Report on the Utilization of EVA Suit S-1 during Crew 48 Mission

Background:

The utilization of EVA suit S-1 was scheduled for EVA # 12 during an emergency rescue operation simulation. The EVA crew consisted of G. Gröemer, A. Soucek, M. Spiss and Ch. Hutsteiner. EVA started at 1450 and ended at 1650. All operations were performed in the vicinity of the Hab.

Suit-Donning of S-1:

The suit-donning was performed with the MDRS manual at hand. Crew 48 had not used the S-1 suit before and therefore relied on the short manual, which proofed to be helpful (especially the images showing donning procedure). The donning itself went fairly well, apart from short time delays due to familiarisation of the EVA crew with the new suit. The trouser-legs of S-1 were slightly shorter than those of the old suits, enough for reaching the shoes but not enough for covering them completely (comfortably) down to the ankle (at a body size of 184cm). Hence, the gaiters were useful to provide for a complete coverage / protection of the lower leg. At a closer look it turned out that the length of both trouser-legs had been extended already by attaching a 20cm piece of fabric, which allows for more flexibility in adjusting the actual length, as it is attached to the trouser with Velcro. This Velcro is a bit unpleasant when it has direct contact with the skin (or through a thin layer like a trouser, flight suit, long underwear) and therefore could graze the skin during longer EVAs. The problem was overcome by using long, thick socks and paying attention to slip the flight suit trouser-legs (second layer) in the shoes and fix them there.

Fixing the jacket and trouser with the white tube required several tries and was not fully satisfactory. The cord to attached the tube / ring firmly did not easily pass through the foreseen holes, as its ends were worn out (hence the diameters did not fully match, requiring some care and patience). Thanks to M. Spiss, who works at the Austrian Mountain Rescue Service and who is used to working with ropes and cords, this problem could be overcome after some minutes of trying.

Before mounting the PLSS, the crew had some doubts whether the tube just above the hip would cause any problems once the PLSS was on the back, as it passed between back and PLSS, being a potential dent. Surprisingly, nothing was felt by the test subject after finishing suit donning and throughout the EVA.

Use During EVA:

During EVA, the personal sensation of the crew member wearing S-1 was not substantially different compared to the other EVA suits worn previously. One reason is that the body parts being used most during EVA, being most sensitive and having close contact with parts of the suit, are the head, the hands and the feet - and all three were covered by suit parts used beforehand: the MDRS helmets, the AustroMars gloves and the normal MDRS EVA shoes (white shoes). This fact might have contributed to a similar sensation during EVA. Flexibility inside and with the suit was good.

Personal Opinion:

In my opinion, S-1 is a good and comfortable system. I have not discovered the major advantage this system has compared to the old one. One drawback (which might be due to the "first use" problem) is the slightly increased complexity during suit-donning, attaching and fixing the tube, whereas the old suit is easier to put on and close. This is admittedly just a minor detail, but nevertheless an observation I find worth telling. Also, the Velcro-solution to extend the length of the trouser-legs is not optimal. I don't know whether this was made on purpose (to be more flexible in terms of trouser-leg length) or not, but in any case it is not very stable. The thumb loop attached to the sleeves is nice in principle, but if you need to stretch your arm / hand (e.g. during glove donning) it hinders the movement. I did not use these loops in the end. All in all, I regard S-1 as comfortable suit with minor weak points. I doubt, however, that it makes the suit-donning procedure easier.