On Tue, 30 Oct 2012 15:51:22 -0400, Jeff Findley
wrote:


Currently, the U.S. Air Force indicates that the Boeing Delta IV
Heavy falls slightly short of meeting the performance needed for
an NRO mission scheduled to launch before 2010. The Air Force is
confident that modifications to the Delta IV will provide
sufficient lift. The cost of these modifications to attain the
required performance improvement is estimated to be on the order
of $200 million.

Note that this was the RS-68A engine upgrade which debuted on the
Delta IV launch in June. RS-68A is beneficial across the Delta IV line
because the extra performance allows the boosters to be built to a
common spec instead of each one being one-off, which should lower
costs.

$200 million in development money isn't enough for a *huge* increase in
lift capacity, which is what SLS would provide.

NASA is paying for SLS development regardless (the Senate is seeing to
that whether we like it or not) so there should be no R&D cost to DoD.
They'll have to pay NASA to fly something on it and whatever payload
handling modifications are necessary, but that's lost in the noise of
space launch budgets.

Also, the heavy launch needs of NSS weren't huge. From what I gathered,
when the paper was written in 2006, there were 10 payloads requiring
"heavy lift" (Delta IV Heavy) through the year 2020, which is less than
one per year.

Of course, any hypothetical military SLS flight would be deep in the
2020s (NASA has already said the first two SLS flights will be 2017
and 2021, on NASA missions) so this report going only to 2020 is
pretty much irrelevant.

Brian