Tag: engineering

From the rim to the floor of Valles Marineris

5:01 pm

Overview map

From the rim to the floor of Valles Marineris
Click for full image.

For today’s cool Martian image, we begin from afar and zoom in. The overview map above shows the solar system’s largest canyon, Valles Marineris, 1,500 miles long, and 400 miles wide at its widest. The white dot on the north rim of the section of the canyon dubbed Melas marks the location of the photo to the right, rotated, cropped and reduced to post here and taken on January 28, 2011 by the wide angle context camera on Mars Reconnaissance Orbiter (MRO).

I have added elevation numbers to this picture to give it some understandable scale. From the rim to the interior canyon floor — a distance of about ten miles — the canyon wall drops about 19,000 feet. Compare this with Bright Angel Trail in the Grand Canyon, which from the rim to the Colorado River drops about 4,400 feet in about the same distance. The wall of Valles Marineris is about four times steeper.

Even that doesn’t give you the full scale. Having hiked down to that interior canyon floor, you are still about 10,000 feet above Valles Marineris’s main canyon floor, with fifteen more miles of hiking to go to reach it.

The white rectangle marks the area covered by the MRO high resolution image below.
» Read more

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CAPSTONE completes mid-course correction

10:39 am

Engineers at Advanced Space today successfully completed CAPSTONE’s first mid-course correction, following a quick investigation that determined why communications with the probe was lost for almost a full day.

The communications blackout was apparently due to software issues and human error.

During [in-flight] commissioning of NASA’s CAPSTONE (short for Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment) spacecraft, the Deep Space Network team noted inconsistent ranging data. While investigating this, the spacecraft operations team attempted to access diagnostic data on the spacecraft’s radio and sent an improperly formatted command that made the radio inoperable. The spacecraft fault detection system should have immediately rebooted the radio but did not because of a fault in the spacecraft flight software.

CAPSTONE’s autonomous flight software system eventually cleared the fault and brought the spacecraft back into communication with the ground, allowing the team to implement recovery procedures and begin commanding the spacecraft again.

All looks good for a November 13, 2022 arrival in lunar orbit.

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Scientists: Impacts on rubble-pile asteroid are different than on planets

10:27 am

Landslide on Bennu from impact
Click for full image.

Using data collected by OSIRIS-REx at the asteriod Bennu, scientists have determined that the ejecta from impacts on a rubble-pile asteroid behaves in a very different manner than on planets with higher gravity.

Instead of flying away at about the same speed as the impactor and escaping into space, as expected in the weak gravity, the material is lifted up at a very slow speed, falls back down, and then rolls downhill like a landslide. The graphic to the right from the press release, reduced and enhanced to post here, illustrates what the scientists think happened when one of Bennu’s larger craters was created.

[M]ost of that material, called ejecta, returned to the surface and slid down the face of the asteroid, starting a wide avalanche that slowly rolled toward Bennu’s equator. Perry said the only way this could happen on a small object like Bennu, which is less than 500 meters (1,640 feet) in diameter and has low gravity, is if the dust had low or next to no cohesion.

“Because Bennu is so small, its escape velocity is less than a few tenths of a mile per hour, so any particle ejected faster than that would leave the surface,” he said. “These slow speeds are possible only if Bennu’s surface is weaker than we thought, even weaker than very loose, dry sand. This extremely low surface strength also means material on a slope is easily disturbed, and that’s what led to the landslide.”

In other words, the low cohesion prevents the impact’s energy from being transferred efficiently to the asteroid’s particles. They move, but only slowly, and thus end up sliding away more or less along the asteroid’s surface.

This discovery helps explain how these rubble-pile asteroids accumulate material, despite their low gravity.

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U.S. missile test explodes 11 seconds after launch

9:33 am

A test flight of a Minotaur missile with an updated warhead delivery system exploded 11 seconds after liftoff from Vandenberg Space Force Base in California on July 6th.

Despite a news release saying the Minotaur II+ test would take place Thursday morning from the northern section of the base, the launch occurred the night before, at 11:01 p.m.

More than an hour after liftoff, Vandenberg officials confirmed the booster had exploded approximately 11 seconds after launching from Test Pad 01. There were no injuries in the explosion and the debris was contained to the immediate vicinity of the launch pad, Vandenberg officials said in a statement released early Thursday.

The military would not explain the change in launch time, nor provide much information about the explosion. According to the article, it is even possible that the contradiction between the announced launch time and when it actually occurred was because “military officials failed to account for the one-hour time difference between California and the home of the Air Force Nuclear Weapons Center at Kirtland Air Force Base in New Mexico.”

Seems utterly absurd, but completely possible considering the general overall incompetence of our modern federal government.

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Virgin Galactic is replacing its WhiteKnightTwo mother ship

9:21 am

Virgin Galactic yesterday announced that it has hired Aurora, a Boeing subsidiary, to build two new mother ships to to replace WhiteKnightTwo and launch its SpaceShipTwo suborbital space planes.

Virgin Galactic Chief Executive Officer Michael Colglazier said: “Our next generation motherships are integral to scaling our operations. They will be faster to produce, easier to maintain and will allow us to fly substantially more missions each year. Supported by the scale and strength of Boeing, Aurora is the ideal manufacturing partner for us as we build our fleet to support 400 flights per year at Spaceport America.” [emphasis mine]

The press release claims the first new mother ship will begin operations in 2025.

Forgive me if I am very very skeptical. The highlighted words tell us a lot about this company. First, we now have confirmation that the company has had problems maintaining WhiteKnightTwo. This fact was strongly implied when all planned flights in ’21 and ’22 were cancelled following that first passenger flight in July ’21 in order to do a full maintenance refit of WhiteKnightTwo. This press release tells us that the company’s management has recognized that WhiteKnightTwo cannot be maintained much longer.

Second, the company continues to overhype its future, even without Richard Branson. The chances of it flying 400 times per year, anytime in the near future, is so slim as to be non-existent.

Third, the need to hire an outside company to build these new mother ships also suggests that Virgin Galactic no longer has the capability of doing it itself.

Right now the company’s stock is selling for about $7 per share, well below its initial price of about $12. Expect it to fall again.

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SpaceX launches another 53 Starlink satellites

8:38 am

Capitalism in space: Earlier this morning SpaceX successfully launched 53 Starlink satellites, using its Falcon 9 rocket.

The first stage was flying its thirteenth flight, and supposedly landed successfully, though the stage’s video cut off just before landing, the drone ship video did not show it on the pad, and the confirmation of that landing was very late. It is possible it landed on a spot that the camera did not show, or that the landing occurred in the ocean and the stage was lost. We shall have to wait and see.

The leaders in the 2022 launch race:

28 SpaceX
21 China
8 Russia
4 Rocket Lab
4 ULA

The U.S. now leads China 40 to 21 in the national rankings, and the entire world combined 40 to 35.

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Having regained communications with CAPSTONE, engineers prepare for first mid-course burn

8:55 pm

Engineers are now preparing CAPSTONE for its first first mid-course engine burn, slightly late due to a loss of communications during the past two days.

The spacecraft is in good health and functioning properly.

The CAPSTONE team is still actively working to fully establish the root cause of the issue. Ground-based testing suggests the issue was triggered during commissioning activities of the communications system. The team will continue to evaluate the data leading up to the communications issue and monitor CAPSTONE’s status.

If all goes well, that engine burn will occur as early as 11:30 am (Eastern) on July 7th.

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How did sand dunes get to the top of a Martian mesa?

1:51 pm

Sand dunes at the top of a Martian mountain
Click for full image.

Cool image time! The photo to the right, cropped and reduced to post here, was taken on January 1, 2022 by the high resolution camera on Mars Reconnaissance Orbiter (MRO) and shows one of the peaks of a 5,000+ foot high mesa inside Juventai Chasma, one of Mars’ deep mostly-enclosed chasms north of Valles Marineris.

I grabbed this picture because its label, “Bedform Change Detection in Juventae Chasma”, suggested something had changed from past photos, probably related to the sand dunes that hug the upper slopes of this peak. Unfortunately, in comparing this image with the earliest high-res image taken by MRO back in February 2018, I could not spot any change, probably because the resolution of the pictures released is not as high as MRO’s raw images.

However, the caption written for that 2018 image tells us where that change has likely occurred:

This image reveals a unique situation where this small dune field occurs along the summit of the large 1-mile-tall [mesa] near the center of Juventae Chasma. The layered [mesa] slopes are far too steep for dunes to climb, and bedform sand is unlikely to come from purely airborne material. Instead, the mound’s summit displays several dark-toned, mantled deposits that are adjacent to the dunes and appear to be eroding into fans of sandy material.

In other words, somewhere in the full resolution image scientists have spotted a change in the bedform sands that make-up these high mountain dunes that hug the peak. Since the data so far has suggested that the source for the sand of these high elevation dunes likely comes from the mesa itself — not from any distant source — any change found will help confirm or disprove that hypothesis.

The white box indicates the area covered by the close-up higher resolution picture below. Also below is an overview map, showing both the location of this mountain in Juventai Chasma as well as Juventai’s location relative to Valles Marineris.
» Read more

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China begins construction of commercial spaceport

9:39 am

The new colonial movement: China’s state-run press today announced the ground-breaking of a spaceport on the southern island of Hainan that will be dedicated to launches by that country’s pseudo-commercial companies.

The location is in Wenchang City, the same location of the country’s Wenchang spaceport used to launch government’s newest Long March rockets. While it isn’t clear from the Chinese news report, this new facility is likely at the same location.

Though China touts this as a commercial facility for private commercial launch companies, everything in China is still controlled and owned by the government. Nothing will happen at this new site that China’s military does not approve.

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Rocket Lab to launch twice in 10 days for NRO

9:11 am

Capitalism in space: Rocket Lab announced yesterday that its next two launches, scheduled for July 12th and July 22nd, will demonstrate the ability of the company to quickly launch reconnaissance satellites for the National Reconnaissance Office (NRO).

The NROL-162 and NROL-199 missions will carry national security payloads designed, built, and operated by the National Reconnaissance Office in partnership with the Australian Department of Defence as part of a broad range of cooperative satellite activities with Australia. The satellites will support the NRO to provide critical information to government agencies and decision makers monitoring international issues.

These twin missions will be a demonstration of responsive launch under NRO’s Rapid Acquisition of a Small Rocket (RASR) contract for launching small satellite through a streamlined, commercial approach, and are the third and fourth missions contracted to Rocket Lab by the NRO under the contract.

Several federal military agencies have been testing this capability with almost all the new rocket companies, from the large, such as SpaceX, to the small, such as Rocket Lab and Astra.

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Engineers propose flying gliders on Mars

9:00 am

Proposed sailplane flights in Valles Marineris
Proposed sailplane flights in Valles Marineris. Click for full image.

Engineers at the University of Arizona are developing a prototype sailplane that they think could fly for long distances on Mars at higher altitudes than a helicopter and not be reliant on solar batteries.

Using dynamic soaring, the sailplane utilises increases in horizontal wind speed with gaining altitude to continue flying long distances. It’s the same process albatrosses use to fly long distances without flapping their wings and expending crucial energy.

After lifting themselves up into fast, high-altitude air, albatrosses then turn their bodies to descend rapidly into regions of slower, low-altitude air. With the force of gravity providing downward acceleration, the albatross uses this momentum to slingshot itself back to higher altitudes. Continuously repeating this process enables albatross and other seabird species to cover thousands of kilometres of ocean, flap-free.

It’s the inspiration for the sailplane’s own propulsion system, enabling it to cover the canyons and volcanoes dotted across the red planet currently inaccessible to Mars rovers.

The graphic above, figure 1 from the engineers’ research paper, shows one possible sailplane mission, deploying two gliders, one to observe the canyon wall and a second to survey the canyon floor. Both would become a weather station upon landing. While the paper doesn’t state a Mars location for this concept, the graphic strikes a strong resemblance to the section of Valles Marineris where scientists have recently taken “Mars Helicopter” high resolution images using Mars Reconnaissance Orbiter (MRO). This paper and those images might be related, or they could be illustrating the general interest by many scientists for this Mars’ location.

Regardless, the engineers are now planning test flights at 15,000 feet elevation, an elevation that will most closely simulate the atmosphere of Mars, on Earth.

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Engineers lose contact with CAPSTONE on its way to Moon

2:24 pm

Shortly after the spacecraft was successfully deployed from its Proton upper stage on yesterday, engineers lost contact with the spacecraft as it headed towards the Moon.

“The spacecraft team currently is working to understand the cause and re-establish contact. The team has good trajectory data for the spacecraft based on the first full and second partial ground station pass with the Deep Space Network,” NASA spokesperson Sarah Frazier wrote in an emailed statement today (July 5).

“If needed, the mission has enough fuel to delay the initial post-separation trajectory correction maneuver for several days,” Frazier added. “Additional updates will be provided as soon as possible.”

The spacecraft will not arrive in lunar orbit until November, but along the way it needs to do a number of course corrections. Thus, there is some time pressure to reestablishing communications. That task now falls with the private company Advanced Space, which won a contract to operate the spacecraft for NASA.

UPDATE: More details are provided by the operators of the spacecraft, Advanced Space press, here. Though they canceled a course correction burn today, they apparently have plenty of time to do it, since the probe is already on a course to reach lunar orbit. The burn was simply intended to increase the accuracy of the trajectory.

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Europe’s new long term space strategy calls for its own independent and competing manned program

10:25 am

Figure 6 from the Terrae Novae policy paper

The new colonial movement: The European Space Agency (ESA) yesterday unveiled a new roadmap for its future space effort, aimed primarily in developing an independent space program capable of launching its own astronauts and taking them to both the Moon and Mars.

The program is dubbed Terrae Novae (“New Worlds”) and aims to put European astronauts on other worlds using its own rockets and landers by the 2030s. The graphic to the right, figure 6 from the policy paper, illustrates this long term goal.

From the full document [pdf]:
» Read more

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ArianeGroup chosen by Europe to develop reusable rockets

9:47 am

The new colonial movement: The European Commission, which makes the major decisions for the European Space Agency, has chosen the European commercial company ArianeGroup to run two programs designed to produce that continent’s first reusable rocket.

From the press release [pdf]:

The SALTO project will facilitate the first flight tests of the Themis reusable stage demonstrator in Kiruna, Sweden. The ENLIGHTEN project will speed up the development and introduction of reusable engine technologies.

The main goal of SALTO will be to develop the kind of vertical landing technology that SpaceX now does routinely. ENLIGHTEN in turn will develop rocket engines using either methane or hydrogen as the fuel. The total budget allocated for both is just under 50 million euros, which seems quite small. The press release also made no mention of a schedule for accomplishing these tasks.

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Scientists: Comet 67P/C-G’s make-up matches the rest of the solar system

9:33 am

A detailed review of the archived data from the Rosetta mission that studied Comet 67P/Churyumov-Gerasimenko closely in 2014-2016 now strongly suggests that the comet’s overall make-up closely matches the rest of the solar system.

“It turned out that, on average, [the comet’s] complex organics budget is identical to the soluble part of meteoritic organic matter”, explains [Nora Hänni of the University of Bern] and adds: “Moreover, apart from the relative amount of hydrogen atoms, the molecular budget of [comet 67P/C-G] also strongly resembles the organic material raining down on Saturn from its innermost ring, as detected by the INMS mass spectrometer onboard NASA’s Cassini spacecraft”.

“We do not only find similarities of the organic reservoirs in the Solar System, but many of [comet 67P/C-G]’s organic molecules are also present in molecular clouds, the birthplaces of new stars”, complements Prof. Dr. Susanne Wampfler, astrophysicist at the Center for Space and Habitability (CSH) at the University of Bern and co-author of the publication. “Our findings are consistent with and support the scenario of a shared presolar origin of the different reservoirs of Solar System organics, confirming that comets indeed carry material from the times long before our Solar System emerged.”

These results are not unexpected, but having those expectations confirmed was one of the main scientific goals of the Rosetta mission. Now, almost a decade later, the results are in.

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Sunspot update: For the first time in 2022, sunspot activity eases

3:58 pm

With the year half over, the Sun in June did something it had not done since the start of the year: The number of sunspots seen daily on the Sun’s visible hemisphere actually declined from the month before.

I know this because, as I do every month, I have posted below NOAA’s monthly update of its graph tracking the number of sunspots on the Sun’s Earth-facing hemisphere, with some addition details added to provide a larger context.

» Read more

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The new damage on Curiosity’s wheels

9:30 am

Comparing a Curiosity wheel from January to June 2022
To see the original images, go here and here.

On June 23, 2022 the Curiosity team provided a major update on the rover’s status on Mars, noting that because of new damage discovered on one of wheels, they were increasing the frequency of their wheel checks from once every 1000 meters of travel to once every 500 meters.

The team discovered that the left middle wheel had damaged one of its grousers, the zig-zagging treads along Curiosity’s wheels. This particular wheel already had four broken grousers, so now five of its 19 grousers are broken.

The previously damaged grousers attracted attention online recently because some of the metal “skin” between them appears to have fallen out of the wheel in the past few months, leaving a gap.

The photo comparison to the right might be showing that specific wheel, or not. The top image was taken January 11, 2022, and when compared then with an image taken six months earlier showed little change. Thus, in January 2022 it seemed the wheels were holding up well as Curiosity traveled into the mountains.

The new image at the bottom, taken June 3, 2022, shows new damage (as indicated by the plus sign) which had occurred sometime in the past six months. During that time the rover had attempted to cross the incredibly rough ground of the Greenheugh Pediment, and had been forced to retreat because the ground was too rough.

This most recent wheel survey in June thus confirms that the decision to retreat was a wise one. It appears that while the rover’s wheels can take the general roughness of the terrain in the foothills of Mount Sharp, the Greenheugh Pediment was beyond the wheels’ capabilities.

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Rocket Lab’s Photon completes course corrections, deploys CAPSTONE to Moon

8:45 am

Capitalism in space: Rocket Lab’s Photon upper stage successfully completed its seventh engine burn, putting NASA’s cubesat test lunar orbital on a path toward the Moon.

Following its launch on June 28, CAPSTONE orbited Earth attached to Rocket Lab’s Photon upper stage, which maneuvered CAPSTONE into position for its journey to the Moon. Over the past six days, Photon’s engines fired seven times at key moments to raise the orbit’s highest point to around 810,000 miles from Earth before releasing the CAPSTONE CubeSat on its ballistic lunar transfer trajectory to the Moon. The spacecraft is now being flown by the teams at Advanced Space and Terran Orbital. [emphasis mine]

From here on out CAPSTONE will use its own tiny thrusters to do any course corrections as it heads for an arrival in lunar orbit on November 13, 2022.

The highlighted words in the quote above are significant in and of themselves. The spacecraft is not being operated by NASA. In fact, other than paying for it, NASA has little to do with CAPSTONE. It was designed and built by Terran Orbital. It was launched by Rocket Lab. And it is now being controlled by Advanced Space, a private commercial company focused on providing in-space operations for others.

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One of Perseverance’s two wind sensors damaged by wind-blown material

5:09 pm

According to the principal investigator for Perseverance’s two wind sensors, one was recently damaged by a wind-blown tiny pebble.

Pebbles carried aloft by strong Red Planet gusts recently damaged one of the wind sensors, but MEDA can still keep track of wind at its landing area in Jezero Crater, albeit with decreased sensitivity, José Antonio Rodriguez Manfredi, principal investigator of MEDA, told Space.com. “Right now, the sensor is diminished in its capabilities, but it still provides speed and direction magnitudes,” Rodriguez Manfredi, a scientist at the Spanish Astrobiology Center in Madrid, wrote in an e-mail. “The whole team is now re-tuning the retrieval procedure to get more accuracy from the undamaged detector readings.”

…Like all instruments on Perseverance, the wind sensor was designed with redundancy and protection in mind, Rodriguez Manfredi noted. “But of course, there is a limit to everything.” And for an instrument like MEDA, the limit is more challenging, since the sensors must be exposed to environmental conditions in order to record wind parameters. But when stronger-than-anticipated winds lifted larger pebbles than expected, the combination resulted in damage to some of the detector elements.

The term “pebble” implies a larger-sized particle than what probably hit the sensor. I suspect the “pebble” was no more than one or two millimeters in diameter, at the most.

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Lucy solar panel almost completely open

11:19 am

Engineers have now been able to get the one solar panel that did not deploy completely after launch on the Lucy asteroid probe almost completely open.

From May 6 to June 16, NASA’s Lucy mission team carried out a multi-stage effort intended to further deploy the spacecraft’s unlatched solar array. The team commanded the spacecraft to operate the array’s deployment motor for limited periods of time, allowing them to closely monitor the response of the spacecraft. As a result of this effort, the mission succeeded in further deploying the array and now estimates that the solar array is between 353 degrees and 357 degrees open (out of 360 total degrees for a fully deployed array). Additionally, the array is under substantially more tension, giving it significantly more stabilization. The mission team is increasingly confident the solar array will successfully meet the mission’s needs in its current tensioned and stabilized state.

The spacecraft’s orbit is now moving into a position where communications will be limited until October, so further attempts to completely open the array will have to wait until then.

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Virgin Orbit puts seven Space Force smallsats in orbit

10:05 am

Capitalism in space: Virgin Orbit last night successfully launched seven smallsats for the Space Force, using its Cosmic Girl 747 carrier plane and its LauncherOne rocket.

This was the company’s first night time launch, and its second in 2022. The leader board for the 2022 launch race remains the same:

27 SpaceX
21 China
8 Russia
4 Rocket Lab
4 ULA

The U.S. now leads China 39 to 21 in the national rankings, and the entire world combined 39 to 35.

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In 2022 freedom continues to fuel the launch industry towards new records

4:27 pm

With 2022 now half over, we can now get a quick sense of the state of the world’s rocket industry by the number of launches that have so far been accomplished this year.

Last year was the most successful year in rocketry since the launch of Sputnik in 1957. Both nations and private companies managed to launch successfully 134 times, one more than the previous record in 1975. Similarly, with 48 launches in 2021, the U.S. completed the most launches since the height of the 1960s space race, 48 total.

These high numbers last year also suggested that the growth was not a one time thing, but based on a wider sustained growth that would continue.

It now appears that both these records will be smashed in 2022. Below is a graph showing the total number of successful launches year-by-year by the United States since Sputnik, as of June 30, 2022.
» Read more

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Strange pitted and isolated ridges on Mars

2:30 pm

Context camera image of isolated ridges
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken on February 17, 2012 by the wide-view context camera on Mars Reconnaissance Orbiter (MRO). It shows a section of the northern lowland plains of Mars, latitude 31 degrees north, where several very inexplicable and isolated ridges can be seen.

One ridge meanders mostly in a north-south direction, while a second instead meanders east-west. The shape of both says that neither has anything to do with any past impact crater. In fact, their random snakelike shape doesn’t really fit any obvious explanation. For example, they do not fit the look of the many fossil rivers found on Mars, where the hardened and dry riverbed channel resists erosion and becomes a ridge when the surrounding terrain erodes away.

What geological process caused them? In the decade since this photo was taken the scientists who use MRO have only been able to snap a handful of high resolution images of these ridges. The image below is the most recent, covering the area in the white rectangle above.
» Read more

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Kepler signs up D-Orbit’s orbital tug for its next two satellites

9:56 am

Capitalism in space: The Canadian company Kepler — which already has nineteen satellites in orbit providing data communications — will use the orbital tug developed by the start-up D-Orbit and dubbed ION on its next two satellites.

After separating from the launch vehicle, D-Orbit intends to use ION to drop Kepler’s satellites off at a sun-synchronous orbit (SSO) between 500 and 600 kilometers. Each satellite is the size of six cubesats, a standard smallsat form factor measuring 10 centimeters on each side.

Kepler previously had a deal to use Momentus’s Vigoride tug, but delays and further in-orbit technical problems with that tug has apparently forced it to switch to D-Orbit.

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New research confirms long term bone loss during long missions in weightlessness

9:46 am

According to new research done on ISS, scientists have confirmed what Soviet-era scientists had learned back in the 20th century, that long term bone loss during long missions in weightlessness can take many months to recover once back on Earth.

The bone density lost by astronauts was equivalent to how much they would shed in several decades if they were back on Earth, said study co-author Dr Steven Boyd, of Canada’s University of Calgary and director of the McCaig Institute for Bone and Joint Health.

The researchers found that the shinbone density of nine of the astronauts had not fully recovered after a year on Earth – and they were still lacking about a decade’s worth of bone mass. The astronauts who went on the longest missions, which ranged from four to seven months on the ISS, were the slowest to recover. “The longer you spend in space, the more bone you lose,” Boyd said.

The study also confirmed that some exercises in space helped to mitigate the bone loss, which ranged from 1% to 2% per month. No exercises prevented it however.

For missions to Mars, the bone loss appears less of an issue than the loss of muscle strength. Even with extensive bone loss after six months to a year in space astronauts do not notice this loss when returning to Earth gravity. They will certainly not notice it on Mars, with a gravity field 39% that of Earth’s.

More concerning is the loss of muscle strength during long missions in weightlessness. After six months to a year in weightlessness astronauts struggle on Earth to walk after first landing. This is why they are helped immediately placed to chairs upon return. On Mars no such help will be available.

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OneWeb signs up startup rocket company Relativity for future satellite launches

9:34 am

Capitalism in space: The rocket startup Relativity, which hopes to complete its first test launch of its small Terran-1 rocket before the end of the year, yesterday announced that it has won a launch contract with OneWeb to use its larger but not-yet-ready-for-launch Terran-R rocket to place future OneWeb satellites into orbit.

Under the agreement, Relativity will launch OneWeb’s low Earth orbit (LEO) satellites on Terran-R, the first fully reusable and entirely 3D printed rocket, starting in 2025. These launches will support OneWeb’s deployment of its Gen 2 satellite network, which will add capacity and fresh capabilities to build upon the initial constellation of 648 satellites the company is currently building out.

Since its launch contract with Arianespace using Russian Soyuz rockets fell apart due to Russia’s invasion of the Ukraine, OneWeb has been signing up a range of rocket companies, first SpaceX, then India, now Relativity. Apparently the satellite company realized it was a bad idea to depend on only one rocket, and is now lining up several to make sure its satellites can launch on schedule, no matter what.

For Relativity, this agreement solidifies its future, even before it has completed its first launch. It now has five customers for its Terran-R rocket, with contracts worth $1.2 billion. All it has to do now to become a major player in the global launch market is to get its rockets off the ground.

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