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This topic is offered for posts about design/deployment of balloon supported instrument packages for higher elevations in the atmosphere of Venus.
A topic about design of a balloon supported instrument package for deployment at (just above) the surface of Venus stimulated recollection of work done by NASA and others, to design for the more benign environment above the surface.
Since a great deal of work has been done, this topic has the potential to become a collection point for links to and comments about that work.
In addition to official proposals at NASA (and elsewhere) balloon flight in the clouds of Venus is the subject of at least one science fiction series, reported upon elsewhere in the forum archive.
Accordingly, posts about science fiction vision of how balloon flight might occur on Venus would be appropriate for this topic.
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This post, by kbd512 in the ground level topic, is about a possible design for an altitude of 30 kilometers above the surface...
It looks like Toray has some polyamide resins that have a glass transition temperature of 454C or so, meaning a composite airframe operating at half that temperature, at 30km in altitude, should still have usable strength.
Properties and Applications of Toray High Temperature Composites
However, polyamides also dissolve in Sulfuric Acid, so some sort of near-perfect PTFE sealant must be applied to the surface of the craft, or it will literally "come undone" mid-flight.
Glass or Carbon Fiber for strength, high-temperature polyamide resin to hold the airframe together, and then a thick layer or several layers of PTFE, which can also withstand the temperature and has superb Sulfuric Acid resistance. The electronics can be near-conventional (Silicon-Carbide-based) at that operating temperature, with some material substitutions (such as Silver conductors to make up for the loss of electrical conductivity at elevated temperatures; about 65% of IACS at 220C).
This topic is available for designs for all elevations above the surface of Venus where a balloon instrument package might reasonably be expected to maintain position. Please specify the altitude at which the design you are describing would operate.
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Here is another post by kbd512 about a balloon flying at 30 kilometers above the surface of Venus...
tahanson43206,
Even for your Earth-bound hot air balloon example, we have things going on inside the balloon that adjust temperature and therefore gas pressure, which is why a hot air balloon is buoyant within Earth's atmosphere. 30km above the surface of Venus, we're going to thermal soak to 220C (conventional oven baking temperatures). A BNNT fiber reinforced thin PTFE tape can survive the heat and acid, but not the temperatures much below that altitude, so 30km is about as close to the surface as we can get without utilizing much more complex to make and therefore expensive materials. At 30km, we also have 35km/s wind speeds and 9.85X greater atmospheric density than we do at Earth sea level.
It is good to see this topic on the verge of "taking off"!!!
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NASA: Vega 2 balloon 1984
A constant-pressure instrumented balloon aerostat was deployed from the upper heat protection hemisphere of each if the two Vega lander craft immediately after entry into the atmosphere. The primary scientific objective of the Vega balloon probes was to obtain information about the large- and small-scale motions, structure, and cloud properties of the Venus atmosphere at the float altitude. The probes floated at an altitude of about 54 km in the middle, most active layer of the Venus three-tiered cloud system and measured the local atmospheric dynamics, pressure, temperature, lightning, illumination levels, and cloud properties over a period of about 46 hours in both the night- and day-side.
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NASA: balloon JPL hopes to send to Venus
The spherical balloon, 18 feet in diameter, is about the size of an inflatable children's jumper. Its aluminum coating reflects sunlight to protect the balloon from becoming too hot as it flies in Venus' upper atmosphere. Its outer transparent layer of the balloon is made of polytetrafluorethylene, also known as Teflon, the non-stick material found in cookware and on clothing. The material is highly resistant to the sulfuric acid found in clouds surrounding Venus. "The sun shines through the Teflon and reflects off the aluminum, and that keeps the balloon from overheating," said Jeff Hall, JPL's lead balloon engineer.
The balloon's second layer has a mylar film similar to those shiny helium balloons found in a grocery store. The mylar is used to prevent gas from leaking out. The next layer is made of a Vectran fabric that provides the strength to keep the balloon from bursting due to internal pressure. The innermost layer has a polyurethane coating that enables all sections of the balloon to be glued together.
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For RobertDyck re #4 and #5
Thank you for adding these two reports to this topic! It is good to see that NASA has been in the game of Venus exploration, and remains engaged!
Thanks in particular, for details of the construction of the 18 foot diameter balloon that is in development!
For all ... this topic is available for anyone to add news about any probes that may have occurred in the past, and certainly any planned for the future!
Details about the designs (past or future) would be appreciated!
Follow up a bit later:
People also ask
What countries have sent probes to Venus?
As of 2020, the Soviet Union, United States, European Space Agency and Japan have conducted missions to Venus.List of missions to Venus - Wikipediahttps://en.wikipedia.org › wiki › List_of_missions_to_V...
Search for: What countries have sent probes to Venus?
The categories are: fly-by, orbiter, lander and flyer/balloon.
The Soviet Union has the standing record for landers.
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Here is the lift equation of air being warmed for a given lift
https://www.brisbanehotairballooning.co … loons-fly/
https://www.engineeringtoolbox.com/hot- … d_562.html
Hot Air Lifting Force
The lifting force from a hot air balloon depends on the density difference between balloon air and surrounding air, and the balloon volume. The lifting force can be calculated asFl = V (ρc - ρh) ag (1)
where
Fl = lifting force (N, lbf)
V = balloon volume (m3, ft3)
ρc = density cold surrounding air (kg/m3, slugs/ft3)
ρh = density hot balloon air (kg/m3, slugs/ft3)
ag = acceleration of gravity (9.81 m/s2, 32.174 ft/s2)
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For SpaceNut re Post #7
The hot air balloon technology you have shown would seem a stretch at the surface of Venus, but it ** should ** work well at higher elevations, where temperatures are less severe.
You can (if you have time) adjust the formulas you have shown to adapt to the gravity of Venus, which Google reports as:
Venus / Gravity
8.87 m/s²Venus
Planet
With that adjustment, you should be able to work out where (at what elevation) on Venus, a hot "air" balloon, heated by a small nuclear reactor, would work well.
The lift attained needs to overcome the mass of the reactor, the envelope, cords needed for force transfer and containment, and miscellaneous other items.
The exercise (should you have time to carry it out) would seem (to me at least) worth doing, because it would become part of the permanent record in the NewMars archive.
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tahanson43206,
For operating in the upper atmosphere, I think a flying machine that uses aerodynamic lift provides the most general utility, because it can be retasked for overflight of other parts of the planet's surface. In the same way that gliders ascend into the upper atmosphere of Earth by riding thermals (Airbus / Windward Performance Perlan II crewed gliders), a machine with minimal onboard power, supplied by photovoltaics and batteries, could feasibly circle the planet for years, using a high-precision MMW mapping radar that gradually builds a composite radar model of the surface from many passes from varying angles. The radar needs considerable power to penetrate through to the surface, though, which is why this would have to be done using multiple passes. We can use Starship and a very large inflatable HIAD device to protect the mapping drone during reentry, but then we need wings that unfold and deploy, mid-air. After the drone is in flying configuration, because Venus is so much closer to the Sun and CO2 has different properites than Earth's O2/N2 mix and wind speeds are such that even a non-powered balloon can literally circle the planet in a day, it's possible to fly on solar and battery power alone.
Venus TSI is 2,636W/m^2. Using 39.5% efficient triple-junction PV cells, a Perlan II glider with a 24.4m^2 wing area could receive up to 25kW of power on its upper wing surface alone, with perhaps another 50% of that reflected off the surface of the clouds from below by embedding cells in the bottom of the wing as well the top. 37.5kW is plenty of power for a glider to fly on. Perlan II glider, by riding thermals, successfully ascended to approximately 76,000ft here on Earth, which is higher than the U-2 spyplane. We're deleting the crew and landing gear, adding photovoltaics, batteries, a high power MMW mapping radar, radio, and laser communications for high data rate transfer to an orbiting satellite. We'd fly somewhere between 50km and 75km for the mapping mission, which puts us at around 1/4 the distance from the surface that an orbiting satellite could achieve in a low orbit.
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Study Finds Venus’ ‘Squishy’ Outer Shell May Be Resurfacing the Planet
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Thanks to Mar_B4_Moon for the "Squishy" Venus link!
Just above #10 was #9, kbd512's vision of a robust glider for exploration of Venus.
SearchTerm:Glider Venus
SearchTerm:Venus Glider
It seems to me this concept is worth support. If there is mass available, the vehicle might be given a one-time emergency rocket to lift it out of a bad situation it might get into. This vehicle is going to be navigating on it's own for the most part. It might be supported by additional computing power and sensors in orbit.
The challenge of staying aloft will tax the software developers for this vehicle.
A detail that is omitted from Post #9 is the presence of an electric motor powered propeller.
A quick scan of snippets provided by Google seems to confirm the original Perlan glider is a true glider. The Venus flyer could be fitted with a small electric motor and propeller, to help it deal with the intervals between lift opportunities in the atmosphere of Venus.
tahanson43206,
For operating in the upper atmosphere, I think a flying machine that uses aerodynamic lift provides the most general utility, because it can be retasked for overflight of other parts of the planet's surface. In the same way that gliders ascend into the upper atmosphere of Earth by riding thermals (Airbus / Windward Performance Perlan II crewed gliders), a machine with minimal onboard power, supplied by photovoltaics and batteries, could feasibly circle the planet for years, using a high-precision MMW mapping radar that gradually builds a composite radar model of the surface from many passes from varying angles. The radar needs considerable power to penetrate through to the surface, though, which is why this would have to be done using multiple passes. We can use Starship and a very large inflatable HIAD device to protect the mapping drone during reentry, but then we need wings that unfold and deploy, mid-air. After the drone is in flying configuration, because Venus is so much closer to the Sun and CO2 has different properites than Earth's O2/N2 mix and wind speeds are such that even a non-powered balloon can literally circle the planet in a day, it's possible to fly on solar and battery power alone.
Venus TSI is 2,636W/m^2. Using 39.5% efficient triple-junction PV cells, a Perlan II glider with a 24.4m^2 wing area could receive up to 25kW of power on its upper wing surface alone, with perhaps another 50% of that reflected off the surface of the clouds from below by embedding cells in the bottom of the wing as well the top. 37.5kW is plenty of power for a glider to fly on. Perlan II glider, by riding thermals, successfully ascended to approximately 76,000ft here on Earth, which is higher than the U-2 spyplane. We're deleting the crew and landing gear, adding photovoltaics, batteries, a high power MMW mapping radar, radio, and laser communications for high data rate transfer to an orbiting satellite. We'd fly somewhere between 50km and 75km for the mapping mission, which puts us at around 1/4 the distance from the surface that an orbiting satellite could achieve in a low orbit.
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This is a follow up to the vision of kbd512 for a glider to explore Venus.
A natural ally for such a venture would be an educational institution with a proven track record of success in designing, building and flying robot controlled gliders. I asked Google if there might be such an institution, and found this one:
https://physics.ucsd.edu/News/Story/378
DEPARTMENT OF PHYSICS
Prospective Students
Current Students
Faculty/Researchers
Staff
Alumni/Visitors
>
News
>
Friday, September 21st, 2018 - Physicists Train Robotic Gliders to Soar like Birds
PHYSICISTS TRAIN ROBOTIC GLIDERS TO SOAR LIKE BIRDSPhysicists Train Robotic Gliders to Soar like Birds
Bird and glider in tandem flight. Photo montage courtesy of Phil Richardson, © Woods Hole Oceanographic Institution
The words “fly like an eagle” are famously part of a song, but they may also be words that make some scientists scratch their heads. Especially when it comes to soaring birds like eagles, falcons and hawks, who seem to ascend to great heights over hills, canyons and mountain tops with ease. Scientists realize that upward currents of warm air assist the birds in their flight, but they don’t know how the birds find and navigate these thermal plumes.
To figure it out, researchers from the University of California San Diego used reinforcement learning to train gliders to autonomously navigate atmospheric thermals, soaring to heights of 700 meters—nearly 2,300 feet. The novel research results, published in the Sept. 19 issue of “Nature,” highlight the role of vertical wind accelerations and roll-wise torques as viable biological cues for soaring birds. The findings also provide a navigational strategy that directly applies to the development of autonomous soaring vehicles, or unmanned aerial vehicles (UAVs).
Graphic depicts: (a) A trajectory of the glider soaring in Poway, California; (b) a cartoon of the glider showing the vertical wind currents and torque experienced by the glider; (c) the vertical component of the wind velocity (blue) and the vertical wind accelerations (red) experienced by the glider during a typical flight session; (d) the bank angle of the glider during the same flight session as (c) and the corresponding torque experienced by the glider.
Graphic depicts: (a) A trajectory of the glider soaring in Poway, California; (b) a cartoon of the glider showing the vertical wind currents and torque experienced by the glider; (c) the vertical component of the wind velocity (blue) and the vertical wind accelerations (red) experienced by the glider during a typical flight session; (d) the bank angle of the glider during the same flight session as (c) and the corresponding torque experienced by the glider. Figure courtesy of Gautam Reddy
“This paper is an important step toward artificial intelligence—how to autonomously soar in constantly shifting thermals like a bird. I was surprised that relatively little learning was needed to achieve expert performance,” said Terry Sejnowski, a member of the research team from the Salk Institute for Biological Studies and UC San Diego’s Division of Biological Sciences.
Reinforcement learning is an area of machine learning, inspired by behavioral psychology, whereby an agent learns how to behave in an environment based on performed actions and the results. According to UC San Diego Department of Physics Professor Massimo Vergassola and PhD candidate Gautam Reddy, it offers an appropriate framework to identify an effective navigational strategy as a sequence of decisions taken in response to environmental cues.
Close-up of one of the gliders, grounded, used in the research.
Close-up of one of the gliders, grounded, used in the research. Photo courtesy of Gautam Reddy
“We establish the validity of our learned flight policy through field experiments, numerical simulations and estimates of the noise in measurements that is unavoidably present due to atmospheric turbulence,” explained Vergassola. “This is a novel instance of learning a navigational task in the field, where learning is severely challenged by a multitude of physical effects and the unpredictability of the natural environment.”
In the study, conducted collaboratively with the UC San Diego Division of Biological Sciences, the Salk Institute and the Abdus Salam International Center for Theoretical Physics in Trieste, Italy, the team equipped two-meter wingspan gliders with a flight controller. The device enabled on-board implementation of autonomous flight policies via precise control over bank angle and pitch. A navigational strategy was determined solely from the gliders' pooled experiences collected over several days in the field using exploratory behavioral strategies. The strategies relied on new on-board methods, developed in the course of the research, to accurately estimate the gliders’ local vertical wind accelerations and the roll-wise torques, which served as navigational cues.
The scientists’ methodology involved estimating the vertical wind acceleration, the vertical wind velocity gradients across the gliders’ wings, designing the learning module, learning the thermalling strategy in the field, testing the performance of the learned policy in the field, testing the performance for different wingspans in simulations and estimating the noise in gradient sensing due to atmospheric turbulence.
“Our results highlight the role of vertical wind accelerations and roll-wise torques as viable biological mechanosensory cues for soaring birds, and provide a navigational strategy that is directly applicable to the development of autonomous soaring vehicles,” said Vergassola.
This research was supported by Simons Foundation Grant 340106.
At UC San Diego, we prefer the path less traveled. And it has led us to remarkable new ways of seeing and making a difference in the world. The first students to enroll at UC San Diego in 1960 were graduate students in physics. Part of the Division of Physical Sciences, the physics’ graduate program, along with our programs in chemistry and biochemistry, and mathematics, is ranked among the top 20 in the nation (U.S. News & World Report education rankings).
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If there is a member of the forum who is inspired by kbd512's idea, there might be an opportunity to enlist folks from the team that developed the sophisticated glider described above, to consider the even more daunting challenges of staying aloft on Venus.
I'd like to point out this line: This research was supported by Simons Foundation Grant 340106.
A natural ally for a project this ambitious would be a foundation that has already shown interest in something similar.
It would be bold of someone from NewMars forum to approach Simons to ask for support of a Venus flight.
Perhaps the membership includes such a bold person.
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Maybe the Chinese could make the balloon? I hear they are good at that sort of thing :-)
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Venus grade: NASA seeks a lander battery tough enough to survive Earth's evil twin
https://www.space.com/nasa-venus-lander … technology
An Experimental solar sail released from the Akatsuki spacecraft flew past Venus in 2010, MESSENGER observed Venus en route to Mercury; the NASA United States Johns Hopkins University science mission observed Venus during closest pass. Currently BepiColombo a Japanese European mission has been making fly bu of Venus en route to Mercury. The Russians planned 'Venera-D' for the past 20 + years but it has been going nowhere. In the future there is EnVision by ESA and VERITAS by NASA and Shukrayaan-1 planned by the Indians or ISRO.
https://www.thehindu.com/sci-tech/scien … 465971.ece
Lunar and Planetary Science Conference
'Friends, this is my poster for LPSC2023—all about our Venus balloon mission concept, Phantom.'
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New Study About The ‘Tsunami’ In Venus’ Clouds
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The post #15 by Mars_B4_Moon adds additional motivation to solve the high level balloon design problem.
An instrument package borne by a suitable balloon would (apparently) have a wild ride, judging from the reports published at the link that Mars_B4_Moon provided.
Recently Calliban proposed using a vacuum chamber as an energy storage device. The concept of such a chamber as a balloon is not new, but the conditions of the deep ocean are where it has been applied on Earth. The conditions inside such a pressure vessel are not much different from vacuum, as far as the ocean is concerned.
For Venus, it occurred to me that Carbon, fabricated as diamond cones assembled around a spherical form and melted together, might have some advantages over other designs. Diamond is one of the hardest materials known, and in the context of the atmosphere of Venus, pressure on the outside of the shell would "feel" modest compared to the pressures needed to make diamond in the first place.
It should be possible for a forum member with calculator skills to compute the wall thickness for a spherical "balloon" made of diamond cones. There would be a tradeoff between the mass of the Carbon for the wall, the size of the balloon, and the pressure to be borne by the wall of the sphere.
I'll offer as a model a sphere with dimension of 10 meters diameter. Given that size, our (hypothetical) forum member with a calculator might be able to discover the wall thickness of diamond that would withstand the pressure of the atmosphere of Venus while providing buoyancy sufficient to carry an instrument package.
One thing seems reasonable to expect from such a balloon ... it should be able to withstand collision with the surface of Venus, if an errant wind were to drive it there.
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Well creating them seems possible as ,
Sequestering Carbon Dioxide in Diamonds
Using its proprietary technology, the nascent luxury brand pulls carbon dioxide from the atmosphere, converts the greenhouse gas into the hydrocarbon methane, and then feeds this freshly synthesized raw material into a reactor. There, over the course of three to four weeks of a chemical vapor-deposition procedure, the carbon atoms are formed into precious stones.
The company is now working to fulfill more than 175 pre-orders, some from customers who “never previously considered buying a diamond because of the environmental impact.” With Aether’s diamond products priced between approximately $4,000 and $40,000, that initial set of orders totals more than $3 million of pending sales.
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For SpaceNut re #17
You ** really ** hit the spot (for me for sure!) with your discovery of the company that makes diamonds from carbon pulled from the air.
Now ** there ** is a capitalist enterprise that is sure to find favor with Louis, if he were were still watching the forum. My recollection is that Louis was planning/hoping to fund much of the Mars economy with luxury goods made on Mars, or made of Martian materials, and shipped back to Earth.
Here is a wonderful example of people being willing to pay vastly more for a clean diamond than for one dug up by kids in slave-like conditions in some third world nation.
However, it ** is ** most promising for my proposal, because if these folks could make a diamond for a ring, then they should be able to scale up their operation to make custom designed cone shaped components for a spherical wall for that Venus probe.
To clarify a point .... I started out using the generic "cone" shape to try to describe my idea. In actual practice, the wall components would seem most likely to have a hexagonal shape with flat sides that shrink gradually toward the inside of the sphere. I still think one of our members who is handy with a calculator could work out the optimum dimensions for a "balloon" made for the Venus environment.
Because Carbon has an atomic weight of only 12, it would be (potentially) superior to aluminum.
Per lenntech.com, carbon melts at 3652 Celsius.
Per lenntech.com, aluminum melts at 660.4 Celsius
My "balloon" made of diamond is looking better and better, thanks to your discovery!
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A Practical Use for Space Power: Beaming Energy to Probes on Venus
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For Mars_B4_Moon re #19
Thank you for finding and posting the link to the beamed power at Venus article.
The idea of a two stage process, with a balloon in the middle, fits ** really well ** with this topic.
Too bad the lasers for the downleg don't yet exist!
Still, it sounds as though research to find lasers that work at the "window" frequency is under way.
If a probe on the surface had enough power, it might be able to keep itself cool by radiating into the ambient atmosphere.
** That ** would be quite a feat of engineering!
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Floating Seismometers Could Help Peer Into The Core of Venus
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Creating a Venus exploration program
https://thespacereview.com/article/4707/1
This week, planetary scientists will join their earth and space science colleagues in San Francisco for the annual meeting of the American Geophysical Union, or AGU. (The conference is officially called the Fall Meeting, a vestige from a time when the AGU also had a smaller conference each spring.) There will be dozens of sessions on topics ranging from studies of the Moon and Mars to the first results from analysis of samples returned from the asteroid Bennu by NASA’s OSIRIS-REx mission.
There will likely also be, in town hall sessions and side discussions at the conference, grumbling about the state of NASA’s planetary science program. Overall budgets projected to remain flat, at best, in 2024 will put external pressure on programs that, in some cases, are struggling with their own cost and schedule challenges.
At a meeting November 28 of the Outer Planet Assessment Group (OPAG), Lori Glaze, director of NASA’s planetary science division, announced that the agency was delaying the launch of the Dragonfly mission to Saturn’s moon Titan by a year, to mid-2028. That, she said, was caused not by any issues with the mission itself but instead “incredibly large uncertainties” in potential budgets for planetary science in fiscal years 2024 and 2025.
At the same time, NASA is working to revise plans for the Mars Sample Return (MSR) program after an independent review in September concluded there was “a near zero probability” upcoming missions to take samples being collected by the Perseverance rover and bring them back to Earth would launch on schedule and budget. That review concluded the overall cost of MSR would be in the range of $8–11 billion, far higher than previous estimates.
NASA has since kicked off a reassessment of the overall MSR architecture, scheduled to be completed in March. In the meantime, NASA has slowed down work on MSR efforts, again citing budget uncertainty: a Senate bill would provide NASA with less than a third of the nearly $950 million requested for MSR, while a House spending bill would fully fund it.
Dragonfly and MSR are not the only planetary programs under the budgetary gun. NASA has delayed calls for proposals for future Discovery and New Frontiers missions. At OPAG, Glaze warned that missions in development that had not yet passed their confirmation reviews, where NASA sets the formal cost and schedule, could also face delays. “Anything in the portfolio that is not confirmed right now is at risk,” she said. “We’re waiting to see what happens.”
Venus scientists have already felt that pain. A year ago, NASA announced it was postponing work on VERITAS, one of two Discovery-class missions the agency selected in mid-2021 to go to Venus, by up to three years. NASA said the delay was needed to free up resources at JPL, the lead center for VERITAS, for the delayed Psyche asteroid mission and other priorities, like Europa Clipper (see “The hard truths of NASA’s planetary program”, The Space Review, March 20, 2023.)
At a meeting at the end of October of the Venus Exploration Analysis Group (VEXAG), the principal investigator for VERITAS, Sue Smrekar of JPL, made a case to limit that delay. The Psyche mission had launched, the payload for the NISAR Earth science mission had been shipped from JPL to India for launch preparations there, and Europa Clipper was making good progress for a launch next October, all reducing the workload at the lab. “Those issues are essentially behind us,” she said.
The problem now, she said, was not too much work but too little, particularly for people involved with synthetic aperture radars, one of the key instruments on VERITAS that will enable that orbiter to peer through the thick clouds of Venus. “There’s insufficient radar work at JPL. The radar workforce is really at threat,” she said. “It’s a really big technical threat for us.”
Last edited by Mars_B4_Moon (2023-12-29 06:36:22)
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The era of constrained budgets is part of the issue where pet projects are taking every bit of addition funds to keep them going while not getting more funds to make up for the over expenditures of them.
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Commercial Space and Private Science
1st private mission to Venus will search for alien life in clouds of sulfuric acid
https://www.space.com/venus-private-mis … furic-acid
altitudes of 90–120 km or 55.9 miles - 74.56 miles is a region that is generally so cold at night that scientists often refer to it as Venus’s cryosphere.
Some say 125 km
2012 article
ESA Venus Express
https://www.esa.int/Science_Exploration … e_of_Venus
Venus Express has spied a surprisingly cold region high in the planet’s atmosphere that may be frigid enough for carbon dioxide to freeze out as ice or snow.
The planet Venus is well known for its thick, carbon dioxide atmosphere and oven-hot surface, and as a result is often portrayed as Earth’s inhospitable evil twin.
But in a new analysis based on five years of observations using ESA’s Venus Express, scientists have uncovered a very chilly layer at temperatures of around –175ºC in the atmosphere 125 km above the planet’s surface.
The curious cold layer is far frostier than any part of Earth’s atmosphere, for example, despite Venus being much closer to the Sun.
Last edited by Mars_B4_Moon (2024-01-04 13:43:35)
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PhotonBytes asked a most interesting question about proposed balloon exploration at Venus...
The work done at NASA that comes to (my) mind most readily is that of Geoffrey Landis at Glenn Research Center.
In any case, here is the question posed by PhotonBytes:
Out of curiosity, how does NASA plan to get the people off the balloons in Venus back to Earth?
I'm currently doing research on the balloon skin mass for Mars, will be busy for the next few days until I have an answer. I also need to study the feasibility of doing aerobraking in Mars' upper atmosphere with fully inflated airships in the vacuum of space. Will crunch numbers. There are promising numbers so far for solid balloon skin airships in Mars. I have to find an optimal design that balances out having 1 large balloon and multiple smaller ones connected to each other and their skin thicknesses. All this while never exceeding a balloon's no exceed limit in climb for it's structural integrity/tensile strength. The balloon skin mass must not occupy too much of the useful payload. That's the issue here now I'm dealing with. I'm considering multiple materials some metal but some not such as carbon composite and kevlar.
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