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NASA May Decide This Year to Land a Drone on Saturn's Moon Titan (space.com)
113 points by gyre007 57 days ago | hide | past | web | favorite | 52 comments

Dragonfly is such an amazing concept. A nuclear powered quadcopter!


>Unable to use solar power under Titan's hazy atmosphere, Dragonfly would use a Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), like the durable Curiosity rover on Mars. Flight, data transmission, and most science operations would be planned during Titan's daytime hours (eight Earth days), giving the rotorcraft plenty of time during the Titan night to recharge.

An octocopter, from the renderings.

They call it a dual-quadcopter. That may indicate that the configuration is for control redundancy, as well as increased lift and compactness.

Interesting, I've never heard it referred to as "dual-quadcopter". It's a common configuration in the model aircraft hobby where it's referred to as "X8" octocopter. I supposed "X8" doesn't really describe their renderings though, since the airframe doesn't really look like an X.

How about a smallish wheeled rover, with temporary battery pack, powered by the nuclear battery? Guess that would be greatly limiting the power of the main device to fly. At first I was thinking you could try for a solar powered rover, but it's much farther than mars, and you pointed out the atmosphere is blocking.

I feel so lucky to live in this grand age of exploration - where computer power, materials science and advanced engineering enable us to visit our solar system.

Does an RTG count as "nuclear power"?

There’s got to be a way to do that here. Ie replacing oil power generation with nuclear - say for the largest container ships.

It's already being done. Since 1955 in submarines. Since 1959 in ice breakers. Since 1962 in commercial shipping.


I wonder - why don't they use it for container ships and so on? I would imagine fuel savings there, and lower pollution would be immense.

Well, it does result in enriched nuclear material floating all over the ocean, ripe for the taking by pirates or nation-states that we'd rather not have access.

Hopefully one day we'll see fusion powered container ships.

So you use the same naval threat that we already use to deter idiots from our nuclear powered vessels.

Pirates still seize large merchant ships in Asian and African waters on a monthly basis. There are only a few hundred surface vessels capable of effective anti-piracy patrols worldwide from all navies and coast guards; they can't be everywhere at once.

It's been done, commercially. It's proved noneconomic and technically problematic. Even without economic constraints, the US Navy reserves nuclear propulsion for carriers and submarines. It used to operate nuclear cruisers, but no longer does.

Several commercial nuclear powered ships were built, the Savannah by the US, and single ships by both Germany, the Otto Hahn, and Japan, Mutsu. All proved uneconomical, the Mutsu had major technical issues, and were either scrapped or converted to conventional fossil propulsion.

Among the more pressing problems is the size and loss rate of the civillian cargo fleet. From the United Nations Council on Trade and Development's Review of Maritime Transport: 2014. Total fleet size 47,601 registered ships, totaling 1.68 million deadweight tons. By type and deadweight tonnage:

* Container: 12.8%

* Dry Bulk: 42.9%

* General Cargo: 12.8%

* Oil Tanker: 28.5%

* Other: 11.2%

And those sink. With surprising frequency. From from "Monsterwellen", by Donovan Hohn in Outside magazine:

This is one reason merchant seafaring is still, by some accounts, the world's second-most-dangerous occupation, after commercial fishing. According to Imperial College London, 200 supertankers and container ships have sunk in the past two decades due to weather. Wolfgang Rosenthal, a scientist at the European Space Agency, which studies sea conditions via satellite, estimates that two "large ships" sink every week on average. Most of these, he says, "simply get put down to bad weather.'

See: https://old.reddit.com/r/dredmorbius/comments/3c52ll/shippin...

Sure we can do it. Use nuclear plants on land to provide power for the synthesis of carbon neutral artificial liquid hydrocarbon fuels, then burn that in ship engines.

Installing nuclear plants in modern civilian ships is a non-starter for safety, security, and cost reasons.

I think the real breakthrough on some of these probes to other planets isn't so much how they move around, but the growing possibility of self-directed action. Mars is between 3 light minutes and 22 light minutes away. Every command takes at least that long to reach a probe on Mars, then the same amount of time for NASA to be told "Yes, I heard you and did that".

The Curiosity rover has been on Mars for 6 years. It can travel 90m/hour. Theoretically, it could have moved 3,400km by now- that's more than once around the equator of Mars. It's managed almost 20km. While I'm sure there was much to pause and study, I cannot fathom that it could not have done more in it's time were it not constantly waiting for commands.

Saturn is, at closest approach, more than 1 light hour away.

I feel as though there's a real need to put a generic computer system that can be reprogrammed after launch into orbit around whatever planet we're studying. Give it higher-level commands of what we want to see happen, and send us back the highlight reel.

That's all stuff we can try out on Earth first. Maybe build a rover that explores the whole of Antarctica or the Sahara autonomously. There is this idea of sending a submarine to Europa, melt it through the ice, explore the ocean and then come back up. It would be really cool but first we need to do this on Earth.

Biological contamination is absolutely critical. We fucked up Lake Vostok and that was in our own back yard.


Stupid question why don't we flood space craft with like everclear to steralize them? Not much could survive a bath of everclear.

That is something that is being actively worked on. Mars 2020 should already have much more autonomy than Curiosity has. See for example https://arstechnica.com/science/2018/07/from-oasis-to-noah-t...

The circumference of Mars is 21,344km around the equator [0].

[0] https://www.universetoday.com/66605/circumference-of-mars/

Curiosity's top speed across flat ground is just 0.09 mph (0.14 km/h).

And, of course, that is wildly optimistic, given the actual terrain it runs on. https://www.jpl.nasa.gov/news/fact_sheets/mars-science-labor...:

”NASA’s Jet Propulsion Laboratory (JPL), Pasadena, Calif., […] engineered Curiosity […] to travel up to about 200 meters (660 feet) per day on Martian terrain.”

Sorry, got my info from wikipedia. It may not be totally accurate. I was intending to mean '90 meters', not miles.

> It can travel up to 90 m (300 ft) per hour


Is there a way to throw money at specific NASA projects? Ie a way for the crowd to indicate interest. I doubt it, but nasa is pretty popular

No, government agencies may not accept targeted donations due to anti-corruption law.

Apparently it's legal in some cases when you give it directly to people

>Buried in the campaign finance reports available to the public are some troubling connections between a group of wealthy donors with ties to Russia and their political contributions to President Donald Trump and a number of top Republican leaders. And thanks to changes in campaign finance laws, the political contributions are legal.


This partisan op-ed is barely tangentially related to the OP. So tired of seeing worn out sensationalist divisive news where it obviously doesn't belong.

They should sell something. Maybe you can buy a vote on where it goes. Even if scientist proposed their top ten picks and then people could pay to vote on them.

Or also naming rights would be a cool way to get funding. Or early access to the imagery.

Lots of stuff they could do.

Right, the problem in allowing contributions is definitely clear as day. But a work around is clearly possible through indicating directions for taxes. I remember hearing that idea proposed somewhere, not sure where. You can already elect to add some money to public election campaigns on federal taxes, for instance.

Maybe down the road private operations like SpaceX will be funded enough for stuff like this. Doubtful though.

> indicating directions for taxes

That's what political parties are for. The current US duopoly on representation is a problem.

They do a shit job at it.

Quite honestly being opposites on each of the issues is not helping. I think that having a points distribution on every tax return would be amazing. It need not have any legal force, just be released publicly so all can see. Brings a feeling of real impact.

> They do a shit job at it.

That was my point. I other countries there are bigger range of views to choose, other than the US "radical neoliberalism" and "moderate neoliberalism".

At the moment, there's not even anyone there to receive a check. The agency is shut down.

As long as it is not Jupiter's Europa, because, as we know, we should leave it alone.

When did we start calling them drones instead of probes?

We didn’t.

This is a multicopter design that would be able to fly and hover in Titan’s thick atmosphere.

Because it will fly around.

The headline says they’ll land it though.

It's going to land and then fly to a new location from time to time.

You’ve got to enter the atmosphere and come to a stop before you can deploy a drone on another world I would think (Venus notwithstanding).

If it flies like a drone, it's fair to call it a drone.

>But incorporating extraterrestrial drone technology is a means to an end, not the final goal.

they are really trolling the crackpots here by saying incorporating instead of implementing extraterrestrial drone technology...

Well, I really hope they actually decide to do this then, as the concept of YAML (Yet Another Mars Lander, also a serialization language) is starting to bore me. Call me jaded, but I'm a bit tired of looking at pictures of dusty red rocks. I'm ready for the Spaceman Spiff landscapes and aliens surely to be found on the moons of the gas giants. Bring it NASA.

Yes I realize the other option detailed in the article is a comet sample return. Meh, some comets do that for free you know? I say at this point, go big or stay on Earth.

>the concept of YAML (Yet Another Mars Lander, also a serialization language) is starting to bore me. Call me jaded, but I'm a bit tired of looking at pictures of dusty red rocks

They aren't doing it for the pictures of rocks, these missions have science goals you know.

Detailed study of dusty red rocks is all fine and dandy, but I don't think anyone is clamoring to land a man on Mars for #ScienceGoals. The most inspiring space achievements have all been trailblazing, and visually iconic. Think of Earthrise from Apollo 8, first Man on the Moon photo from Apollo 11, the lunar rover, the Blue Marble, the Space Shuttle itself, images from Hubble, landing 2 SpaceX rocket boosters at the same time etc. The Viking landings on Mars count too as well as the first rovers, but we're far into diminishing returns territory at this point.

Given the reality of a limited budget, I'd prefer to see those resources spent towards doing something new, more challenging, and more interesting; such as landing on the moons of Jupiter and Saturn (or even a more durable modern lander/drone on Venus). Also I think there is plenty of science to be had on a geologically active moon with a significant atmosphere.

In the real. of achievable but not yet done, I want a Neptune and/or Uranus orbiter.

A Neptune orbiter could give us a detailed look at both an ice giant and it's dwarf-planet-sized moon Triton, believed to be a captured KBO.

0.14g surface gravity and 1.45 times earth's atmospheric density might make this a very good way to get around.

Edit: The low wattage of RTGs strikes again. This thing will do one hop every Titan day (16 Earth days) [0].

Edit 2: I'm conflating atmospheric pressure and density. However, it appears to have a 98.4% nitrogen atmosphere, so that seems reasonable.

[0]: http://dragonfly.jhuapl.edu/What-Is-Dragonfly/

This is why we need the kilopower.

This is amazing, and it makes so much sense. I hope this project gets off the ground (ha!). I want to know if there's animo acids or RNA floating around that lake.

I would personally find more interest in an exploratory pit mine on the moon.

Drone? Can it fly? Is it a quad copter?

Why are we calling rover deones now? Clickbait?

> Can it fly?


> Is it a quad copter?

No; current designs are showing it to be an octocopter.

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