Patrick, Yes, the PDF file (on the Ares V) by Phil Sumrall needs many corrections of units before it it fit for reprinting!!!
For example, for the J-2X Engine Specification, Specific Impulse (Isp) has the same unit as Exhaust Velocity, in meters per second (in proper SI). That is; Force times time divided by mass reduces to a velocity, in m/s. The present error is writing lbf times seconds divided by lbm; equating and canceling lbf and lbm, and claiming that Isp is expressed in seconds. Mass and Force are distinctly different quantities. Weight (lbf) is not relevant in the definition of Specific Impulse!!! Eugene Mechtly ________________________________________ From: owner-u...@colostate.edu [owner-u...@colostate.edu] on behalf of Patrick Moore [pmo...@asnt.org] Sent: Thursday, May 02, 2013 11:17 AM To: U.S. Metric Association Subject: [USMA:52733] NASA mT and K Have a look at the first page of this NASA publication, a free download: <http://www.nasa.gov/pdf/396782main_mf18_sumrall.pdf>. I was given that picture of four launch vehicles, so I then surfed to its online PDF to clarify the symbols. I could guess that mT did not mean millitesla. I would not have guessed metric ton. The NASA editor apparently knew that k means x1000, but look at the goofy way a cap K is appended to numerals. This image's technical information needs a lot of repair before I can can reprint it. [End]
