Some degree of effort is required to _not_ use et (Ephemeris Time) and, by practice, a spacecraft clock adjustment (SCLK) would be initially loaded. The develo

Some degree of effort is required to _not_ use et (Ephemeris Time) and, by practice, a spacecraft clock adjustment (SCLK) would be initially loaded. The developers would have gone through this routine (initially load SCLK, use Ephemeris Time) literally _thousands_ of times in their coding, developing ... preparing, making .... careers. It's the SPICE baby. so .... WTF?