Tag: science

An astrophysicist explains cosmology’s theoretical failures

8:37 am

Link here. The astrophysicist, Paul Sutter, does a very nice job of outlining the conundrum that has been causing astrophysicists to tear their hair out for the past decade-plus.

In the two decades since astronomers discovered dark energy, we’ve come upon a little hitch: Measurements of the expansion rate of the universe (and so its age) from both the CMB [cosmic microwave background] and supernovas have gotten ever more precise, but they’re starting to disagree. We’re not talking much; the two methods are separated by only 10 million or 20 million years in estimating the 13.77-billion-year history of the universe. But we’re operating at such a level of precision that it’s worth talking about.

If anything, this failure for two measurements of data spanning billions of light years — which is billions in both time and space — is a perfect illustration of the uncertainty of science. Astrophysicists are trying to come up with answers based on data that is quite thin, with many gaps in knowledge, and carries with it many assumptions. It therefore is actually surprising that these two numbers agree as well as they do.

Sutter, being in the CMB camp, puts most of the blame for this failure on the uncertainty of what we know about supernovae. He could very well be right. The assumptions about supernovae used to measure the expansion rate of the universe are many. There is also a lot of gaps in our knowledge, including a full understanding of the process that produces supernovae.

Sutter however I think puts too much faith in theoretical conclusions of the astrophysics community that have determined the age of the universe based on the CMB. The uncertainties here are as great. Good scientists should remain skeptical of this as well. Our knowledge of physics is still incomplete. Physicists really don’t know all the answers, yet.

In the end, Sutter however does pin down the biggest problem in cosmology:

The “crisis” is a good excuse to keep writing papers, because we’ve been stumped by dark energy for over two decades, with a lot of work and not much understanding. In a sense, many cosmologists want to keep the crisis going, because as long as it exists, they have something to talk about other than counting down the years to the next big mission.

In other words, the discussion now is sometimes less about science and theories and cosmology, but instead about funding and career promotion. What a shock!

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A hiker’s view from Mount Sharp

10:10 am

A hiker's view of Gale Crater, taken by Curiosity
Click for full image.

A quick cool image! The photo to the right, reduced to post here, was taken yesterday by Curiosity’s left navigation camera. It looks west across the floor of Gale Crater, at the base of a nearby butte.

The crater rim, as seen by the distant mountains, is about 25 miles away. The butte that towers above Curiosity is probably no more than 50 feet high.

Below is a panorama showing the full view to the west, with Navarro Mountain (the nearby 450-foot-high foothill at the base of Mount Sharp) on the left edge. Based on the rover’s planned route, it will travel to the right of the butte rather than climbing up onto the saddle on the left. This will take it to the western side of Navarro Mt, where it will eventually head south into the canyon Gediz Vallis.
» Read more

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1st water vapor in Ganymede’s atmosphere, detected using data from Hubble

9:06 am

Using Hubble data, astronomers have detected the first evidence of water vapor in the atmosphere of Jupiter’s largest moon, Ganymede.

Though larger than the blistering planet Mercury, the Jovian moon Ganymede is no place to go sunbathing. Located ½-billion miles from the Sun, the water ice on its surface is frozen solid in frigid temperatures as low as minus 300 degrees Fahrenheit. This makes the ice as hard as rock. Still, a rain of charged particles from the Sun is enough to turn the ice into water vapor at high noon on Ganymede.

This is the first time such evidence has been found, courtesy of the Hubble Space Telescope’s spectroscopic observations of aurora on Ganymede spanning two decades. The auroras are used to trace the presence of oxygen, which then is linked to the presence of water molecules sputtering off the surface. Ganymede has a deep ocean located an estimated 100 miles below the surface. That’s too deep for water vapor to be leaking out.

This detection has a margin of uncertainty, but it provides a baseline for the up close observations planned for Europe’s JUICE orbiter, set to launch in ’22 and arrive in Jupiter orbit in ’29. JUICE’s study focus will be the three Galilean moons that appear to have lots of ice, Ganymede, Calisto, and Europa.

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Update on Ingenuity’s 10th flight and Perseverance’s first sample drilling

3:54 pm

Ingenuity landing at end of 10th flight

The news coming from the Perseverance and Ingeniuty science teams has been sparse this past weekend, even though Perseverance had begun drilling its first core sample that it will stored for pickup by a later unmanned robot, and Ingenuity had attempted its 10th and most challenging flight yet.

We do have images however, and the two to the right give us hints about what has happened.

First, the top picture on the right was taken by Ingenuity’s navigation camera just prior to landing. The camera looks straight down and is used by the helicopter to adjust its flight. The dark area is the helicopter’s shadow. Based on this picture and the four preceding images (taken over an eleven second period), it appears the helicopter was landing safely. No other images have yet been downloaded, nor has the Ingenuity team announced any results, so we do not yet know if the flight proceeded as planned.

UPDATE: The flight was a success, as per this JPL announcement:

With the #MarsHelicopter’s #flight success today, we crossed its 1-mile total distance flown to date. It targeted an area called “Raised Ridges,” named for its #geographic features. Flight 10 is #Ingenuity’s most complex flight profile yet, with 10 distinct waypoints and a new #record height of 40 feet (12 meters).

Drill and core sample in the ground

The second image, taken by Perseverance’s left navigation camera and cropped and reduced to post here, is more puzzling. It shows what appears to be the core sample still in the ground after drilling. While this could be entirely as planned, it seems very surprising. Most of what I can find online describing the operation for obtaining these samples implies that the robot arm would drill the hole, and then retract the sample immediately to place it in storage. Nothing suggests the arm would be retracted with the sample still in the ground.

I think however the odds of this picture revealing a problem are low. This JPL press release from February 2021 implies vaguely that the core sample will be released in this manner before retraction. After the core sample, with bit, is separated from the arm, the release suggests they will lift the arm away to inspect the drilling process, then return the arm to retract the core sample for storage. This does make some sense, though grabbing that sample again will be quite challenging.

If this was not supposed to happen as described, then there is a problem that must be resolved. I expect more details in the next day or so to clarify this situation.

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The Oort Cloud: what little is known

5:47 pm

Link here. This is one of the best articles on the theorized Oort Cloud, in that right off the bat the author recognizes this important fact:

We know so little about it that its very existence is theoretical — the material that makes up this cloud has never been glimpsed by even our most powerful telescopes, except when some of it breaks free.

The cloud’s existence is extrapolated from the arrival of long period comets, and seems to make sense. Yet, without any direct observations it remains a theory only, and an unproven one at that.

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SpaceX wins contract to launch Europa Clipper to Jupiter

5:41 pm

Capitalism in space: NASA today awarded SpaceX a $178 million contract to use its Falcon Heavy rocket to launch Europa Clipper to Jupiter.

If all goes according to plan, Clipper will lift off in October 2024 from NASA’s Kennedy Space Center in Florida and arrive in orbit around Jupiter in April 2030. The probe will then study Europa in depth during nearly 50 close flybys of the moon over the course of about four Earth years, mission team members have said.

The award is not really a surprise. Falcon Heavy is really the only operational rocket with the power capable of launching this mission. Because for years Congress had mandated Europa Clipper be launched on SLS, it was designed with more mass than normal for such planetary missions. Delays in the SLS program however finally forced Congress to relax that mandate, but that left NASA with a payload too heavy for all operational rockets except Falcon Heavy, and even that requires this six year flight, with flybys of the Earth and Mars to get it to Jupiter.

The price for the launch is significantly greater than SpaceX normally charges for its Falcon Heavy, but since it was the only game in town, I suspect SpaceX drove a hard bargain.

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Ice, lava, quakes, and faults, all in one Martian image

1:04 pm

A lot of geology in one picture
Click for full image.

Cool image time! The photo to the right, rotated, cropped, and reduced to post here, was taken by the high resolution camera on Mars Reconnaissance Orbiter (MRO) on April 25, 2021. It grabbed my attention because it possibly captures a whole range of Martian geological processes, all in one place, including evidence of quakes, of lava, of faults, and possibly of glaciers.

First, ignore the black rectangle, which is merely a small section of lost data.

The picture itself shows a wide north-south fissure, as indicated by the distinct western cliff and the fainter and less pronounced eastern cliff. This fissure, likely formed along a fault, was created when the crust was pushed and stretched upward by the pressure of underground volcanic magma, part of the long series of eruptions that formed the many similar and parallel north-south fissures south of the shield volcano Alba Mons.

The overview map below illustrates this fissure’s relationship with Alba Mons.
» Read more

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Global dust storm on Mars brought on an early spring in southern hemisphere

9:57 am

Scientists analyzing the climate effects from the 2018 global dust storm on Mars have found that while it did little to change the seasons in the northern hemisphere, it caused winter to end early in southern hemisphere.

The team found that the 2018 storm had profoundly different effects in each hemisphere. At the south pole, where the vortex was almost destroyed, temperatures rose and wind speeds fell dramatically. While the vortex may have already been starting to decay due to the onset of spring, the dust storm appears to have had a decisive effect in ending winter early.

The northern polar vortex, by contrast, remained stable and the onset of autumn followed its usual pattern. However, the normally elliptical northern vortex was changed by the storm to become more symmetrical. The researchers link this to the high dust content in the atmosphere suppressing atmospheric waves caused by the extreme topography in the northern hemisphere, which has volcanoes over twice as tall as Mount Everest and craters as deep as terrestrial mountains.

These differences are likely also related to the eccentricity in the Martian orbit around the Sun, which is greater than that of Earth and actually has a direct effect on its seasons. As noted in this recently published paper about the activity scientists have now documented on the Martian surface in the past decade,

Because perihelion (the closest approach to the Sun) currently occurs [during summer in the south], southern hemisphere seasons are more extreme, with a longer winter and shorter, warmer summer

This difference is probably a major factor explaining the different effects of the global dust storm. It also is probably why the Red Planet’s two polar ice caps are so different.

This difference between the two hemispheres will also likely help drive the intitial human settlement on Mars to the north. Not only does the northern hemisphere have the flat lowland plains, making those first difficult landings easier and safer, it has a more benign climate year round.

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Scientists refine Martian interior based on quakes detected by InSight

9:11 am

Martian quake map as seen by InSight

Scientists today published three studies in the journal Science outlining their conclusions about the interior of Mars, based on the quakes that have been detected by InSight since it arrived on Mars in November 2018.

Reporting in a trio of studies published in the July 23rd Science, the Insight science team has now analyzed about 10 marsquakes to make the first direct observations of the structure within another rocky planet. The results — a surprisingly thin crust, an undifferentiated mantle, and a larger-than-expected core — will help determine how Mars formed and evolved.

There results are essentially what was described in April by the InSight science team at the annual 52nd Lunar and Planetary Science Conference (and reported here but no where else), though now more carefully and thoroughly described.

The discovery that the Martian crust is much thinner than expected, either 12 or 24 miles thick, with a core that is still liquid, has ramifications that might help explain both the planet’s formation and its volcanic history and giant volcanoes.

One piece of good engineering news in connection with the lander InSight:

Despite a dust-fueled energy crisis earlier this year, the solar-powered lander has since regained some power-generating capacity. “We are at least safe for this season’s winter and probably far into 2022,” Stähler says.

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Astronomers detect for the first time an accretion disk around an exoplanet

8:43 am

The exoplanet and its accretion disk
Click for full image.

Using the Atacama Large Millimetre/submillimeter Array (ALMA) in Chile, astronomers have made the first confirmed images of a moon-forming accretion disk around another a very young exoplanet.

The photo to the right shows this, with the top image the wide view showing the exoplanet in its orbit around the star, in an area inside the star’s own accretion disk (the larger ring) that the planet has apparently cleared of debris as it gathered itself. The bottom image zooms into the planet to show its own disk of material.

From the press release:

The disc in question, called a circumplanetary disc, surrounds the exoplanet PDS 70c, one of two giant, Jupiter-like planets orbiting a star nearly 400 light-years away. Astronomers had found hints of a “moon-forming” disc around this exoplanet before but, since they could not clearly tell the disc apart from its surrounding environment, they could not confirm its detection — until now.

In addition, with the help of ALMA, Benisty and her team found that the disc has about the same diameter as the distance from our Sun to the Earth and enough mass to form up to three satellites the size of the Moon.

The exoplanet’s disk is thus very large compared to our solar system, but that isn’t surprising considering the difficulty of observing it at such distances. Disks comparable in size to our solar system and the Earth-Moon system are simply too small for any telescope to yet image in this way.

The new data also found this interesting fact: The other known Jupiter-like exoplanet in this system does not have its own accretion disk or any visible debris orbiting it. Why one planet still has such debris and the other does not is a mystery related to the formation of solar systems that is at present not understood.

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It’s drill time for Perseverance!

8:18 am

The Perservance science team is preparing the rover for its first drill hole and the first collection of a sample to cache so that a future spacecraft can return it to Earth.

They are presently at the general location where they wish to drill, and are looking for the exact right spot.

The sampling sequence begins with the rover placing everything necessary for sampling within reach of its 7-foot (2-meter) long robotic arm. It will then perform an imagery survey, so NASA’s science team can determine the exact location for taking the first sample, and a separate target site in the same area for “proximity science.”

“The idea is to get valuable data on the rock we are about to sample by finding its geologic twin and performing detailed in-situ analysis,” said science campaign co-lead Vivian Sun, from NASA’s Jet Propulsion Laboratory in Southern California. “On the geologic double, first we use an abrading bit to scrape off the top layers of rock and dust to expose fresh, unweathered surfaces, blow it clean with our Gas Dust Removal Tool, and then get up close and personal with our turret-mounted proximity science instruments SHERLOC, PIXL, and WATSON.”

“After our pre-coring science is complete, we will limit rover tasks for a sol, or a Martian day,” said Sun. “This will allow the rover to fully charge its battery for the events of the following day.”

Sampling day kicks off with the sample-handling arm within the Adaptive Caching Assembly retrieving a sample tube, heating it, and then inserting it into a coring bit. A device called the bit carousel transports the tube and bit to a rotary-percussive drill on Perseverance’s robotic arm, which will then drill the untouched geologic “twin” of the rock studied the previous sol, filling the tube with a core sample roughly the size of a piece of chalk.

Perseverance’s arm will then move the bit-and-tube combination back into bit carousel, which will transfer it back into the Adaptive Caching Assembly, where the sample will be measured for volume, photographed, hermetically sealed, and stored. The next time the sample tube contents are seen, they will be in a clean room facility on Earth, for analysis using scientific instruments much too large to send to Mars.

Not all drill samples will be cached in this manner.

With this press release and press conference NASA continued to push the fiction to the press that Perservance’s prime mission is to search for life. That is a lie designed to catch the interest of ignorant journalists who don’t know anything. The rover’s real mission is to study the overall Martian geology in Jezero Crater in order to better under the planet’s present geology as well as the geological history that made it look like it does today.

If the scientists using Perseverance find evidence of life, wonderful, but that is not their prime goal.

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New studies show that the biggest risk to kids from COVID are the policies of governments

3:28 pm

New studies about COVID-19 and its effect on children continue to show that the strigent health policies being demanded by government agencies like the CDC and WHO and many Democrats are actually the biggest health threat for children than the virus itself.

First, a major survey of 48,000 children who had become infected with COVID-19 has found that absolutely no healthy children died from the disease.

Dr. Marty Makary is a medical expert and professor at the Johns Hopkins School of Medicine, Bloomberg School of Public Health, and Carey Business School. His research team “worked with the nonprofit FAIR Health to analyze approximately 48,000 children under 18 diagnosed with Covid in health-insurance data from April to August 2020.”

After studying comprehensive data on thousands of children, the team “found a mortality rate of zero among children without a pre-existing medical condition such as leukemia.”

Let me repeat that. They looked at tens of thousands of kids under the age of 18 and could not find one case where a healthy child died. All recovered. None needed a vaccine, as their young and very strong immune systems did what those immune systems have always done, fought off a sickness to give them an immunity for the rest of their lives.

So kids are safe from COVID, even if they are not vaccined and actually catch the virus and get sick.

At the same time, other studies have found that both masks and the vaccines are actually a greater health threat to children than the virus itself.
» Read more

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NASA funds hopper to jump into shadowed lunar craters and find ice

10:16 am

Capitalism in space: NASA has awarded a $41.6 million contract to Arizona State University and the private company Intuitive Machines to build a tiny hopper that will be used to explore the permanently shadowed craters near the Moon’s south pole, looking for water ice.

Micro-Nova can carry a 1-kilogram payload more than 2.5 kilometers to access lunar craters and enable high-resolution surveying of the lunar surface under the flight path. Intuitive Machines’ Micro-Nova, a lunar hopper that will explore permanently shaded regions of the moon.

…“Intuitive Machines’ Micro-Nova is our first-ever chance to explore from within a lunar permanently shaded region (PSR),” said the mission science lead Mark Robinson, of ASU’s School of Earth and Space Exploration. “We will be able to take very high resolution color images near the hopper and black and white images of about half the PSR. What will we see, that is the question!”

This tiny hopper, only 30 inches square, will be built by ASU and launched on Intuitive Machines’ first Moon lander, Nova-C, presently scheduled for launch in December 2022.

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Ice-filled craters in Mars’ glacier country?

1:10 pm

Craters in Protonilus Mensae
Click for full image.

Today’s cool image returns us to the chaos region dubbed Protonilus Mensae, the middle of three adjacent mensae regions in the northern hemisphere that I like to dub Mars’ glacier country because there is so much evidence of buried ice there.

The photo to the right, cropped to post here, was taken on May 31, 2021 by the high resolution camera of Mars Reconnaissance Orbiter (MRO). Titled “Layered Feature in Crater in Protonilus Mensae,” the section I have posted focuses on several craters, with the one with the central mesa likely the picture’s target. Based on many similar features found in craters in this region, it is somewhat safe to assume that this mesa is made of buried ice.

The overview map below as always provides the context.
» Read more

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Cracks, chaos, and maybe caves in one place on Mars

11:34 am

Mosaic of Avernus Cavi fissures
Click for higher resolution. Original images found here and here.

Today’s cool image to the right is a mosaic I have made from two images taken by the context camera on Mars Reconnaissance Orbiter (MRO), showing a most intriguing region on Mars dubbed Avernus Cavi, located in the large volcanic plain called Elysium Planitia between the giant volcanoes Elysium Mons and Olympus Mons, a region I like to call Mars’ volcano country.

The mosaic shows in one picture much of the typical terrain in Avernus Cavi. We see many linear depressions or cracks, created when the ground stretched and cracked at weak points. We also see many depressions that suggest sinkholes, places where the surface sagged down because of a void below ground.

The area of knobs and mesas in the picture’s southeast quadrant is very typical Martian chaos terrain, the later result of long term erosion of these cracks and depressions.

The white box shows the area covered by the image below.
» Read more

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The lacy rocks of Mars

9:36 am

Lacy rocks on Mars
Click for full image.

Cool image time! The image to the right, cropped and reduced to post here, was taken on July 16, 2021 by the Mars rover Curiosity, using its high resolution mast camera.

There isn’t much to say. These are alien rocks, created in a place with a gravity only about a third that of Earth’s in a climate that is very different. Their delicate nature suggests we are looking at something that was once more substantial and has since been undergoing erosion.

Nor has it been that unusual to find rocks so dainty on Mars. In fact, the more Curiosity has climbed, the more such things have been visible. And similar things were seen by the rovers Spirit and Opportunity.

How such rocks formed initially in the far past, under what climate conditions, remains the number one mystery on Mars. What is now causing it to flake away into such a finespun gossamer of complexity is as much a mystery, tied more to the climate and geology of Mars today.

This rock sits on the bottom flank of Mt Sharp in Gale Crater, at the highest elevation Curiosity has yet climbed. At this point the rover has just entered a new geological unit, what scientists have dubbed the sulfate unit. The evidence gathered from a distance (that so far appears confirmed by recent observations) suggest that this unit was formed under a fluctuating environment that laid down many layers of sediment as conditions ebbed and flowed.

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Hubble returned to science operations

8:49 am

Engineers today completed their testing of their computer hardware fix on the Hubble Space Telescope and took it out of safe mode, allowing science observations to resume after more than a month.

The first observation is scheduled for Saturday afternoon after some instrument calibrations are completed. Most observations missed while science operations were suspended will be rescheduled for a later date.

Now let us all pray that there are no more major failures for the next few years until the U.S. capabilities in space grow and a relatively fast mission to repair the telescope is possible.

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Juno team creates dramatic animation of Ganymede/Jupiter fly-by

10:49 am

Using images from Juno’s fly-by of both Ganymede and Jupiter on June 7th and 8th, the science team has produced a dramatic animation, with background music, showing that fly-by from the point of view of the spacecraft.

I have embedded it below the fold.

The 3:30-minute-long animation begins with Juno approaching Ganymede, passing within 645 miles (1,038 kilometers) of the surface at a relative velocity of 41,600 mph (67,000 kph). The imagery shows several of the moon’s dark and light regions (darker regions are believed to result from ice sublimating into the surrounding vacuum, leaving behind darkened residue) as well as the crater Tros, which is among the largest and brightest crater scars on Ganymede.

It takes just 14 hours, 50 minutes for Juno to travel the 735,000 miles (1.18 million kilometers) between Ganymede and Jupiter, and the viewer is transported to within just 2,100 miles (3,400 kilometers) above Jupiter’s spectacular cloud tops. By that point, Jupiter’s powerful gravity has accelerated the spacecraft to almost 130,000 mph (210,000 kph) relative to the planet.

Among the Jovian atmospheric features that can be seen are the circumpolar cyclones at the north pole and five of the gas giant’s “string of pearls” – eight massive storms rotating counterclockwise in the southern hemisphere that appear as white ovals. Using information that Juno has learned from studying Jupiter’s atmosphere, the animation team simulated lightning one might see as we pass over Jupiter’s giant thunderstorms.

The lightning shown on Jupiter, while entertaining, is a complete fantasy. The flashes are much too bright and large. At the scale created, some would cover the Earth. In reality, that lightning wouldn’t be visible until you are very very close, and even then probably difficult to spot in the vastness of Jupiter.

» Read more

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Thales Alenia to build first two modules of Axiom’s commercial space station

9:24 am

Capitalism in space: The Italian company Thales Alenia today announced it has finalized the contract to build the first two modules of Axiom’s private commercial space station, set to be docked to ISS initially but eventually to fly independent once ISS is decommissioned.

Total price for the contract is 110 million euros. According to the press release, they are targeting 2024 and 2025 for launching these modules, which will be able to house as many as eight residents.

Based on its past successful experience in building modules for the International Space Station, Thales Alenia Space is responsible for the design, development, assembly and test of the primary structure and the Micrometeoroid & Debris Protection System for the two Axiom modules.

The welding activities of the primary structure of the first module will start in September 2021, with the assembly process concluding in 2022. The first module will arrive at Axiom facilities in Houston in July 2023, where Axiom will integrate and outfit the core systems and certify it for flight prior to shipping to the launch facility.

With the launch of this station, human spaceflight in the United States will become completely independent of the federal government. Private companies will own the rockets, spacecraft, and stations, and the government will no longer have a major say on what goes on in space. The NASA bureaucracy that makes getting an experiment onto ISS cumbersome, difficult, and discouraging will be out of a job. (An example: In the 2000s American scientists studying plant growth in weightlessness ended up launching their experiments with the Russians because getting NASA approval turned out to be too difficult.)

This doesn’t mean that it will be easy to get a payload or experiment onto Axiom’s station. The demand will be quite high. It just means that the decision will no longer reside with the government, but with the private companies and citizens of the United States.

As it always should have been.

Furthermore, that the demand is going to exceed the supply will mean that additional stations will be built, and quickly, because the lure of profit will be there. For example, many of the commercial medical experiments that were on the verge of paying off but were shut down after the Challenger accident in 1986 could very well be brought back to life.

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