IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA!

For many aspiring scientists/engineers (self included), the JPL seems like a far-off city on a hill. So my question for you: what was your journey that led you to work at one of the most esteemed labs in the country?

So my story of getting there is very much based on luck, so I'll give you my story and then the story of one of my labmates as well.

For me I applied online through their website in the Fall and then didn't hear anything until roughly May, when I got an email out of the blue asking if I was still interested and giving me a summer offer. Obviously I said yes, but ended up having to cancel on another internship which made some people pretty unhappy with me.

For my labmate, he went to a few conferences and kept talking to JPL people doing similar work to his. Eventually he tried to propose a grant to work with JPL. Unfortunately that didn't work out, but it put him in contact with the right people and they invited him out for the summer.

Basically you just have to put yourself out there as much as possible because there are so many well qualified people who want to work at NASA and especially JPL. Some programs to look at depending on where you are in school are NASA Academy, NASA Pathways, and JPL Planetary Science Summer School (for grad students and post docs this one is probably the best way to get your foot in the door).

Always wanted to understand how if there are lots of satellites and debris orbiting the earth, how can a rocket safely pass unimpeded into orbit. Are all objects tracked? What about top secret satellites from other countries?

So it basically comes down to space being absurdly big. Earth has a radius of about 6378 km whereas a big satellite is maybe a few meters. So you'd just need millions of objects up there to fill that space. Its the same thing with the asteroid belt, its more than one Earth worth of mass we believe(edit: I misremembered see explanation below), but so spread out that we don't really do anything exceptional when flying through it.

As to tracking things, we have most large objects tracked currently, and anything currently operating is being tracked.

The entire asteroid belt is less than 4% the mass of the moon.

Sorry you are correct, I mispoke. I was reading a paper recently about recreating the formation of the asteroid belt, where they approximated the mass at a specific time during its formation and that is where I got the above number from.

Would u rather hang out with Neil degrase Tyson or Carl Sagan?

I know reddit will be mad, but I gotta go with Sagan. The original Cosmos is something I watched at a really pivotal time in my education so Im very sentimental about it. Also Sagan worked and the Voyager missions which are basically the reason I'm interested in space. I have seen NDT talk though and it was a surprisingly moving experience.

How might a recent graduate with an MS in Computer science go about getting an internship/entry level job over at JPL? I'm about 30 minutes drive to Pasadena, but all I've been able to see for entry level are internships for current students.

If you have any advice on how to get my foot into the door without the benefit of being a current student I would be greatly appreciative.

My thesis was on embdedded system security, if that matters.

I wish I could be of more help, but the best I can say is that I believe their website has a fulltime position section

How cool is it to make explosions for a living?

I bet that would be really cool, I'll ask some friends from undergrad. I unfortunately mostly sit in front of a computer for work...alas

How cool is it to work with data from explosons for a living

Mad cool!

Idk if this is in your department, probably not, but is ripping holes in the space time continuum possible, and how would a person do it?

Definitely outside of my area of expertise, but I can suggest looking into Einstein's theories of relativity as they relate to worm holes. Unfortunately that's the best I can really do for you.

What's your PhD thesis about?

What was your favorite experience working at JPL?

Thesis:

So say we have something like the Earth-Moon system, we can get a pretty good model of their motion by assuming they are perfect spheres, even though they aren't really. The nice thing about assuming they are spheres is that their shape cancels out upward and downward gravity forces (every particle in a sphere has an corresponding particle that will have the opposite gravity direction except for the gravity on the line directly between the two bodies). Asteroids on the other hand are very much not spheres and that means we have to come up with a way to account for the effects of each individual particle. Now binary asteroids are when we have two asteroids orbiting each other, so now we have two very non-spherical bodies interacting with each other and we have to account for the effects of every particle. Fortunately for us some 1800 and 1900's mathematicians did some really cool stuff that lets us consolidate the effects of all the particles into an infinite series where each step in the series has a less important effect than the previous step. We'll call each step in this series an inertia integral, because that's what we call them. So part of my research right now is trying to understand how important each level of inertia integral and how sensitive the dynamics are to each inertia integral. Once we understand this we can use the knowledge of sensitivity to these inertia integrals to look at binary asteroid system and estimate its inertia integrals based on its motion. Knowing this gives us insight into the mass and make up of the asteroids which gives us insight into the history of the solar system.

Hopefully this is clear?

JPL Experience:

There is a tour at JPL of their mission control room, the so called "center of the universe". Basically this room is where any communication with any space mission beyond Earth's orbit goes first. So getting to go into this room and see things like Voyager 1/2, New Horizons, and Curiosity all communicating live is pretty awe inspiring. Also the guy who gives the tour of mission control there is really interesting and always has great stories to tell.

Currently a junior aerospace student. I've never even heard of inertia integrals before (unless second moment of area counts) but that seems like a super obvious direction to go to look at structures you can't idealize or don't want to! The work you've done is simply fascinating to me.

Do you have any advice for someone who is applying for every internship they get their hands on but no dice?

Haha I'm goad you haven't heard of them. I hadn't heard of them until I started researching binary asteroids, and I still dont't have a great sense as to what inertia integrals physically mean. The only people I have seen use them are two people from the 60's and then about 3 other people working on binary asteroid modelling. Normally when modelling a single asteroid one would use what are called spherical harmonics, which are related to an expansion of a volume integral. Spherical harmonics tend to muck up the equations for binary asteroids though, so someone smart tried using inertia integrals.

As for advice it sort of depends on where you are academically. But, really it boils down to making sure you have the best grades you can and applying to any opportunity that comes up. Once you get one internship it is much much easier to get other and better ones, sort of a catch22.

So are you a numericist? If so, what type of simulations are you doing? Are you running FMM on modified gravitational kernels?

If you are doing analysis, then all I can say is good luck.

I primarily do numerical simulations, though there's a but of analytical work when computing equilibria and some other behavior. In terms of simulations, I run full 12 degree of freedom models of these bodies (12 being 3 each for attitude and the. 3 each for translation).

Have the people that you've worked with all go to fancy universities or are there some that went to more average schools?

There is definitely a range, and a lot of the good space schools are not necessarily the ivy league schools. It is certainly easier if you go to a prestigious university, but from my experience there is a good variety. JPL specifically has programs to hire students from local community colleges, so the opportunity is out there.

How long have you been working online your PhD and when do you expect to finish? Do you think it has been worthwhile? How hard is it to navigate funding/grants/etc as a grad student?

(In case you can't tell, I'm considering going for my astrophysics PhD!)

I'm in my second year of my PhD and expect to take about 4-5. So far it has been worthwhile and really interesting, but that's partially because there weren't many other jobs I wanted after I finished undergrad. It is definitely challenging and causes you to question your intelligence and commitment constantly.

In terms of funding/grants I'm on the engineering side of astrodynamics so the funding is pretty different from the science side. Engineering has a lot more money available and fewer people competing for the money. My advisor has been very helpful with funding and obviously things worked out for me (mentioned I'm on NSF GRFP in the summary text). I did have to TA for a semester and I know some people who are paying for grad school that way. I wish I could give you more advice about funding from the physics side of things, but I just haven't had a chance to talk to people in that are about their funding situation.

If you want some advice on grad school or to get a better idea of what it is like, I'd suggest r/gradschool, its a great resource!

What exactly do you need funding for? Where does the money go?

PhD students don't have an income really so we can't pay for school on our own. We also need fancy equipment and health care. So we ask the government for money or we offer to TA and pay for ourselves that way.

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EM drive I believe has had Chinese and American researchers independently reproduce the results so it seems possible. There is also some proposed research that is trying to link EM drive to the flyby effect. This would be really cool for people in my field because flyby effect is basically our inability to explain an energy difference in spacecraft when they perform a flyby at Earth. So it could be that the physics explaining both seeming anomalies could be the same and help us navigate spacecraft better.

As for project Orion, that's my favorite piece of space trivia/history and I suggest everyone go watch the TED talk on it. As for other nuclear propulsion technologies, I'm really interested to see what happens with VASIMIR, which is a plasma engine being worked on currently.

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Not sure about Pulse Detonation Wave Propulsion Engines, not something I've studied.

I see where you're coming from, but Project Orion would have been a pretty challenging feat of engineering to make actually work and then to mitigate radiation enough for human travel.

How big is space?

Really really big!

Is there any consideration going towards how to utilize the ITS for probes and such once SpaceX gets it rnning?

I have no idea, until very recently SpaceX was keeping all of that very under wraps. Its would certainly be useful to have that much thrust behind you, but I can't say for certain.

still... not exactly a brain surgeon are you?

This is one of my favorite mitchell and webb skits, go you!

Do you think sub-atomic particles travel at the speed of light?

Good question, but unfortunately not really my area of expertise. My focus is orbital mechanics. I can suggest you look into tachyons though.

Do you think it's funny that the general public thinks the earth rotates around the sun?

I'm unclear as to what you are getting at?

Good question, but unfortunately not really my area of expertise. My focus is orbital mechanics. Sorry

So to mars or to the moon first then mars? Thoughts?

Moon first, its a much easier test location. Also from my understanding not as much Mars tech is as ready as people may like to think. For instance, if I remember correctly the reentry to Earth from a Mars trajectory requires you to either wait in orbit around Earth for about 6 months to slow down or enter the atmosphere at a velocity that generates so much heat in the atmosphere that no material we know of could withstand it (air molecules are literally broken apart you are going so fast).

I have an engineering background, but from my somewhat related experiences, just persevere, keep motivated and make sure you strike a healthy life balance.

Have you read about the Neumann Drive? What are your thoughts on this new ion drive?

No idea sorry, I don't really have too much work related to propulsion

If you could change one thing from your undergrad days what would you change? (Regarding academics)

That's a great question. If I honestly think about it any struggles I had in undergrad still got me to a pretty good place as of now, so I think I probably wouldn't change anything. There are certainly things that happened that I'm less than thrilled about, but I'm doing pretty well now so something must have lined up just right.

Seeing that you're going to school for your PhD, you have obviously been in school for a while. How do you keep yourself motivated to continue on? I personally have been in school for quite a few years and feel as if I'm just standing still. Also do you have any other advice for an undergraduate student?

Hmm, I'll go with advice first because that's a bit easier. My general advice to an undergrad is to just keep pushing and applying to everything you can. Also to keep as healthy of a life balance as you can.

As for motivation to keep going, which I guess is integral to my advice, I'm not sure I have a good answer. I still struggle with motivation at times because in the end it is really difficult to keep pushing when you don't see progress. You just have to trust that things will work out as long as you keep swimming.

So when I got my name added to a CD that was going to fly with New Horizons back in 03. Did it end up going? I pretty much never hear about it since.

I would assume so, but can't say for certain sorry

SAE or metric?

Oh god metric. Physics hardly works in freedom units.

How do you plan to service the JWT in Lagrangian L2 if something goes wrong with it? How long would it take for a team to get there and fix it, if it is even possible?

So on worked on JWST several years ago, and their servicing plans may have changed, but that is sort of the thing about sending something out to L2. It would be quite an ordeal to send anyone out there as I think trajectories there take on the order of months.

OK I'll ask you something. :Lke, who gives a shit?

Ah, the question I ask myself regularly.

So like most of academia if you take the goal of the research just on its own it doesn't really make much sense, but let me give a bit of context. So our current understanding of solar system formation has several unsolved questions that astronomers are currently trying to explain. The two most important related to my work are that we can't really explain how planetary systems go from being pebble sized rocks and dust to asteroid or planetesimal sized objects, our math basically says everything should fall into the sun long before it has time to coalesce into larger objects. The other question is about how these asteroid and planetesimal sized objects combine to create planets how these forming planets migrated through the solar system. There is a lot more to be said about these issues and tons of work being done, but I'm going to try and stay somewhat brief.

Okay so we have these unsolved questions and it would appear that both of them have to with asteroids and conveniently most asteroids have really only interacted with other similarly aged asteroids. This leads us to believe that asteroids hold a fairly pristine history of the solar system. Now this makes astronomers want to send a spacecraft to one of these asteroids so that we can study what are essentially time capsules from the formation of the solar system. The mission to asteroid that I care about most is called AIDA) and thats because this mission wants to go to a binary asteroid system (Didymos) and do a bunch of really important science relating to solar system formation and planetary protection. Unfortunately for everyone trying to design the AIDA mission, we have never been to a gravitational environment quite like a binary asteroid (see a comment explaining my research elsewhere in this ama as to why that is a challenge).

So after a long train of explanation this is where my research comes in. I study the dynamics of these binary asteroid systems in order to develop the tools that a mission like AIDA will need to understand what the asteroids are doing when it gets to the Didymos binary system. Once it can estimate things accurately, the spacecraft will safely know where everything will be overtime and make sure its operating safely to get the best science it can.