Questions tagged [rtg]
RTG is a Radio-isotope Thermo-electric Generator. It uses the heat generated by the decay of a radioactive material to generate power. Often the heat as well, to hold off the cold temperatures in space or other planets.
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Why use plutonium when sunlight is everywhere? Any proposals to use concentrated solar power instead of Pu238 as a heat source for TGs?
Why use plutonium when sunlight is everywhere? The case for powering thermoelectric generators (TG) with concentrated solar rather than plutonium:
Spacecraft operating in the inner Solar System ...
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Apollo 13's plutonium RTG re-entry into the Tonga Trench: Good shootin' or good luck?
Plutonium powered RTGs are encased to survive re-entry. According to the Wikipedia article on Apollo 13
RTGs were used to power … the scientific experiments left
on the Moon by the crews of Apollo …...
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How would we power probes or spaceships over hundered or thousands of years?
There are different optimal power sources for probes and spaceships for different kinds of missions.
Solar
Well suited for many missions in the inner solar system. Only limited degradation over time ...
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Efficiency of "liquid cooled" RTG
One of the big problems in the vacuum of space is getting heat away. RTG that rely on a temperature differential from the hot to the "cold" side to produce electricity will probably suffer a ...
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Apollo ALSEP RTG shorting switch to prevent overheat of the RTG?
I found these lines in the Apollo 14 Lunar Surface Journal:
116:07:37 Mitchell: Houston, the current reading is 8.
116:07:42 McCandless: Understand 8 amperes before pressing the
(shorting) switch.
...
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How many watts of electricity are available for systems during a Mars transit?
The 40+ year old Voyager probes have three Radioisotope Thermoelectric Generators (RTGs) currently producing 249 watts, losing around 4 watts per year. They began with 470 Watts.
The Curiosity Rover's ...
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Is lunar exploration going to need a whole heck of a lot of RTGs? If so, have they started firing up the RTG-making reactors yet?
The November 16, 2021 Northrop Grumman Press Release Highly specialized team to design vehicle for sustainable lunar surface mobility operations begins
Northrop Grumman Corporation (NYSE: NOC), is ...
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Why did Cassini require so much more power than other probes?
Inspired by the comment by Nick S on this answer by Organic Marble, what made Cassini require so much power?
An excerpt from the aforementioned answer:
The flight units used by mission, with power ...
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Why are there four RTGs in a row sitting in this room? What are they waiting for? Were they built together and stored for separate launches?
The extremely cool NASA JPL video Triumph at Saturn (Part I) is really worth a watch and/or listen.
At about 17:40 it discusses Cassini's RTG and at ...
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How can they be so sure that Dragonfly will "freeze to death" as opposed to simply (and eventually) running out of RTG power? (238Pu decay)
tl;dr: "...will probably freeze to death...before it runs out of power..." If power keeps it from freezing to death and it hasn't run out of power, why would it freeze to death?
Space.com's ...
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Does curiosity's RTG generate neutrons as this NASA CheMin X-ray detection system webpage suggests? If so, how?
mars.nasa.gov's CheMin for Scientists (found here) says (about half-way down):
Detection of X-ray Photons by the CCD
CheMin will use a 600 × 600 E2V CCD-224 frame transfer imager operated with a 600 ...
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Does an RTG generate power instantly or slowly? [duplicate]
The Mars rovers Perseverance and Curiosity use RTG to generate power and they move slowly...
Does it produce enough enery so that we can use it on electric cars that go fast?
And will the cars go fast ...
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Why are RTGs so inefficient?
I recently learned about how an n-type and p-type "sandwich" with different thermal properties can create a potential difference in the presence of a temperature gradient. The subsequent ...
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Can we power things (like cars or similar rovers) on earth in the same way Perseverance generates power?
I was watching a video on the engineering of Perseverance and it states that the rover is powered by 4.8kg of Plutonium Dioxide. I was wondering if that similar process of electricity generation can ...
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Venus probe with refrigerated electronics powered by an RTG (more like the Mars rovers)
Because of the very high surface temperatures on Venus (~450 oC) conventional semiconductor electronics will not work. Discussion of surface probes to Venus talk about using vacuum electronics, ...
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What is hot shoe and cold shoe in MMRTG?
As I was going through the book 'The Design and Engineering of Curiosity' by Emily Lakdawalla, I stumbled on these two words. Are they hot and cold section of thermocouple? What actually they do?
The ...
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Why is Perseverance's RTG lifetime only 14 years?
The MMRTG uses Pu-238, which has a half-life of 87.7 years. So after 14[1] years it should be able to output a little over 80% of the power, which naively to me seems like it should be enough.
What is ...
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Why exactly does Curiosity's RTG make more electricity on cold days?
There is a fascinating factoid in this answer to MMRTG- thermal and electrical output:
The electric power of the thermocouples depends on cooling influenced by the environment. On a cold day on Mars ...
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MMRTG- thermal and electrical output
I haven’t been able to find a definitive number for the thermal output (in watts) of the MMRTG used aboard the Perseverance rover. The numbers I’ve seen range from 1950 watts to over 2000. I also ...
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Could Ingenuity stay warmer at night by landing on (or near) Perseverance's RTG?
One concern in How long could the Mars helicopter Ingenuity keep up with the Perseverance rover if it wanted to? is that the helicopter must cycle its battery every night to stay warm, and that could ...
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Why is the supply of RTGs running short?
I always hear that NASA has only a limited amount of radioisotope thermoelectric generators (RTGs) remaining.
I did some superficial research on how they work and what is needed to produce them and ...
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Which wears out faster on RTGs; the R's or the TG's? (the radioisotopes or the thermocouples)
Below this answer to Are there any safe-to-launch alternatives to RTG's for outer solar system exploration? I saw the comment:
...the Voyager RTG cores are still putting out plenty of heat. The ...
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Why do many RTGs have finned heatsinks, when this is considered bad for radiation heat transfer?
Related: Finned heatsinks in space
Multi-fin heatsinks are not normally considered good for heat dissipation in space because adjacent fins radiate into each other, and you would be better off with ...
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Are few kilogram RTG's possible with similar mass-specific power to current designs?
This answer to Mass ratio of solar-electric versus radioisotope thermo-electric power for propulsion; beyond how many AU do RTGs win? estimates a crossover at about 4.3 AU, so a trip to the outer ...
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Are RTG-powered spacecraft restricted to only some launch vehicles? [duplicate]
This answer by PearsonArtPhoto mentions for spacecraft powered by an RTG there's "only a single rocket that can launch them (Atlas rockets)". Of course that probably doesn't apply to non-US launches, ...
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How do Stirling radioisotope generators maintain a temperature differential in a vacuum?
I was reading the wikipedia page on RTGs and happened to stumble upon the section about efficiency. There were three methods that seemed to rely on direct conversion of thermal energy into electrical ...
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Mass ratio of solar-electric versus radioisotope thermo-electric power for propulsion; beyond how many AU do RTGs win?
Solar-electric propulsion has been used several times now in deep space missions. This question explores the scalability in comparison to Radioisotope thermoelectric generation or other nuclear-based ...
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How (and when) was the RTG in the lunar modules installed?
In this answer, it is explained that the space probes RTG's are not installed until a couple days before launch because of the heat those things generate.
Now I'm curious about the Apollo RTGs. From ...
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Can Dragonfly make it to one of Titan's Lakes?
Dragonfly is a drone set to land on Titan in the mid 2030s. As I've read, Saturn - and thus, Titan - won't be in the right orbital position at the time to allow for direct contact with the drone if it ...
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What is the current status of Stirling engine-based radioisotope generator technology?
@Heopps' cool answer to the question Any proposed missions to explore the black liquid on Titan? Technical challenges? has an interesting line:
ASRG generator was planned as compact energy source ...
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Why did Voyager have to shunt unused electrical power and radiate as heat?
Reading about Voyager in The oldest computer (not) on Earth I saw the image below, where is shown a science instrument calibration panel and shunt radiator.
According to the November 1980 NASA News ...
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Why are planetary probe RTGs tilted at a jaunty angle?
This image from here: Does the Dragonfly project (quadcopters on Titan) envision attached RTG's or would they be static and revisited for charging?
and this image
show that the RTGs on these two ...
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Does the Dragonfly project (quadcopters on Titan) envision attached RTG's or would they be static and revisited for charging?
In this answer I link to the Phys.org article Researcher sets eyes on Saturn's largest moon which describes the Dragonfly project, a way to explore extended areas of Titan's surface difficult to probe ...
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How exactly does Curiosity's floating bus work, and how does it continue to operate when voltage drops from 11 to only 4 volts?
@Hobbes's answer calls attention to Emily Lakdawalla's book The Design and Engineering of Curiosity : How the Mars Rover Performs Its Job which led me to reading excerpts in several Planetary Society ...
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What delta-v per orbit would a spacecraft need to hover next to Saturn's rings?
In order to collect Saturn's ring particles for sample return to Earth, a spacecraft would need to share the orbit of this debris. If it is inclined it will have to pass through the rings twice each ...
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Radioisotope thermoelectric generator behavior on reentry
The RTG has become a major source of power in places where solar power just wont cut it. but there has always been an issue with sending them into space. if the launch fails, radiation comes raining ...
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How an americium-241 RTG would differ from one using plutonium-238?
@TomSpliker's great answer mentions that ESA might be looking at producing Radioisotope (powered) Thermoelectric Generators (RTGs) based on the radioisotope americium-241. 241Am is a "kinder and ...
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Which countries have built RTGs and used them in Earth orbit and/or beyond?
I know the US has; a few have even left the solar system, there's some on the Moon, one on Mars, and one inside Saturn, though now "extensively modified". Rosetta had to hibernate for 2.5 years for ...
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How much RTG fuel does China have?
Chang'e 3 is still operating, 3 years later, sending good science from its LUT (Lunar-based Ultraviolet Telescope) - running on RTG batteries.
NASA is supposedly scrapping the bottom of the barrel ...
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Tritium as energy source for probes?
There's this ingenious little hack video: "How to make tritium nuclear battery at home".
The idea is very simple: "tritium keychain lights" - tubes with tritium and luminophor - placed between solar ...
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If Curiosity had lights, could it drive or work in the evening?
If the Mars rover Curiosity had been equipped with lights, would it be able to drive or do other work in the evening? This could be some combination of LED headlights, wheel-lights, and/or a spotlight ...
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Why are RTGs different colors?
This is an image of the radioisotope thermoelectric generator (RTG) for Cassini:
This one was for one left on the Moon:
And this one is for the Multi-Mission RTG, used by Curiosity on Mars:
One is ...
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What were the uses of the RTGs in the Apollo spacecrafts?
I was listening to the Plutonium episode of "the Elements" on the BBC, and between 07:00 and 08:30 they talked about uses of plutonium such as spacecraft power and heat. While the returning astronauts ...
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Does Curiosity pose a radiation hazard for would be colonists?
I understand Curiosity is powered by plutonium decay. I was wondering if that kind of battery leaks.
If humans ever go to Mars, and they want to meet with Curiosity, would they need to take extra ...
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What's the total specific energy of RTG?
How many joules of electric energy can you draw out of an RTG battery over its lifetime - and what's the mass of that battery? (whole; shell, thermocouples, fuel and all.)
(realizing, that the power ...
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Why wasn't an RTG used on the Juno spacecraft?
When I first heard about the Juno spacecraft, I was surprised that it would be using solar panels to generate power throughout the mission. Why wasn't a radioisotope thermoelectric generator (RTG) ...
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How does the launch risk for a plutonium RTG and a uranium fission reactor compare?
I was looking at this answer that talks about how a good alternative to Radioisotope Thermoelectric Generators would be fission reactors. It makes a number of good points, but in the comment thread ...
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Why was radio contact with Pioneer lost earlier than with Voyager?
Why was radio contact lost with the Pioneer probes much earlier than with the Voyager probes? The Voyagers were launched only 4 years after the Pioneers, yet the Voyagers are projected to last into ...
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Could radiated heat propel space-craft in outer space?
The comment chain on What is the feasibility of launching a probe to Sedna? indicates RTG thermocouples decay. With the passage of time the thermocouple may even have the ability to transduce an ...
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Could electricity propel Curiosity on Venus?
To-date the humans have dispatched surface missions to
Mars
Luna
Venus
Mars has a thin atmosphere. Luna lacks one. Venus has a soup-thick atmosphere.
Landing a static craft on Venus is one thing. ...
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