Glider for Exploration of Venus at Higher Elevations

tahanson43206 · 2022-11-30 18:36:22

This topic launches with another terrific idea from kbd512, which first appeared in a topic about a balloon supported instrument package.

kbd512 wrote:

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.

Having flown in a glider as a passenger, I can appreciate the power of this idea.

The vehicle could be fitted with a propeller for rare situations it might be needed. My understanding is that air movement in the cloud layers of Venus should provide all the lift a true glider would need to stay aloft for years at a time.

This topic is available for development of a complete, detailed plan for design, construction, shipment, deployment and operation of such a probe.

The programming problem seems (to me at least) comparable to that needed for glider drones to capture water from air masses on Earth, and to deliver that water to locations on Earth where water is needed.

I would expect AI to figure prominently in flight algorithms for both applications.

(th)

SpaceNut · 2022-11-30 21:25:39

Atmospheric profile

something to read later
https://www.faa.gov/regulations_policie … _front.pdf

So where would we want to fly is the question for altitude above the planet in this glider
Glider aircraft flies at highest-ever altitude – a blood-boiling 76,000ft (VIDEOS)

while we will not have any pilots onboard the altitude is comparable to those we can achieve on Venus as well since that is above the clouds of acid.

Of course, this will be radar units to map the surface and peek at its chemical atmosphere to ground level in detail.

tahanson43206 · 2022-12-01 07:34:04

For SpaceNut re #2

Thanks for giving this new topic a substantial boost!

Here is a search result done by Bing...

search: glider on venus proposed
200
About 4,700,000,000 resultsAny time
Stingray Glider to Explore the Cloudtops of Venus
https://www.universetoday.com/144045/stingray...
Nov 16, 2019 · Whether its stingray-inspired gliders in the atmosphere of Venus, dragonfly-inspired drones in the skies of Titan, or snake-inspired robots …
Estimated Reading Time: 5 mins
A Glider Might Search For Life In The Atmosphere Of Venus In 2025
https://www.iflscience.com/glider-might-search-for...
Jan 12, 2017 · A report by Keith Cooper in Astrobiology Magazine says that US and Russian scientists may search for life on Venus by sending a balloon or glider into its atmosphere in …
Author: Jonathan O'callaghan
People also ask

That 2017 report is interesting because it seems to hint that (in 2017) collaboration between US and Russian scientists was still happening.

***
For SpaceNut re atmosphere profile of Venus ....

I've seen something (somewhere) that indicates the Troposphere may be (relatively) free of acid, and (relatively) clear for viewing.

If you can find anything to support that impression it would be a helpful addition to this topic.

Flying through clouds seems like a less than ideal choice, if clear air is available below them.

A glider needs updrafts to navigate/regain-altitude, but I would expect there would be plenty of them considering the temperatures registered on the surface of Venus.

If we have a member with a bit of free time, it would be interesting to see if either of the citations above are current/productive.

(th)

SpaceNut · 2022-12-01 20:02:25

The protection system to get the glider through to that clear of acid area is a tough problem to solve without adding to much mass that we must shed before it can glide. Once available to glide the glider has the same equations as what is used to glide in the upper atmosphere where a heat shield is required until it is get slowed enough to get rid of it.

https://www1.grc.nasa.gov/beginners-gui … es-glider/

https://www.mech4study.com/fluid-mechan … orce.html/

https://www.whiteboxlearning.com/c/appl … l0303.html

https://www.phys.uconn.edu/~rozman/Cour … -11-05.pdf

If Venus has up lift to winds, they sure will help the glide be able to sustain speed that is a huge factor since the atmosphere is going to provide due to air pressure quite a bit of drag to the glider.

kbd512 · 2022-12-01 20:29:11

SpaceNut,

If the glider's skin has a PTFE coating applied to it, then whether or not there's some Sulfuric acid present it'll be protected. Sulfuric acid shouldn't harm ALON or glass or most technical ceramics.

tahanson43206 · 2022-12-01 20:53:21

For anyone who might be interested .... in the topic where Void has been talking about Venus recently, there is a post that reports (or links to a report) that says that there are a great number (on the order of 100,000 ? ) locations on the surface of Venus where gases are welling up constantly. These would appear to be useful for a glider under the turbulent rolling layer at the bottom of the clouds.

Apparently there is a phase change that happens as hot gases rise to a point where the temperature is 200 degrees Centigrade/Celsius. At that point (if I followed the presentation correctly) the chemicals change state and fall back as a solid, only to be melted and lifted up again.

It seems to me (at this point of limited knowledge) that a fairly detailed weather model for Venus might help a glider design team to plan ahead to catch updrafts.

(th)

SpaceNut · 2022-12-01 21:03:47

https://www.engineersedge.com/finishing … atings.htm

https://desertcoating.com/coating/indus … -coatings/

got it.

so how do we make a glider that is from Alon when we need moving parts to be able to control it.

tahanson43206 · 2022-12-01 21:28:59

For SpaceNut re question posted in #7

This is NOT an attempt to answer the question. I'm hoping these observations will help whoever comes along to try ...

Aircraft (on Earth) normally have control surfaces that move on pivots.

Some ultra-modern aircraft have flexible wings, but I get the impression many generations of aircraft did not have flexibility built into the fuselage or wings.

It is the moveable control surfaces that have traditionally allowed a pilot to direct the movement of the craft.

One thing that I recall from earlier posts about ALON(r) ... it ** can ** be manufactured in curved shapes (eg, domes for aircraft for military customers).

However, I'm not convinced that a glider for higher elevations ** needs ** to be made of ALON(r). If temperatures are below 200 degrees Centigrade/Selsius, then more traditional materials might serve well.

(th)

kbd512 · 2022-12-02 04:12:31

SpaceNut,

The glider will be made from conventional composite materials, but the sensor windows will be made from ALON. If the glider remains between 50km and 75km above the surface, then it does not operate at temperatures that would normally damage conventional CFRP / GFRP composites. Build a conventional glider, coat its airframe exterior with PTFE to protect the bonding resin from acid attack, and use ALON vs plexiglass or some other material so that exposure to Sulfuric acid doesn't damage the sensor windows / apertures or airframe. Here on Earth, composites airframes and boat hulls are protected from UV exposure by using a gelcoat and/or reflective white paint on top of the composite. Shrink-wrapping PTFE to the airframe is the same basic concept, and here on Earth plastics are also shrink-wrapped to Aluminum airframes as well as cars, instead of or in conjunction with painting them, so that colorful designs and logos can be easily applied and changed at will.

A drone / powered glider is close enough to the Sun that photovoltaics and batteries will work acceptably well to provide propulsion when required. The thermals from below will help this machine stay aloft at night on the dark side of the planet, which it will traverse in a matter of hours thanks to the wind speeds of the jetstream on Venus.

SpaceNut · 2022-12-02 20:47:56

Agreed above the cloud cover that it would work quite well as you stated in the near-earth like atmospheric pressure levels.

This also makes the solar powered helicopter possible as well though for the same proposed area of operation or even higher where the atmosphere is even thinner as demonstrated by the mar's units.

kbd512 · 2022-12-03 15:14:02

SpaceNut,

Unfortunately, no. Helicopters require more power to generate sufficient lift to remain airborne than pretty much any type of fixed-wing motor-glider that I'm aware of, and quad-copters are worse. This is why there are no helicopters that operate where Perlan II did. Here on Earth, the absolute altitude record limit for helicopters is around 41,000ft or so. Meanwhile, Perlan II flew higher than the turbojet-powered U2 (by several thousand feet; I think COVID killed the program) and was intended to fly higher than the SR-71 (no idea if they continued testing or not, but I've little doubt that Perlan was capable of flying higher than any jet aircraft; "zooming" with a jet and then stalling the turbine is not "flying", either). It may not be technically impossible to fly higher, as JPL's Mars helicopter proved, but there was nothing particularly efficient about that drone. It had to charge its batteries for a day or more, and was then in the air for a few minutes before it ran out of power and had to land. The Mars helicopter was / is still a remarkable achievement, but it doesn't scale-up very well, and unlike Mars, there's no landing on Venus if you run out of power. You need to store or continuously generate any required power to stay aloft, so it's a different kind of flight problem.

A Robinson R22 can carry two people and achieve a maximum range of 241 miles using a 124hp engine, with a 16.9 gallon fuel capacity. Its initial rate of climb is 1,200fpm and cruise speed is 110mph. MTOW is 1,370lbs.

A Sonex Xenos motor-glider, which is not particularly efficient from an aerodynamics or weight standpoint, and made from Aluminum (like the R22) rather than composites (most frequently used in gliders), can also carry two people and achieve a maximum range of 500 miles using a 120hp engine, with a 20 gallon fuel tank. It's initial rate of climb is 2,000fpm and cruise speed is 140mph. MTOW is 1,275lbs.

Airbus / Windward Performance Perlan II, made entirely from CFRP, is almost twice the size of Sonex's Xenos, but empty weight is around 1,100lbs and MTOW is 1,800lbs. Perlan II has 1.8X the wingspan of Xenos, yet both are 6g capable machines (neither are delicate or flimsily-constructed, in other words).

All types of helicopters and quad-copters and tilt-rotor machines are not very energy-efficient, which is why I suggested using a very efficient motor-glider made from composites, with a superb glide ratio (read as "superb L/D", implying very little power is required to keep it airborne) and aerodynamics (Perlan's ability to operate comfortably within the jet stream), which doesn't describe any helicopters that I'm aware of. A lot of people seem to think that because a drone can fly acceptably well, that it can be scaled up to significant sizes to carry a large payload, but this is manifestly untrue, which is why most of the "human-sized" multi-engined quad-copter-style layouts you see have very short ranges, very high power requirements, and very low payloads for a given max takeoff weight.

From an efficiency standpoint, Perlan is a thing of beauty. It wasn't designed to win any maneuverability or pure speed contests, but it's basically a rifle bullet with wings attached to it. There's plenty of room for a mapping radar, the batteries can go into the wings near the solar panels, and this thing can soar for a very long time in an Earth-like atmosphere with a strong jet stream and thermals to carry it around the planet. We would want a scaled-down version of it, since we're not trying to carry 2 people inside. Larger versions could be built later on, once humans have begun colonizing Venus.

SpaceNut · 2022-12-03 19:49:04

With earth altitude in mind and for where we are operating on for mars, I do think that we can do one of that size and it would operate continuous since there is no landing pad for it with Venus unless we make one for a balloon or blimp. Of course, that means we are in the same or higher for a Venus helicopter to operate as well. That means we are above the clouds and would be probing with radar.

https://www.engineeringtoolbox.com/stan … d_604.html

As you indicated below the cloud ceiling then it gets much harder to stay aloft in the over 10 bar atmospheres. Where only nuclear power could even achieve the power required.

Last edited by SpaceNut (2022-12-03 20:51:38)

tahanson43206 · 2023-03-01 09:12:53

This is a follow up to the vision of kbd512 for a glider to explore Venus.

The original post appeared in a topic about balloons.

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
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Staff
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>
News
>
Friday, September 21st, 2018 - Physicists Train Robotic Gliders to Soar like Birds
PHYSICISTS TRAIN ROBOTIC GLIDERS TO SOAR LIKE BIRDS
Physicists 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.

(th)

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#1 2022-11-30 18:36:22

Glider for Exploration of Venus at Higher Elevations

#2 2022-11-30 21:25:39

Re: Glider for Exploration of Venus at Higher Elevations

#3 2022-12-01 07:34:04

Re: Glider for Exploration of Venus at Higher Elevations

#4 2022-12-01 20:02:25

Re: Glider for Exploration of Venus at Higher Elevations

#5 2022-12-01 20:29:11

Re: Glider for Exploration of Venus at Higher Elevations

#6 2022-12-01 20:53:21

Re: Glider for Exploration of Venus at Higher Elevations

#7 2022-12-01 21:03:47

Re: Glider for Exploration of Venus at Higher Elevations

#8 2022-12-01 21:28:59

Re: Glider for Exploration of Venus at Higher Elevations

#9 2022-12-02 04:12:31

Re: Glider for Exploration of Venus at Higher Elevations

#10 2022-12-02 20:47:56

Re: Glider for Exploration of Venus at Higher Elevations

#11 2022-12-03 15:14:02

Re: Glider for Exploration of Venus at Higher Elevations

#12 2022-12-03 19:49:04

Re: Glider for Exploration of Venus at Higher Elevations

#13 2023-03-01 09:12:53

Re: Glider for Exploration of Venus at Higher Elevations

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