Report paints troubling picture for NASA’s spacesuit program
NASA’s active spacesuit inventory is based on a model that is more than 40 years old, and if a recent report from the NASA Office of Inspector General (OIG) is accurate, the much-needed successor to the venerable design may still be years away, potentially placing astronauts at greater risk and limiting deep space operations.
’70s design still in use today
The spacesuit design currently used on the International Space Station (ISS) is the result of iterative upgrades of a spacesuit whose development began in 1974. Originally meant for use on the Space Shuttle, the current spacesuits – also known as an Extravehicular Mobility Unit (EMU) – follow a lineage of EMUs dating back to the Gemini program that allowed astronauts to exit their spacecraft and work in space.
More than simply a garment to maintain an astronaut’s body in a pressurized environment, an EMU is more akin to a personal spaceship than a garment. Indeed, the spacesuit must handle temperature swings of several hundred degrees, protect the astronaut from debris strikes, and even provide emergency propulsion in the event the astronaut gets separated from the spacecraft or station.
However, NASA’s inventory of these EMUs isn’t as robust as one might think.
Though the spacesuits used throughout the Space Shuttle and ISS programs have largely served NASA and its astronauts well, the spacesuits have been victim to several systemic malfunctions.
In the 204 spacewalks covered in the report, it was noted that 27 “significant incidents” had occurred on those extravehicular activities (EVAs), five of which were serious enough to warrant cutting short the walk and returning to the craft.
Historically, slightly more than 15 percent of spacewalks since 1983 have encountered a “significant incident”, with the 43 EVAs since 2010 resulting in a greater than 1-in-5 (20.93 percent) occurrence.
While there is no consensus across the agency as a whole, Johnson Space Center’s Office of Safety and Mission Assurance, Flight Safety Office, defines a “significant incident” as:
[…] an event that resulted in or could have resulted in loss of life, resulted in the injury or temporary incapacitation of an astronaut or otherwise compromised the astronaut’s ability to perform critical tasks, resulted in the potential for critical or catastrophic damage to spacecraft, caused a spacewalk to be aborted or terminated early, or has some other unique significance.
Luckily, none resulted in the death or permanent injury of an astronaut. There have, however, been some close calls.
Nearly drowning – in space
On ISS EVA 23 in July 2013, astronauts Chris Cassidy and Luca Parmitano exited the station to perform some exterior work on the orbiting outpost. The spacesuit Parmitano was wearing had been a subject of concern from the previous EVA as it had been victim to water intrusion that investigators had initially attributed to a leaking drinking bag. Parmitano was the occupant of the spacesuit for that EVA and would be wearing it on EVA 23.
Forty-four minutes into the EVA, Parmitano reported that he felt a moderate amount of water inside the back of his helmet. While the first thought was that it was another leaky drinking bag, it was quickly apparent that the volume of water was insufficient to attribute to the bag.
Since no source of the leak could be quickly determined, and the helmet continued to fill, the EVA was terminated approximately 23 minutes after Parmitano reported the problem.
As Parmitano made his way back to the airlock, water began obscuring his vision and collected around his nose. At one point, Parmitano worried that he might drown.
“By now, the upper part of the helmet is full of water and I can’t even be sure that the next time I breathe I will fill my lungs with air and not liquid,” noted Parmitano in a blog entry.
Worryingly, five of the six water intrusion incidents experienced by astronauts have occurred during the 2010s.
Thin supply, modified scope, and delayed maintenance
While one may think NASA has a warehouse full of spacesuits ready to use when needed, the reality is far more sobering. In fact, one of the key components – the Primary Life Support System (PLSS) “backpack” – has dwindled to only 11 functioning units out of the 18 originally produced.
If a spacesuit needs maintenance and cannot be repaired on-station, a very real possibility, then it must be returned to Earth for an overhaul. Relatedly, it is this lack of field serviceability that has contributed to the worrisome failure rates.
The EMU was originally designed to be used for short periods during a Shuttle mission, after which time it would be serviced after the Shuttle landed. Indeed, the spacesuits were only certified to be used for a single mission from 1982 to 1995, after which their service interval was increased to 25 EVAs over 180 days in order to support the ISS construction.
Gradually, the service interval was increased from 180 days to the currently-accepted maintenance timeframe of 6 years. However, with the retirement of the Space Shuttle program in 2011, even that 6-year interval has proven problematic.
With SpaceX’s Dragon vehicle being the sole spacecraft capable of returning significant mass from the ISS, it can be difficult to adhere to even the laxest of schedules. In fact, many spacesuits on the station regularly exceed the 6-year interval, with one recently reaching nearly 9 years before it could be serviced.
However, even the current supply of spacesuits may be inadequate to support ISS operations through 2024. Should a spacesuit suffer irreparable damage, or be lost in a launch incident as on CRS-7, NASA’s inventory of spacesuits may not be sufficient to fill the gap.
Next-generation spacesuit needed, but development lags
NASA has long understood the need for a next-generation spacesuit, not just to replace the aging fleet of current EMUs but also to address the needs astronauts may encounter as the agency looks to the Moon, Mars, and beyond for human exploration.
Even if the current EMUs were in pristine condition, they would be inadequate for human exploration of planetary surfaces. Surface operations require significant hip, knee, and ankle articulation – something the current spacesuit lacks.
Unfortunately, though NASA has initiated several programs to develop a new EMU, the badly needed replacement spacesuit may not be ready for several more years. This may be partly blamed on funding issues and with the agency not having a clear direction from one administration to the next.
However, the agency continued to fund an EMU design for the Constellation Space Suit System (CSSS), which was for the ill-fated Constellation program, through early 2016. More than $80 million was spent on the CSSS from fiscal years 2011 through 2016, even though the Constellation program itself was canceled in 2010.
Furthermore, the Advanced Space Suit Project, being developed in parallel to the CSSS, was at a more mature stage of development — with some components significantly more advanced than those in the CSSS – according to the OIG report.
Though it’s not clear if the Advanced Space Suit Project would be further along in development had it been the beneficiary of greater funding, it is evident this leading design was never supported at the same level as the CSSS.
Further placing pressure to field a new spacesuit are the crewed launches of the Orion spacecraft on the Space Launch System (SLS). Ideally, the ISS would be used as a testbed for the new spacesuit prior to it being used on deep space missions. However, the test article for new spacesuit’s PLSS may not make it to the ISS until 2023, dangerously close to the current retirement date for the station.
The OIG report outlined three recommendations for the agency, which NASA agreed to address, though the agency does not necessarily agree with some of the assessments included in the report, notably as they relate to the CSSS. Nevertheless, the agency expects to formally address the OIG’s recommendations by the end of September 2017.
Curt Godwin has been a fan of space exploration for as long as he can remember, keeping his eyes to the skies from an early age. Initially majoring in Nuclear Engineering, Curt later decided that computers would be a more interesting - and safer - career field. He's worked in education technology for more than 20 years, and has been published in industry and peer journals, and is a respected authority on wireless network engineering. Throughout this period of his life, he maintained his love for all things space and has written about his experiences at a variety of NASA events, both on his personal blog and as a freelance media representative.