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OMS TESTS (DTO 242) Three DTO’s: a simulated engine failure, an engine restart, and an interconnect test. 
-01: the simulated engine failure will be performed on the OMS-3 burn. Test is primarily for prop tests (seeing prop system transfer transients when performing mid-burn xfeed). It’s not to verify guidance.... PEG4 is not required, & its not required to trim out the out-of-plane residuals. 
NOTE: (1) Stopping an engine mid-burn (e.g. 6 seconds into burn, as originally planned) shuts off an engine without the purge => better from the point (as well as guidance) to target for a 2 engine burn, but never take 2nd engine to ARM/PRESS.
(2) If the cross-axis component becomes > 6 ft/sec, the burn won’t terminate

-02: the engine restart is scheduled as “OMS-5” - there’s a move to make this the OMS-4 burn (may not be a great idea). Consists of 2 burns - 1st is 10 seconds, only to settle the propellant (10 seconds isn’t critical); 6 minute wait is the minimum restart time; 15 seconds for the 2nd burn is chosen only so that OMS gauging will be updated (it waits 15 seconds into a burn before it looks at actual probe)
NOTE: current plan - schedule this right after -03, the interconnect test, so that (1) OMS ganging is updated (2) know “quickly” whether He was ingested into tank during (-03) [determined from gauging] (3)this is a pre-requisite to doing a real “cold re-start” on STS-3  (4) this burn will be performed in OPS2