Commercial Spaceflight Participant (SFP) Medical Screening

What to do

Step 1 — Find out the flight profile

Step 2 — Screening checklist (suggested, based on FAA guidance and review literature)

Step 3 — Red flags to escalate to the operator flight surgeon

Step 4 — After the flight

Ask about dizziness on standing, nausea or vertigo, falls, vision change, back or neck pain, leg swelling and urinary symptoms. For orbital trips, advise no driving until balance is back to normal and the flight surgeon agrees (NASA crew are usually advised against driving in the first post-landing week [10]) — see Orthostatic intolerance and Postflight recovery.

Overview: the regulatory picture

Under 14 CFR Part 460, operators must inform each spaceflight participant in writing of known hazards, unknown hazards, the possibility of death or serious injury, the vehicle safety record, and that the U.S. Government has not certified the vehicle as safe; SFPs must also be trained to respond to emergencies such as smoke, fire, loss of cabin pressure and emergency exit [2]. Crew with a safety-critical role must hold an FAA second-class airman medical certificate issued within 12 months of launch [2]. Part 460 does not set medical standards for SFPs [2].

The FAA’s 2006 report Guidance for Medical Screening of Commercial Aerospace Passengers (DOT/FAA/AM-06/1) is advisory. It proposes [1]:

The same guidance assumes vehicles stay within +4 Gz (−2 Gz), ±4 Gx and ±1 Gy, and lists general contraindications: conditions that could cause an in-flight emergency or death, be aggravated by flight, or compromise the safety of other occupants [1].

Clinical considerations

• Acceleration. Acceleration is dysrhythmogenic, and +Gz threatens consciousness (G-LOC); care is advised with rapid-onset profiles of +3 Gz or more sustained for 5 seconds or longer in people with compromised cardiovascular function [1].
• What the centrifuge data show. In 77 lay volunteers aged 22–88 who underwent simulated suborbital profiles, most with well-controlled conditions tolerated the G-forces [4]. In 86 volunteers with hypertension, cardiovascular disease, diabetes, lung disease or back/neck problems (age 20–78), peaks reached HR 192, SBP 217 mmHg; grayout (69%), nausea (20%) and chest discomfort (6%) were common complaints, yet no subject had a significant adverse physiological response [5]. Screening by questionnaire, exam and ECG with documentation of known disease identified people able to tolerate the profiles; anxiety reactions were the hardest to predict [6]. These are analog data (centrifuge, not spaceflight) in self-selected volunteers.
• Orbital SFPs face the same early adaptation problems as astronauts: space adaptation sickness, congestion, headache, back pain, fluid shifts and urinary retention, followed by orthostatic intolerance and imbalance at landing [8].
• Civilian orbital data are starting to appear. The 3-day Inspiration4 mission found physiological, stress, neurovestibular (ocular misalignment) and neurocognitive changes, almost all of which did not differ from baseline after return [7].

Mission-type differences

Terrestrial parallels

• Fitness to fly / altitude assessment for airline passengers with heart or lung disease — but G-loads and the lack of quick diversion are new.
• Pre-dive medicals (barotrauma, pneumothorax, PFO questions).
• Pre-operative risk assessment: “optimize, document, communicate” applies directly.

Gaps and limitations

• No validated, published risk score for SFPs; operator criteria are largely proprietary.
• Centrifuge data are short exposures in volunteers; in-flight outcome data for older and medically complex SFPs are sparse [3][7].
• The FAA guidance dates from 2006; whether it reflects current vehicle profiles is pending verification.

Commercial spaceflight notes

This entire article is commercial-specific. Operators flying NASA astronauts follow NASA requirements by contract; private passengers follow the operator’s own program [9].

Clinical pearls

• Ask “who is your flight surgeon?” before writing any clearance letter — and write “no contraindication identified to the operator’s medical evaluation,” not “cleared for spaceflight.”
• Anxiety, not hemodynamics, was the most common unexpected problem in centrifuge trials of laypeople [6].