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Lesson 7 Archive Notes: May 17, 2010

Posted by drspaceshow in Uncategorized.

Space Show Classroom Lesson 7:  Human Factors, Part One

 Sunday, May 16, 2010

 Archive Notes and Program Information

 The Space Show Classroom Lesson 7 can be downloaded or heard at:


Guests:  CLASSROOM:  Dr. Jim Logan, Dr. John Jurist.  Topics:  Lesson 7, Human Factors Part 1.  This program was Lesson 7 and the first part of a two part series on human factors for space travel.  Please visit The Space Show Classroom blog for presentation material (its copyrighted) and post all comments and questions for the guests on the blog at https://spaceshowclassroom.wordpress.com.  In the first segment of the program, our guests summarized the major human factors and medical issues for suborbital and very short term spaceflight.  As Dr. Logan noted, this is the 49th year of human spaceflight, about 500 people have flown and there have been about 260 space missions.  This comes to an 85 person/year of spaceflight experience.  He said there were no real surprises or show stoppers for this category of spaceflight.  We addressed bone loss issues and talked about G-loading positions for spaceflight participants to minimize acceleration stresses.  We compared these positions to those flying in a high performance fighter jet.  Centrifuge training was discussed in detail and why its so important to fly the suborbital or spaceflight profiles that one intends to take.  We talked about cardiac dysrhythmia, medical qualifications, beta blockers, and corrective steps if medical conditions were found to exist in someone that wants to fly in space.  Our guests talked about the disqualification process and explained it to us.  Listen carefully as it was not what I thought would be and some of you may also be surprised by what our guests said about potentially adverse medical conditions.  This is an important discussion so don’t miss it.  Floating around in the space vehicle was also brought up and discussed as a potential risk factor.  We had a question from Mel for Dr. Logan asking him about the tricks to avoid getting air sick if one has the opportunity to fly in a high performance military jet with a downright “evil” pilot.  You will enjoy this discussion!  During this segment, we spent more time talking about cardiac issues and the usage of pharmaceuticals in space.  One drug combination Dr. Logan talked about was ScopeDex for space sickness.  Our guests also suggested that spaceflight participants fly different zero g parabolas to experience weightlessness and see how they react to it and what “space sickness” is like.  Another issue that came up that would be critical for suborbital or any spaceflight was the ability for the person to do a rapid egress from the vehicle in case of an emergency.  Bone loss and osteoporosis were discussed in more detail during this segment.  A listener asked about flying children and here the age of consent came up as a problem/obstacle.  When asked about pregnant women in space, our guests said that all women of child bearing age must have a pregnancy test to fly.  You don’t want to miss this discussion.  Later in this segment, Jerry inquired about NASA space medical personnel and their ability to speak freely within NASA and outside the NASA line of command.  During the second segment, our guests repeated the three “commandments” for human spaceflight:   Do no danger to yourself, do no danger to the mission, and do no danger to others.  Dr. Jurist also talked about the risks of space diving explaining the major issues and risks associated with it.  I asked Dr. Logan about what to eat before a spaceflight.  Later in this segment, we talked about high altitude military jet ejections in the context of the earlier discussion on space diving.  Toward the end of the program, we talked about space radiation issues which were not said to be that significant for a very short suborbital flight.  While we discussed radiation in some detail, it will be a major focus of the second part of the human factors discussing in Lesson 8.  As we neared the end of the program, we talked more about the g-loading as well as a question from Bill on radiation issues for the ISS and a potential solar incident during a suborbital flight.  At the end, I asked each guest to prioritize the research as well as research dollars for suborbital and short duration human spaceflight.  The final show topic was in response to a question about obesity and spaceflight participants.  If you have questions or comments about this program or for Drs. Logan and Jurist, post them on The Space Show Classroom blog where this program is archived.  Visit https://spaceshowclassroom.wordpress.com.  Any emails sent me will be posted back on the blog under the sender’s name as we want the discussion to be part of the Classroom series.


1. Joe Evans - May 17, 2010

I listened intently to the fascinating show and the context for head turning was in a fighter doing aerobatic maneuvers designed to make you sick. My question relates to the exact opposite extreme, i.e., what is the minimum or lightest and softest spinning required, i.e., the safest level to avoid vertigo in space and still expose their bodies to short duration partial gravity. Huhm? Makes you wonder, doesn’t it? It is easy to make someone sick if that is your intent. The difficult problem yet resolved in space is finding the right spin rate and radii and limited head motion that makes it hard for you to get sick.

Also, my challenge to a long radius tethered vehicle spinning at a slow rate concept is what if it turns out after spending millions of dollars that it makes you sick in space as well? You have just wasted millions of dollars that the buy-in people are destined to assume will happen before buying it because it still remains an unanswered question when in space. The buy-in people will want the answer to this question in the cheapest and safest way. I believe the answer could be produced from the short-radius end first rather than at the long-radius end simply because it is cheaper and easier to ascertain. It stands to reason, if you can do it cheaply without getting sick in a short-radius centrifuge inside of a space experiment platform such as the ISS, you can do it without getting sick in a long-radius tethered vehicle and hence someone will buy the tethered vehicle. Isn’t this all about getting someone to buy it? Talking about it and proving it with hard evidence are two different things. Which way do you suppose someone would choose when making this type of purchase?

I also respectfully refuse to believe the ISS’s purpose is to discover what happens to the body in zero-G and exposed to space radiation. We have many fingers already pointing to bad end results. I believe one of the ISS’s purposes is to discover what we can do to stop bone loss by intermittently spinning small animals and eventually humans which would minimize the need to constantly grow a seemingly endless series of all types of crystals that COULD cure various diseases. There is no such thing as zero vibrations on the ISS. It is truly not a 24/7 micro-gravity laboratory due to all of the crew exercising and dockings and orbit boosting going on. It is truly an intermittent micro-gravity laboratory. Just go look at the crew schedules for yourself. They have periods of micro-gravity to do micro-gravity experiments, and then they do non-micro-gravity activities during all other periods which are much larger than micro-gravity periods. Some say, “Well it is enough to get something of value”. These people say this because they feel they are lucky they get any micro-gravity periods at all to do their experiments. This appears to me to be a carrot leading the horse. Growing crystals in space does not need humans sitting up there watching them grow. We have the capability to grow crystals and return them without humans flipping on and off switches. The ISS is about international cooperation in our global pursuits to discover safe ways to explore things outside of low earth orbit, and not about taking beautiful pictures of the ground.

I am a firm believer in tethered vehicles used to stop bone loss. The path to building and buying a tethered vehicle becomes extremely clear if the answer to the spinning vertigo problem is first solved in space in a short-radius centrifuge. I believe we can’t duplicate this experiment with the same results using ground-based centrifuges since gravity always enters the equation when spinning on the ground. We can approach the desired results but we will never know for sure until we do it in zero-G. And the buy-in people are going to want to know for sure before buying it.

Thanks as always for always offering a listening ear.

2. jmj - May 19, 2010

I suspect that the limiting factors for tethers is the engineering issues related to structures, operations from a tethered habitat, spinup and spindown. A lot of work was done in the 1960s on vertigo resulting from angular accelerations and Coriolis effects. Additional research was performed on small animals raised in centrifuges at various elevated g-levels and high angular velocities. Thank you for your observations.

3. Andy Hill - May 24, 2010

Out of interest if you subject someone to greater than 1G in a centrifuge on Earth for a period every day would their bodies create extra bone mass or are we limited to the amount we have normally?

This always assumes that an individual would be able to cope with being constantly spun every day of course.

If you could increase bone mass before going into space it might be advantageous.

4. jmj - May 25, 2010

Theoretically, they might. We don’t know the desired additional bone mass let alone the requisite g level and exposure time per day and how those factors would vary with age, sex, etc. Also, ramping up bone mass so one could safely lose more bone while in space sounds a bit like packing on the pounds in order to lose them later. Bears can do it, but yo-yo dieting in humans is fraught with health hazards.

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