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After TLI burn, just before Transposition, Docking and Extraction, the later design crafts jettisoned 4 pieces of the SLA fairing/shroud. These 4 pieces supposedly would follow similar path as the CSM/LM assembly, with the difference that they wouldn't reduce their speed for Lunar Orbit Insertion. What happened to them? Are they still in Earth orbit somewhere out there (they wouldn't leave Earth gravity influence since the spacecrafts after TLI burn didn't quite reach Earth escape velocity) or did they collide with something during all these years?

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This paper by Dan Adamo states that their fate is unknown.

Other Apollo Program hardware certainly accompanied some of the components cited here into interplanetary space. Unfortunately, there are no empirical data relating to these objects' trajectories. Likely the largest such undocumented disposed components are four spacecraft/LM adapter (SLA) panels explosively jettisoned from each S-IVB at Command-Service Module (CSM) separation during trans-lunar coast. Although these jettisons were performed on missions Apollo 8 and Apollo 10 through Apollo 17, missions Apollo 13 through Apollo 17 targeted S-IVB disposal via lunar impact. In any of these cases, zero to four SLAs may have entered interplanetary space.

(emphasis mine)

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    $\begingroup$ Interesting paper. Thanks for the link. Apparently they put the earlier S-IVB's to have the slingshot around the moon. That might give required delta-v to leave the earth orbit. $\endgroup$ – LeoS Nov 20 at 13:58
  • $\begingroup$ Since apollo 11 was sent on free-return trajectory, theoretically the fairings should follow this path and come back to earth rather than be slingshotted to heliocentric orbit. However the summary is conclusive: unknown is unknown :), therefore I'm accepting this as the answer. $\endgroup$ – LeoS Nov 21 at 9:58
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The four pieces of the SLA fairing would follow a similar path as the third stage S-IVB of the Saturn V. The SLA pieces were separated by explosive devices only, so their additional acceleration was very, very small. See apollomaniacs.

After Wikipedia, the S-IVB stages of the missions 8 to 12 are in heliocentric orbits now and of the missions 13 to 17 were crashed on the lunar surface as seismic tests.

In my opinion, the SLA pieces shared the fate of the S-IVB stages.

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  • $\begingroup$ I'm not sure about other flights, but Apollo 11's S-IVB was definitely maneuvered after TDE. "This is Apollo Control at 5 hours, 11 minutes into the mission. The S-IVB slingshot maneuver was completed about 5 minutes ago. Designed to put the third stage of the launch vehicle into a trajectory that will take it behind the trailing edge of the Moon and then into a solar orbit. " See history.nasa.gov/afj/ap11fj/03tde.html#0050319. It doesn't say exactly what maneuver involved, but I assume firing the engine, as without additional delta v it would not reach heliocentric orbit. $\endgroup$ – LeoS Nov 20 at 13:10
  • $\begingroup$ Velocity after TLI for Apollo 11 was 10844.5 m/s, which is less than Earth escape velocity: "002:51:21 Aldrin: Roger, Houston. Apollo 11. We're reading a VI of 35579 and the EMS was plus 3.3. Over." Quote from here history.nasa.gov/afj/ap11fj/02earth-orbit-tli.html#0024416 Aldrin is reading their velocity in feet per second. Fairings would be having this velocity as they were jettisoned before the S-IVB maneuver. $\endgroup$ – LeoS Nov 20 at 13:11

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