| NOTE: Original task was with Principal Investigator (PI) Jeffrey Somers and period of performance 7/2/2014-10/31/2016; PI change with the delayed start, per E. Connell/JSC SHFH element (Ed., 8/10/16)
Currently the impact load imparted to crewmembers landing in the Soyuz vehicle is unknown. This study is the first systematic assessment of the number and types of injuries associated with Soyuz landing. To date, we have found than more than a third of US Orbital Segment (USOS) crewmembers are experiencing injuries. Most of these injuries are minor, but they exceed expected rates based on analysis of seat accelerometer data from airborne and drop tests of the vehicle. The yet to be answered question is whether spaceflight deconditioning renders crewmembers more susceptible to landing impact injuries. Another possibility is that the Soyuz landing load is higher than our current estimates. It could also be that our analytical tools are insufficient to predict injury rates accurately for space vehicles. A final possibility is that some combination of these factors are responsible.
The following are the specific aims for this task:
1. Collect retrospective post-landing questionnaire data and develop injury database
2. Determine the occurrence of landing injuries to crewmembers
3. Determine whether the Soyuz meets current Multi-Purpose Crew Vehicle (MPCV) and Commercial Crew Program (CCP) requirements
4. Evaluate whether injury rates are consistent with the results of Finite Element (FE) modeling
Using data contained in the flight medicine databases, supplemented with data collected from crewmembers, flight surgeons, Russia sources, and international partner sources, an accurate estimation of the occurrences of injury during Soyuz landings will be determined. In addition, post-landing questionnaires have been developed for retrospective data collection to supplement the above sources.
Through collaboration with our Russian colleagues, information about Soyuz landings will be collected to determine the dynamics of landing. The goal will be to obtain actual landing accelerations for individual landings; however, this may not be possible. If not available, all available information about nominal and off-nominal landings will be collected to develop a statistical model of possible landing distributions.
Initial scope of this investigation included development of a Finite Element model of the Soyuz seat to be used in conjunction with the Test Device for Human Occupant Restraint (THOR), Hybrid III, and Human FE models. Using the landing data obtained or calculated, landing simulations would then be conducted.
The resulting THOR, Hybrid III, and Human FE responses would be compared to the injury occurrences and current requirements. These comparisons would allow for an estimation of the true risk of injury to deconditioned crew related to THOR and Hybrid III metrics. However, NASA has currently descoped this aspect of the investigation.