Components | Suit Characteristics | Testing | Publications


Hard Upper Torso | Soft Goods | Air System | Backpack | Liquid Cooling Garment

Hard Upper Torso (HUT)

The MX-2 HUT is the HUT constructed for the MX-1 with only slightly modified shoulder interfaces and a completely new lower torso assembly (LTA) interface. The hard upper torso (HUT) of the suit was designed to be the central body of the entire suit just like in the EMU or Orlan space suits. As opposed to the waist-entry configuration of the EMU, a rear entry configuration was adopted for the Orlan suit. A rear-entry hatch was implemented along with planar shoulder bearings, allowing both for simple don/doff procedure and maximum control over shoulder/arm flexibility and range.

The HUT was constructed using an epoxy resin fiberglass composite. Aluminum blocks were incoporated between layers to become integral hard points for mounting a variety of attachments to the HUT. Finally, the arm bearings, helmet ring, and LTA interface were attached using both high-strength Hysol epoxy and stainless steel fasteners. [top]

Soft Goods
The two arm segments and lower torso assembly (LTA) are collectively known  as the soft goods. With the increased operational pressure of the MX-2, the neoprene soft goods were replaced with a layout much like the Orlan and Shuttle EMU suit, comprised of a pressure bladder and a separate restraint layer. Flat pattern mobility joints are designed into the fabric of both the restraint layer and the pressure bladder to facilitate range of motion requirements.

An additional layer was also added to the soft goods for the MX-2 design. This outer layer is similar to the thermal/micrometeoroid garment on the Shuttle EMU in that it provides an outer covering to protect the inner layers. This layer also acts as an integral ballast system.

The MX-2 arm assemblies now end with a quick disconnect which mates with the standard Shuttle EMU wrist ring disconnect.

The MX-2 boots are industrial boots that have been integrated into the restraint layer. The soles of these boots have been fitted with the standard aluminum heel connector used on EMU boots to interface with the standard NASA foot restraints used on orbit. [top]


Air System
The MX-series air system is an open-loop system which nominally feeds supply air to the suit from the surface, and eventually returns exhaust back to the surface, thus eliminating any bubbles during operation. Surface air is supplied from a human-rated air compressor and filtration system. After passing through a sensor suite on the surface, the air passes through an umbilical and into the monitoring system in the backpack. From here the air is forced to circulate around the interior of the suit via air channels before being returned to the surface for venting.

Dual redundant air supplies are also designed into the air system in case of a surface air failure. The first redundant air supply is controlled by a demand regulator set to supply air should the supply pressure drop below a set value. The second redundant supply is attached to a scuba regulator located within the helmet. In the unlikely event of a failure in all three suit supplies, the helmet ring can be removed by a safety diver who can then provide air for an emergency ascent. [top]

The backpack was designed to have the same external envelope as the Shuttle EMU. A pressurized aluminum box that contains all air system, cooling water, and audio communication components constitutes the bulk if the backpack volume. Spare room is also allocated for future electronics associated with bio-instrumentation or human factors experiments. Dual redundant air supplies sit above this pressurized box and fill out the rest of the backpack volume. [top]

Liquid Cooling Garment (LCG)
To prevent the test subject from overheating during a simulation, a liquid cooling garment (LCG) was developed. Much like the same garments found in NASA’s EMU and the Russian Orlan suit, the MX-1 LCG is a tight fitting garment laced with tubing. The garment itself is made from an inexpensive lycra dive skin with 1/8th" tubing spaced 1" apart. Chilled water is pumped through from the surface and then released through a tap in the backpack to the ambient water. This tap can alternatively be fitted with a hose for use out of the tank in a laboratory environment.

Currently, the MX-1 LCG is being compared to a less expensive and simpler LCG design for MX-2. Results from these studies will determine which LCG is used in the MX-2. [top]

Questions? Comments? Contact Shane Jacobs