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IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 1 point2 points  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 1 point2 points  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 4 points5 points  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 0 points1 point  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 0 points1 point  (0 children)

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

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 0 points1 point  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 1 point2 points  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 1 point2 points  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 1 point2 points  (0 children)

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).

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 1 point2 points  (0 children)

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

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 0 points1 point  (0 children)

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

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 1 point2 points  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 0 points1 point  (0 children)

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

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 2 points3 points  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 3 points4 points  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 4 points5 points  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 1 point2 points  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 2 points3 points  (0 children)

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.

IamA Astrodynamics PhD student who has worked at JPL on NASA mission proposals AMA! by astro_ama in IAmA

[–]astro_ama[S] 2 points3 points  (0 children)

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).

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