NASA's Dragonfly mission to Titan

[James Kerman]

NASA intends to utilize a quad rotor probe to sample many sites on Titan. Dragonfly will launch in 2026 and arrive in 2034.

https://www.nasa.gov/press-release/nasas-dragonfly-will-fly-around-titan-looking-for-origins-signs-of-life/

[kerbiloid]

Let's hope their rotors can work at -180°C, while landing legs won't melt the surface.

[RealKerbal3x]

This is very cool.

Crossing my fingers that it won't be cancelled

[Codraroll]

If I understand correctly, driving a rover on Mars is basically like: "OK, we've spent the past week finishing the terrain survey from the rover's current position, and the third party control agrees it's safe to continue onwards. Today's business for the entire team is making sure the rover traverses the next fifteen centimeters of landscape as calmly and controlled as possible. Maybe we can go ten more centimeters next week if everything goes well."

Okay, maybe not that slow, but still, the rovers aren't built for a pace faster than that of a walking plush toy whose batteries are about to run out. How would they handle helicopter operations on a body so much further away than Mars?

[Wjolcz]

28 minutes ago, Codraroll said:

If I understand correctly, driving a rover on Mars is basically like: "OK, we've spent the past week finishing the terrain survey from the rover's current position, and the third party control agrees it's safe to continue onwards. Today's business for the entire team is making sure the rover traverses the next fifteen centimeters of landscape as calmly and controlled as possible. Maybe we can go ten more centimeters next week if everything goes well."

Okay, maybe not that slow, but still, the rovers aren't built for a pace faster than that of a walking plush toy whose batteries are about to run out. How would they handle helicopter operations on a body so much further away than Mars?

My guess is they want to figure all this out with Mars 2020 and it's cubecopter. That thing will have to be autonomous even on Mars because the delay there is significant too.

[Guest]

Hmmm, the pics taken from something like that would be amazing @_@!

[MinimumSky5]

3 hours ago, Codraroll said:

If I understand correctly, driving a rover on Mars is basically like: "OK, we've spent the past week finishing the terrain survey from the rover's current position, and the third party control agrees it's safe to continue onwards. Today's business for the entire team is making sure the rover traverses the next fifteen centimeters of landscape as calmly and controlled as possible. Maybe we can go ten more centimeters next week if everything goes well."

Okay, maybe not that slow, but still, the rovers aren't built for a pace faster than that of a walking plush toy whose batteries are about to run out. How would they handle helicopter operations on a body so much further away than Mars?

It's much easier to find a good landing site, than plot out a route to drive in a boulder strewn landscape, as you don't need anywhere near the amount of good terrain. Also, aerial photograph really helps these things! 

[magnemoe]

2 hours ago, Codraroll said:

If I understand correctly, driving a rover on Mars is basically like: "OK, we've spent the past week finishing the terrain survey from the rover's current position, and the third party control agrees it's safe to continue onwards. Today's business for the entire team is making sure the rover traverses the next fifteen centimeters of landscape as calmly and controlled as possible. Maybe we can go ten more centimeters next week if everything goes well."

Okay, maybe not that slow, but still, the rovers aren't built for a pace faster than that of a walking plush toy whose batteries are about to run out. How would they handle helicopter operations on a body so much further away than Mars?

Flight is easier as you only need an safe landing area with no large rocks or slopes who can tilt you. 
This is even more important on titan as you will have no direct control, you just program an jump and execute. 

[Hannu2]

9 minutes ago, MinimumSky5 said:

It's much easier to find a good landing site, than plot out a route to drive in a boulder strewn landscape, as you don't need anywhere near the amount of good terrain. Also, aerial photograph really helps these things! 

It may be, but helicopter must choose landing site fully autonomously. There will be no orbiting probes to survey good landing sites (or is it included in mission) and no time to wait instructions from Earth. I am quite sure, that RTG does not produce even near enough energy for continuous flying. They must load batteries slowly and then they can fly a short trip.

That will be very interesting project. Real science and not manned circus tricks which are now so fashionable. I really hope that it will success in my lifetime.

[James Kerman]

NASA has used Cassini data to select a landing site and timing for calm weather.
 

Quote

 It will first land at the equatorial “Shangri-La” dune fields, which are terrestrially similar to the linear dunes in Namibia in southern Africa and offer a diverse sampling location. Dragonfly will explore this region in short flights, building up to a series of longer “leapfrog” flights of up to 5 miles (8 kilometers), stopping along the way to take samples from compelling areas with diverse geography. It will finally reach the Selk impact crater, where there is evidence of past liquid water, organics – the complex molecules that contain carbon, combined with hydrogen, oxygen, and nitrogen – and energy, which together make up the recipe for life. The lander will eventually fly more than 108 miles (175 kilometers) – nearly double the distance traveled to date by all the Mars rovers combined.
https://www.nasa.gov/press-release/nasas-dragonfly-will-fly-around-titan-looking-for-origins-signs-of-life/

 

[Hannu2]

8 minutes ago, magnemoe said:

Flight is easier as you only need an safe landing area with no large rocks or slopes who can tilt you. 
This is even more important on titan as you will have no direct control, you just program an jump and execute. 

Your mileage may vary. I bought "simple" and "slow" RC-aircraft to my daughter and I have to say that it is crazy hard compared to RC car, which is probably much harder to drive that very slow all wheel driving rover. I hope that there are dead calm weathers at Titan during the mission.

I have also had a coaxial helicopter and based on my experience I am happy that my job is not to program automatic flight algorithm for use in conditions turning flipped helicopter (and changing of rotor blades) costs billions and take decades.

 

[magnemoe]

3 minutes ago, Hannu2 said:

Your mileage may vary. I bought "simple" and "slow" RC-aircraft to my daughter and I have to say that it is crazy hard compared to RC car, which is probably much harder to drive that very slow all wheel driving rover. I hope that there are dead calm weathers at Titan during the mission.

I have also had a coaxial helicopter and based on my experience I am happy that my job is not to program automatic flight algorithm for use in conditions turning flipped helicopter (and changing of rotor blades) costs billions and take decades.

 

For humans yes, for us navigating on ground is easier, for computers its the other way around. 
Far less stuff to worry about: wind turbulence and not landing to hard. On issue is that stuff happens much faster who is not much of an problem for an computer. 

Also for an rover its problems increase as its get smaller as its easier for it to get stuck. 

[kerbiloid]

There should be a column of vapor above the RTG.
-160°C outdoors.

[farmerben]

On Earth 1 kW/kg is good for a quadcopter.  On titan maybe 6-8 kg per kw?

Batteries are good for about 0.2 kWh/kg.

Plutonium 238 is good for 0.5 kW/kg thermal... probably about 0.05 kW/kg electrical for the entire system.  So 1 kg of RTG can charge 6 kg of batteries per day.  And that is enough for a 1kW unit to fly for over an hour (72 minutes) per day.

Polonium RTG's could run continuously, but they would have to be made in the Jovian magnetic field and replaced every year.

There is no chance a thing like this could carry its own solar panels on Titan and have a decent charging rate.

It should have legs rather than skids.  Insects have no trouble landing on tilted or uneven surfaces.  Skids are only better if you want to slide.

[mikegarrison]

1 hour ago, farmerben said:

It should have legs rather than skids.  Insects have no trouble landing on tilted or uneven surfaces.  Skids are only better if you want to slide.

Skids imply a box structure, which is inherently stronger than individual legs for the same mass. Perhaps that's a factor.

[James Kerman]

A short video presentation by NASA about the mission:

 

Edited June 29, 2019 by James Kerman
Grammark

[IncongruousGoat]

Huzzah! I've been rooting for this to be selected ever since I heard about the proposal, back when it was just one of 12 proposed missions. Titan is definitely worthy of a detailed investigation. It's especially good that this was picked considering that the alternative (a proposal called CAESAR) was lame and unoriginal in the extreme: sample return from where else but our old friend 67P/Churyumov-Gerasimenko. Yeah, sample return from a comet's nucleus would be nice in a general sense, but when you compare that with the chance to send a freakin' quadcopter to Titan, well...

[Guest]

It’s a promising destination to be sending missions to imo, not because it’s an interesting place but because it says to me that things are getting real. Titan is probably one of the most valuable resources in the solar system $_$!

Just as promising as NASA wanting to get back to the moon (Luna) to start checking out some of these southern pole craters. It might be interesting science but I’m sure it also has something to do with getting to the best resource locations before China lol... 

Maybe with space being on the verge of opening up to commercial interests, we are seeing the beginnings of the next goldrush.!

[Scotius]

10 hours ago, Dale Christopher said:

It’s a promising destination to be sending missions to imo, not because it’s an interesting place but because it says to me that things are getting real. Titan is probably one of the most valuable resources in the solar system $_$!

Just as promising as NASA wanting to get back to the moon (Luna) to start checking out some of these southern pole craters. It might be interesting science but I’m sure it also has something to do with getting to the best resource locations before China lol... 

Maybe with space being on the verge of opening up to commercial interests, we are seeing the beginnings of the next goldrush.!

Do you want a target for the goldrush? Check out this puppy

https://en.wikipedia.org/wiki/16_Psyche

This single asteroid contains 1% of the mass of the whole Asteroid Belt!

If it is indeed exposed metallic core of a shattered protoplanet, there might be untold riches in valuable metals contained inside.

[natsirt721]

 

15 hours ago, mikegarrison said:

Skids imply a box structure, which is inherently stronger than individual legs for the same mass. Perhaps that's a factor.

Skids also let you touch down with a bit of lateral velocity (just a bit, mind you) which might be helpful when landing in windy conditions. That being said, I suspect that there simply isn't enough energy flux on Titan to create meaningful winds.

On 6/28/2019 at 2:15 AM, kerbiloid said:

Let's hope their rotors can work at -180°C, while landing legs won't melt the surface.

Thermal management will be heavily controlled, with only the parts that actually require it being heated. The RTG provides a convenient source of heat, so I suspect something like a 'thermos' configuration where all of the electronics and batteries are stored in a heavily insulated box with heat pipes from the RTG to keep warm. The electric motors will probably use electric heaters while the batteries are charging, and to supplement them while in flight.  The rotors themselves will probably be as cold as the air, plus conductive heating from the motors (this will probably be the largest source of convective cooling because of the mass flow across the blades). The lower structure will probably be nearly as cold as the surface, because if they aren't that means you're wasting heat.

[Mitchz95]

How much faster could Dragonfly get to Titan if it launched on a Starship and refueled in orbit? Eight years is a long time to wait.

Edited June 30, 2019 by Mitchz95

[RealKerbal3x]

3 hours ago, Mitchz95 said:

How much faster could Dragonfly get to Titan if it launched on a Starship and refueled in orbit? Eight years is a long time to wait.

Elon Musk tweeted a while ago (don’t have a link...I don’t really want to wade into the enormous mess of Twitter ) that Starships could get heavy payloads really far if unnecessary hardware was removed, like the legs and heatshield, essentially creating an expendable stage. If a stripped-down Starship can get big payloads a long way, imagine how fast it can get the relatively light Dragonfly payload to Titan.

[darthgently]

Necromancing the thread here, if there is a better topic, please guide me there.  The budget is decreasing by some millions so NASA is planning how to scale back the mission.  It is 2023, NASA, do a GoFundMe for the shortfall!

https://spacenews.com/dragonfly-mission-studying-effects-of-potential-budget-cut/

[Minmus Taster]

Sorry for the necromancing but Dragonfly's review and launch have been postponed and liftoff is now targeted in 2028;

https://spacenews.com/nasa-postpones-dragonfly-review-launch-date/

I'll admit I'm starting to become concerned for this mission, at least in it's current form, these cuts to the budget are quite extreme.

[darthgently]

I wish people could make direct donations to specific government programs.  But, alas, this would be unconstitutional as it bypasses Congress' budgetary control.  One can donate to government, but Congress gets to decide where your money goes.  Yeah....nope

Edited December 1, 2023 by darthgently