1112-CommandersReport

Commander Report

11/12/2014

Digby Tarvin

Today we really got to know our space suits by undertaking a four person walking

endurance EVA. The plan was to walk a circuit consisting of a three waypoints.

The first was 'North Hills' 1.16km North of the hab. The second was 'breakdown',

the site of our ATV problems East of the first way point, and the third was

'brain rock', South of way point 2 and about 1.34km east of the hab.

Our plan was to leave the hab at 9:30, and keep walking the circuit until just

before sunset, to get an idea of what distances are feasible in the suits. We

equipped ourselves with water bottles that would allow rehydration without

removing the helmet, and even a cereal bar that could be manoeuvred to our

mouths at lunch time.

We entered the airlock at 9:50am, having (as always) taken longer than expected

to get all the suits adjusted satisfactorily. We made our way to our first

waypoint, arriving at 10:30, and spent approximately 15 minutes taking samples.

However we were not able to communicate with the hab from this location, and

Christiane had to climb to a nearby ridge before we could report in. This was

achieved at 11:17, allowing us to continue to our second waypoint. At 11:59 the

hab called the EVA asking for our position, and we had to stop for a while to

respond. Twenty minutes later we arrived at our second waypoint and commenced

the sampling and permafrost experiment practice.

At 12:44 we second waypoint, and headed for brain rock. At 1:35 we reached a

point 200m from brain rock, but as it was a mountainous feature, it was another

thirty minutes before we located the waypoint position on the side furthest from

the hab. We left brain rock at 14:37 and headed back in the direction of the

hab, arriving at 15:08. We took the opportunity to have the hab place radio in

the airlock so that we could swap one that I had been having trouble

transmitting with. At 15:25 I decide that there was just time to proceed back to

waypoint 1, and then directly back to the hab to arrive before nightfall, so we

departed the hab again. We reached reached North Hills again and return to the

hab arriving at the airlock at 16:39.

So what did we learn? Fitness is important. Not just for the usual reasons that

apply when walking normally, but even more so in a space suit. Fitness effects

how soon you start to breath heavily, and when I started to breath heavily, my

helmet started to mist up very quickly. Especially in the cold morning air. The

other problem is that when physical exertion causes heavy breathing, it is

because more oxygen is needed, and it is much more difficult to get ones breath

back in the restricted environment of a space helmet. The fans in the backpack

only deliver so much air. And as the day gets on and the batteries lose power,

the air flow decreases significantly.

The best idea seems to be to walk at a leisurely pace so as not to become too

tired. When doing that, the spacesuit is not too much of an impediment. I did

have trouble with my radio transmissions in the bulky gloves. I think there was

a problem with the first radio, but even with the second which seemed to work, I

frequently failed to press the transmit key effectively. This may be a problem

that can be avoided with the VOX option, which I have not tested yet.

In the end, we had covered about 12km in six and a half hours, stopping at three

sampling points for up to about half an hour each. I expect the younger and

fitter members of the EVA team could have gotten further than I did, but hiking

in a space suit is definitely harder.