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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Are there any safe-to-launch alternatives to RTG's for outer solar system exploration?

In the past two decades, NASA has launched at least three missions that use RTG's: Cassini Mars Science Laboratory New Horizons Those launches include plutonium, which is a reason for some to oppose ...
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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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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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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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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 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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5 votes
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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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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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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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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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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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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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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 posed by plutonium compare to the launch risk posed by propellants?

For outer solar system exploration, virtually the only feasible power subsystem are Radioisotope thermoelectric generators (RTGs). These include plutonium, which may carry considerable risks (see ...
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How far from the Sun can solar power be used as a reliable energy source?

Space probes headed for the far reaches of our Solar System rely on radioisotope thermoelectric generators for power (Cassini–Huygens, Voyager 1, Voyager 2). Presumably this is because solar power ...
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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'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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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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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 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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9 votes
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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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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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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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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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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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3 votes
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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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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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9 votes
1 answer
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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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7 votes
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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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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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3 votes
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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 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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