On Tue, 9 Dec 2014 15:56:05 -0800 (PST), wrote:

Because goals are defined to cover a range. There are minimum goals,
and there are extended goals.

So this almost $2 billion dollar project (just barely) accomplished minimum goals.

Not at all. Philae was not a $2 billion dollar project. Philae was
like a single instrument on Rosetta. Rosetta has exceeded its goals,
and the Philae probe exceeded its minimum goals (indeed, had Philae
failed completely Rosetta would still be considered highly successful,
as Philae's success was not seen as a requirement).

Not that it matters. If you achieve the minimum goals, the mission is
a success.