Sol 87 EGA Boot Failure

8/23/2008

D. Hamara

Sol 87 EGA Boot Failure

•2008/08/23 01:45:11.014 –TEGA Boots

•TEGA preheats for 35 minutes, collecting engineering data

•2008/08/23 02:21:01.062 –Command EGA On

•2008/08/23 02:21:04.932 –EGA Power On

•2008/08/23 02:21:24.932 –Expected First EGA Message

•2008/08/23 02:22:06.972 –MSG_EGA_NO_HEART: Heartbeat Timer Expires

•2008/08/23 02:22:58.204 –Block times out waiting for GV_TEGA_EGA_DONE

Sol 87 EGA Boot Failure

•Longer EGA ON duration in cruise run due to GV check being later in the block.

•7mA current difference is reasonable for starting 20°C colder

•This appears to be a repeat of the EGA boot failure we experienced in cruise

•Bakeout#9, 12/31/2007, ISA # Z-92017

Sol 87 EGA Boot Failure

Debug Path

Turn EGA On Again

•Set EGA to boot from EEPROM side B

•Turn EGA On Again

•Set EGA to boot from PROM

•Turn EGA On Again

Turn EGA On, side A

Degraded operation from PROM

•EGA is dead

•Not sure if there is anything else we can do

Sol 87 EGA Boot Failure

Moving Forward

•Rerun Sol 87 blocks on Sol 89

–First debug step is to turn the EGA on again

–If it boots, we will close the oven and run the low temp ramp

•we have only lost 2 sols

–If it doesn’t boot, we will run for 1 minute and safe

•Current is normal, so no indications we would do any damage to EGA

•We will begin debugging operations on sol 91

•Success-Based Planning

–We will uplink the mid-temp ramp for Sol 90

•If we don’t boot on Sol 89, we will be safedand will not run mid-temp