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By Jack Maxwell
Jun 29, 2021
Mercury. Gemini. Apollo. These names, drawn from ancient mythology, still resonate today with those who remember the awe and excitement generated when the U.S. National Aeronautics and Space Administration (NASA) started sending humans into space in the 1960s.
Crew Dragon. Starliner. New Shepard. SpaceShipTwo. Though they may lack the cosmic provenance of their predecessors, these names — and the innovative spacecraft they adorn — are creating a different kind of buzz. They represent an opportunity the original astronauts could scarcely have imagined: nonprofessionals following in their vapor trails to experience the magic of spaceflight.
As SpaceX, Blue Origin, and other private companies move ever closer to sending private citizens into space, ASTM International’s committee on commercial spaceflight () is working on standards that will help ensure the safety of those individuals as well as the crew members they’re flying with. Strengthened by the unique perspectives of two former astronauts, there is a special urgency to their efforts.
“I just enjoyed looking at the window, videoing the Earth, the portholes, the station. It was just wonderful. It just was — whatever I had expected, the best I had expected times 10. It was the best experience of my whole life, those eight days."
These are the words of Dennis Tito, the man considered to be what many call “the world’s first space tourist.” A financier who paid $20 million for his 2001 trip to the International Space Station (ISS), Tito faced a number of challenges before achieving his dream. NASA and its other ISS partners were not pleased with the Russians’ unilateral decision to allow Tito to fly. In fact, NASA refused to train him in accordance with the medical and training guidelines that had been established by the Russian Space Agency.
However, the trip went smoothly, and its success helped advance the premise that a person need not be in perfect physical health, nor a professional astronaut, to visit space, and that he or she could do so without endangering the welfare of ISS crew members or compromising their missions.
One thing that has not happened in the 20 years since this mission is the establishment of a consensus on how to address medical qualifications for civilian space travelers.
“The U.S. Federal Aviation Administration [FAA] has been medically certifying pilots for aviation flight for decades, but has never certified passengers for spaceflight,” explains Dr. James Vanderploeg, F47 member and current president of the International Academy of Aviation Space Medicine. “What is different about this is that we don’t have a great amount of knowledge of what micro-gravity and acceleration forces do to people who have medical problems.”
Vanderploeg points out that most of the centrifuge work done over the years has involved young, healthy males, mostly fighter pilots. However, one good source of information on the effects of centrifugal force on less-fit individuals is research done by The University of Texas Medical Branch (Vanderploeg is also an adjunct professor of aerospace medicine at UTMB).
“Physicians from UTMB, through the FAA’s Center of Excellence for Commercial Space Transportation, published about 15 articles where we were centrifuging research test subjects who had diabetes, heart problems, pacemakers, back problems, these sorts of things, but that was limited, only a centrifuge, not micro-gravity,” he says.
Vanderploeg cites other sources of similar data but notes, “That was just a few people, and now we’re talking about large numbers of people. So this is why it’s critical that there be data collection on these individuals and debriefs on how they did so that we’ll know in the future.”
Despite the absence of , various private companies are forging ahead with plans to send “regular” people — mostly extremely wealthy regular people, to be sure — beyond the Kármán line, the 62-mile (100 km)-high boundary between Earth’s atmosphere and space.
Committee member Dr. Richard Jennings feels strongly that the proposed standards on medical qualifications for suborbital () and orbital () passengers currently in progress are taking the
right tack.
“I like the way this guidance is structured right now, where it really looks at the function. Are they able to function and do everything that’s required to safely do the mission, but also be open enough that there can be opportunities for a lot more individuals to safely fly into space?” says Jennings, who is a nonresident fellow in the Baker Institute Space Policy Program and a clinical professor in space medicine at UTMB. He is also lead flight surgeon for Space Adventures, a member of the Commercial Crew Safety Advisory Panel for SpaceX, and a medical consultant for Virgin Galactic.
“The term ‘standard’ often implies something that’s very prescriptive and regulatory in nature,” Jennings continues, “but what our committee is really developing is more of a standard in the sense of a guideline or a process that commercial operators should pay attention to as they begin flying paying passengers.”
Space will no longer be for professionals only.
He points out that Virgin Galactic, SpaceX, Blue Origin, and other private companies are well down the road to space tourism, and have their own medical programs and advisers. “So in that sense, this is documenting what’s already been developed and put in place by the folks who are actually doing this,” Jennings says.
A sub-orbital flight is commonly understood as one that leaves Earth’s atmosphere but does not complete a trip around the planet. Passengers on such flights will generally experience only a few minutes of zero-G weightlessness. Orbital flights, on the other hand, involve at least one, and often many, circumnavigations of Earth, and an extended period of zero gravity.
The physical demands placed on passengers will clearly be greater on orbital flights, and thus, the state of a person’s health and mobility will be more critical. According to Jennings, “You have a little advantage with the sub-orbital missions because those flights might be in space just a few minutes, with the total length of the flight an hour, hour-and-a-half. You can do a lot more with that than you can with an , where they’re going to be remote from medical care for a while, and they might land in the ocean or a remote location like Kazakhstan.”
Vanderploeg expands on this point. “In the sub-orbital world, people who are flying are flying as passengers, they have no responsibility on the flight to do anything other than enjoy the view and have a great time. The orbital flights are a little different, in that instead of 15 minutes long for the actual spaceflight portion, they may be several days long, or a week, or two weeks. So the medical standards have to be a little more involved because you don’t have an immediate returnability if something medically were to occur.”
One difference between the sub-orbital and orbital standards is the evaluation regimen. Jennings describes a three-tiered testing system: one level for sub-orbital flight, a second level for orbital flight, and a third for those with medical issues.
“There will be certain people that, when you look at whether this could hurt them or make an existing condition worse, are going to be a little bit more of a problem for orbital flight,” he says. “Can they wear personal protection equipment such as a spacesuit, if that’s needed, and successfully egress in an emergency? Will prolonged exposure to microgravity have a deleterious effect on a preexisting medical condition that could end the mission prematurely? It’s likely the people who can fly in orbit will have to be a little bit healthier than some of the people you can allow to fly sub-orbital.”
Referencing work done at Virgin Galactic with much older individuals — some in their 70s and 80s — Vanderploeg notes that as long their medical conditions were well-controlled, they did fine. “We used the centrifuge to produce the G-forces of the launch and re-entry, so they were exposed to the identical acceleration, deceleration, and G-forces that they would experience in a spaceflight, and we monitored them throughout that simulation,” he says.
“NASA has a rich history with regard to medical qualification of astronauts and the effects of zero gravity upon the human body, from which all commercial spaceflight providers can draw.”
Christopher Ferguson, to whom this quote is attributed, should know. A major contributor to Boeing’s Starliner program and currently that company’s director of mission integration and operations, he is also a former NASA astronaut with three space shuttle missions to his credit.
“If you think about it, everything in human spaceflight is really about crew safety,” he says. “So the question was, where do we focus this effort? After a short discussion with some Boeing colleagues, we decided to focus on emergency systems, the systems that remain after all the inherent fault tolerance within the vehicle is exhausted, the systems that will be used to get the crew to safety on a bad day.”
The work of Ferguson and fellow members of the subcommittee on occupant safety of orbital vehicles (F47.02) is being compiled as the new practice for crew safety (). Specific areas addressed include pre-launch and post-landing emergency egress, breathable atmosphere, cabin pressure loss, fire, and loss of control.
Cryogenic fuel is inherently risky. As Ferguson points out, a small leak can quickly escalate into a major conflagration. “The ability for the crew to self-extract and quickly get to safety outside of the potential blast radius is essential, and both of NASA’s human transportation services spacecraft have such systems in place that have been derived from similar agency designs.”
The proposed new crew safety practice also covers ways to re-establish clean cabin air following a fire or toxic substance release that compromises breathability. “A spacecraft must be able to restore its atmosphere to a breathable state. Emergency portable breathing devices generally only last tens of minutes, which compounds the urgency,” says Ferguson.
The former astronaut sees great value in sharing insights with his colleagues as part of the ASTM standards development process. “Given that most of our recent experience with has involved long-duration ISS crewmembers, it has been interesting to look at the inherent safety systems designed into the ISS that were designed to support life for decades, as opposed to the emerging commercial transport vehicles, which may support life for missions that last days.”
The outline and two of the major subtopics for the proposed practice on crew safety have been written and are in the process of being organized into the standard ASTM format for review.
“Back before he passed away, I had the opportunity to work with Professor Stephen Hawking, who wanted to do a spaceflight. We never got close enough, the timing and the delays that we’ve experienced in the last 15 years were too long for him, but he was kind of the ultimate challenge, if you will. How can we make that happen for somebody like a Stephen Hawking?”
Vanderploeg’s thoughts could serve as a kind of mission statement for the work being done by ASTM to help commercial space operators open up the wonders of space to the widest possible audience.
Jennings believes the guidance provided by the new medical qualifications standards will enable everyone, even those with disabilities, to travel safely. “The standard basically says you don’t want to hurt somebody, you don’t want to make a condition they have worse. It essentially helps these companies to make practical decisions for people who are going to be in less than perfect health,” he says.
Looking beyond the current push to get the space tourism business off the ground, Vanderploeg adds that creating consensus standards now will help operators in the future as well. “I think the value of having sets of standards like those that are under development is to provide the foundation for what comes next,” he states. “Who’s the next Virgin Galactic or the next Blue Origin or the next SpaceX that’s going to come along in a few years and want to fly people and doesn’t have the 10 or 15 years of background getting to the first human flight?”
Crew Dragon. Starliner. New Shepard. SpaceShipTwo. The journeys these spacecraft and their passengers take in the years to come will fire the imaginations of all those who, like Hawking, dream of space travel — and the work being done today by ASTM will help make it more likely that these dreams come true. ■
Jack Maxwell is a freelance writer based in Westmont, N.J.
July / August 2021