Up Close with the Orion Crew Survival System
As Artemis II circles the moon, the neon orange suits worn by the crew of have quickly become an iconic part of the mission. These Orion Crew Survival System, or OCSS (pronounced “ox”) suits, as they’re known, are an integral part of keeping the crew of Orion safe during all phases of flight. Space Scout got the chance to get up close and personal with a low-fidelity training example of the OCSS, known as a faux-OCSS while at the Johnson Space Center in Houston, and discuss the suit’s capabilities with OCSS engineers Heidi Clark and Katherine Plaza.
The suit is what is known as an IVA suit, or a suit designed for intra-vehicular activity. The primary function of such a suit is to keep crew members safe during high risk flight phases, such as launch and entry. In the event of a catastrophic depressurization of the Orion spacecraft at any point in flight, the OCSS would protect the crew until they could safely splash down. While any depressurization would be a severe malfunction of the spacecraft, there are higher risk phases of flight where such events are more likely. In a nominal mission, IVA suits like the OCSS are worn during these high-risk phases as a precaution. However, the possibility for depressurization always exists. IVA suits play an important role in protecting astronauts in all phases of flight, as a crew may have to rapidly don them at any point in a mission during an off-nominal situation to stay safe.
The OCSS, however, has a much more challenging job in this respect compared to its low-earth-orbit bound companions. Since the OCSS is intended for deep space, it needs to be able to be worn continuously for up to six days. While an emergency return can typically be made from Low Earth Orbit in a matter of hours, returning from the Moon takes much longer. Should an Orion capsule experience some catastrophic event resulting in a cabin depressurization while at the moon, it could take up to six days to return to earth. The OCSS needs to keep its wearer alive while suited for that entire duration. Doing so requires a number of unique design accommodations to support such a long-endurance mission.
The first unique element of the OCSS is its iconic orange shade. The bright orange Nomex outer layer was chosen specifically for maximum contrast against a blue ocean, providing for maximum visibility for the crew in the event of an off-nominal splashdown. On the suit’s torso are two metallic ports, one red and one blue. These ports allow the suit to interface with Orion’s Environmental Control and Life Support System, or ECLSS, which allows the Orion spacecraft to provide the air needed for breathing. The blue port provides flow to the suit, and the red is the return to the Orion. These ports negate the need for the backpack life support system typically found on suits for spacewalking, known as EVA suits.
When the astronauts are walking out to the rocket, their orange suits are complemented by a number of blue pouches attached to the lower legs and under each arm. The pouches on the legs are emergency oxygen bottles – these bottles provide about a ten minutes’ supply of pure oxygen for any emergency situations that may arise at the pad that render the air unbreathable. The pouches under the arms are life preservers: in the event of an emergency while splashed down, the crew may need to exit the Orion spacecraft, and these life preservers will expand and provide buoyancy while the astronauts make their way to a life raft.
The suit has several layers to keep the astronauts safe. The innermost layer is the waste management system, which handles the wearer’s bathroom needs while occupied. Above that is the liquid cooling garment, which surrounds the astronaut in small tubes through which cool water is pumped, keeping the astronauts comfortable. The temperature can be adjusted by changing the amount of water flowing through the garment, which is accomplished by the small green knob on the astronaut’s right leg. Beyond the cooling garment is the pressure layer, which contains the atmosphere inside the suit. The outermost layer is the orange fire-resistant Nomex layer.
The configuration of the suit differs slightly between the nominal and off-nominal cases. In the nominal situation on Artemis II, the crew will wear the OCSS during reentry. When worn for reentry, the suit includes an “orthostatic intolerance garment.” OCSS engineer Heidi Clark told Space Scout that the garment is worn during a nominal reentry to provide compression to the lower legs and torso. “Spending a long duration in space, [the crew] actually lose some of their blood volume, so coming back into Earth’s gravity, they can experience symptoms like dizziness and nausea, similar to if you’ve ever stood up too quickly” she told us. “That’s what we call orthostatic intolerance – so in those situations, we want that compressive garment to keep their existing blood flow in the upper part of their body.”
The orthostatic intolerance garment would not be worn during the off-nominal, long-duration case. The lack of the orthostatic intolerance garment is one of a number of differences in the design of the suit for the off nominal situation. Another major difference is the waste collection system – in the nominal case, the crew would wear the nominal waste management system, which engineer Katherine Plaza described as “essentially [an] adult pull-up.” However, in the off-nominal case, the crew would wear the off-nominal waste management system, a unique system designed to accommodate waste for up to the full six day off-nominal mission duration. The system handles liquid waste by flowing it through a port in the suit’s thigh into Orion’s plumbing, from which it is vented overboard through the secondary wastewater vent (notably, not the vent which has experienced issues during the Artemis II mission). Solid waste is managed internally within the suit.
In an emergency cabin depressurization scenario, speed would be of the essence in donning the suits. To facilitate that speed, the suits are designed to be self-donned in an emergency scenario. While the nominal case involves astronauts buddying up to don the suits one at a time, all four astronauts can self-don their suits in parallel should an emergency arise. The suit’s zipper can be equipped with a self-donning lanyard to assist the astronauts in zipping themselves up in much the same way Mission Specialist and surfer Christina Koch has likely done countless times when donning a traditional earthbound wetsuit. A test of the astronauts’ ability to rapidly don the OCSS occurred during flight day 5 of the Artemis II mission, when Mission Commander Reid Wiseman and Pilot Victor Glover put on their suits in under 15 minutes. While they did not entirely self-don the suits, this test demonstrated an important capability for crew safety.
The suit’s helmet (Plaza and Clark assured reporters that “helmet” is the technical term) also has special design considerations to facilitate the off-nominal long duration case. The helmet is equipped with a small port that an astronaut can insert a straw through. This port will serve as the access point for all the astronaut’s hydration, nutrition, and medication needs. In that off-nominal case, astronauts would drink water essentially as normal, but would see their meals replaced with a kind of protein shake that can be consumed through the port in the helmet. They also have a unique tool that can interface with the helmet port to allow medication to be taken in pill form – the astronauts can essentially use a straw-like implement to scoop pills out of a container and draw into the helmet. This capability is essential in keeping astronauts healthy during what would be a uniquely stressful situation.
All told, the OCSS suit is a unique system among IVA suits. With the Artemis program calling for more ambitious missions than ever before, the OCSS requires a level of capability never before demanded in human spaceflight. More than just eye-catching, OCSS is an essential part of keeping the crew of Artemis II and future Artemis missions safe as they push the limits of exploration farther than ever before.
