Chapter 1, Problem 95FP

As mentioned on page 13, the MCO was lost because of a mix-up in the units used to calculate the force needed to correct its trajectory. Ground-based computers generated the forte correction file. On September 29, 1999, it was discovered that the fortes reported by the ground-based use in MCOnavigation software were by a factor of 4.45. The erroneous trajectory brought MCO 56 km above thesurface of Mars: the correct trajectory would have brought the MCO approximately 250 km above the surface. At 250 km, the NCO would have successfully entered the desired elliptic orbit. The data contained in the force correction files were delivered in lb-sec instead of the required Sl units of newton-sec for the MCO navigation software. The newton is the SI unit of force is described in Appendix B. The British Engineering (gravitational) system uses a pound (b) as a unit of force and ft / s² as a unit of acceleration. In turn. the pound is defined as the of on unit of mass at a caused by gravity 32.174ft / s². The unit of mass this is the slug, which is 14.59 kg. Thus,
   $\text{BE unit of force = 1 pound = }\left(\text{slug}\right)\left({\text{ft / s}}^{\text{2}}\right)$

Use thisinformation to confirm that
   $\text{BE unit of force = 4}\text{.45×SI unit of force}$

   $\text{1 pound = 4}\text{.45 newton}$