Herb Schaltegger wrote:

... my point was that a crew of three living, breathing,
excreting and metabolizing human beings is not functionally equivalent
to a crew of one such plus a bunch of lead shot bags.

For a fifteen-minute suborbital flight, I don't think the difference in
function is relevant. For the X-prize requirements, the difference is
*explicitly* not relevant.

Read it already and again, it seems to me that in my experience with
reading and interpreting "requirements" the part I posted corresponds to
a Tier 1 or Level 1 requirement, while the part you quoted corresponds
to a Tier 2 or 3 requirement; had the X-Prize been trying to come up
with workable designs for an ordinary revenue customer, someone surely
would have written up a RID (Review Item Discrepancy) and asked why the
Tier 2 requirement was written to weasel out of the Tier 1.

The informal description of the X-prize you posted is not "requirements"
at all. It's an after-the-fact *summary* of the requirements, written for
people who don't care to slog through the relatively long official rules.

Your having read the summary first doesn't mean you should consider the
rules to be derived from the summary.