FMARS-15 Engineering report 25-07-2023

By Caleb Pool

The day began with a 2 crew EVA of Andrew and Andy donning suit simulators with Caleb as bear watch. It was found that the EVA suits and backpacks were in mediocre shape and required some modification which delayed the departure of the EVA to near noon. The strap buckles and adjusters had not been installed properly, severely limiting their usefulness and range. Mismatching of air vent diameter will require determining helmet/backpack compatibility at this facility. The helmet latching mechanisms, which get a lot of use, require shaking and excessive force to latch, and in some cases do not latch. A jumble of trickle chargers for the backpack batteries was found and sorted. It was noted that some of the wires had been cut for some reason as yet known. Two out of three chargers are inoperative and are on the Engineering bench for review. Communication during the EVA was accomplished through helmet-to-helmet communication primarily, with some comm through radio between the EVA team and the hab. The hab was heard loud and clear by the three member EVA team, and it was difficult for the hab to hear us through the helmets. The in-helmet earpieces and microphones were also in a tangled pile of wires. All but one mic/earpiece unit have failed and are on the Engineering bench for review. 

Genny, the generator we have been primarily using has leaked three times in the same location after two repairs. The failure mode is a splitting of the fuel line 5 cm “upstream” from the fuel intake. The tube is not the OEM fuel tube and was not installed by the FMARS15 crew. Due to the repeated failure, it is suspected that the replacement tube is weathered and too stiff to withstand the continued vibration of operation. There is a length of tube inside the hab that might not be as stiff that we will attempt to use for repair. In the interim, we are using Bambi and Rachel.

We have been running the generators most of the waking day since we started sim, we have not yet exhausted 1 of 2 diesel barrels of fuel, same goes for the gasoline. It has been noted that a mixture of 1/3 old diesel to 2/3 new diesel will run, but not as smoothly as fresh fuel. This is an emergency option as it will also likely clog the engine.

By end of day, the suit with crotch ripped open (labeled #2) had all major patches and sewing repairs complete. As with the other suits, more minor repairs remain, but Suit #2 is now in adequate condition for future EVAs. Only 2 usable sewing machine needles remain, and are being used as carefully as possible.