4 ms·

Are you sure that e.g. Zond-7 - https://en.wikipedia.org/wiki/Zond_7 https://en.wikipedia.org/wiki/Zond_7 - wasn't doing it earlier?

• eesmith 4y ago
  It may be missing a qualification? https://en.wikipedia.org/wiki/Non-ballistic_atmospheric_entry https://en.wikipedia.org/wiki/Non-ballistic_atmospheric_entr... > The Apollo Command Module used what is essentially a one-skip reentry (or partial skip), as did the Soviet Zond and Chinese Chang'e 5-T1. More complex multi-skip reentry is proposed for newer vehicles like the Orion spacecraft.
  • avmich 4y ago
    Doesn't look like what Orion actually performed includes multi-skip reentry. Maybe it's proposed for some future flights, but the central point of the article isn't confirmed.
    • eesmith 4y ago
      It also looks like Apollo defined skip as having <0.2 g, and by that definition, the Apollo re-entries never did a skip. According to https://space.stackexchange.com/questions/49546/did-the-apollo-command-module-really-skip-within-or-off-of-the-atmosphere-as https://space.stackexchange.com/questions/49546/did-the-apol... . That links to a thesis at https://dr.lib.iastate.edu/server/api/core/bitstreams/a620f652-d273-42fb-94d1-c107a5492587/content https://dr.lib.iastate.edu/server/api/core/bitstreams/a620f6... which says that with <0.2 g the craft is within the Kepler phase, that is, it's ballistic. And http://www.astronautix.com/d/details810.html http://www.astronautix.com/d/details810.html says "The [Zond] 7K-L1 then made the first successful double skip trajectory, dipping into the earth's atmosphere over Antarctica, slowing from 11 km/sec to suborbital velocity, then skipping back out into space before making a final re-entry onto Soviet territory." Meaning my thought about single- vs. multiple- skip was wrong. I don't know.