India's Chandrayaan-3 takes the moon's temperature near lunar south pole for 1st time

[Admin]

Chandrayaan-3 creates first temperature profile near the moon's south pole; ISRO offers more updates on the historic lunar mission.

India's Chandrayaan-3 takes the moon's temperature near lunar south pole for 1st time : Read more

 

[Denny_Crane's_Interwev]

That's some stellar resolution from the camera!

 

[rod]

So, USA, Russia, China, and now India have gone to the Moon and landed on it. There is no flat moon or flat earth

 

[piuspatel]

Dear friends,
Latest research of ISRO will be really helpful as below.
ISRO has published moon south pole grade’s temperature gradient. As per the information, temperature on surface is around 70 degree C and temperature at 80mm below grade is around minus 10 degree C. With this much temperature gradient we can develop an electric generator to produce electricity as per ‘Seebeck’ effect. If two plates will be installed, one on grade and second 80mm or deeper and run insulated cable between these two plates, it will produce enough electricity to heat a small room, it also can be stored in batteries to use power during moon night time. This research will be a really useful to make moon more habitable for human exploration.

 

[piuspatel]

There are other methods to produce electricity from a temperature gradient besides the Seebeck effect. One interesting approach involves using shape memory alloys (SMAs) like Nitinol (a nickel-titanium alloy) to generate power.

Nitinol exhibits the shape memory effect, where it can “remember” a particular shape and return to it when heated. This effect can be harnessed for energy conversion using a process known as the “thermodynamic shape memory effect” or the “thermoelastic martensitic transformation.”

Here’s a basic idea of how it works:

1. When the Nitinol is heated, it changes shape due to the phase transition from austenite to martensite.
2. As it cools back down, it returns to its original shape, releasing stored mechanical energy.

By cyclically heating and cooling Nitinol with a temperature gradient, you can create mechanical motion, which can then be converted into electricity using various mechanical-to-electrical conversion methods, such as piezoelectric generators.

Keep in mind that while this approach is intriguing, there are challenges and limitations associated with efficiency, cycle life, and the specific design of the device. Additionally, Nitinol-based systems might not produce large amounts of power, but they could be useful for certain niche applications or as part of a broader energy harvesting strategy.

 

[Unclear Engineer]

NiTiNOL goes back to its annealed shape when heated, but, when cool is easily bent into any shape. It has been used for making antennas that can be wadded into a ball for transit to someplace like Earth orbit, and the deployed by heating it with an electrical current to make a dish shaped mesh antenna.

It has limitations to how much force it can produce to push on resisting object as it is trying to return to its high temperature shape, and can become a different high temperature shape if it is restrained and heated. (I got a piece to play with when I worked at NOL.)

 

[piuspatel]

Nitinol engines are already made by NASA which is working on temperature gradient.
5MW capacity can be possible.

5- Megawatt Nitinol Engine by Mcdonnell Douglas

View: https://youtu.be/8-dCIkJAjyM?si=c-uTW96qBFrRBugW
via @YouTube

 

[Unclear Engineer]

Interesting link, thanks.

But, McDonnell Douglas company only existed between 1967 and 1997, so this has to be at least 26 years old, and maybe more like 50 years old, which is the era that I remember NiTiNOL being a topic of conversation.

So, if it is really so great, why aren't we now using it for irrigation, cheap electricity production in remote locations, etc,. etc.? What didn't actually work out?

 

[piuspatel]

The cost of Nitinol might be a factor for payback.
It can be used where solar energy is source. Cost recovery will take more time.

 

[Unclear Engineer]

I don't think cost is the problem - you can buy the stuff on Amazon (see https://www.amazon.com/Nitinol-Wire/b?ie=UTF8&node=11260363011 ).

It is currently used for medical devices, so it is not unobtainium.

 

[piuspatel]

You may be right but still 5MW may need huge amount of material. Day by day cost has reduced but someone to do cost analysis. I have also seen other video where they used a Nitinol bar/ rod instead of spring or wires. I am not able to find that video.

 

[Unclear Engineer]

5 MW is a lot of power. Applications like pumping irrigation water are much lower power at a farm level. I am just suspecting that there are better ways of doing the things that NiTiNOL motors can do. Maybe cheaper on Earth - maybe less weight to get into orbit. It is not that the technology isn't available, it is available but has not been used as envisioned in that old film clip.

That is not saying that it will never be used, but I am not seeing it as a breakthrough that will make space exploration of colonization work better than we are already projecting.

 

[piuspatel]

Wherever there is a potential of temperature gradient. This technology will be used to produce power, No idea about farms and other applications. As space missions have more budget it will be used one day for sure. There is quite a huge development in pipe line for more efficient solar cells means more and more efficient solar cells are coming in the market which are more efficient than this Nitinol engine, still where you have temperature gradient available nitinol will be the winner. Moon grade has that potential gradient as per ISRO research. Still we need to wait and watch.

 

[Unclear Engineer]

Undisturbed temperature gradients are not necessarily going to produce much power once they are disturbed and the temperatures are evened out. It depends on the size of the reservoirs of different temperatures and how quickly heat energy can move within them. Regolith doesn't seem like a good reservoir for producing power.

 

[DrRaviSharma]

Kindly also review my post of Community on CHandrayaan-3 in last couple of days.
Why would we not assume a fairly large reservoir over a good size area until we reach either PSR Permanent shadow areas or masons implying different materials in lunar topography Lunar "geoid"?
Therefore after lot of posts above we have to favor the idea of generation based on this large temperature gradient. An alternative to RTG if considering a colony or roomful of stationary temperature controlled equipment. Lander and rover are thus providing useful temperature gradient data.
Further, Why could there be not a icemixed permafrost 10Cms deep on lunar south pole areas?
Hence good possibility of Water!

Thanks.
Ravi
(Dr. Ravi Sharma, Ph.D. USA)
NASA Apollo Achievement Award
Former MTS NASA HQ MSFEB
ISRO Distinguished Service Awards
Former Scientific Secretary ISRO HQ
Ontolog Board of Trustees
Particle and Space Physics
Senior Enterprise Architect

 

[piuspatel]

Dr. Ravi,
Thank you for reply. I agree with you. There could be water in further depth in the form of ice. Temperature gradient will increase as we go in more depth because moon core is not active like earth core. Here on earth we use to geothermal energy, similarly on moon if surface is hot and grade is cold we get good temperature gradient without going in too much depth. Overall we could utilize the temperature gradient for power generation.

 

[Unclear Engineer]

The problem I am seeing with this proposal is that the heat is coming from the Sun, rather than from the interior of the Moon, which implies that the heat input from the Sun is not penetrating far below the surface. Any mechanical device that derives "work" by transmitting the heat from the surface into the areas below the surface will tend to warm the volumes that are currently cold. Unless there is good thermal conductivity through the materials that are cold, those areas will quickly be warmed and there soon will be no thermal gradient from which to extract energy in the form of "work". A thermal gradient in sunlit areas near the surface tends to indicate that the heat energy is not being conducted very far into the materials below the surface. That is the thermal conductivity problem that I am seeing with the hopes some are expressing for using this gradient to support a human habitat with electrical power.

So, if there isn't really any significant geological (lunarlogical?) heat in the interior of the Moon, then lunar-thermal energy is not going to be available like geothermal energy is tapped and used on Earth. (But, the determination of the lunar temperature profile over depths of miles would be needed to evaluate that.)

If it is only a matter of collecting the heat energy provided by the Sun during the 2-week long "day" for use during the 2-week long "night" on the Moon, there are probably better materials to use than the surface regolith. Besides solar panels and batteries, there may be options like mirrors focusing sunlight onto underground tanks of fluids, heating them during the lunar day, and then taking energy from them during the lunar night, maybe for direct heating, or for some sort of electrical power generation. The key concept is that there needs to be some sort of reservoir of heat in a material that can quickly absorb it and just as quickly release it - implying a good heat conducting material, or at least one that can flow and has a good heat capacity. The regolith would effectively be the tank insulation, if it is good enough at insulating.

 

[piuspatel]

Yes I agree that surface temperature is may be due to sun. I am surprised that even on south pole it is gaining this much of solar gain. During the moon day time of 14 /15 earth days we have to collect that heat and generate power through thermal gradient and then we have to storage the power in batteries to use for the 14/15 earth nights. Storage of hot water within insulated tank could be an option too.

If the man mission is for 14 earth days then it could be easy that we can avoid to stay during night. For permanent to make it habitable is little difficult when naturally it is made not habitable.

 

[DrRaviSharma]

I Like the ideas expressed above. It is too early as we have one of many points we expect from this mission and then similar data before we reach conclusions on thermal power, its scale for example for small enclosures Vs larger habitats. Cost and benefit from RTGs and long term scenario then can evolve.

But the fact that solar incidence is heating the surface so well demonstrated by Chandrayaan Chaste experiment is praiseworthy.

Another aspect triggered by your above comments relates to albedo and or emissivity and thermal gradient and hence surface types with mix of Lambertian and specular reflectance. These factors will also impact practical devices design.
Have there been such type of data from China Missions on far side? any different findings or papers published would help?
Thanks.
Ravi
(Dr. Ravi Sharma, Ph.D. USA)
NASA Apollo Achievement Award
Former MTS NASA HQ MSFEB
ISRO Distinguished Service Awards
Former Scientific Secretary ISRO HQ
Ontolog Board of Trustees
Particle and Space Physics
Senior Enterprise Architect

 

[piuspatel]

Using a refrigerant heat pipe system to transfer heat between a solar panel and a storage unit is a viable and efficient option, especially in environments like Mars where temperature control is crucial. Here's how such a system could work:

1. **Solar Panel:** Solar panels on Mars can generate electricity from sunlight. However, they can become too hot due to the lack of convective cooling atmosphere. The excess heat can be detrimental to the panel's efficiency and longevity.

2. **Refrigerant Heat Pipes:** A heat pipe is a device that efficiently transfers heat from one location to another. In this case, a refrigerant heat pipe system could be integrated with the solar panel. When the panel gets too hot, the heat pipe transfers the excess heat away from the panel's surface.

3. **Storage Unit:** The heat transferred by the heat pipe can be directed to a storage unit or thermal mass where it is stored for later use during the cold moon night. This stored thermal energy can be used for heating within a habitat or to maintain operational temperatures for equipment.

Using refrigerant heat pipes has several advantages:

- Efficient Heat Transfer: Heat pipes are highly efficient at transferring heat, making them well-suited for applications where temperature control is critical.

- Passive Operation: Heat pipes operate passively, without the need for pumps or fans, which reduces energy consumption and maintenance requirements.

- Thermal Storage: By storing excess heat during the day, the system can provide a heat source during the frigid Martian nights, enhancing comfort and safety for occupants.

This type of thermal management system would be beneficial for Moon or Mars missions or habitats where temperature control is essential. However, it would require careful design and integration with other systems to ensure reliable and efficient operation in the challenging Moon and Mars environment.

 

[Unclear Engineer]

Basically a good idea, but making it work with passive heat pipes might be difficult. The controlling parameter should be the solar panel temperature. But, using just passive means like gravity, or capillary action to move the coolant is unlikely to naturally mimic the cooling needs of the solar arrays. Using the solar arrays to provide electrical power to small circulating pumps for the refrigerant would probably be easier to engineer. That way, it is certainly a doable concept to make maximum use of the available solar energy.

 

[DrRaviSharma]

Vikram Hop was suggested by me in 2020 in Space.com article
Please read this Op-Ed published about ISRO Chandrayaan 2 and NASA.
https://lnkd.in/dUTpHehD
https://www.space.com/india-moon-landing-not-a-failure.html
ALSO SUGGESTED THIS FOR STEP TOWARDS SAMPLE RETURN CAPABILITY AND ALSO RTG REQUIRED FOR NIGHT DATA COLLECTION AND CONTINUITY OF INSTRUMENTS AND SYSYTEMS.
With Vikram's hop there have been 12 propulsive flights from the Moon's surface:
Thanks.
Ravi
(Dr. Ravi Sharma, Ph.D. USA)
NASA Apollo Achievement Award
Former MTS NASA HQ MSFEB
ISRO Distinguished Service Awards
Former Scientific Secretary ISRO HQ
Ontolog Board of Trustees
Particle and Space Physics
Senior Enterprise Architect

1.
Surveyor 6 (Hop) - 1967
2.
Apollo 11 (Crewed launch) - 1969
3.
Apollo 12 (Crewed launch) - 1969
4. USSR - Luna 16 (Sample return) - 1970
5.
Apollo 14 (Crewed launch) - 1971
6.
Apollo 15 (Crewed launch) - 1971
7. USSR - Luna 20 (Sample return) - 1972
8.
Apollo 16 (Crewed launch) - 1972
9.
Apollo 17 (Crewed launch) - 1972
10. USSR - Luna 24 (Sample return) - 1976
11.
Chang'e 5 (Sample return) - 2020
12.
CY3 Vikram (Hop) - 2023

Courtesy @TitaniumSV5 Twitter/X

Space.com: NASA, Space Exploration and Astronomy News

 

[Unclear Engineer]

Wondering how much dust was deposited on the "already sleeping rover" when the lander performed its "hop". I think the rover is about 100 meters from the lander, and the lander moved less than 1/2 meter toward the rover with that hop. So, I am wondering how much dust gets deposited 100 meters away from the lander when it fires its rocket.

Besides sample return missions, "hopping" vehicles might be really important on lunar bases, because there is so much obstruction to rolling vehicles. Especially in the "mountainous" areas near the lunar south pole, where ridges that create shadows are of particular interest, it seems to me that the ability to fly above the surface to get to interesting locations is going to be crucial. But, doing that has the potential to coat surrounding infrastructures with lunar dust.

 

[Classical Motion]

To me, the most amazing and historical slant of this event is........the cost. Many private interest can go to the moon now. And beyond.

How much does a movie cost? How much does it cost(and time) for environmental studies? And geo studies? And permits and royalties?

Private space might actually catch on. Open source space.