How a long-gone Apollo rocket returned to Earth – Astronomy Magazine

Spacecraft sleuthing

If J002E3 was, in fact, a spent S-IVB, the next question researchers asked was, Which one was it?

Early test flights with the S-IVB all ended with the third stage splashing into the ocean or disintegrating during reentry. This was also true for the S-IVBs from the Apollo 4, 5, 6, and 7 missions and the Saturn IB flights that carried astronauts to Skylab. The Apollo lunar landing missions numbered 13 through 17 all intentionally crashed their S-IVBs onto the lunar surface to create artificial moonquakes that could be measured by seismic instruments placed by prior landings. But it was the middle Apollo missions (numbered 8 through 12), however, that all intentionally placed their S-IVBs into heliocentric orbits. Any of these missions could have given rise to J002E3.

Further analysis of J002E3 suggested it first left Earth orbit in 1969, narrowing things down to Apollo 9 through 12 (Apollo 8 orbited the Moon in December 1968).

This animation, which has the Sun to the left, shows J002E3 being captured into a chaotic orbit around the Earth.

Paul Chodas and Ron Baalke

Many people find the notion of discovering an intact piece of Apollo-era hardware appealing, and these feelings are amplified by the large size of the Apollo S-IVB. Flown Apollo hardware will always be significant, says Teitel. We've been to the Moon nine times and most of the hardware that enabled those missions was destroyed the Saturn V stages crashed into the ocean or were smashed into the Moon, most of the lunar module ascent stages were smashed into the Moon, and the service modules didn't return. That leaves nine command modules, all of which are on display in museums. Flown hardware has an allure simulators and non-flown items just don't have.

In the case of J002E3, the hardware is still flying. Shortly after its discovery, the object left Earth orbit in 2003, returning to a heliocentric orbit. But researchers suggest that it may yet be recaptured by our planet, with the first opportunity for recapture coming up in the mid-2040s.

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How a long-gone Apollo rocket returned to Earth - Astronomy Magazine