Yuri Borisov, the head of Roscosmos, yesterday predicted that Russia’s new space station, dubbed the Russian Orbital Station, will launched and deployed by 2027.

“We will create sovereign infrastructure for human space flights to low near-Earth orbit. Its key element will be the Russian orbital station whose deployment we have scheduled for 2027,” he said.

The Russian space agency will carry out all the required feasibility studies by Cosmonautics Day celebrated in Russia on April 12, the Roscosmos chief said.

Based on Russia’s track record for the past three decades, this prediction will fail. Since the fall of the Soviet Union Russia’s space industry has consistently made many such predictions, none of which launched on time, with most never launching at all. Yet, that was during a time when Russia’s economy was booming, it was getting lots of revenue from the international markets, and wasn’t saddled with a draining war in the Ukraine. Now, international sanctions limit what it can get from that market, and its oil revenues have declined considerable due to the war. Moreover, the war prevents Russia from obtaining many cutting edge space components it needs for such a project. Replacing these with home-built components will take time.

If this station gets built, its launch will likely not happen before 2030.

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Stacked Starship and Superheavy complete first full wet dress rehearsal countdown

9:06 am

SpaceX yesterday successfully completed a full wet dress rehearsal countdown of its stacked Starship prototype #24 and Superheavy prototype #7, fueling both completely and taking the countdown down to T-0.

On this rehearsal however the Superheavy engines were not fired. From two SpaceX tweets:

Starship completed its first full flight-like wet dress rehearsal at Starbase today. This was the first time an integrated Ship and Booster were fully loaded with more than 10 million pounds of propellant

Today’s test will help verify a full launch countdown sequence, as well as the performance of Starship and the orbital pad for flight-like operations

Next step: Another full wet dress rehearsal countdown that includes a short static fire test of all 33 Superheavy Raptor-2 engines. Once that is done successfully, the company will be ready for that first orbital launch.

Meanwhile, SpaceX awaits its launch license from the FAA. I remain pessimistic that it will be issued on a timely manner, as there are clear signs the Biden administration wants to use its power against Musk, whom it now sees as an enemy.

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Classified Chinese test satellite releases second object in orbit

8:55 am

A classified Chinese test satellite, launched on January 8th, apparently released a second object into orbit on January 16th, suggesting the satellite might be doing robotic rendezvous and docking tests, similar to tests by an earlier classified satellite.

China’s Shijian 21 satellite, which launched in 2021, also reached GEO and released a satellite, which was then used for tests. Shijian 21 then proceeded to dock with the defunct Chinese navigation and positioning satellite Beidou-2 G2 and towed it away to an orbit out of the way of the active spacecraft in GEO.

China is clearly attempting to develop the same robotic servicing technologies that commercial companies in the west are beginning to fly.

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Russians successfully test replacement Soyuz capsule for leaks

8:49 am

The next Soyuz capsule to launch to ISS has now been passed its leak tests on the ground as it is being prepared for a February 20th launch.

“At the Baikonur cosmodrome, leak tests of the Soyuz MS-23 transport crewed spacecraft have been completed,” the [Roscosmos press release] said. In the coming days, checks of the propulsion system’s automation equipment, onboard digital computerized system and radio engineering systems will follow. Also, the thermal control system is to be filled with a coolant.

The launch has been moved up one month in order to speed the replacement of the leaking Soyuz presently on ISS.

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Rocket Lab successfully completes first launch from the U.S.

8:35 am

Using its Electron rocket, Rocket Lab yesterday placed three smallsats into orbit, launching for the first time from Wallops Island in Virginia.

The company now has three launchpads, one in Wallops and two in New Zealand. Expect its launch pace in 2023 to ramp up to, at a minimum, once per month.

The 2023 launch race:

5 China
5 SpaceX
1 Rocket Lab

In the national rankings, the U.S. leads China, 6 to 5. No one else has yet launched, though Japan plans a launch today.

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Curiosity’s drill fails for the fourth time to drill into the marker band layer on Mt Sharp

5:11 pm

The fourth attempt yesterday to use Curiosity’s drill to drill into the marker band layer on Mount Sharp once again was unable to drill down deep enough to obtain a sample.

Despite giving it the “old college try,” Curiosity’s attempt to drill into the Marker Band at the “Encanto” site did not reach sampling depth. Because other rocks around the rover look similar to “Encanto” and are likely also too hard to drill, the Science Team decided to convert the plan to a “Touch and Go.”

Although the Science Team is disappointed to leave this Marker Band location without a sample, Curiosity will use MAHLI, APXS, and ChemCam LIBS to analyze the chemistry and texture of the shallow “Encanto” drill hole and tailings, targeting the intriguing light-toned material exposed in the wall of the drill hole. We may see another location in the Marker Band worth sampling in the near future, but even if we don’t, there will certainly be many more exciting drilling opportunities to look forward to as Curiosity continues her climb up Mt. Sharp!

This drilling difficulty is not a surprise. The marker band is a very distinct flat layer that is seen at about the same elevation on all sides of Mount Sharp. It flatness suggests it is resistant to erosion, which also suggests its material will be hard. The inability of Curiosity’s drill to penetrate it only confirms this.

It also makes getting a drill sample to test even more intriguing. I suspect that the science team is going to try a few more times as it travels forward across the band, as indicated by the red dotted line in the panorama below.
Panorama as of January 17, 2023
Click for full image.

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Jupiter and two of its Moons, as seen by Cassini during 2018 fly-by

4:41 pm

Cool video time! Back in December 2000 the spacecraft Cassini made a fly-by of Jupiter on its way to Saturn, which it then orbited from 2004 to 2017. In 2018 JPL scientist Kevin Gil took the images from that flyby to create a short movie, first showing two of Jupiter’s moons, Io and Europa, as they drifted above the Great Red Spot.

Then, for the second half of the movie Gil used Cassini images taken when in orbit around Saturn to show the moon Titan moving across the rings of Saturn.

I have embedded this short video below. If I had posted this back in 2018, I don’t remember. No matter. It is amazing enough to watch again.

Hat tip BtB’s stringer Jay.
» Read more

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New evidence suggests the Earth’s inner core no longer rotates faster than the planet’s outer layers

8:41 am

The uncertainty of science: The same scientists who in the late 1990s thought they had detected evidence that the Earth’s inner core rotates faster than the planet’s mantle now say that this faster rotation ceased sometime around 2009.

In 1996, Song and another researcher reported studying earthquakes that originated in the same region over three decades, and whose energy was detected by the same monitoring station thousands of kilometres away. Since the 1960s, the scientists said, the travel time of seismic waves emanating from those earthquakes had changed, indicating that the inner core rotates faster than the planet’s mantle, the layer just beyond the outer core.

…Now, Yang and Song say that the inner core has halted its spin relative to the mantle. They studied earthquakes mostly from between 1995 and 2021, and found that the inner core’s super-rotation had stopped around 2009. They observed the change at various points around the globe, which the researchers say confirms it is a true planet-wide phenomenon related to core rotation, and not just a local change on the inner core’s surface.

It is important to note that there has not been a consensus on this data, that some scientists even doubt the super-rotation ever existed. The data itself is sparse enough and includes enough gaps to allow for this disagreement, which also means this new conclusion is also uncertain.

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Communications issue shuts down one of Webb’s instruments

8:30 am

The near infrared instrument on the Webb Space Telescope, NIRISS, has been unavailable for science observations for more than a week due to a communications issue.

On Sunday, Jan. 15, the James Webb Space Telescope’s Near Infrared Imager and Slitless Spectrograph (NIRISS) experienced a communications delay within the instrument, causing its flight software to time out. The instrument is currently unavailable for science observations while NASA and the Canadian Space Agency (CSA) work together to determine and correct the root cause of the delay.

According to the update, the instrument’s hardware, as well as the rest of the telescope, has been unaffected and remains in good condition.

In November the telescope’s mid-infrared instrument MIRI experienced its own problems with one of its “grating wheels” that allows it to some spectroscopy. Since then the instrument has been in use, but it is unclear if the issue was resolved or observations have had to be adjusted to avoid the problem.

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Martian crater with mound of ice? mud? hardened sand?

12:17 pm

Crater with mound
Click for full image.

Cool image time! The photo to the right, cropped to post here, was taken on October 31, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a small 4,000-foot-wide crater that is practically filled with a smooth, almost perfectly spherical mound, with the rest of the crater interior filled with sand dunes and what appears to be glacial debris.

Is that mound also glacial debris, covered with a layer of dirt and dust to protect it? If so, one wonders how the ice ended up in this shape. There are other craters with similar mounds in this region, all suggesting glacial debris but with the same question. Craters with lots of near surface ice in this region more often have a squishy blobby look.

Is the mound instead possibly mud, expressing the existence of a mud/ice volcano? If so, it shows no central pit or caldera, which is typical of such things.

Is it hardened sand? Martian dust that gets blown into craters generally gets trapped there, building up over time. If so, however, why does it have a smooth almost perfectly rounded shape? The ripple sand dunes surrounding it are more like what you would expect.

The small craters on the mound also tell us that it is hardened and old, no matter what it is made of.
» Read more

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Animation of Jupiter’s clouds

9:19 am

Cool video time! Using a photo taken by Juno during its 2018 fly-by of Jupiter, citizen scientist Thomas Thomopoulos has created a short animation showing the flow of Jupiter’s clouds. He also added some 3D relief by assigning elevation to the image’s greyscale, with lighter regions assigned higher altitudes.

I have embedded the animation below. Run it at the slowest speed for the best effect. It is quite spectacular, though it is also important to note that it is not reality. Thomopoulos is simply giving us a hint of the natural evolution of the cloud structures, both in elevation and in time.

You can see another equally impressive animation by Thomopoulos here of several of Jupiter’s polar storms, using AI technology to smooth out the loop.
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