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Friday, 20 June 2014

My First Week at NASA!

Hello and welcome to a rather special and exciting update! I have been granted the opportunity to work as an intern at the Johnson Space Center, NASA's main site for everything to do with human spaceflight! As such, I am proud and happy to be able to write about my time there, so if you're interested, keep reading!

The opportunity was established through the International Space University. Their Masters of Space Studies program concludes with a 3 month internship at space agencies, companies, and research centres all over the world and I set up my internship after meeting with NASA's policy ambassador to Europe. After visiting the ISU, and teaching us about NASA's policies and long-term plans, the Ambassador had lunch with several students. There, I discussed my interest in space radiation shielding, and after sending him my CV (curriculum vitae), he helped me get in contact with people at NASA who were working on an active radiation shielding project. A couple of emails and phone calls later, and I was set up to intern at NASA!

It has taken a little longer than expected to get settled in Houston, Texas. I have had many little obstacles which have made things interesting, like not having a car and knowing that the nearest grocery store is a half hour walk away. Or, having my security clearance take a week longer to process than my two roommates. It was a particularly ironic and frustrating moment when I walked my roommates to the front gate of NASA, only to have to turn around and go home. I am living right next to the center, but until this week, I was unable to get on site.

When I finally did, it took me a few days to settle in and I must admit that I felt somewhat disheartened. I understand that there is a difference between expectation and reality, but I was surprised when the first few days didn't feel overwhelmingly magnificent. This is NASA, the name and its reputation speak volumes, and I expected to feel caught up in something greater than myself. While everyone I knew was so happy and proud and excited for me, I checked into the security building, was driven to the nearest building to the front gate, escorted to an office, and went straight to work. I was here to work, but I thought, well, I guess I thought there would be more pageantry, more spectacle, more recognition of the greatness of joining such a prestigious team. But, for everyone else, it was another day on the job.

It may sound strange to have expected this, but I was frustrated that I wasn't feeling as overly excited as I thought I should be. I have this reaction sometimes, as I tend to subdue and control my feelings, so when I think that I should be excited, and I find that I am not, I feel disappointed.

Added perspective always helps in these situations. I realized a few things very quickly. The first, is that it is a job, and like any other job, you often get straight to work, and that's that. The second thing is that I am an intern, but I am not part of NASA's typical internship program. I am not filling a spot NASA has had for years, I essentially created my own internship. I found a researcher working on something I believe in and support, and I established myself in a position to help out. While I am particularly proud of this, I had to realize that there would be no pageantry because the division was not used to having interns.

The third thing, the thing you're probably yelling right now is, "It's NASA!" Getting here is an amazing opportunity and I should realize this and appreciate every moment I have here.

Once I thought these three things, everything else fell into place. I have had an excellently productive week and I really feel like I am part of the team. Let me walk you through my work!

The Project: Active Radiation Shielding
As you may have previously seen here at Embrace Space, I have been interested in active radiation shielding for some time. The concept, similar to "deflector shields" seen in science fiction like Star Trek, involves using large electromagnetic fields to deflect harmful radiation from spacecraft. Currently, materials alone do not work effectively, so NASA is conducting this study into the concept of active radiation shielding. They have released a Phase 1 study, which can be downloaded from here, which looked at the preliminary design of such a system. Phase 2 has started, and will continue until late August, to further define the requirements and constraints of such a system.

My assignment so far

In the Phase 1 study, there was a high-level look at the thermal control system required for the mission. The architecture of the main system can be seen below.
(Westover, et al. 2012)
The habitat, where the astronauts would live and work, is surrounded by 6 large superconducting coils. These coils would produce the magnetic fields which would surround the entire spacecraft preventing incoming ionizing particles. 

In order for the coils to work effectively, they have to be cooled to 40 K, or -233°C/-387.67°F. The Phase 1 study assumed they would not be thermally protected while on Earth, meaning that they would be launched around 300 K, or around 27°C/80°F. When you add the heat from the Sun, the heat reflected by the Earth, and the internal heat of the system, you might come to understand the amount of cooling which is required to get this system operational. My task is to research the thermal control requirements, find appropriate equipment, and create designs which could meet or exceed these requirements. Finally, I will perform a trade-off study where I compare different aspects and show flexibility in the design. Trading mass for cooling effectiveness, for example, or cooling power vs. electrical input required. This is the first task to which I've been assigned, and I'm hoping to pick up other tasks along the way.

Status Report

I have been researching the requirements and the equipment which could cool the system. As is usual in engineering design, there are many options and considerations. The first thing you try to do is understand the problem, in this case the source and value of the heat loads.

The launch temperature, the Sun, and the Earth's reflected heat (known as Earth shine or Earth infrared/IR) constitute the external sources. I might also have to consider zodiacal light and light reflected from the Moon, or Mars, (depending on the use of operation of the system), but I believe these to be much smaller than the sources mentioned above. The internal heat loads consist of the heat of the habitat (kept much warmer than 40 K in order to support astronauts), as well as any heat from the electronics and superconducting coils.

The original study considered this and suggested that cryocoolers, essentially really effective refrigerators, would be necessary for cooling the system. I have been researching this and other possibilities.

One promising alternative, or possibly supplement, to the thermal control of the system could be the use of a sunshield.

The James Webb Space Telescope is using a sunshield in their thermal control system. As seen in the images below, and this website, the sunshield will block the majority of the incoming solar light and heat, allowing only a small amount to emit from the cold side toward the equipment. The temperature difference between one side of the shield and the other is over 300°, which is quite remarkable!

While this does seem to be an effective solution for the external sources, there are still the internal sources with which to contend. Here, active thermal systems, such as cryocoolers, may be necessary, but thanks to the sunshield, may not have to work as hard.

This past week has been full of reading as I work to better understand the problem. I have been refreshing myself on the techniques of thermal engineering, reading reports on space-qualified equipment, and documenting my work and progress. What started out as a dismal perspective has shifted entirely and I finished the week with a strong confidence and enthusiasm for my work and contribution to it. My supervisor and I had a teleconference with other researchers working on other aspects of the project and I felt really good about being competent of all aspects involved. I provided valuable input, questioned design choices, made suggestions, and felt more like an engineer than ever before. I haven't seen much of the Johnson Space Center yet, but I did meet two astronauts, am slowly working my way around, and hey, it has only been the first week!

Thanks for reading!

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