SPECIAL relativity deals with speeds approaching C
GENERAL relativity is applicable at any speed.
well for earthbound relativistic endeavors i.e electrickery or lasers; SR is important
For other activities since the system is so comparatively small against a massive and just too obvious reference [Earth] that use of GR reference frames would not increase the number of signifigant figures to be worth it, as stated...not an expert on it at all, but...you could try
