Tag: spaceflight

Russia launches Progress freighter to ISS

9:18 pm

Russia tonight successfully launched a new Progress freighter to ISS using its Soyuz-2 rocket.

The leaders in the 2020 launch race:

6 China
6 SpaceX
6 Russia

The U.S. now leads both China and Russia 10 to 6 in the national rankings. This is the first time that Russia has been able to keep up with China in launches in several years. Since China had expected to launch more times than Russia in 2020, this suggests that China’s launch rate has been reduced because of the Wuhan flu. It at least appears that many of their smaller launch rockets have suspended launches.

We have also heard nothing recently about China’s planned mid- to late-April first launch of its Long March 5B. With only six days left in the month, one wonders if this launch too has been delayed.

One comment

Movie of OSIRIS-REx’s 1st landing rehearsal

12:55 pm

Closest NavCam-2 image during rehearsal
Click for full movie.

The OSIRIS-REx science team has released a short movie taken by one of the spacecraft’s navigation camera (NavCam-2) during its first landing rehearsal on April 14. The image to the right, cropped to post here, is the closest image in the sequence, and shows the relatively smooth Nightingale target landing site near the bottom of the image, approximately 50 feet in diameter.

According to the release,

NavCam 2 captures images for the spacecraft’s Natural Feature Tracking (NFT) navigation system. The NFT system allows the spacecraft to autonomously guide itself to Bennu’s surface by comparing real-time images with an onboard image catalog. As the spacecraft descends to the surface, the NFT system updates the spacecraft’s predicted point of contact depending on OSIRIS-REx’s position in relation to Bennu’s landmarks. During the sample collection event, scheduled for August, the NavCam 2 camera will continuously image Bennu’s surface so that the NFT system can update the spacecraft’s position and velocity relative to Bennu as it descends towards the targeted touchdown point.

When the image above was taken the spacecraft was at its closest point, about 213 feet above the surface. Based on this movie, it looks like the system was working, and the spacecraft was refining its aim to head towards Nightingale.

Still, the landing site is not in the center of the image, which I would think is a concern, especially because Nightingale is only one-third the size of the kind of smooth target areas they had designed the system for. (When launched they expected to see smooth areas at least 160 feet across, and designed the system for this.)

The second rehearsal is presently scheduled for June 23, and will drop OSIRIS-REx to within 82 feet of the surface.

Leave a comment

NASA’s safety panel rubberstamps May 27 manned Dragon launch

11:03 am

NASA’s safety panel has apparently reluctantly given its “okay” for the launch of the first manned Dragon launch on May 27th.

NASA’s Aerospace Safety Advisory Panel (ASAP), meeting by teleconference April 23, said it was unable to talk with NASA’s commercial crew program during its quarterly meeting, which was held virtually because of the coronavirus pandemic. The panel’s chair, Patricia Sanders, said that scheduling issues prevented a meeting, but that her committee planned to hold a “part 2” of their quarterly meeting in early May to discuss commercial crew and other topics not taken up this week.

Sanders said the panel has been kept up to date by NASA about commercial crew activities, including plans for SpaceX’s Demo-2 crewed test flight scheduled for May 27. “We are aware of a few technical items that remain to be more fully understood,” she said, “but the path forward appears feasible.”

In other words, it appears that NASA’s management might have taken advantage of the Wuhan panic to cut the panel off from the decision-making process, possibly because this panel has acted now for years to slow progress and in fact discourage any American manned launches at all, out of an almost irrational fear of any failure.

Their recommendations have sometimes verged on the ludicrous, such as an insistence that no manned launch be scheduled until a lot of paperwork was filled out.

It could also be that the panel has recognized at last (or maybe NASA management told them in no uncertain words) that we now have to proceed with American manned missions, since with the expiration of our contract with the Russians we have no other options.

2 comments

Scientists fine tune the cause of the super-rotation of Venus’ atmosphere

10:39 am

Scientists using data collected from the Japanese Venus orbiter Akatsuki have now refined their theories on the atmospheric processes that cause that atmosphere to rotate sixty times faster than the planet.

This super-rotation increases with altitude, taking only four Earth days to circulate around the entire planet towards the top of the cloud cover. The fast-moving atmosphere transports heat from the planet’s dayside to nightside, reducing the temperature differences between the two hemispheres.

What they found was that at equatorial latitudes the heat transfer is generated by what they call “atmospheric tidal waves”, generated by the dayside solar heat. At high latitudes the transfer is instead caused by atmospheric turbulence.

From what I can gather, they are calling these tidal waves because the Sun’s heat causes the atmosphere to expand upward on the day side, much as the Moon’s gravity pulls the ocean upward on Earth. It then is quickly drawn to the colder night side, driven I think in one direction because of the planet’s slow rotation.

As always, we must recognize the uncertainties. The data here is somewhat limited because there have been so few atmospheric orbiters so far sent to study Venus. While several future missions are under study in the U.S. and Russia, only India appears to have one targeted for launch, though the date has been pushed back from 2020 to 2023.

3 comments

China names its 2020 Mars mission

10:19 am

China’s official state-run press today announced that their 2020 Mars mission will be called Tianwen-1, noting that this name will be applied to all further planetary missions.

The link goes to that government state-run press, which provides no further information on Tianwen-1, such as where on Mars its lander/rover will land, its exact launch date, the instruments on board, etc. So far very very few details have been released.

What this propaganda press announcement does do is spout a lot of blather about how wonderful China is, and how we should all be thankful the communists have been in charge there. Here are some snippets to lighten your day:

  • …signifying the Chinese nation’s perseverance in pursuing truth and science
  • …a window for the Chinese public and the world to get a better understanding of China’s aerospace progress.
  • Chinese space engineers and scientists have overcome various difficulties and achieved aerospace development through self-reliance and independent innovation.
  • …promoting human welfare on the basis of equality, mutual benefit, peaceful utilization and inclusive development.

While China’s achievements in space are real (though much of the engineering was stolen or borrowed from others), these propaganda claims are junk and lies. Chinese space engineers are “self-reliant” and have “independence”? Don’t make me laugh. Everything done in their space program is dictated and controlled from the top, by the Chinese government and the Communist Party. No one is free to do anything, without their permission.

As for China’s pursuit of “truth and science”, their behavior during the Wuhan flu epidemic, originating from their country and very possibly caused deliberately or incompetently by them, makes this claim ludicrous on its face. They have lied, arrested scientists, blocked research, and distorted the scope and magnitude of the epidemic from day one.

Even a tiny bit of truth from them, from the beginning, might have prevented the panic that has overtaken the world which in turn appears to have triggered the next great economic depression, what I like to now call the Great Wuhan Depression.

One comment

SpaceX rolls out next Starship prototype

9:59 am

Capitalism in space: SpaceX has completed construction of its next Starship prototype and has moved it to its test stand in preparation for further tests.

This is the fourth prototype. If the tank pressure tests go well, they hope to add engines and do a twelve mile hop with this prototype, landing vertically. If not, they will try again with later prototypes. Regardless, the goal is to do that hop this year.

Leave a comment

Swarm and Momentus team up to launch and position satellites

9:37 am

Capitalism in space: Swarm, builder of the tiny cubesats dubbed SpaceBees, has teamed up with Momentus to use that company’s Vigoride cubesat upper stage to position its satellites in different orbits after launch.

Under an agreement announced April 22, Momentus will arrange rides for 12 Swarm SpaceBee satellites on a SpaceX Falcon 9 rideshare mission in December 2020 with additional SpaceBee launches scheduled in 2021 and 2022.

To offer global coverage for customers seeking to relay messages through the internet, Swarm satellites must be stationed in different orbital planes and spread out within those orbital planes like a string of pearls, Sara Spangelo, Swarm co-founder and CEO, told SpaceNews.

For the Falcon 9 launch in December, Momentus will not move Swarm SpaceBees to a new orbital plane. In the future, Momentus’ Vigoride in-space shuttle will offer Swarm the option of moving SpaceBees from the rocket’s drop-off point to different locations, Negar Feher, Momentus vice president of product and business development, said by email.

Both companies have raised significant investment capital.

Leave a comment

Firefly signs deal with satellite broker Spaceflight

9:29 am

Capitalism in space: Firefly Aerospace has signed a deal whereby the satellite broker Spaceflight will provide the payloads for one of Firefly’s Alpha rocket launches, planned for 2021.

The smallsat launch company already has several other launch contracts, even as development of its rocket proceeds.

Firefly is in the final phases of development of Alpha, and hopes to perform its first launch later this year. Markusic said the company is assembling the first flight vehicle, with plans to perform static-fire tests of the second stage in May and the first stage in June. Once those tests are complete, the vehicles will be shipped to Vandenberg, where work is continuing to modify Space Launch Complex 2 West, a former Delta 2 pad.

A lot can happen between now and 2021, but so far Firefly appears a strong candidate to launch and compete with Rocket Lab.

Leave a comment

The first complete geologic map of Moon

9:15 am

Geologic map of Moon

Using data from several recent lunar orbiters, scientists have compiled and now released the first comprehensive geologic map of the Moon.

To create the new digital map, scientists used information from six Apollo-era regional maps along with updated information from recent satellite missions to the moon. The existing historical maps were redrawn to align them with the modern data sets, thus preserving previous observations and interpretations. Along with merging new and old data, USGS researchers also developed a unified description of the stratigraphy, or rock layers, of the moon. This resolved issues from previous maps where rock names, descriptions and ages were sometimes inconsistent.

“This map is a culmination of a decades-long project,” said Corey Fortezzo, USGS geologist and lead author. “It provides vital information for new scientific studies by connecting the exploration of specific sites on the moon with the rest of the lunar surface.”

The image to the right shows the Moon’s near side.

The complete map file is free to download, and I guarantee that scientists and engineers in China are downloading it even as I type, planning to use it to establish their ownership to the Moon’s most valuable real estate that we scouted for them.

4 comments

SpaceX successfully launches 60 more Starlink satellites

1:28 pm

Capitalism in space: SpaceX today successfully launched 60 more Starlink satellites.

The launch was significant in several ways. They reused the first stage for the fourth time, landing it successfully. They reused the fairing for the second time.

And with this launch, the Falcon 9 has now flown more than the Atlas 5, and has the most launches of any active American rocket.

This flight marks a major point in U.S. launch operations, as Falcon 9 reaches 84 flights to its name and officially takes the mantle from Atlas V as the most flown, currently operational U.S. rocket.

Atlas V began flying on 21 August 2002 and has 83 flights to its name after 18 years — for an annual rate of 4.6 launches. Falcon 9 began flying on 4 June 2010 and will reach 84 flights in just under 10 years with a flight rate of 8.4 launches per year.

That SpaceX overtook the Atlas 5 so quickly indicates exactly how successful SpaceX has been in grabbing market share from all its launch competitors.

I have embedded the video of the launch below the fold.

The leaders in the 2020 launch race:

6 China
6 SpaceX
5 Russia

The U.S. now leads China 10 to 6 in the national rankings.
» Read more

12 comments

Stucco on Mars

1:13 pm

Stucco on Mars
Click for full image.

As a break from Wuhan flu madness I give you another cool image, cropped and reduced to post here, taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO). I call this stucco on Mars because that is exactly what it looks like. It is as someone laid down a layer of damp concrete and then ran over it roughly with a trowel to raise the knobs scattered across the surface.

The uncaptioned MRO image calls this “Aligned Mounds with Broad Summit Pits”. Those aligned mounds run across the top of the image. I suspect they are pedestal craters, left over because the impact had packed and hardened the crater so that it resisted erosion as the surrounding terrain was worn away.

The two insets, posted below at full resolutoin, focus on one of those pedestal craters as well as the distinct mesa at the bottom of the photo.
» Read more

Leave a comment

Iran launches its first military satellite

9:09 am

UPDATE: The U.S. military has confirmed that two objects reached orbit, one the satellite and the other likely the rocket’s upper stage.

Original post:
————————————
Iran yesterday claimed it had successfully completed its first military orbital launch.

Using a mobile launcher at a new launch site, the Guard said it put the “Noor,” or “Light,” satellite into a low orbit circling the Earth. While the U.S., Israel and other countries declined to immediately confirm the satellite reached orbit, their criticism suggested they believed the launch happened.

There is no doubt Iran is aggressively trying to raise its presence as a space power. However, until this launch is firmly confirmed as successful, we must be skeptical of any claims they make, as they have lied repeatedly about previous launches.

At the same time, the use of a mobile launcher to attempt to get a satellite into orbit indicates they are developing very dangerous capabilities. With a mobile launcher, there is no need to build a complex launch facility. You can launch from practically anywhere, which makes it just about impossible to destroy the rocket facility beforehand.

2 comments

Rock droplets hitting a Martian plain

12:42 pm

Depressions in Amazonis Planitia
Click for full image.

Cool image time! The photo the right, rotated, cropped, and reduced to post here, is not only cool, it contains a punchline. It was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on February 11, 2020 and shows one small area between two regions in the northern lowlands of Mars, dubbed Amazonia Planitia (to the south) and Arcadia Planitia (to the north) respectively.

This region is thought to have a lot of water ice just below the surface., so much in fact that Donna Viola of the University of Arizona has said, “I think you could dig anywhere to get your water ice.”

I think this image illustrates this fact nicely. Assuming the numerous depressions seen here were caused by impacts, either primary or secondary, it appears that when they hit the ground the heat of that impact was able to immediately melt a wide circular area. My guess is that an underwater ice table immediately turned to gas so that the dusty material mantling the surface then sagged, creating these wider circular depressions.

Of course, this is merely an off-the-cuff theory, and not to be taken too seriously. Other processes having nothing to do with impacts could explain what we see. For example, vents at the center of these craters might have allowed the underground ice to sublimate away, thus allowing the surface to sag.

So what’s the punchline?
» Read more

One comment

Russians slash their launch prices by 39%

9:08 am

Capitalism in space: Having lost their entire commercial market share because of SpaceX’s lower prices, the Russians have finally decided to slash their launch prices by 39%.

As the article notes, the cost for a Proton rocket launch was once $100 million. Then SpaceX came along with a $60 million pricetag. At first the Russians poo-pooed this, and did nothing. When their customers started to vanish however they decided to finally compete, so a year ago they cut the Proton price to match SpaceX’s.

Because of SpaceX’s ability to reuse its first stages, however, that $60 million price no longer worked. SpaceX had a year earlier lowered its prices even more, to $50 million, for launches with used first stages.

This new price slash by Roscosmos probably brings their price down to about $36 million, and thus beats SpaceX.

We shall see whether it will attract new customers. It definitely is now cheaper, but it is also less reliable. Russia continues to have serious quality control problems at its manufacturing level.

That SpaceX’s arrival forced a drop in the price of a launch from $100 million to less than $40 million illustrates the beautiful value of freedom and competition. The change is even more spectacular when you consider that ULA, the dominant American launch company before SpaceX, had been charging between $200 to $400 million per launch. For decades the Russians, ULA, and Arianespace refused to compete, working instead as a cartel to keep costs high.

SpaceX has ended this corrupt practice. We now have a competitive launch industry, and the result is that the exploration of the solar system is finally becoming a real possibility.

Correction: I originally called ULA “the only American launch company before SpaceX.” This was not correct, as Orbital Sciences, now part of Northrop Grumman, was also launching satellites. It just was a very minor player, with little impact. It was also excluded from the military’s EELV program, and thus could not launch payloads for them after around 2005.

13 comments

Interstellar Comet 2I/Borisov has an excess of carbon monoxide

8:48 am

Astronomers using two difference space telescopes have found that Comet 2I/Borisov, the first known interstellar comet, has an abundance of carbon monoxide when compared to solar system comets.

The team used Hubble’s unique ultraviolet sensitivity to spectroscopically detect carbon monoxide gas escaping from comet Borisov’s solid comet nucleus. Hubble’s Cosmic Origins Spectrograph observed the comet on four separate occasions, from Dec. 11, 2019 to Jan. 13, 2020, which allowed the researchers to see the object’s chemical composition change quickly, as different ice mixtures, including carbon monoxide, oxygen, and water, sublimated under the warmth of the Sun.

The Hubble astronomers were surprised to find that the interstellar comet’s coma, the gas cloud surrounding the nucleus, contains a high amount of carbon monoxide gas, at least 50% more abundant than water vapor. This amount is more than three times higher than the previously measured quantity for any comet entering the inner solar system. The water measurement was made by NASA’s Neil Gehrels-Swift satellite, whose observations were conducted in tandem with the Hubble study.

Carbon monoxide ice is very volatile. It doesn’t take much sunlight to heat the ice and convert it to gas that escapes from a comet’s nucleus. For carbon monoxide, this activity occurs very far from the Sun, about 11 billion miles away, more than twice the distance of Pluto at its farthest point from the Sun. In contrast, water remains in its icy form until about 200 million miles from the Sun, the approximate distance of the inner edge of the asteroid belt.

However, for comet Borisov, the Hubble measurements suggest that some carbon monoxide ice was locked inside the comet’s nucleus, revealed only when the Sun’s heat stripped away layers of water ice. “The amount of carbon monoxide did not drop as expected as the comet receded from the Sun. This means that we are seeing the primitive layers of the comet, which really reflect what this object is made of,” Bodewits explained. “Because of the abundance of carbon monoxide ice that survived so close to the Sun, we think that comet Borisov comes from a much colder place and from a very different debris disk around a star than our own.”

With solar system comets, the ratios between water and carbon monoxide are the reverse, with much more water detected. They theorize, based on these results, that the comet might have come from a cool red dwarf star, but with the available data that is nothing more than a guess at this point.

Leave a comment

Strange terrain in the Martian lowlands

12:42 pm

Strange terrain in northern lowlands
Click for full image.

Cool image time! The science team for the high resolution camera on Mars Reconnaissance Orbiter (MRO) yesterday released a new captioned image, entitled “Disrupted Sediments in Acidalia Planitia”, noting that the photo

…shows a pitted, blocky surface, but also more unusually, it has contorted, irregular features.

Although there are impact craters in this area, some of the features … are too irregular to be relic impact craters or river channels. One possibility is that sedimentary layers have been warped from below to create these patterns. The freezing and thawing of subsurface ice is a mechanism that could have caused this.

The image to the right, rotated, cropped, and reduced to post here, shows the lower quarter of the full image. While in some areas it does appear as if changes below the surface caused the surface to warp and collapse, as suggested by the caption, in other places it looks more like the top layers themselves sublimated away without disturbing what was below them.

Note for example the pits near the bottom of the photograph. They clearly show sedimentary layers on their cliff walls, including the tiny circular mesa in the middle of the rightmost pit.

If these pits were collapsing from below, their cliffs would be more disturbed, because it would have been those lower layers that sublimated first. Instead, it appears that the top layer disappeared first, followed by each lower layer, one by one.

This region of strange terrain is located in the middle of the northern lowland plains. The overview map below gives some context, with the small white box showing this photo’s location.
» Read more

Leave a comment

First manned Dragon flight scheduled for May 27th

10:30 am

Capitalism in space: NASA today officially announced May 27, 2020 as the scheduled launch date for the first manned Dragon flight to ISS, the first time American astronauts will fly from American soil on an American rocket in an American spacecraft since the shuttle was retired almost a decade ago.

The launch is set for 4:32 pm (Eastern), and I am sure will be live streams by both NASA and SpaceX.

5 comments

SpaceX reuses sections of damaged Starship prototype for next version

9:07 am

Capitalism in space: In building its fourth Starship prototype for testing, SpaceX has decided to reuse large sections of the previous Starship prototype, badly damaged during a pressure test several weeks ago.

On April 15th, eight days after Starship SN3’s [the damaged third prototype] remaining aft section was cut in half, the rearmost half – known as the skirt – was spotted stacked beneath a brand new engine section built for SN4. While confirming that a significant part of SN3 will be reused on SN4, it also indicates that only a less critical SN3 remnant was fit to join SpaceX’s next prototype.

Though they are not reusing the engines from that third prototype, I have full confidence they will, as they were part of the same bottom section of that prototype that was damaged during the test. This statement is incorrect. I had mistakenly assumed that because SpaceX had said it planned actual test hops eventually with this third prototype that three engines were already in place. They were not.

3 comments

Space radiation may increase risk of cancer

8:59 am

Using mice and models, scientists have concluded that humans who spend long periods in space, exposed to its radiation, will have a 3% higher risk for cancer.

A team led by researchers at Colorado State University and Frederick National Laboratory for Cancer Research, which is part of the National Institutes for Health, used a novel approach to test assumptions in a model used by NASA to predict these health risks. Based on the NASA model, the team found that astronauts will have more than a three percent risk of dying of cancer from the radiation exposures they will receive on a Mars mission. That level of risk exceeds what is considered acceptable. [emphasis mine]

And how did they come to this conclusion?

…For the study, Weil and first author Dr. Elijah Edmondson, a veterinary pathologist and researcher based at the Frederick National Laboratory for Cancer Research in Maryland, used a unique stock of genetically diverse mice, mimicking a human population. Mice were divided into three groups with the first group receiving no radiation exposure and the other two receiving varying levels of exposure.

Edmondson, who conducted the research while completing a veterinary residency in pathology at CSU, said that for this type of research project, genetic variability is crucial. “Humans are very genetically diverse,” he explained. “You want to model that when it’s appropriate and feasible to do so.”

Weil said although the research team saw different tumor types, similar to humans, but the heavy ions did not cause any unique types of cancer. They also saw differences by sex. In humans, women are more susceptible to radiation-induced cancers than men; one of the main reasons is that women live longer, allowing sufficient time for cancer to develop. In assessing the cancer risk between male and female mice in the study, scientists said the findings parallel human data.

Edmondson said the study validates the NASA model to measure cancer risks for humans from space radiation.

In a sense, this study is junk. First, it discovers the obvious (radiation increases your chances of getting cancer). Second, it is too model-dependent, so assigning any precise percentage to that increase in humans is absurd, especially when based on a sample comprised of mice.

Third, and most important, it completely forgets the reality that life is risk, exploration is dangerous, and to do great things you need to take greater chances. That NASA concludes these questionable numbers are unacceptable means that NASA will never send humans anywhere beyond Earth orbit. Ever.

9 comments

Chang’e-4 and Yutu-2 reactivated for 17th lunar day on Moon’s surface

8:40 am

Engineers have reactivated both the lander Chang’e-4 and the rover Yutu-2 for their seventeenth lunar day on the far side of the Moon.

The report comes from the state-run Chinese press, so of course, it provides no useful new information other than what I wrote above. It did have this bit of Chinese propaganda, however:

The Chang’e-4 mission embodies China’s hope to combine wisdom in space exploration with four payloads developed by the Netherlands, Germany, Sweden and Saudi Arabia. [emphasis mine]

China’s wisdom sure did everyone a lot of good in Wuhan, didn’t it?

Leave a comment

Splashdown of Apollo 13

7:09 am

Today marks the fiftieth anniversary of the successful safe return to Earth of the Apollo 13 astronauts, Jim Lovell, Jack Swigert, and Fred Haise. Below is CBS’s coverage of that splashdown, in three videos.

If you are still under Wuhan flu house arrest, spend the time to watch them all. Each will automatically start after the previous ends.

Once again it is astonishing to see the differences from today. Note the shot of the quiet crowds watching the telecast in Grand Central Station, and their calm but joyous applause at their first view of the capsule, its parachutes deployed, gently descending safely to the ocean.

As with the moment when the failure occurred on April 13th, the news coverage continues to be detailed and focused on covering the event, not showing off news anchors and pundits. There are no shots of Walter Cronkite in his studio. He is not the story, and he knows it.

The coverage is also patient. For long periods while the divers are securing the capsule in the water, not much happens. There is no effort to return to the studio, or to break for commercials. The focus is on the story, and the story only.

Will someone please tell this to Anderson Cooper, Jim Acosta, and others of their modern ilk?

5 comments

Rover update: Curiosity heads downhill

2:49 pm

Curiosity's last look across the Greenheugh Pedimont
Click for higher resolution.

[For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater. For the updates in 2018 go here. For a full list of updates before February 8, 2018, go here.]

After finally reaching the top of the Greenheugh Pedimont (see both the March 4 and March 8, 2020 rover updates) and spending more than a month there, drilling one hole, getting samples, and taking a lot of photos, the Curiosity science team in the past week has finally sent the rover retreating back downhill, following the same route it used to climb uphill.

The panorama above was taken on April 10, 2020, and shows the last view looking south across that pedimont towards Mount Sharp, before that descent. As you can see, trying to traverse that terrain would have been very difficult, and probably very damaging to Curiosity’s wheels.
» Read more

Leave a comment

Movie of OSIRIS-REx touch-and-go rehearsal

10:47 am

Checkpoint rehearsal: last image
Click for movie.

The OSIRIS-REx science team yesterday released a short movie, compiled from thirty images taken during the April 14, 2020 rehearsal of the spacecraft’s planned August touch-and-go sample grab from the asteroid Bennu.

The rehearsal brought the spacecraft through the first two maneuvers of the sampling event to a point approximately 213 feet (65 meters) above the surface, before backing the spacecraft away. These images were recorded over a ten-minute span between the execution of the rehearsal’s “Checkpoint” burn, approximately 394 feet (120 meters) above the surface, and the completion of the back-away burn, which occurred approximately 213 feet (65 meters) above the surface. The spacecraft’s sampling arm – called the Touch-And-Go Sample Acquisition Mechanism (TAGSAM) – is visible in the central part of the frame, and the relatively clear, dark patch of Bennu’s sample site Nightingale is visible in the later images, at the top. The large, dark boulder that the spacecraft approaches during the sequence is 43 feet (13 meters) on its longest axis.

The image to the right is the last frame of the movie, as the spacecraft has begun its retreat. The smoother area of Nightingale is at the top.

Based on the video, it appears as if the spacecraft would have missed the Nightingale target site had the rehearsal continued to touchdown. This might not be so, however. And even if it is, the reason for the rehearsal is to allow engineers to refine the process to make it more accurate. We shall see what changes in the second rehearsal in about a month or so.

Leave a comment

Rocket Lab steals Arianespace customer

9:04 am

Capitalism in space: It turns out that a new launch contract won by Rocket Lab this week was actually a payload that was originally going to fly on Arianespace’s Vega rocket.

What Tuesday’s announcement did not include was the fact that the Japanese company [Synspective] shuffled this launch from a Vega rocket onto Electron. The Vega rocket, which had its first failure in 15 launches last July, has yet to return to flight. The spaceport it launches from in French Guiana remains closed due to the coronavirus.

Synspective had signed a major agreement with Arianespace last year to launch what is hoped will become a 25-satellite constellation. It appears that because of the Vega rocket failure, along with its higher price, Rocket Lab is going to get that business instead. That Rocket Lab can provide Synspective a dedicated launch, to the orbit of its choice, also encouraged the switch.

The background of this deal suggests that Rocket Lab’s future is bright, assuming New Zealand and the United States are ever allowed to go back to normal as free and open countries.

Leave a comment

Baby Martian volcanoes

1:28 pm

Cratered cone near Noctis Fossae
Click for full image.

Cool image time! I came across this strange feature shown on the right in my normal rummaging through the archive of the high resolution camera on Mars Reconnaissance Orbiter (MRO). The photo, rotated, cropped, and reduced to post here, focuses on what they label a “cratered cone.”

The immediate thought is that this is a volcano cone, and the craters at its peak are not impact craters but calderas. In science however such a knee-jerk conclusion is always dangerous. For example, this might instead be a pedestal crater, where the surrounding terrain was worn away over eons, leaving the crater sitting high and dry.

It is therefore important to look deeper to determine what origin of this feature might be.

First, its location, as shown in the overview map below, provides us our first clue.
» Read more

One comment

Confirmed: Comet ATLAS has broken apart

8:47 am

Astronomers have now confirmed the fact that Comet ATLAS has broken into several pieces, and will not put on a spectacular sky show this coming May.

Just a month ago, it looked like the icy wanderer, officially known as C/2019 Y4 Atlas, might put on a dazzling sky show around the time of its closest approach to the sun, or perihelion, which occurs on May 31.

But relatively lackluster behavior soon dimmed such hopes. And optimism surrounding the comet is now pretty much extinguished, for it’s no longer in one piece. Comet Atlas “has shattered both its and our hearts,” astrophysicist Gianluca Masi, the founder and director of the Virtual Telescope Project in Italy, said in an emailed statement on Sunday (April 12). “Its nucleus disintegrated, and last night I could see three, possibly four main fragments.”

A nice picture of the break-up can be seen here.

We are due for another great comet, like Comet Hale-Bopp in the late 1990s. Unfortunately, Comet ATLAS won’t be that comet.

One comment

OSIRIS-REx successfully completes touch-and-go rehearsal

8:44 am

OSIRIS-REx yesterday successfully completed its first dress rehearsal of the maneuver that will allow it in August to touch the surface of the asteroid Bennu and grab a sample.

Four hours after departing its 0.6-mile (1-km) safe-home orbit, the spacecraft performed the Checkpoint maneuver at an approximate altitude of 410 feet (125 meters) above Bennu’s surface. From there, the spacecraft continued to descend for another nine minutes on a trajectory toward – but not reaching – the location of the sampling event’s third maneuver, the “Matchpoint” burn. Upon reaching an altitude of approximately 246 ft (75 m) – the closest the spacecraft has ever been to Bennu – OSIRIS-REx performed a back-away burn to complete the rehearsal.

During the rehearsal, the spacecraft successfully deployed its sampling arm, the Touch-And-Go Sample Acquisition Mechanism (TAGSAM), from its folded, parked position out to the sample collection configuration. Additionally, some of the spacecraft’s instruments collected science and navigation images and made spectrometry observations of the sample site, as will occur during the sample collection event.

They plan one more rehearsal, getting even closer to the asteroid, before the August 25 sample grab.

Leave a comment

New changes to the brain found from long space missions

8:38 am

Scientists have discovered a “significant increase” in the brain’s white matter that occurs after astronauts have completed long missions in weightlessness.

The team conducted brain MRIs of 11 astronauts before they traveled to the ISS, and then again one day after they returned. Scans were then performed at several interval across the following year. “What we identified that no one has really identified before is that there is a significant increase of volume in the brain’s white matter from preflight to postflight,” Kramer says. “White matter expansion in fact is responsible for the largest increase in combined brain and cerebrospinal fluid volumes postflight.”

These changes remained visible one year after spaceflight, which the researchers say indicates they could be permanent alterations. Past research has suggested that changes in the volume of cerebrospinal fluid (CSF) specifically could be a key driver of Visual Impairment Intracranial Pressure in astronauts. The authors of the new study also observed an increase in the velocity of CSF through the cerebral aqueduct, along with deformation of the pituitary gland, which they believe is related to higher intracranial pressure in microgravity.

The uncertainties for this work remain very large. For one thing, the sample (11 astronauts) is very small. For another, the permanence of this change is only suggested and remains unproven.

Nonetheless, this research adds to the growing body of research that suggests that long term weightlessness is generally not good for the human body. It also reinforces the desperate need for research into the effects of even a small amount of artificial gravity. To most efficiently design spacecraft that provide some form of centrifugal force as artificial gravity, we need to find out the minimum required. It could be providing only 10% or 30% Earth gravity could be sufficient. Or not. We just don’t know.

The engineering challenges however go up significantly the more gravity you need to create. For future interplanetary travel this information is critical.

4 comments

Seasonal avalanches in Martian dune gully

11:01 am

Seasonal changes in Martian dune gully
Click for full image.

The science team for the high resolution camera on Mars Reconnaissance Orbiter (MRO) today released a very cool pair of images, taken a Martian year apart, showing some significant changes that had occurred during that time in a large sand dune slope inside a crater. On the right is that pair, reduced and with the top image slightly lightened to bring out the features. As they wrote in the caption,

One large gully in particular has had major changes in every Martian winter since [MRO’s high resolution camera] began monitoring, triggered by the seasonal dry ice frost that accumulates each year.

This time there was an especially large change, depositing a huge mass of sand. The sand divided into many small toes near its end, or perhaps many individual flows descended near the same spot. Additionally, a long sinuous ridge of sand was deposited. This could be a “levee” that formed along one side of a flow, but there is not much sand past the end of the ridge, so it might also be the main body of a flow.

Nor is this dune gully the only active one in this crater, dubbed Matara Crater, located in the southern cratered highlands at about 50 degrees south latitude. If you look at the full image and compare it with an image from 2009 there are many changes across the entire slope field that extends a considerable distance to the north and south of the cropped section shown above.

At this latitude atmospheric carbon dioxide settles as frost during the winter, then sublimates away with the coming of spring. The freeze-sublimation process disturbs the sand each year, causing these avalanches.

4 comments
1 … 221 222 223 224 225 … 477