[USMA:33411] RE: metric usage in launch vehicle

[Hillger, Don]

I now remember that Metric Today published an article about rockets a couple years ago.  So I looked back to find the article in the March/April 2003 issue.  According to Spaceflight Now, the source of the information, the rockets are actually being built to metric dimensions, so my skepticism was unwarranted.   NEW DELTA 4 ROCKETS MEASURED IN SI UNITS The new, more powerful sets of Delta 4 rockets, built by Boeing, were built to metric system dimensions, according to an article on the Spaceflight Now Web site of 12 November 2002. Justin Ray, the writer of the article, states that these Delta 4 rockets provide an earth-shaking power to launch much larger cargoes than possible in the past. The rockets are used to launch commercial, military, and civilian spacecraft into space from Cape Canaveral, Florida and from Vandenberg Air Force Base in California.   To manufacture these powerful rockets, Boeing has built a huge plant in Decatur, Alabama, which is considered the largest and most state-of-the-art facility of its kind in the world. Justin writes: “There are 5 versions of the Delta 4 launcher, each incrementally increasing the size or weight of the payload to be placed in space.” More information on these rockets may be obtained by accessing Web site www.space fightnow.com/delta/delta4/02111 2delta4/. MT   Also, not sure if I ever posted this, but on a tour of Ball Aerospace in Boulder CO a few months ago, I asked a question of the tour guide about metric usage, and was told that they built metric-dimensioned satellites if asked (probably in foreign and military contracts, my added comment).  So the space industry is far more metricated than the aircraft industry!   Don   From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Terry Simpson Sent: Thursday, 2005 June 30 05:50 To: U.S. Metric Association Subject: [USMA:33409] RE: metric usage in launch vehicle   >This does not necessarily mean that the rocket was designed in metric units, >although that might be true (?), only that it’s marketed metrically, I suspect for the non-U.S. market.   Delta IV marketing information: http://www.boeing.com/defense-space/space/delta/backgrounders/delta_4_backgrounder.htm   Delta IV specification information has metric dominant (pdf): http://www.boeing.com/defense-space/space/delta/product_card/pc_d4_tech_print.pdf http://www.boeing.com/defense-space/space/delta/docs/Delta_IV_PPG_Update_Nov_2002_change_pages.pdf     Boeing 737 publications now give meters rather than feet for runway lengths. ************************************************** http://www.b737.org.uk/bfos.htm Question “Performance information comes in different units for different 737 variants, shouldn’t the units be standardized since many pilots fly numerous variants in daily operations? <ANSWER> Boeing has traditionally customized performance data to accommodate individual airline operators' units preferences. In general, data in LB and KG is available for almost all airplane-engine combinations. In the distant past, runway lengths from common airport information sources and incidentally, the AFM, were published in FT, which is why metric unit (KG-C) performance data was presented with English unit distances (i.e. FT) in our older books. As more sources of runway data became available in meters, we received increasing operator requests for runway distances to be published in meters. Beginning with the 777, the digital AFM (AFM-DPI) also provided the option to calculate runway distances in meters, and so we began publishing metric-units books in meters rather than feet. This policy was carried over on the newer 737 "next generation" models, which created an inconsistency between runway length units for mixed fleet operators of 737 "classic" and 737 "next generation" airplanes. For mixed fleet operators of airplanes purchased or leased new from Boeing, we will convert the distance units as desired by the operator at no charge. However, under the current economic environment, we cannot guarantee a firm schedule on when this can be completed.” **************************************************