0.5.12 - ci-build
SpaceflightHealthSimulationsReferenceDocumentation - Local Development build (v0.5.12) built by the FHIR (HL7® FHIR® Standard) Build Tools. See the Directory of published versions
When astronaut Scott Kelly completed his 340-day mission aboard the International Space Station, he spent an average of 2.5 hours every single day exercisingrunning on a treadmill with a harness pulling him down to simulate Earth's gravity, lifting weights on the Advanced Resistive Exercise Device (ARED), and cycling on the stationary bike. Despite this heroic effort, he still lost significant bone density and muscle mass. This stark reality reveals the fundamental challenge of human spaceflight: in microgravity, the human body begins to atrophy almost immediately, and exercise becomes not just fitness training, but a medical countermeasure critical to mission success and crew survival.
On the ISS, astronauts face a paradox: they must exercise more intensely than Olympic athletes, yet they're doing it in an environment where even simple movements require conscious effort. The ARED system can simulate loads exceeding 600 pounds, making it possible to perform squats and deadlifts in space. The T2 treadmill, vibration-isolated to prevent shaking the entire station, allows running at speeds up to 12 mph while a harness system pulls the astronaut downward with carefully calibrated force. Every workout session generates data: heart rate, simulated body weight, power output, exercise duration, and recovery metricsall critical for physicians on the ground to assess whether the crew's fitness program is preventing the inexorable physiologic decline of spaceflight.
| Profile | Purpose | Key Features |
|---|---|---|
| SpaceExerciseActivityMeasure | Individual exercise measurements | Duration, intensity, heart rate, power output, modality-specific metrics |
| SpaceExerciseActivityGroup | Panel grouping related measures | Links type, duration, intensity for a single session; mission context |
| SpaceEVSMinutesPerWeek | Weekly exercise volume summary | EVS (Exercise Vital Sign) minutes, aggregated across modalities |
| SpaceExerciseSession | Procedural record of exercise event | Links to prescriptions, goals, devices, and observation panels |
These profiles extend standard FHIR resources while incorporating space-specific terminology and requirements, following the same architectural patterns established in radiation and nutrition tracking modules.
Exercise tracking in space incorporates multiple data dimensions:
All measurements link to MissionContext extensions used throughout the IG.
New code systems and value sets:
Integration with existing terminologies:
Exercise in microgravity is fundamentally different from Earth-based trainingit's not about athletic performance enhancement, but about preventing catastrophic physiologic deterioration. Picture an astronaut six months into a mission: without exercise, their bones would be losing 1-2% of their mass every month, their muscles would have atrophied by 20%, and their cardiovascular system would have adapted to the point where standing up after landing could cause them to faint. Exercise is the primary countermeasure against this collapse.
T2 Treadmill:
ARED (Advanced Resistive Exercise Device):
CEVIS (Cycle Ergometer with Vibration Isolation and Stabilization):
Analogous to radiation dosimetry's multi-layered approach, exercise monitoring integrates real-time telemetry, physiologic measurements, and long-term trend analysis. Every exercise session becomes a data-rich event that physicians analyze for signs of adequate countermeasure effectiveness or early indicators of deconditioning.
Comprehensive fitness testing including VO₂max, strength assessment, and functional movement screening to establish astronaut's baseline capabilities and inform personalized exercise prescriptions.
Daily exercise sessions logged as Procedures with linked ActivityGroup observations, tracking compliance with individualized prescriptions based on mission requirements and crew member fitness status.
Intensified resistive training protocols in the weeks before scheduled EVAs, with increased focus on upper body strength and endurance to handle 7-hour suited operations.
Structured reconditioning program post-landing, monitoring return to baseline fitness levels and identifying any residual deficits requiring rehabilitation.
Longitudinal tracking across multiple missions to identify trends, optimize training protocols, and assess cumulative effects of spaceflight on musculoskeletal and cardiovascular systems.
Aggregated de-identified data enabling studies of exercise countermeasure effectiveness, equipment performance, and correlation between in-flight exercise adherence and post-flight outcomes.
{
"resourceType": "Observation",
"meta": {
"profile": [
"http://hl7.org/fhir/uv/aerospace/StructureDefinition/space-exercise-activity-measure"
]
},
"status": "final",
"category": [
{
"coding": [
{
"system": "http://terminology.hl7.org/CodeSystem/observation-category",
"code": "activity",
"display": "Activity"
}
]
}
],
"code": {
"coding": [
{
"system": "http://hl7.org/fhir/us/physical-activity/CodeSystem/pa-temporary-codes",
"code": "duration",
"display": "Duration of physical activity"
},
{
"system": "http://hl7.org/fhir/uv/aerospace/CodeSystem/space-exercise-modality-cs",
"code": "treadmill",
"display": "Treadmill running in microgravity"
}
]
},
"subject": {
"reference": "Patient/AstronautExample"
},
"effectiveDateTime": "2025-06-01T13:30:00Z",
"valueQuantity": {
"value": 30,
"unit": "min",
"system": "http://unitsofmeasure.org",
"code": "min"
},
"extension": [
{
"url": "http://hl7.org/fhir/uv/aerospace/StructureDefinition/mission-context",
"valueCodeableConcept": {
"coding": [
{
"code": "iss-expedition-75"
}
]
}
}
]
}
{
"resourceType": "Observation",
"meta": {
"profile": [
"http://hl7.org/fhir/uv/aerospace/StructureDefinition/space-exercise-activity-group"
]
},
"status": "final",
"category": [
{
"coding": [
{
"system": "http://terminology.hl7.org/CodeSystem/observation-category",
"code": "activity",
"display": "Activity"
}
]
}
],
"code": {
"coding": [
{
"system": "http://hl7.org/fhir/us/physical-activity/CodeSystem/pa-temporary-codes",
"code": "PAPanel",
"display": "Physical activity panel"
}
],
"text": "ISS T2 treadmill session"
},
"subject": {
"reference": "Patient/AstronautExample"
},
"effectivePeriod": {
"start": "2025-06-01T13:00:00Z",
"end": "2025-06-01T13:30:00Z"
},
"hasMember": [
{
"reference": "Observation/ISS-T2-Run-Type-001"
},
{
"reference": "Observation/ISS-T2-Run-Duration-001"
},
{
"reference": "Observation/ISS-T2-Run-MeanHR-001"
}
],
"extension": [
{
"url": "http://hl7.org/fhir/uv/aerospace/StructureDefinition/mission-context",
"valueCodeableConcept": {
"coding": [
{
"code": "iss-expedition-75"
}
]
}
},
{
"url": "http://hl7.org/fhir/uv/aerospace/StructureDefinition/exercise-device",
"valueReference": {
"reference": "Device/ISS-T2-Treadmill"
}
},
{
"url": "http://hl7.org/fhir/uv/aerospace/StructureDefinition/harness-load",
"valueQuantity": {
"value": 75,
"unit": "%",
"system": "http://unitsofmeasure.org",
"code": "%"
}
}
]
}