The 'Gale crater' search of NASA doc's gives a count of 18, but I see your reference to the NTRS reduction in the total for that section of the library.
Another White House adjustment with less technical information.
http://www.infodocket.com/2013/05/09/more-data-please-president-obama-signs-open-data-executive-order-and-releases-open-data-policy/
California follows, but UC and others will be excepted.
http://lj.libraryjournal.com/2013/05/oa/california-open-access-bill-clears-committee/
Will the tech information ever be relisted? Copies apparently are present for much of the missing or removed totals. The 'cloud' search keyword process is useful for indexed materials.