This interview was recorded in March 2012 while I was a participant in the Spaceward Bound program for teachers in the Mojave National Preserve near Baker, California. Dr. Mogul brought a team of pre-service teachers from the California State University system to do field research in the Mojave Desert. We collected biological soil crusts (BSCs) at three sites in the desert along Kelbaker Road and studied them in the laboratory at the CSU Desert Studies Center on Zzyzx Road.

David Black:

How did you become interested in science and specifically in astrobiology?

Rakesh Mogul:

I have always had an interest in science ever since I was a young kid. And I think it must have been pictures of astronauts and pictures of spaceships on my school classroom walls that got me into NASA, think- ing about what it means to be an astronaut, what it means to discover life and other types of chemicals in outer space. I’ve had an interest in this stuff since I was a little kid, very little kid.

David:

So what pathway did you take to get from high school up to working for NASA?

Rakesh:

It was a bit circuitous, really, I took the traditional route of basic science. I got an undergraduate degree in chemistry, a PhD in organic chemistry with a research emphasis in biochemistry, or protein chemistry, or chemical biology, depending which way you want to define it. And then I did a postdoc and I got a lecture position and I was got my first academic job and basically pure organic chemistry, biochemistry. I always had the NASA thing kind of in my back pocket. And finally, I had a chance to apply for a fellowship to go to NASA and I got the fellowship and ended up at NASA Ames Research Center for two years in the early 2000s. And that was my first real major endeavor into the NASA sciences and I’ve just been continued ever since then.

David:

So what sort of things have you done at NASA?

Rakesh:

I worked with plasma sterilization and the bio- molecular effects of low temperature plasma such as CO2 plasma and O2 plasma, was on biomolecules and certain microorganisms, also did some work on bio nanotechnology using engineered proteins from extremophiles. And in more recent history, I’ve been working with extremophiles isolat- ed from the assembly facilities, where they build spacecraft. These microorganisms are found in these facilities, and are tolerant to the conditions found in the clean rooms. So what we do in my lab is some entomology, some proteomics and some remote microbiology, on these microorganisms. Basically we’re trying to study why they are resistant to things like hydrogen peroxide or ultraviolet radiation.

David:

So right now you’re working with the Office of Planetary Protection, but explain what that office does and what its role is.

Rakesh:

The Office of Planetary Protection’s primary role is to minimize the biological contamination of the solar system that may result from human based exploration – robotic exploration and basic human exploration. So these type of things involve correct fly paths to planetary bodies of interest, and especially the sterility and the cleanliness of the spacecraft that goes study the surfaces of planets such as Mars and maybe Europa in the future and Enceladus. In a nutshell, that’s planetary protection.

David:

So what are the protocols or some levels of protection used by the Office of Planetary Protection to determine if a certain space probe or a certain mission is going to need to be highly decontaminated?

Rakesh:

There are different categories for missions, categories one through five, depend- ing on where the mission is going, what the target location is. So if you’re going to Earth’s moon, there’s really no sterility requirements. There are some requirements. For example, cataloguing the number oforganic molecules, organic compounds that might be on the spacecraft, but there are no cleanliness or sterility requirements beyond that for things such as Venus and Earth’s moon. But if you’re going to Mars looking for life and looking for signs of habitability, there are certain dimensions that have to be met. Those dimensions include the number of spores per meter squared, and the total spores found on the spacecraft. So these are the types of things that are considered. There are also a number of probability factors, for example, the impact probabilities and contamination probabilities that must be calculated out for planets such as Mars and icy satellites, such as Europa, and Enceladus.

David:

So you essentially calculate what the risks are, and then communicate back to the missions what their sterilization protocols are going to be?

Rakesh:

Yeah, well, it’s more the mission’s responsibility to do the calculations and then to come up with a plan. And then they submit this stuff as a formal doc- ument called the Planetary Protection Plan. And they do this before the spacecraft is really assembled, and before launch ever occurs, and then that is approved or modified by the Planetary Protection Officer. And then it goes back and forth until they agree on something and then they move forward. And so there it’s not so rigid. The requirements are there because there are requirements, but if you can’t meet them, there are certain ways around them. There are waiver requests, there’s sometimes alternative methods to bring the bioburden down or to reduce the impact or probabilities or to reduce the impacts of contamination.

David:

Alright, so we have the Mars Science Laboratory on its way to Mars. Obviously, since it’s also going to be trying to detect organic molecules, the protocols here have to be really high. So what are some of the methods that were used to sterilize or decontaminate MSL?

Rakesh:

So, MSL was not, did not undergo full system sterilization will they sterilize the entire spacecraft all at once. They kind of haven’t done that in a long time. But they had to clean certain parts with ethanol and isopropanol, kind of cleaned it off and made sure the bioburden was quite low. I believe a few parts may have been sterilized by vaporous hydrogen peroxide, but I’m not confident of that one, they may have been so. And maybe a few parts, just tubing and I forgot the other examples – I think there were one to two or three parts that they did sterilize via dry heat microbial reduction, or DHMR. They use a variety of things. And it was all basically depending on the type of material that they’re going to sterilize and where it was.

David:

So taking the material from the robotic arm, which is taking regolith back to the SAM instrument, obviously, the arm has to be decontaminated.

Rakesh:

Yes, and it was a category 4A mission, so they’re not looking for life. And they’re not really looking for that many hardcore signs of life. So their sterility requirements were probably the least stringent for going to Mars for landing on Mars. So there’s differ- ent levels of sterility, if you will, or cleanliness for a Mars mission that lands on Mars and rolls around or just stays put. And those different categories are 4 A, B, and C. And MSL is 4A, where Phoenix was a 4B, and Viking, the equivalent would be 4C.

David:

How did you get involved with Spaceward Bound?

Rakesh:

I heard about Spaceward Bound somewhere between 2006 and 2007, from a colleague of mine, and I had known Chris from my prior days at Ames Research Center. So I simply emailed Chris out of the blue asked about the program and asked if I can participate in some form or another. And he wrote back almost immediately and said, Yeah, come on by and participate. So as the first year I came, I was just a participant, like many people here come for the first time, I didn’t have any science plan. And I came up and I just got a real good introduction to what field science is. And up until that point, all of my work was in the lab. Even if those were NASA related it was always in the lab. And I had done no field work and had no experience with field work all throughout graduate school, my academic career, and through my time at NASA Ames. Always an in the lab guy, in vitro, if you will. And so my first Spaceward Bound was my first introduction to field science. The next year, I came back as part of the science crew. And I was doing actually then redox essays on the soil crusts, and different soil communities around here looking for bulk properties of reduction or oxidation. And then the following year is when I started this program, then involved the CSU undergraduates and master’s students. And ever since then, we’ve been running this program.

David:

So a combination of students come in from CSU, scientists from NASA and other places, all combining together to do field research with a desert focus.

Rakesh:

Yes, that’s exactly right. And to add on to that the fundamental point to Spaceward Bound as it’s evolved with the CSU, the California State Uni- versity system, is basically a program designed to bring pre-service teachers, basically teacher wan- nabes, who are undergraduate and or master’s students and bring them out to the desert to give them (A) an introduction to astrobiology, (B) an introduction to field science, especially it relates to astrobiology, and then (C), most importantly, to give them hands-on experiences with doing real science in the aspect or concepts of NASA.

David:

So why study soil crusts?

Rakesh:

Soil crusts are surface communities and microorganisms that live in a symbiotic manner. So it is a simplistic form of a multicellular community that is very intrinsically dependent on the health of each one of the members. So it does relate to early forms of life. So when microbes all live by themselves eventually live in symbiosis communities, and many of these are known as stromatolites and microbiolites. So I would believe that it might be that the biological soil crusts are another form of that. They are also found in semi-arid environments and arid environments, which means they’re quite temperature resistant, quite resistant to ultraviolet radiation, and they are quite resistant to desiccation. So they are potentially very good analogs for surface communities that may be found on Mars. They may not be found on Mars, maybe they were at some point. So it’s still a very good thing to study.

David:

At least how they grow similarly to how things might grow on Mars.

Rakesh:

Correct. Correct. High UV environment, dry, and not connected to any vegetation. And very much dependent on – they’re very much a critical member of the health, if you will or fertility of soil. So as the BSCs go, so does it refer to the fertility of the soil.

David:

Just kind of like a barometer.

Rakesh:

They are definitely a barometer. If the biological soil crusts are dying, that means the land itself is not so fertile and that comes back to the water retention that they add to the soil properties and the carbon and nitrogen and recycling.

Transcribed by https://otter.ai