00:36 in the June 2019 NASA video Dragonfly: NASA's New Mission to Explore Saturn's Moon Titan the animation shows it landing then deploying a circular disk with a spiral pattern of dots at
00:44. There's a zoomed/sharpened detail of a screenshot shown below which reveals a spiral pattern of "T"-shaped little spots circling about 6 times; dense in the middle, sparse along their spiral path at the edge.
@Hobbes' answer to Does the Dragonfly project (quadcopters on Titan) envision attached RTG's or would they be static and revisited for charging? has several newer details and images of the helicopter and they show the disk.
From a labeled heat shield diameter of 3.7 meters we can estimate that end-to-end Dragonfly is roughly 3 meters long(!!) and the disk roughly 80 to 100 cm in diameter.
I'm thinking "high gain antenna" and superficially comparing to Curiosity's and Perseverance's highly articulable HGA. This one looks a heck of a lot thinner, but part of that may be artistic license and part due to it being larger in diameter than those of the rovers.
- How does Curiosity know how to point and move it's high gain antenna in real time?
- Has the Curiosity rover ever communicated directly with Earth via its high-gain antenna? Signal strength & data rate?
click images for larger size left: Curiosity's High Gain Antenna (articulated dirty hexagon). Cropped from here. right: Curiosity's High Gain Antenna gain in downlink modes, from MSL Telecommunications System Design.
We can see that Dragonfly is expected to do a lot of communicating each Titan solar day of 15.92 earth days. "Why solar day? on a moon with an opaque atmosphere an radioisotope thermoelectric power so far from the Sun" you might ask? Because from 10 AU the Earth and the Sun are always within about 6 degrees of each other. It's not as close as the 0.4 degrees for the Voyagers but Earth's radio visibility will be synchronized to solar rather than sidereal days on Titan. How well can Voyager 1 separate Earth signals from Solar noise these days?
Source: R. D. Lorenz et al. Johns Hopkins APL Technical Digest, Volume 34, Number 3 (2018), www.jhuapl.edu/techdigest Dragonfly: A Rotorcraft Lander Concept for Scientific Exploration at Titan
Figure 7. Energy management and communication concept of operations. MMRTG continuously recharges the battery, but downlink and especially flight demand significant energy. Activities can be paced to match MMRTG in situ capability while maintaining healthy margins on the battery state of charge.
What is the pop-up circular disk with spiral pattern in this NASA animation of the Dragonfly helicopter for Titan? Is it a high gain antenna? If so, what kind, how does it work, what band will it use and "who" will it talk to?
"Bonus points:* Why do the little "T" shapes rotate by only 180 degrees each time the spiral completes a full circle?
Related to spiral and concentric circle antennas:
- Why were the antennas on the spherical surface of some early satellites spiral-shaped?
- What's the spiral pattern on this satellite?
- What is the large circular device with a dozen concentric circles on Sentinel 3B?
Related to phasings, phased array antennas and beam forming; no evidence of a spiral pattern of individual radiator elements anywhere!:
- How is GAIA's phased array configured, mechanically and electrically?
- How does the pattern on the MarCo cubesat's antenna boost data-transmission?
- When is a phased array antenna not a phased array?
- Need help identifying this (likely to be) phased array antenna used to track launches
- How should we point our SpaceX Starlink ground transceiver antennas?
- CICERO orbit design and optimization for GPS occultations? phased array GPS antennas
- Are Starlink satellites flaring? Iridium phased array images, old and new
- Why do these satellite antennas look so weird? (strangely shaped with little white dots...)
- How do commercial broadcast satellites in GEO produce such carefully shaped signal footprints?
Screen shots from Starlink Teardown: DISHY DESTROYED!. See also How does this SpaceX Starlink ground station antenna's gear mechanism move it in both altitude and azimuth?](https://engineering.stackexchange.com/q/40749/6264) and Teardown of “Dishy McFlatface,” the SpaceX Starlink user terminal
click images for larger size