Tag: engineering

Chinese smallsat snaps pictures of Chinese space station

9:45 am

One third of the way through their month long mission, on Sunday the two Chinese astronauts aboard Tiangong-2 released a smallsat designed to maneuver around the station and take images of it.

The cubical craft deployed from Tiangong 2 on Sunday is about the size of a printer, and it took sharp black-and-white pictures of the space lab and the Shenzhou 11 crew transport craft docked together around 235 miles (380 kilometers) above Earth. Fitted with a 25-megapixel camera and an ammonia-based propulsion system, the Banxing 2 satellite is expected to loiter around Tiangong 2 and Shenzhou 11, and eventually return to the vicinity of the complex to take pictures from above with Earth in the background, according to Chinese state media reports.

The first batch of photos from Banxing 2’s departure are looking up at the mini-space station complex, with the blackness of space as a backdrop. In addition to the imagery taken by the micro-satellite’s visible camera, Banxing 2 captured more than 300 infrared pictures during the flyaway sequence.

This is a neat idea, one that neither Russia nor the U.S. ever did on their stations. Moreover, to provide this smallsat a propulsion system is significant, since satellites this small have traditionally not had one. Testing that system is certainly one of the smallsats main purposes.

The image at the link of the station and capsule docked together reveals how relatively small Tiangong-2 really is, compared to the Shenzhou manned spacecraft as well as other Russian single module stations. Shenzhou is about as long as Tiangong, and though the Chinese have made their manned capsule bigger than the Soyuz spacecraft they based it on, it isn’t that much bigger. In fact, the article says that the combined station and spacecraft is about 60 feet long. Russia’s Salyut stations, which were also a single module like Tiangong-2, were about that long, before the Soyuz was added.

In other words, Tiangong-2, as was Tiangong-1, are exactly what the Chinese have said they are, prototype testbeds for testing the engineering needed for building a much bigger multi-module station in 2020. What is unclear is whether the modules of that bigger station will be bigger as well.

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The effect of weightlessness on the spine

9:04 am

New observations of astronauts before and after four to seven month long missions to ISS has found the back pain many astronauts experience appears to be caused by significant muscle atrophy.

The MRI scans indicated significant atrophy of the paraspinal lean muscle mass —which plays a critical role in spinal support and movement—during the astronauts’ time in space. The lean muscle, or “functional,” cross-sectional area of the lumbar paraspinal muscles decreased by an average of 19 percent from preflight to immediate postflight scans. A month or two later, only about two-thirds of the reduction had recovered. There was an even more dramatic reduction in the functional cross-sectional area of the paraspinal muscles relative to total paraspinal cross-sectional area. The ratio of lean muscle decreased from 86 percent preflight to 72 percent immediately postflight. At follow-up, the ratio recovered to 81 percent, but was still less than the preflight value.

In contrast, there was no consistent change in the height of the spinal intervertebral discs. Dr. Chang and coauthors write, “These measurements run counter to previous hypotheses about the effects of microgravity on disc swelling.” Further studies will be needed to clarify the effects on disc height, and whether they contribute to the increase in body height during space missions, and to the increased risk of herniated disc disease.

These results are very encouraging, because they indicate that the back problems seen are mostly attributable to weakened muscles, not actual spinal damage, and can therefore be more easily mitigated by new exercises while in orbit.

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Aggressive SETI observations of Tabby’s star upcoming

8:29 am

Breakthrough Listen, an effort to listen for radio signals from alien civilizations that, plans to devote significant time this year observing Tabby’s star to see if an alien mega-structures are causing that star’s unexplained dimming.

While Siemion and his colleagues are skeptical that the star’s unique behavior is a sign of an advanced civilization, they can’t not take a look. They’ve teamed up with UC Berkeley visiting astronomer Jason Wright and Tabetha Boyajian, the assistant professor of physics and astronomy at Louisiana State University for whom the star is named, to observe the star with state-of-the-art instruments the Breakthrough Listen team recently mounted on the 100-meter telescope. Wright is at the Center for Exoplanets and Habitable Worlds at Pennsylvania State University.

The observations are scheduled for eight hours per night for three nights over the next two months, starting Wednesday evening, Oct. 26. Siemion, Wright and Boyajian are traveling to the Green Bank Observatory in rural West Virginia to start the observations, and expect to gather around 1 petabyte of data over hundreds of millions of individual radio channels.

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Juno successfully completes engine burn with smaller thrusters

7:01 pm

Having successfully left safe mode, engineers had Juno do a 31 minute engine burn on Tuesday to adjust its orbit using its smaller thrusters.

The burn, which lasted just over 31 minutes, changed Juno’s orbital velocity by about 5.8 mph (2.6 meters per second) and consumed about 8 pounds (3.6 kilograms) of propellant. Juno will perform its next science flyby of Jupiter on Dec. 11, with time of closest approach to the gas giant occurring at 9:03 a.m. PDT (12:03 p.m. EDT). The complete suite of Juno’s science instruments, as well as the JunoCam imager, will be collecting data during the upcoming flyby.

That they will definitely collect data during the December 11 flyby means that they are going to delay again the main engine burn that will reduce the spacecraft’s orbit to 14 days, its official science orbit. This also means that they are still uncomfortable firing that main engine. It is also not clear from the press release whether this burn was planned, or was added to compensate for the main engine issues.

The vagueness makes me think that Juno has some serious issues that they haven’t yet told us about.

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The storms of Jupiter’s south pole

10:12 am

storms on Jupiter

Cool image time! Even though Juno has been unable to gather any additional data since its first close approach of Jupiter in August because of technical problems, the science team has set up its website to allow the public to download the images produced so far, process those images, and then upload them to the site for the world to see.

The image to the right, reduced in resolution to show here, is one example of the many different processed images produced by interested members of the general public. It highlights the seemingly incoherent storms that are raging at Jupiter’s south pole.

close-up of storms

To the left is a cropped section of the full resolution image. It shows the complex transition zone between the darker polar regions and the brighter band that surrounds it. This chaotic atmospheric behavior is something that no climate scientist has ever seen before. It will take decades of research to untangle and even begin to understand what is happening.

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Schiaparelli failure focuses in on altimeter data

9:50 am

The investigation into the landing failure last week of the ExoMars 2016 lander, Schiaparelli, is now focusing on a failure in the spacecraft’s altitude software.

The most likely culprit is a flaw in the craft’s software or a problem in merging the data coming from different sensors, which may have led the craft to believe it was lower in altitude than it really was, says Andrea Accomazzo, ESA’s head of solar and planetary missions. Accomazzo says that this is a hunch; he is reluctant to diagnose the fault before a full post-mortem has been carried out. But if he is right, that is both bad and good news.

European-designed computing, software and sensors are among the elements of the lander that are to be reused on the ExoMars 2020 landing system, which, unlike Schiaparelli, will involve a mixture of European and Russian technology. But software glitches should be easier to fix than a fundamental problem with the landing hardware, which ESA scientists say seems to have passed its test with flying colours. “If we have a serious technological issue, then it’s different, then we have to re-evaluate carefully. But I don’t expect it to be the case,” says Accomazzo.

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Russia considers using Ukrainian rocket

9:46 am

For the first time since it annexed Crimea, Russia has opened negotiations with a Ukrainian company to possibly use its Zenit rocket to launch a Russian satellite.

RKK Energia of Korolev, Russia, entered negotiations with KB Yuzhnoe of Dnepropetrovsk, Ukraine, on a potential deal to launch a satellite for Angola on a Ukrainian-built Zenit rocket. Under the proposed plan, the Angosat-1 satellite would ride the last fully assembled Zenit rocket still remaining in Baikonur. The mission is seen by industry insiders as the first step in the resumption of Zenit missions, which if successful, will eventually shift from Baikonur to the Sea Launch ocean-going platform based in Long Beach, California.

The situation here is beyond complicated. Russia remains in many ways in a state of war with Ukraine. Yet, the Sea Launch platform, recently purchased by a Russian airline company, needs the Ukrainian Zenit rocket. It appears that this need is forcing the Russians to once again buy from the Ukraine. At the same time, Sea Launch remains parked in the U.S., and will likely not be available until Sea Launch and Russia settle the lawsuit Boeing has filed against the company. Meanwhile, the Zenit rocket in question however needs refurbishing and was originally built to launch a different satellite, which will have to agree to fly on a different launch vehicle.

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ISRO begins ground tests of its first lunar lander

9:36 am

The competition heats up: ISRO, India’s space agency, has begun testing the sensors its first lunar lander, Chandrayaan-2, will use to descend safely to the surface.

ISRO Satellite Centre or ISAC, which is the lead centre for the country’s second moon mission, has artificially created eight to ten craters to make the terrain resemble the lunar surface. This terrain is now the test bed for the lunar Lander’s sensors. Between Friday and Monday, a small ISRO-owned aircraft carrying equipment with the sensors flew a few times over these craters to see how well they performed.

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Musk answers questions on reddit

10:02 am

In a reddit Q&A session yesterday, Elon Musk answered a host of questions about his Mars mission plans.

Key takeaway: They are far away from actually flying this rocket. The engine needs tests, its giant tanks need a great deal of development, and they are only beginning the concept work for the ship itself.

His comments on Falcon 9 re-usability, however, were somewhat more interesting, and far more grounded in present reality.

Musk did not answer any questions submitted about the status of the company’s Falcon 9 rocket, grounded since a Sept. 1 explosion during preparations for a static-fire test destroyed a Falcon 9 and its Amos-6 satellite payload. He did, though, briefly address an upcoming, and “final,” version of the rocket, which he called Block 5, that is designed for frequent reusability. “Falcon 9 Block 5 — the final version in the series — is the one that has the most performance and is designed for easy reuse, so it just makes sense to focus on that long term and retire the earlier versions,” he wrote. That version includes many “minor refinements” but also increased thrust and improved landing legs, he said.

The first of the Block 5 Falcon 9 vehicles will begin production in three months, with an initial flight in six to eight months. With its entry into service, he said he doesn’t expect recovered first stages from the older Block 3 and Block 4 versions of the rocket to be reused more than a few times.

In a speech earlier this month, SpaceX President Gwynne Shotwell said she believed the updated version of the Falcon 9 could be reused up to 10 times. Musk, though, was more optimistic. “I think the F9 boosters could be used almost indefinitely, so long as there is scheduled maintenance and careful inspections,” he said.

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Changing seasons on Titan

9:15 am

Since entering Saturn orbit in 2004, Cassini has seen the seasons on Titan shift through half a Saturn year.

As Titan approaches its northern summer solstice, NASA’s Cassini spacecraft has revealed dramatic seasonal changes in the atmospheric temperature and composition of Saturn’s largest moon. Winter is taking a grip on the southern hemisphere and a strong vortex, enriched in trace gases, has developed in the upper atmosphere over the south pole. These observations show a polar reversal in Titan’s atmosphere since Cassini arrived at Saturn in 2004, when similar features were seen in the northern hemisphere.

Sadly, there will not be any spacecraft at Saturn during the second half of this Saturn year. After Cassini ends its mission in 2017 it will likely be many decades before another spacecraft arrives, since at this moment none has even been proposed.

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Saturn’s changing north pole

10:38 pm

A comparison of images taken by Cassini in 2012 and then in 2016 of Saturn’s north polar region shows a significant change in color.

Scientists are investigating potential causes for the change in color of the region inside the north-polar hexagon on Saturn. The color change is thought to be an effect of Saturn’s seasons. In particular, the change from a bluish color to a more golden hue may be due to the increased production of photochemical hazes in the atmosphere as the north pole approaches summer solstice in May 2017.

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Did fueling procedures cause Falcon 9 launchpad explosion?

6:18 pm

This Wall Street Journal article today speculates that “problematic fueling procedures” might have caused the September 1 Falcon 9 launchpad explosion.

Company officials have said it is too early to arrive at definitive answers, though one person familiar with the investigation said initial concerns about potentially substandard welds have been relegated to a low priority. If testing bears out early findings focusing on problematic fueling practices instead of hardware flaws, SpaceX likely will avoid a major redesign effort or extensive quality-control checks that could drag on for months.

Caution must be exercised here. The article depends on unnamed sources, and does not provide any details describing how fueling procedures could have caused the explosion.

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Something in the Kremlin is jamming GPS

6:14 pm

It appears that any GPS unit that approaches the Kremlin in Moscow can no longer pinpoint accurately its location.

A programmer for Russian internet firm Yandex, Grigory Bakunov, said Thursday his research showed a system for blocking GPS was located inside the Kremlin, the heavily guarded official residence of Russian President Vladimir Putin. Users of GPS have complained on social media in recent months that when they are near the Kremlin their GPS-powered apps stop working or show them to be in Moscow’s Vnukovo airport, 29 kilometers (18 miles) away.

The problem has frustrated those requesting taxis via services such as Uber or looking to catch Pokemons in the popular game played on mobile devices. Large numbers of people running the Moscow marathon last month complained that their jogging apps lost track of how far they had run when they passed the Kremlin.
“I got 40 kilometers added on to my distance. It happened by the Kremlin,” marathoner Andrey Yegorov wrote on Facebook as part of a discussion by runners.

Not surprisingly, the agency in charge of security at the Kremlin declined to comment.

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MRO images Schiaparelli on Mars

12:06 pm

before and after Schiaparelli

A comparison of images taken by Mars Reconnaissance Orbiter before and after Schiaparelli’s failed attempt to land on Mars have revealed changes that are likely the lander on the surface. The image on the right is a composite that I’ve made showing the two images. The black spot near the top and the white spot near the bottom are not in the first image.

It is thought that the white spot is likely Schiaparelli’s parachute, while the dark spot is thought to be the lander’s impact point.

The larger dark spot near the upper edge of the enlargement was likely formed by the Schiaparelli lander. The spot is elliptical, about 50 by 130 feet (15 by 40 meters) in size, and is probably too large to have been made by the impact of the heat shield.

The large size of the dark spot suggests that the lander hit the ground hard enough to create this large scar.

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Did Viking discover life on Mars?

11:30 am

Link here. The article provides a very detailed review of the conflicting results from the various 1970s Viking lander experiments, one of which strongly suggested the presence of microorganisms.

Overall, these life-detection experiments produced surprising and contradictory results. One experiment, the Labeled Release (LR) experiment, showed that the Martian soil tested positive for metabolism—a sign that, on Earth, would almost certainly suggest the presence of life. However, a related experiment found no trace of organic material, suggesting the absence of life. With no organic substances, what could be, or seem to be, metabolizing?

In the forty years since these experiments, scientists have been unable to reconcile the conflicting results, and the general consensus is that the Viking landers found no conclusive evidence of life on Mars. However, a small minority of scientists argues that the Viking results were positive for life on Mars.

The contradictory Viking results have never been fully explained. Many theories have been proposed, ranging from the chemical to the biological, but none have satisfied anyone.

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Virgin Galactic lawsuit against Firefly moves forward

9:37 am

Virgin Galactic last week moved forward aggressively in its lawsuit against Firefly Space Systems, its officers, and its business partners for using stealing trade secrets.

According to the Complaint, Galactic hired Markusic in 2011 as its VP of Propulsion. Markusic’s role gave him intimate knowledge of the Company’s research into liquid rocket propulsion, space vehicle architecture, “aerospike” technology, and other confidential projects. While still employed at Galactic, Markusic allegedly solicited business partners and founded Firefly based on concepts and data he obtained in the course of his work. Galactic maintains that Markusic and Firefly relied on and continues to use the Company’s technical and marketing information, as well as Markusic’s engineering notes from his tenure at Galactic, to develop products such as a recently announced small launch vehicle.

The worst thing about this court battle to me is that if Virgin Galactic has developed worthwhile technology in connection with the aerospike engine, they have done nothing to develop it, and are now acting to squelch someone else’s effort.

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Did Opportunity see Schiaparelli?

9:43 am

Opportunity image of Schiaparelli?

Because Schiaparelli was aimed at a landing site somewhat close to the Mars rover Opportunity, the science team aimed the rover’s panoramic camera at the sky yesterday, taking fourteen pictures in the hope of capturing the lander as it came down. Of those fourteen images, the image on the right, reduced in resolution, is the only one that shows that bright streak in the upper right.

close-up of streak

Though this streak might be an artifact, I do not think so. To the left is a close-up from the full resolution image, showing the streak in detail. That doesn’t look like an artifact. It still could be a meteorite, but I also think that doubtful. The coincidence of a meteorite flashing across the sky at the same exact moment Opportunity is looking to photograph Schiaparelli’s landing is too unlikely.

If this is Schiaparelli, expect a press release from NASA in the next few days.

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Schiaparelli landing apparently a failure

8:32 am

This report from russianspaceweb.com provides some details about the apparent landing failure of the European Mars probe Schiaparelli on Wednesday.

The very preliminary analysis of the data revealed a number of serious problems in the final phase of the parachute descent. The telemetry showed that the back heat shield holding the parachute had been ejected earlier than scheduled — 50 seconds instead of 30 seconds before the touchdown. Also, the lander was apparently descending at a speed higher than planned. There were also indications that the soft-landing engines had fired for only three or four seconds and all communications from the lander were cut 19 seconds later, or shortly before touchdown. By that time, Schiaparelli’s landing radar had been activated.

It appears the parachutes were released too soon so that they did not function properly and slow the spacecraft down enough. When the retro-rockets fired the spacecraft was probably also closer to the ground than planned and falling too fast, so they failed to stop it from impacting the surface hard and prematurely.

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Fate of Schiaparelli remains unknown

4:06 pm

While Europe’s Trace Gas Orbiter has successfully gone into orbit around Mars, it remains unknown whether the lander Schiaparelli was able today to land successfully on the surface.

The carrier signal from Schiaparelli recorded by Mars Express abruptly ended shortly before landing, just as the beacon tone received by a ground-based radio telescope in India stopped in real-time earlier today.

Paolo Ferri, head of ESA’s mission operations department, just gave an update on the situation. “We saw the signal through the atmospheric phase — the descent phase. At a certain point, it stopped,” Ferri said. “This was unexpected, but we couldn’t conclude anything from that because this very weak signal picked up on the ground was coming from an experimental tool.

“We (waited) for the Mars Express measurement, which was taken in parallel, and it was of the same kind. It was only recording the radio signal. The Mars Express measurement came at 1830 (CEST) and confirmed exactly the same: the signal went through the majority of the descent phase, and it stopped at a certain point that we reckon was before the landing.

“There could be many many reasons for that,” Ferri said. “It’s clear these are not good signs, but we will need more information.”

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Juno enters safe mode prior to Jupiter close approach

1:25 pm

Because Juno entered safe mode prior to its close approach of Jupiter today, no science data was gathered.

NASA’s Juno spacecraft entered safe mode Tuesday, Oct. 18 at about 10:47 p.m. PDT (Oct. 19 at 1:47 a.m. EDT). Early indications are a software performance monitor induced a reboot of the spacecraft’s onboard computer. The spacecraft acted as expected during the transition into safe mode, restarted successfully and is healthy. High-rate data has been restored, and the spacecraft is conducting flight software diagnostics. All instruments are off, and the planned science data collection for today’s close flyby of Jupiter (perijove 2), did not occur. “At the time safe mode was entered, the spacecraft was more than 13 hours from its closest approach to Jupiter,” said Rick Nybakken, Juno project manager from NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We were still quite a ways from the planet’s more intense radiation belts and magnetic fields. The spacecraft is healthy and we are working our standard recovery procedure.”

This problem, combined with the thruster valve problem that prevented engineers from putting the spacecraft into its proper 14-day science orbit today, is significantly delaying science operations. They will not be able to adjust the orbit again until its next close approach December 11 (assuming the thruster problem has been solved by then), and until then it will also not be able to do much science.

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Landslides on Charon

8:40 am

Landslide on Charon

Images from New Horizons have detected evidence of past avalanches on Pluto’s largest moon, Charon. The image on the right is a reduced version of a perspective view created using data from various instruments.

This perspective view of Charon’s informally named “Serenity Chasm” consists of topography generated from stereo reconstruction of images taken by New Horizons’ Long Range Reconnaissance Imager (LORRI) and Multispectral Visible Imaging Camera (MVIC), supplemented by a “shape-from-shading” algorithm. The topography is then overlain with the PIA21128 image mosaic and the perspective view is rendered. The MVIC image was taken from a distance of 45,458 miles (73,159 kilometers) while the LORRI picture was taken from 19,511 miles (31,401 kilometers) away, both on July 14, 2015.

close-up of landslide

To the left is a close-up taken from the annotated image. You can see the slump materials at the base of the mountain left behind after the material slide down the mountain. It is not clear whether it is Charon’s lower gravity and alien composition and environment (very very very cold) that makes this look more muddy than one would expect, or whether it is because of the limited resolution of the original image and the modeling to create the oblique version.

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Comet 67P/C-G slowly breaking apart

5:56 pm

A comparison of Rosetta images before and after Comet 67P/C-G’s close approach to the sun last year found new fractures and an enlargement of older fractures.

The fractures appear to be developing as forces subtly bend the comet to and fro, Stubbe Hviid, a planetary scientist at the German Aerospace Center Institute of Planetary Research in Berlin, reported October 17 in a press conference at a meeting of the American Astronomical Society’s Division for Planetary Sciences. Hviid and colleagues combined maps from Rosetta with computer simulations of all the forces at work within the comet to determine how the cracks develop. They found that the two bulbous ends rock in opposite directions as the comet spins, flexing the neck and creating severe stress. Because the comet isn’t held together strongly — it’s a conglomeration of dust and ice not much stickier than snow, Hviid said — the neck is starting to break. After a few hundred more years, he said, the comet could fold itself in half as the two lobes snap apart and smoosh together.

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Active volcano on Venus?

5:18 pm

The uncertainty of science: A new analysis of past data from a variety of Venus orbiters suggests that at least one volcano is active there.

The review of old data from the Magellan and Venus Express orbiters suggests that some lava flows on the volcano’s slopes are fresh, though how fresh remains unknown. However, computer models and the detection of excess heat by Venus Express on the mountain’s eastern slopes adds weight to the theory that the volcano is spewing out lava.

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Mars rover update

10:49 am

Emily Lakdawalla at Sky & Telescope today provides an update of the two Mars rovers, but takes a different approach than I have. While I have been focusing on tracking where the rovers are going and what they are doing, she gives a very nice overview of each rovers’ condition, what instruments continue to work and what have failed.

I myself have not done a new rover update since October 6 for several reasons. First and foremost, neither rover has gone anywhere since my last report. Opportunity is still sitting on Spirit Mound, studying the rocks there. Curiosity is still in the flats south of Murray Buttes, preparing to drill another hole.

Secondly, there was a delay this past weekend in downloading data, especially from Curiosity. I strongly suspect that the delay was simply because the Deep Space Network was being used to help with communications between Europe and its ExoMars probes, now set to arrive at Mars tomorrow. When the lander Schiaparelli separated from the orbiter on Sunday they had had some initial communications problems, and it is likely that though ESA was using its own deep space network, they also enlisted ours to help.

Thirdly, I have been very tied up trying to finish my cave project monograph. This is done now, so I finally have more time to work on Behind the Black.

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