Former NASA astronaut and Drexel University alumnus Jim P. Bagian visited Philadelphia Nov. 19 to lecture at Drexel’s College of Medicine.
Bagian, who graduated from Drexel as a mechanical engineer but obtained a doctor of medicine degree from Thomas Jefferson University, spoke on the medical aspects of spaceflight. His presence was part of the Henry Rosenberg, M.D., Endowed Lectureship in Anesthesiology, which was established in 2007.
“It’s a little out of the ordinary and probably of general interest that you normally wouldn’t stumble across,” Bagian said. “There actually is a very good research base behind [certain medical practices], which when I was in anesthesia nobody ever talked about and maybe didn’t even know, but it actually came from aerospace medicine.”
His experience on the subject stems from two space shuttle flights, STS-29 and STS-40, in 1989 and 1991, respectively. Over the course of his NASA career, Bagian had over 337 hours of spaceflight. He also held a position as the first director of the Veterans Affairs National Center for Patient Safety and was the first chief patient safety officer for the VA.
For current students hoping to become astronauts, he offered a few words of wisdom.
“You should be following what you have a passion for,” Bagian said. “If you look at the background of most of the astronauts, especially if they’re not pilots, they weren’t pilots, the backgrounds tend to be quite varied. Of the ones with [doctoral] degrees, the single biggest percentage are physicians. Among the males, they usually had a hard-science undergraduate degree, so usually engineering or physics or something like that.”
That was the route Bagian took, though he did not initially plan it that way.
“I still look at myself as an engineer who’s a physician, not the other way around,” Bagian said.
Dr. Jay Horrow, anesthesiologist in the College of Medicine, introduced the lecture audience to Bagian. He and Bagian met while in their medical residency at the University of Pennsylvania, but as they realized, they had also been part of the same class at Central High School in Philadelphia.
Bagian began the lecture by defining the scope of his talk.
“I’m just going to talk about the [medical aspects of spaceflight] that are operationally significant,” Bagian said. As an aid to his narrative, he showed a video of STS-29 on the space shuttle Discovery.
“You weigh twice as much as you did a couple thousandths of a second before,” Bagian said about the launch, adding that launch and ascent required such finesse that they were a matter of checklists and cue cards.
The crew used their time in orbit to release a Tracking and Data Relay Satellite and to conduct several experiments. Among others, they measured the effect of zero gravity on crystal formation, fluid pressure in the eye, and the development of chicken embryos. In the latter test, chicken eggs that had been fertilized the day before failed to develop further, unlike those fertilized a week earlier.
Bagian and crew also took detailed video images of Earth, providing about 75 percent of the orbital footage for the 1990 IMAX film “Blue Planet.” He discussed some of the benefits of orbital observation with the audience.
“We can see about a thousand miles in any direction,” Bagian said. “What ancient mariners figured out, … we can see very clearly from orbit,” he said regarding the tendency of clouds to form over land. The then-recent eruption of Pacaya in Guatemala gave insight into plate tectonics. “You can see fault lines that nobody knew were there.”
During their five-day mission, the crew did have time for recreation. Dry tortillas zoomed around the cabin, unencumbered by gravity, and they played with floating drinks.
“Virtually anything that has any kind of moisture to it will stick together,” Bagian said as he told personal anecdotes of the mission. Their exercise on a treadmill was visibly difficult. “It doesn’t feel like running, it feels like pushing a cart.”
Having given an overview of the conditions astronauts faced, Bagian turned to his core topic of medicine.
“When you’re pulling 3 G’s, a lot of people have trouble breathing,” he said of launch. “Your sense of balance is degraded. … The problem is, we train in 1 G.” He explained that intensive and repetitive practice with the shuttle’s complex control systems counteracted this disorientation.
One of the other challenges that astronauts face is decompression sickness, a risk that develops as they go from the environment of the shuttle to a spacesuit and back. Pre-breathing high-oxygen air before extravehicular activity is an option but is not a very desirable one, nor is pressurizing suits to nine pounds per square inch. Even the commonly used four pounds per square inch makes work difficult.
“Your most valuable commodity on-orbit is your time,” Bagian said. “When you’re in the suit, it’s like a big balloon. … The ideal physique would be like Popeye. You want to have huge forearms.”
Formerly, space adaptation syndrome was astronauts’ big worry. Similar to motion sickness, astronauts might become nauseous and disoriented once in space, limiting the work they could do. The condition affected as many as 75 percent of first-time astronauts and 45 percent of veterans. Using an aircraft flying in a parabolic arc to simulate zero G, NASA tested a variety of methods to prevent SAS.
“Some things would actually prevent you from getting sick on this, [but] they never worked on orbit,” Bagian said.
Bagian played a crucial role in making SAS a thing of the past.
“On my first flight, we tried doing something that had not been done in space before; it’s a drug that had been used on Earth before but never in space,” Bagian said. “It’s no longer an issue anymore.”
According to Bagian’s lecture, when NASA wanted to try a new drug after this, it couldn’t find any volunteers — the astronauts felt that the old drug was working fine.
“Sometimes academic curiosity takes a backseat to what makes sense,” Bagian said.
Another medical problem Bagian tackled in detail was that of blood vessels’ hydrostatic pressure.
“When you’re on orbit, it doesn’t matter, you don’t need hydrostatic pressure,” he said. But upon landing, a lack of hydrostatic pressure can cause fainting, especially because the shuttle crew is in an upright position. Special suits and harnesses protect the shuttle crew from this problem.
“The Russians are lying on their backs, so it’s no big deal,” Bagian said.
Research is ongoing in some long-term effects of space travel. A loss of strength and endurance, calcium loss in the bones, and vitamin D deficiency can plague astronauts, though this is mitigated with exercise and dietary supplements. The bones remineralize over time upon return to Earth, but some effects remain.
“There’s some evidence that’s suggestive [of the fact] that the way the bone is laid down is not as high-quality as before,” Bagian said in response to an audience question.
In conclusion, he pointed to interplanetary radiation as the biggest worry for a manned mission to Mars. Around Earth, in contrast, the Van Allen Belt shields astronauts from sustained high radiation doses.
Bagian attended a dinner after the lecture and gave a Grand Rounds lecture to medical students and faculty the following day.