# How does the Dragonfly helicopter for Titan compare to Perseverance, Ingenuity and a human in terms of size, mass, weight and daily range?

It wasn't until Are Perseverance's wheels really this big? that I realized just how big Curiosity and Perseverance probably are. Writing What is the pop-up circular disk with spiral pattern in this NASA animation of the Dragonfly helicopter for Titan? Antenna? Kind, band, target? I realized that the Dragonfly helicopter for Titan is much bigger than I imagined as well.

I thought it was like 3 feet long, but it's more like 3 meters!

Question: Is it possible to directly compare the 1) sizes (longest dimension), 2) masses, 3) weights, and 4) daily ranges of Dragonfly, Perseverance, Ingenuity and an average human side-by-side in a table and some kind of composite image?

For weight please use their target bodies and leave the human on Earth.

For daily range use approximate typical or maximum design numbers, whichever is convenient and just note which it is.

## 1 Answer

tl:dr; cropped from large image below (own work).

quick bash, can't find actual dimensions, details seem to vary on vehicle as evidenced by nose.

3m box for aeroshell reference

human is about 5'9" (1.75m) tall as an average

generally articles say 3m, to fit inside heatshield aeroshell.

Preliminary studies and modeling contemplate a baseline 450 kg mass for the rotorcraft packed in a 3.7 m diameter heatshield.

A constraint in this application that is somewhat unusual for rotorcraft is the necessity to be packaged in a hypersonic aeroshell. The geometric trade of unblocked rotor disk area versus number of rotors with such a constraint suggests that, in fact, four is optimal.

the size of a Martian rover (3 meters by 3) but much faster, will be launched in 2026 and will arrive on Titan in 2034. It will fly from point to point analyzing Titan's hydrocarbon clouds and its ethane lakes, and hundreds of kilometers in its two years of being on mission.

Dragonfly, expected to weigh around 1,200 pounds, will be the size of the largest Mars rovers.

At the end of each of its four arms, two 53-inch counter-rotating rotors, one atop the other, will provide lift.

From helicopter to quad rotor:

‘We want to maximize the disk area of the rotor, and the way we will do that is I’ll make a coaxial-rotor helicopter [with two counter-rotating propellers on a single axle] that fits exactly inside the aeroshell of the spacecraft,’

“But it turns out that you can actually get a larger net disk area with a multi-rotor, with a quadrotor.”

“When the rotors are spinning, this rotor can stick way outside the circle that defines the aeroshell,”

The reason why you go with an octocopter—with the stacked rotors—is so that you get some redundancy. So you can lose one rotor and you can still fly safely.

Basic dims., sorry got them from the usual places:

Perseverance

Length  2.9 m
Diameter    2.7 m
Height  2.2 m
Launch mass 1,025 kg


Ingenuity

Fuselage (body): 13.6 cm × 19.5 cm × 16.3 cm
Landing legs: 0.384 m
Diameter    Rotors: 1.2 m
Height  0.49 m
Landing mass
Total: 1.8 kg
Batteries: 273 g


Dragonfly (guess)

Length  2.9 m
Diameter 2.9 m
Mass: <600kg


https://danielmarin.naukas.com/2019/06/27/la-nasa-elige-dragonfly-nos-vamos-a-titan/comment-page-2/

https://beyondnerva.com/2019/07/09/dragonfly/

https://www.nasa.gov/dragonfly/frequently-asked-questions/index.html

https://factburger.com/read/dragonfly-nasa-titan-adventure.39

https://techcrunch.com/2019/06/27/nasas-dragonfly-will-fly-across-the-surface-of-titan-saturns-ocean-moon/

https://www.hems-workshop.org/13thWS/Presentations/04%20Danell.pdf

https://dragonfly.jhuapl.edu/News-and-Resources/docs/34_03-Lorenz.pdf

https://www.airspacemag.com/airspacemag/skies-over-titan-180975602/

https://space.skyrocket.de/doc_sdat/dragonfly.htm

Note: I know the legs and shapes are incorrect for Dragonfly, my initial 3d was based off interpreting bad pictures of what turned out to be early concepts. I'll fix it at some point...

• Can you mention from which reference the image comes? It's important to note the source of the image; if it's your own work then note that as well. Thanks!
– uhoh
Jun 28 '21 at 2:21
• @uhoh - All of the images are from the links above, aside from the 3D ones, which i supplied (and may fix if i have time..) Jun 28 '21 at 2:31
• Oh, you mean it's an "own work" personally assembled composite of images from other sources?
– uhoh
Jun 28 '21 at 2:32
• That sounds right. Is that a no-no? Jun 28 '21 at 2:34
• i think i misread your comment - the 3d stuff - that is me and my unfinished or part assembled 3d... so no, it won't be in any of the links because i grabbed them from my pc.. hth ! Jul 6 '21 at 4:32