Putting humans on Mars has been one of NASA’s driving missions for years, but they are still in the early stages of deciding what exactly that mission architecture will look like. One major factor is where to get the propellant to send the astronauts back to Earth. Advocates of space exploration often suggest harvesting the necessary propellant from Mars itself – some materials can be used to create liquid oxygen and methane, two commonly used propellants. To support this effort, a group from NASA’s COMPASS team detailed several scenarios of the infrastructure and technologies it would take to make an in-situ resource utilization (ISRU) system that could provide enough propellant to get astronauts back to a Mars orbit where they could meet up with an Earth return vehicle. However, there are significant challenges to implementing such a system, and they must be addressed before the 8-9-year process of getting the system up and running can begin.
To understand these challenges, it’s first essential to understand some of the requirements the team was trying to meet. The goal was to provide 300 tons of liquid oxygen and liquid methane to a Mars Ascent and Landing Vehicle (MALV) being developed at other parts of NASA. That much propellant is necessary to get a crew of astronauts back into orbit, where they can be met by an orbiting Earth return vehicle.
Creating liquid oxygen and methane requires many ISRU systems, such as pumps, electrolyzers, dryers, scrubbers, and significant power systems, to run all these machines. Some raw materials, such as CO2, can be pulled from the Martian atmosphere. However, the system will also require 150 tons of water, which could be trucked in from Earth or harvested from Mars.
Fraser discusses how ISRU can provide resources to use for exploration.Designing the overall system architecture is the first step in determining the best method for getting enough propellant to get the astronauts back off of Mars. A paper from the group compares five different approaches to solving that problem and details three of them, focusing on three different methods of getting water to use in the creation of liquid propellants on the surface of Mars.
Let’s first look at the two options for extracting water locally on Mars. One architecture uses a borehole drill to melt subsurface ice and pump it back to the surface, which can be used in electrolysis. The other architecture uses surface harvesting techniques, where soil with a high frozen water content can be sorted, and the water itself melted to provide sufficient stockpiles for creating propellant.
Drilling a borehole deep enough to access subsurface ice has never been done before. It does have some advantages over other water collection methods, including taking less time and requiring one less MALV delivery of equipment (i.e., making it lower cost). However, it does require more power plants and some specialized equipment to be developed.
Fraser speculates on how a real Mars mission could play out.Collecting water from surface regolith utilizes some technologies already being developed at NASA – including the RAZZOR surface mining system that could be used on the Moon or Mars. However, it requires as much time and as many launches as shipping water from Earth, with many possible unknown failure points in the architecture.
By comparison, sending 150 tons of water directly from Earth, while it might be expensive in terms of launch costs, simplifies the overall architecture significantly. There would still technically be ISRU in this scenario, as the water would still be used to create propellant from local Martian resources. However, the added step of getting that water locally would be eliminated.
Even that is a more complicated process than the other two options the team considered, without as much detail in the paper as the actual ISRU setups. Mission designers could send either the methane or both the methane and oxygen from Earth directly, bypassing the need for any ISRU to happen. While these options require potentially more MALV landers, their overall risk is minimized, as the necessary chemicals would be available for use at any point the astronauts would need them. However, they would take longer to set up – especially the option of sending all of the propellants directly from Earth, which could take upwards of 10 years to get set up.
Fraser interviews Dr. Michael Hecht, an expert in ISRU on Mars.Other challenges abound for utilizing Martian resources to create propellants – including limited locations where the necessary water may be found. This geographical restriction might not overlap with where astronauts might be needed to do exciting science, so the architects would have to prioritize either scientific discovery or derisking the ISRU equipment – they likely couldn’t do both.
So, all things considered, if the purpose is to send people to Mars and back safely, it seems like the best, most reliable option is to send the total amount of propellant from Earth. However, in the long run, if humanity plans to make a sustainable presence on Mars, we will need to utilize local resources. The paper from the COMPASS team clearly defines a few strategies that could do that, and someday, it will become the better option – just maybe not quite yet.
Learn More:
Oleson et al – Kiloton Class ISRU Systems for LO2/LCH4 Propellant Production on the Mars Surface
UT – A Single Robot Could Provide a Mission To Mars With Enough Water and Oxygen
UT – Resources on Mars Could Support Human Explorers
UT – Mars Explorers are Going to Need air, and Lots of it. Here’s a Technology That Might Help Them Breath Easy
Lead Image:
Architecture Design of the water from Earth delivery option.
Credit – Oleson et al. / NASA
The post Scaling Propellant Production on Mars is Hard appeared first on Universe Today.
There are good reasons to keep an eye on the Leonid meteors this year.
It’s still one of the coolest things I ever saw. I was in the U.S. Air Force in the 90s, and November 1998 saw me deployed to the dark skies of Kuwait. That trip provided an unexpected treat, as the Leonid meteors hit dramatic storm levels on the morning of the 17th. Meteor came fast and furious towards local sunrise, often lighting up the desert floor like celestial photoflashes in the sky.
Once every 33 years or so, the ‘lion roars,’ as Leonid meteors seem to rain down from the Sickle asterism of the constellation Leo. And while the last outbreak was centered around the years surrounding 1999, there’s some interesting discussion about possible encounters with past Leonid streams in 2024.
The Leonids in 2024To be sure, 2024 is otherwise slated to be an off year for the shower. The normal annual maximum for 2024 is expected to occur on Sunday, November 17th at around ~4:00 Universal Time (UT), with an expected Zenithal Hourly Rate (ZHR) of 15-20 meteors per hour seen under ideal conditions. This favors Europe in the early dawn hours.
The Leonid radiant, looking east at 2AM local. Credit: Stellarium. A Leonid Outburst in 2024?But there are also a few other streams that may arrive earlier this week and are worth watching for. Jérémie Vaubaillon of the Paris Observatory IMCCE notes that Earth may encounter three older streams from periodic comet 55P/Tempel-Tuttle. The comet is the source of the Leonids. On a 33.8 year orbit, a meteor shower occurs when the Earth plows headlong into the stream of dust and debris laid down by the comet.
The three suspect trails are:
-A trail laid down in 1633 (the source of the 2001 meteor storm). Earth is near this trail on November 14th at 16:37 UT, favoring northwestern North America in the early morning hours.
-A dust trail from 1733, peaking on November 19/20th at 23:53 to 00:54 UT, favoring north/central Asia.
-And finally, an encounter with a string of older (more than a millennium old) streams on November 14th at 16:37 UT, (the same time as the 1633 stream). It is worth noting that the 1733 stream was the suspected source of the 1866 Leonid meteor storm.
A bright green Leonid from 2023. Credit: Frankie Lucena.Watching this Thursday morning on the 14th could be a harbinger as to whether or not we’re in for a show. Unfortunately, the Moon is waxing gibbous and headed towards Full this week on November 15th, meaning that it with provide increasing illumination and cut down observed meteor rates.
The Leonids on past recent years have held steady at predicted rates of about or so 20 per hour. It’s worth noting that another encounter with the 1699 stream and possible outburst is predicted for next year, 2025.
Leonid TEFF (Total Effective observation time) rate versus meteors over the years. Credit: the International Meteor Organization (IMO). Meteor Shower… or Storm?Meteor storms occur when the zenithal hourly rate tops 500 or more per hour. Keep in mind, a ZHR of a thousand or higher means that you’re seeing a meteor every few seconds. The October Draconids and the December Andromedids are also prone to great outbursts, but the Leonids are the most notorious and well-known. The 1966 shower seen over the U.S. southwest topped an amazing ZHR of up to 150,000 per hour (!)
A depiction of the 1833 outburst over Niagara Falls. Credit: Mechanic’s Magazine/Popular Domain. Observing and Imaging the LeonidsEarly morning hours are best to see meteors, as you’re standing on the swath of the surface of the Earth that’s turned forward in to the stream. Pinpoint meteors will occur near the shower radiant, while long streaks will stand out out in stark profile about 45 to 90 degrees away on either side of the radiant. I like to aim my tripod-mounted DSLR at these regions, set the lens to the widest field of view possible, and simply let it run taking auto-exposures and see what turns up. An intervalometer is a great device to automate this process. This allows me to just sit back with a steaming hot cup of tea (a must for cold November mornings) and simply watch the show, as meteors slide by.
A Leonid pierces the night sky over southern Arizona. Credit: Eliot Herman.Perhaps, we’ll simply have to wait for 2030s to see strong activity from the Leonids again. But do you really want to risk missing a surprise show? To quote hockey player Wayne Gretzky: “You miss 100% of the shots you don’t take.” The same holds true for missing versus catching meteor storms: you just have to show up and watch.
The post Is an ‘Off-Year’ Leonid Outburst in the Cards For November? appeared first on Universe Today.
Everybody has their own theory about the most important factor leading to the Democrats’ loss a week ago. People blame Biden, Harris, the Republicans (whose supporters are characterized as fascistic racists), the left-wing press, and the wokeness of Democrats, which pushed Harris and the party away from the center towards the “progressive” (far Left) side.
In the 40-minute video below, Sam Harris zeroes in on the last factor—the fulminating wokeness of Democrats. Make no mistake about it, Harris was a vehement opponent of Trump, but here he is—as I often do—noting the problems with “Democratic” views that make them lose elections. In this case, it’s wokeness, especially the brand centered on “trans” issues.
Sam’s overall take: the Left “did not pivot to the political center in a way that the voters found credible.” He adds that the planks of Harris’s platform were “rotten”, especially those supporting identity politics. As he says, “identity politics is over, nobody wants it.”
In particular—and for this Sam will be excoriated for transphobia, though he’s not transphobic—he says that “activism about transgender politics has deranged our politics as long as Trump has been in politics.” Harris emphsizes that he supports transgender rights (meaning “legal rights”), but thinks the electorate rejects the idea that males identifying as females should be competing in sports against biological females. Neither do I and neither does Sam, but he adds that “if [that] sounds like transphobia to you, then you are the problem.” He goes on to characterize gender activism as a “new religion” or a “cult”, but again emphasizes that it is the excesses of that movement that turns him off just as it repelled potential voters for Harris. (Sam says, as an aside, that “We should help those who are truly gender dysphoric.”)
Where readers might disagree is Sam’s emphasis on gender activism as THE factor that turned off centrists and moderates, and may have swung the election. As he says,
“A shocking percentage of Democrats imagine that all the controversy about trans rights and gender identity in kids is just right wing bigotry, and a non-issue politically, whereas it is obvious that for millions of Americans it might as well have been the only issue in this election–not because they’re transphobic assholes, but because they simply do not accept the new metaphysics, and even the new biology, mandated by trans activists and the institutions that htye have successfully bullied and captured. . . . Congratulations, Democrats: you have found the most annoying thing in the fucking galaxy and hung it around your necks.”
Sam has apparently abandoned the calmness accompanying the meditation he practices, for the piece is larded with uncharacteristic profanity, including Sam’s peevish claim that if we Democrats continue this way, “You’re going to get President Candace Fucking Owens some day.” But I applaud the increasing use of profanity in such podcast, for that’s the way people actually talk.
Sam then appends the claim that cultural issues, not inflation or the border, may have been the crucial factor that swung the election towards Trump—although of course there may have been many factors, each of which, if mitigated, could have changed the course of a close election. These include the following:
a.) The degradation of major cities run by Democratic mayors, who don’t do anything about homelessness or pervasive theft in retail stores.
b.) The lack of policing or criticism of policing in many places. As he says, officials “won’t police the streets but they police the language.”
c.) The failure of Democrats to take Islamism, and terrorist organizations like Hamas, sufficiently seriously. “Democrats needs to figure out,” he says, “that civilization needs to be defended from barbarism.” While he notes that both Biden and Harris did support Israel, during the election they—and by this he means Kamala Harris—”talked out of both sides of their mouths.” Indeed she did, for I paid close attention.
In the end, Sam concludes that “Democratic moral confusion cost the Democrats millions of votes.” While you may say that equivocation and both-sides-of-the-mouth talking is the heart of politics, Sam is saying that the moral rectitude was not rocket science, but comprised centrist and populist views that wokeness prevented Democrats from espousing. And the GOP picked up on this moral weakness, making it the subject of many pro-Trump ads like the one below.
I recommend that you listen to Sam’s audio here. I’ve put two extra items below it.
Here’s one of the Trump ads that excoriated Democrats for wokeness, concentrating on Kamala’s support for government-funded gender surgery for incarcerated immigrants who entered the country illegally (yes, she did say that):
And here’s a kerfuffle at CNN showing how vehemently some liberals take gender activism. One guy goes ballistic when the speaker, Republican Shermichael Singleton, suggests that boys (who assume the female gender) shouldn’t be able to compete in in women’s athletics, saying “they’re not boys”. And then the room explodes, with the moderator demanding “respect” for that view and suggesting that the athletics ban is “transphobic”. Singleton keeps saying that this is what “regular people” think, and he’s right. It’s the insistence on that kind of misguided activism that, says Harris, is precisely why the Democrats lost. Well, weigh in below.
“I am NOT going to listen to transphobia at this table!”
CNN panelist loses their mind over “slur” used by Republican strategist during trans sports debate. pic.twitter.com/5PXnSJW4A0
— Brigitte Gabriel (@ACTBrigitte) November 9, 2024
Today’s photos come from reader Rik Gern of Austin, Texas. Rik’s captions are indented, and you can enlarge the photos by clicking on them.
Earlier this year I sent you a few batches of pictures of fungi taken in Wisconsin’s Northwoods in September of last year, mostly from Copper Falls State Park. These pictures are from the same trip, but with the camera pulled back to reveal larger growth and let the region show off its fall colors. Unfortunately I was not using the Seek by iNaturalist app with these shots, so I’ve had to try to identify species by comparing my pictures to images found using a search engine. Consider all species identification tentative!
The trip began near Eagle River, an area full of small lakes. Fortunately, the fall colors were in full force!:
Along the way we stopped by the Smith Rapids covered bridge in Fifield. The bridge is not the rustic relic of the past one might expect; it was built in 1991! Here it is, next to a nice looking balsam fir (Abies balsamea):
Copper Falls State Park has eight hiking trails, totaling seventeen miles. With limited time and accompanied by my 89 year old mother, we opted for the shortest trail, Doughboys Nature Trail, which is is a little less than two miles long. As you enter the trail, the woods are heavily populated by white pine (Pinus strobus), though maple trees are also in abundance, as can be seen by their leaves along the path.
Here is a lot of young growth, mostly white pine, birch and maple:
Paper birch (Betula papyrifera) gives a light touch to the woods:
The mushrooms sprouting from this recently fallen tree show how quickly the forest recycles itself. Maple saplings are all over, ready to replace the falling trees:
Here is a white pine that didn’t even bother to fall down before rotting away!
A stairway leads to an observation tower where you can get a more elevated perspective of the trees.
I’m not sure if these are red maple (Acer rubrum) or sugar maple (Acer saccharum). I don’t know botany, but I know what I like!:
Here are some smaller maples. The picture wouldn’t cooperate with me, so I played around to give it sort of an impressionistic look:
For all the wide-eyed gazing I did, I’m sure I missed more than I saw. Though I didn’t observe any animal life, I was no doubt observed by many woodland critters who remained hidden to me. That thought inspired this image (taken from the same stand of young maples as the previous picture) and an accompanying haiku:
Predator and prey
Blending with nature’s patterns
Playing hide and seek
On September 11, 2001, as part of a planned terrorist attack, commercial planes were hijacked and flown into each of the two towers at the World Trade Center in New York. A third plane was flown into the Pentagon, and a fourth crashed after the passengers fought back. This, of course, was a huge world-affecting event. It is predictable that after such events, conspiracy theorists will come out of the woodwork and begin their anomaly hunting, breathing in the chaos that inevitably follows such events and spinning their sinister tales, largely out of their warped imagination. It is also not surprising that the theories that result, just like any pseudoscience, never truly die. They may fade to the fringe, but will not go away completely, waiting for a new generation to bamboozle. In the age of social media, everything also has a second and third life as a You Tube or Tik Tok video.
But still I found it interesting, after not hearing 911 conspiracy theories for years, to get an e-mail out of the blue promoting the same-old 911 conspiracy that the WTC towers fell due to planned demolition, not the impact of the commercial jets. The e-mail pointed to this recent video, by dedicated conspiracy theorist Jonathan Cole. The video has absolutely nothing new to say, but just recycles the same debunked line of argument.
The main idea is that experts and engineers cannot fully explain the sequence of events that led to the collapse of the towers and also explain exactly how the towers fell as they did. To do this Cole uses the standard conspiracy theory playbook – look for anomalies and then insert your preferred conspiracy theory into the apparent gap in knowledge that you open up. The unstated major premise of this argument is that experts should be able to explain, to an arbitrary level of detail, exactly how a complex, unique, and one-off event unfolded – and they should be able to do this from whatever evidence happens to be available.
The definitive official report on the cause of the collapse of the two towers is in the NIST report, which concludes:
“In WTC 1 , the fires weakened the core columns and caused the floors on the south side of the building to sag. The floors pulled the heated south perimeter columns inward, reducing their capacity to support the building above. Their neighboring columns quickly became overloaded as columns on the south wall buckled. The top section of the building tilted to the south and began its descent. The time from aircraft impact to collapse initiation was largely determined by how long it took for the fires to weaken the building core and to reach the south side of the building and weaken the perimeter columns and floors.”
The process in WTC 2 was similar, just with different details. Essentially the impact of the commercial jets dislodged the fireproofing from the core columns. The subsequent fires then heated up and weakened the steel, reducing their ability to bear load until they ultimately failed, initiating collapse. Once a collapse was initiated the extra load of the falling floors was greater than the ability of the lower floors to bear, so they also collapsed.
There really is no mystery here – a careful and thorough analysis by many experts using all available video evidence, engineering designs of the building, and computer simulations have provided an adequate and highly plausible explanation. But Cole believes you can just look at the videos and contradict the experts – he explicitly argues for this position, even that it is “obvious” what is happening and all the experts are wrong. He then cherry picks reasons for not accepting the expert conclusion, such as, why haven’t we seen this before? Where are the pancaked floors? But again, he is just anomaly hunting. What he fails to consider is that the WTC towers were the largest structures ever to collapse in this way, and that you cannot simply scale up smaller building collapses and think you can understand or predict what should have happened with the towers. The energies involved are different, and therefore the relevant physics will behave differently. This is like trying to understand what will happen if a person falls from a height by your experience with small insects falling from relatively similar heights.
The two main anomalies he focuses on are the absence of recognizable debris and the apparent “explosions”. He says – where are the pancaked floors? Meanwhile, lower Manhattan was covered with a layer of concrete dust. Where do you think that dust came from? Again – at this scale and these energies the concrete was mostly pulverized into powder. This is not a mystery.
His second line of evidence (again, nothing new) is the apparent series of explosions ahead of the collapse. However, these explosions are simply the air pressure and immense power of the building collapsing down, causing an explosive sound as each floor was encountered by the collapse, and causing air to be blown out the windows. This is not an incredibly precise sequence of explosions ahead of the collapse – it is the collapse. I love how the “controlled demolition” advocates argue that the collapse looked like such a demolition. But actually look at videos of controlled demolitions – they look nothing like the collapse of the towers. In such cases you see the explosions, usually happening at roughly the same time, a moment before the collapse. The sequence is – explosions then collapse. But with the WTC collapses the collapse comes first, and the apparent “explosions” (which do not look like any demolition video I have seen) are at the leading edge of the collapse. This would requires a fantastically timed sequence of demolitions that is virtually impossible.
In essence Cole and other die-hard 911 conspiracy theorists are replacing a well modeled and evidenced explanation for the collapse with wild speculation, causing far more problems than the imaginary ones they conjure up.
There is also the fact that conspiracy theorists rarely provide any positive evidence for their conspiracy. They only try to poke holes in the official explanation, then insert a sinister interpretation. But here we are, 23 years later, and still there isn’t a lick of evidence (even through multiple subsequent administrations) for a conspiracy. The conspiracy narrative also doesn’t make sense. Why would they arrange to have commercial jets laden with fuel crash into the towers, and then also take on the risk of rigging them for controlled demolition, and then setting off the demolition in front of the world and countless cameras? And then take the risk that an official investigation, even in a later administration, would not reveal the truth. This is a bad movie plot, one that would pull me from my sustained disbelief.
There is no evidence for an inside job. There is no evidence that a massive project to plant explosives in both towers (or three, if you include WTC7) had occurred. There is no evidence from actual expert analysis that the towers fell due to controlled demolition. Cole’s analysis is not convincing to say the least. I find it childish and simplistic. But it is easy to use anomaly hunting to create the impression that something fishy is going on, and that is partly why these conspiracy theories persists, long past their expiration date.
The post 911 Conspiracy Theories Persist first appeared on NeuroLogica Blog.
Rarely does something get developed which is a real game changer in space exploration. One example is the Skylon reusable single-stage-to-orbit spaceplane. Powered by the hypersonic SABRE engine it operates like a jet engine at low altitude and more like a conventional rocket at high altitude. Sadly, ‘Reaction Engines’ the company that designs the engines has filed for bankruptcy.
Launching rockets into space is an expensive business and it has often been a significant barrier in space exploration. This is largely because traditional rockets include a significant proportion of expendable elements. A typical launch into low Earth orbit for example can cost anything from tens to hundreds of millions of dollars due to those single use components. Movement has however been seen with reusable rocket technology like the Falcon 9 and Starship rockets which are refurbished and reused for multiple launches. This has helped to drive down the cost of a rocket launch but still about $2,000 per kilogram there is still much to do to drive down the cost of space exploration.
A SpaceX Falcon 9 rocket sends the European Space Agency’s Hera spacecraft into space from its Florida launch pad. (Credit: SpaceX)The idea for a fully reusable single-stage-to-orbit (SSTO) spaceplane is one such development and was the brainchild of Reaction Engines Limited. The Skylon spaceplane was designed to take off and land like a conventional aircraft significantly reducing the launch costs. Instead of relying upon multiple expendable stages during ascent, Skylon’s Synergetic Air-Breathing Rocket Engine (SABRE) combines jet and rocket propulsion technology to reach orbit. Instead of being fuelled by conventional rocket propellant carried aloft, it utilises atmospheric oxygen reducing the need to carry heavy oxygen and therefore drastically improves fuel efficiency. Once at sufficient altitude, the SABRE engine switches to rocket mode and only then starts to use onboard oxygen to reach final orbit.
An artist’s conception of Reaction Engines’ Skylon spacecraft. Credit: Reaction EnginesReaction Engines Limited was formed in the UK back in 1989 and focussed its attention on propulsion technology. In particular to address access issues to space and hypersonic flight. The SABRE engine they developed showed successfully that a dual-mode rocket could efficiently transition between high speed flight within the atmosphere to rocket powered flight in space. It relies upon a pre-cooler system that cools incoming air from over 1,000°C to room temperature in fractions of a second to drive high speeds without the engine over heating.
The company is based in Oxfordshire and has to date, secured significant investments including BAE Systems, Boeing and the European Space Agency. Unfortunately, the company has been struggling to source funding to continue operations so formally entered administration on 31 October 2024. An eight week process is now underway to develop plans to restructure, sell the company or liquidate its assets. Most of its 200 employees have now been laid off.
Source : Reaction Engines Limited
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Bats are scary and rabies is deadly, but do you need to worry about you or your pets catching the disease from them?