Editing Transit (satellite) (section)

===Satellites===
The satellites (known as '''''OSCAR''''' or '''''NOVA''''' satellites) used in the system were placed in [[low Earth orbit|low]] [[polar orbit]]s, at an altitude of about {{convert|600|nmi|mi km}}, with an orbital period of about 106 minutes. A ''constellation'' of five satellites was required to provide reasonable global coverage. While the system was operational, at least ten satellites &ndash; one spare for each satellite in the basic constellation &ndash; were usually kept in orbit. Note that these ''OSCAR'' satellites were not the same as the [[OSCAR]] series of satellites that were devoted to use by [[amateur radio]] operators to use in [[satellite communications]].    

The orbits of the Transit satellites were chosen to cover the entire Earth; they crossed over the poles and were spread out at the equator. Since only one satellite was usually visible at any given time, fixes could be made only when one of the satellites was above the horizon. At the equator this delay between fixes was several hours; at mid-latitudes the delay decreased to an hour or two. For its intended role as an updating system for [[SLBM]] launch, Transit sufficed, since submarines took periodic fixes to reset their [[inertial guidance system]], but Transit lacked the ability to provide high-speed, real-time position measurements.

With later improvements, the system provided single-pass accuracy of roughly {{convert|200|m|ft}}, and also provided [[Time transfer|time synchronization]] to roughly 50 microseconds. Transit satellites also broadcast encrypted messages, although this was a secondary function.{{citation needed|date=April 2018}}

The Transit satellites used arrays of [[magnetic-core memory]] as mass data storage up to 32 kilobytes.<ref>
Ronald K. Burek.
[http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.132.2475&rep=rep1&type=pdf "The NEAR Solid-State Data Recorders"].
1998.
</ref>