| ▲ | gdubs 5 hours ago | |||||||
One of my favorite stories about the Voyager mission was how they wanted to grab photos of the outer planets but the click of the tape drive was enough to ruin the long exposures. I made a YouTube short about it a while back: | ||||||||
| ▲ | mek6800d2 3 hours ago | parent [-] | |||||||
I enjoyed your video and it is well done. Unfortunately, I don't think it's true. The Voyager tape drives were similar (if not largely identical) to the earlier Viking Orbiters' DTRs. The Voyager engineers were certainly familiar pre-launch with the motions imparted to the spacecraft by the mechanical movements of the tape drive. The Voyager DTRs were specifically mounted to minimize the effects on the roll axis. Potential problem were expected and planned for with Voyager 2's flybys of Uranus and Neptune. Because of the long exposures required for these more distant planets, like you pointed out, the engineers had to account for the attitude effects of both (i) the DTR movements and (ii) panning the cameras to keep them focused on a single point while the spacecraft was moving past at high speed. This was especially a problem at Uranus, which is tilted on its side. Voyager 2 was approaching at its north pole; with the plane of the moon's orbits perpendicular to the ecliptic - like an arrow flying into an archery target. As a result of this configuration and Voyager 2's high speed, the high-resolution observations of Uranus and its moons were compressed into a 6-hour period. These engineering efforts are described in detail in a 1985 paper, "Voyager Flight Engineering: Preparing for Uranus", by W.I. McLaughlin and D.M. Wolff. Abstract: https://arc.aiaa.org/doi/abs/10.2514/6.1985-287 (The full paper can be found online with some effort; doi:10.2514/6.1985-287) Here's a quote from the paper (AACS is the attitude control computer and CCS is the command computer): | ||||||||
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