Hi reddit, I'm a rocket propulsion engineer for Airbus Defence and Space working on developing new technologies for future rocket engines.

I'm currently living in Munich and I moved here for this job.

Proof has been sent to the mods.

Go ahead, AMA

Edit1: Info on European rocket engines (and the company)

Comments: 163 • Responses: 54  • Date: 

karmanaut17 karma

How much of your work involves using theoretical materials and products? For example, do you ever design something that requires X lightweight material or Y superfuel or whatever, even though X and Y don't exist yet?

Trust_in_Thrust23 karma

No, we don't dream that far in my department. We are looking into technologies that might fly on Ariane 6 or in spaceplanes. We try to take avaliable technologies and raise their TRL from 3 to 6. Those kinds of thoughts use TRL technologies of about 1 or 2.

BetterWhenImDrunk10 karma

Whats the best rocket scientist joke or quip you know? And how do you refrain from saying "Trust me I'm a rocket scientist"?

Trust_in_Thrust30 karma

Actually I don't like the term "scientist" that much, I prefer calling myself rocket engineer, but of course it slips out sometimes.

My favorite joke:

Whats a rocket engineer? - Someone with his feet firmly on the ground, his head in space and his hands in the taxpayers pockets.

BetterWhenImDrunk9 karma

Very nice, thank you for your time.

I like to yell "Trust me I'm a doctor" I fix computer things in a non medical field.

Edit: I think you should throw out "I'm a Rocketeer" everyone once and a while.

Trust_in_Thrust8 karma

Yeah, the only place I could apply that phrase that comes to my mind is the middle east, and I don't think I'm allowed to go there

pvfc10 karma

Do you frequently utilise Solidworks at work?

Ex Aero Eng M.eng student. I fucking hate it. FEA is cool but seeing "this feature cannot mate" 1000 times a day god damn


Trust_in_Thrust8 karma

I don't use it, as I'm not doing construction, but even then it's more Catia

krogort2 karma

I work in design for Airbus DS, we use Catia V5 (soon to be V6) .

Trust_in_Thrust3 karma

Man, didn't you get the memo? We're not supposed to use any abbreviation of Defence and Space :D

Where are you based?

FunwithMatt10 karma

What prevents big planes from going faster? Will we ever see airbus planes going at Concorde speeds?

What can we expect as far as speed is concerned, in the near future?


Trust_in_Thrust13 karma

Well, energy is a big factor as the air resistance rises exponentially with the speed. You need big engines and a lot of fuel.

Then the market needs to be right for this kind of plane. At the moment the market is more focused on fuel consumption, luxury and price per passenger per mile. I was quite surprised when I heard the A350 the first time, it's pretty quiet.

two_off6 karma

Which specific part/component do you work on? How much do I have to worry about you getting it fault-free?

(Did you start this AMA as soon as you realized Portugal had no chance?)

Trust_in_Thrust10 karma

Yes, yes I did :D

I work on the thrust chamber and the technologies that go with it.

Fault-free is not so important at our level, no one gets hurt if a test bench blows up, it's just money. We rather try to test to the limits than not know where the line is

underdabridge3 karma

What are the limits of what you do? Are you refining internal combustion systems or looking at alternate models of propulsion altogether?

Trust_in_Thrust8 karma

It's more a refining, making small changes on the design, sometimes a few on a new engine, never that much, a rocket is expensive

Abstract_Entity1 karma


Trust_in_Thrust3 karma

Yes, we look at turbopumps as well, although not my focus. I work more on combustion chambers. Yes, system wide change is hard to push through.

cathedrameregulaemea1 karma

Don't know if you're still reading this, but there was a discussion here about how 3D printing has reduced costs of rocket engines drastically. As I mention in that comment

IIRC, the superdraco has a single piece combustion chamber + injector

Have you worked with/studied both types? Conventionally manufactured, and 3D printed ones? (Injectors and combustion chambers). Could you comment on the differences?

Trust_in_Thrust2 karma

Yes, we have, the major differences are in design, the direction of the layers is crucial.

The powder that stays in the channels and on the walls is a pain to get rid of, if you don't do it properly, you get all kinds of problems, but mostly colored flames :D

Abstract_Entity3 karma


Trust_in_Thrust3 karma

Eagerness to see them perform - the first few years are critical, but it seems like they're here to stay-

We know we can't be SpaceX, but we watch them closely and try to learn. The US-business is different from the European one

Abstract_Entity1 karma


Trust_in_Thrust2 karma

How you manage your first real failure depends on how much you will be trusted in the future. Failures happen, you just have to treat them the right way

krogort1 karma

Don't you fear what they could so to your market share? They seems much more "lean" than Airbus that still hasn't gotten rid of all its old "public company" traits.

Trust_in_Thrust3 karma

True, but we serve a slightly different market. You'll see the Ariane 6 will be more like Ariane 4, but cheaper. We try to compete for the overlap in markets.

A big market is the US Defence budget, only US companies get access, and SpaceX has just entered it. Other US companies will have more trouble adapting

TheToppestLel2 karma

What degree did you do in university... And how good is the pay on the job? :P

Trust_in_Thrust8 karma

I studied aeronautical engineering in Germany... Pay is pretty awesome, I get more than I deserve :)

username7672 karma

I'm currently a junior pursuing a bachelors and masters in Mechanical Engineering at a top engineering school in the US. What you're doing sounds exactly like what I want to do. Do you have any tips or suggestions to help me get there?

Trust_in_Thrust5 karma

Get a network together, go to conferences, ask your professor about possible jobs, find out who might hire and what they expect/need.

In my case it was a lot of luck and fun. I chose the space courses because they were awesome and because I had my combustion specialization as another option. I never expected to get this job

Syaam2 karma

Thanks for doing this! What space propulsion technologies are you currently working on?

Trust_in_Thrust3 karma

I'll try to keep it a bit vague, you'll have to excuse me. We're working on new igntion systems, new materials and new injectors. I'll add a good site to the post in a sec

Patches672 karma

Do you ever catch yourself at work saying "It's not like it's rocket science! -Oh wait." -?

Trust_in_Thrust2 karma

Nope, never at work, sometimes when other people boast

Mantisbog2 karma

Seriously, how does a plane fly? All of that curved top of the wing stuff with there being lower pressure air going over because it's going faster-apparently that's bunk?

Trust_in_Thrust2 karma

Yes and no. Planes fly because they transfer impulse to the air. The impulse forward with the engines accelerating the air. The impulse upwards with the wings. So much for basics...

...the hard part is talking about HOW the wing does it. Yes the pressure stuff is true, but it's not everything. Redirection of air flow also gives an impulse. Then you have vortices and everything gets more complicated. But you get the idea - Impulse

Mantisbog1 karma

And those upturned wing tips. Decoration?

Trust_in_Thrust3 karma

Nah, reducing vortices and thereby air friction or something something

Mantisbog1 karma

And what about the plane on the treadmill problem?

Trust_in_Thrust2 karma

Yeah, Mythbusters explained that one. But with the information given above, you should be able to understand. An aircraft is only giving impulse to the air to accelerate, unlike a car, which gives impulse to the ground to go forward :)

Mantisbog2 karma

Oh God, why are you planes so complicated?!?

Trust_in_Thrust5 karma

Have you met rocket engines?

Flirter2 karma

What is stopping mankind from building faster rockets? Will we in our lifetime have spacecrafts traveling at like 1 million KM/hr?

Trust_in_Thrust4 karma

An energy source. with electric energy you need a nuclear power station to get the power to lift off. Once you've got that figured out, the sky's the limit.

And I hope so, but I don't think so

grandpa_faust2 karma

So, rocket science- is it really as hard as the popular aphorism suggests?

How did you get to where you are now? Model rockets, a love of engineering...?

Trust_in_Thrust13 karma

A love of engineering and some luck.

It can be quite tough during studies, we had lots more fluid dynamics and thermodynamics than other engineers. Once you get the hang of those two it's fairly easy. It gets really easy once you get a job.

Casen_2 karma

Do you play Kerbal Space Program?

Trust_in_Thrust7 karma

Yes, I discovered it in my holidays before starting my job (2 years ago) and even though it was sunny that summer I only got a screen tan ;)

C-A-S_Bear2 karma


Trust_in_Thrust2 karma

Keep focused when you need to, no need giving 100% all the time, that way you don't have reserves when you need 150%

petrichorE62 karma

What has been your most memorable day at work?

Trust_in_Thrust8 karma

Driving a company car for the first time and getting a ticket for speeding - can't live that down

petrichorE69 karma

Well you are a rocket propulsion engineer, making stuff speed up is literally in your job title.

Trust_in_Thrust5 karma

I'll remember that one next time the topic comes up

JETwaterpipes2 karma

Have you ever heard of electrogravitics?

Trust_in_Thrust3 karma

Yes, freaky stuff

[deleted]1 karma

Are there people working on this problem? http://xkcd.com/1382/

Serious question: What application for a rocket would you be most happy to see or construct?

Trust_in_Thrust1 karma

Nah, we don't do calf shields, that's someone elses problem :) And no, we don't do rocket jetpacks, unfortunately. I would like to build one though, so yeah.

More seriously, I'd like to see a super-heavy launcher in my lifetime, something that puts more mass into LEO (low-earth orbit) than the Saturn V (around 120t to LEO).

Paddyish1 karma

Is your job difficult? I mean, it's not exactly brain surgery...

Trust_in_Thrust1 karma

If you're having fun, nothing is difficult, so no :)

00000000i1 karma

  1. i really curious about why this plane's range is much more shorter than this giant. isnt it unlogical?

  2. do you think U.S dominate the air industry(i am asking because of electrcal component makers for planes like Honeywell, Rockwell Collins, P&W and GE)

  3. what do yo thinnk about air industry, generally

Trust_in_Thrust3 karma

  1. Well no, not illogical, you can have business jets with more range, it all depends what the market wants. If your customers don't need to fly long distances you design your aircraft that way. Smaller fuel tanks need less structure and efficiency is everything

  2. No, they are the biggest player, but not dominating. Although ITAR can be a pain in the ass for components

  3. They fly too low ;)

Sincerely_dishonest1 karma

What kinds of combustion behavior have you encountered that surprised you or were counterintuitive? For instance, have you ever set up a test and had one of those, "Wow, that's weird!" kind of moments?

Trust_in_Thrust1 karma

No, something similar though when the exhaust is "engine-rich" and the wall disintegrates. That can produce beautiful colors

Sincerely_dishonest1 karma

Thanks for the reply! Is engine rich another way of saying oxygen rich?

dfuinghl1 karma

or fuel-rich?

Sincerely_dishonest2 karma

Usually if a rocket engine is fuel rich the reaction gets limited by the amount of oxygen. However metal will burn spectacularly in the presence of high temps and excess oxygen. I've just never heard the term "engine rich" before.

Trust_in_Thrust1 karma

I heard it a couple of weeks ago and I never get to use it

TheMarmelator1 karma

Im Currently in german Highschool and what youre doing is like the exact Job Ive been dreaming of. What would you recommend me to do after ive finished school. Ive been thinking of studying aerospace engineering here in Germany, Berlin any other recommendations?

Trust_in_Thrust5 karma

Uni Stuttgart, TU Munich, RWTH Aachen - in that order :)

_dumbledore1 karma

I hope to be a rocket propulsion engine engineer soon! Start at Penn State this fall for engineering and then hopefully Aerospace Engineering in two years. Any advice to someone just starting school?

Trust_in_Thrust3 karma

Enjoy life, but you have to get your shit together every now and then. Just make sure you know when and do it - no excuses

Fishrage_1 karma

Do you ever visit the Filton site? I'm currently there on a 6 month contract.

Trust_in_Thrust2 karma

No, unfortunately not, I have a friend working there, but as I'm not in the aircraft divison, it's very unlikely

scrabs921 karma

So... Is it rocket science?

Trust_in_Thrust2 karma

Yes, yes it is :)

EUreaditor1 karma

Did the cancelled order from Emirates affect you?

Trust_in_Thrust2 karma

Me personally not at all, I can't speak for the company

EUreaditor2 karma

Thanks. I was wondering if they were separate companies when it comes to budget or they share the incomes... btw how's the atmosphere with the 4-0 over Portugal?

Trust_in_Thrust2 karma

Well, it's a group with three relatively independent divisions. Aircraft, Helicopters and Defence and Space.

The atmosphere is awesome, although not as awesome as the Dutch win on Friday, that was spectacular

d0uble0h1 karma

What's a typical day in the life of a rocket engineer like?

Trust_in_Thrust6 karma

It's an office desk job most of the time. During test campaigns it gets more fun as we get to handle some hardware and make some noise. So either 9 to 5 or 7 to 7

treerabbit231 karma

What are the primary domains in which you seek to push innovation?

By which I mean - alternate fuels? alternate physical designs? alternate materials?

Thanks for taking the time!

Trust_in_Thrust2 karma

Alternate materials, alternate designs mostly, but also different fuels. Hydrogen, Methane, and Alcohol, to name the most popular at the moment

Mantis__Toboggan_MD1 karma

Does the work ever feel like it's too hard? are there times when you're given a problem or task that you just can't solve or achieve? If so, how does something like this play out?

Trust_in_Thrust2 karma

Rarely - hard problems are usually not solved alone. It's mostly trying to get stuff done in time that make is hard

HitlersHysterectomy1 karma

How do you feel about Roy Orbison - specifically his 1979 album "Laminar Flow"?

Trust_in_Thrust1 karma

While I did listen into some songs on youtube, I have no specific feelings, sounds like 70's music

HitlersHysterectomy1 karma

ha ha. It is.. it is. I was going to ask about my weird habit of choosing not to sit next to the engines on a commerial aircraft just in case something snaps and comes flying through the fuselage. I like to think I'm avoiding additional risk by doing so, but it's probably far less likely that an engine will explosively disassemble itself than it is for another human being to attempt to bring down the aircraft intentionally. So yeah. I asked about Roy Orbison because I didn't want to come off as some kind of paranoid lunatic.
Thank you for looking, though! Hooray for Rocket Appliances!

Trust_in_Thrust1 karma

Don't worry, the engines have a protection around them to avoid fragments flying everywhere. But sometimes the fragments are a bit bigger :)

American 767 At LAX June 2, 2006 American Airlines Boeing 767 doing a high power engine run had a #1 engine HPT failure. HPT let go and punctured left wing, #2 engine, peppered fuselage and set fire to the aircraft. The turbine disk exits the engine and slices through the aircraft belly and lodges in the outboard side of the #2 engine.

(HTP = high pressure turbine)

Awesome picture

But don't worry, that rarely happens, terrorists have kidnapped your plane a lot until you get sliced by engine parts

Oinikis1 karma

What is the effective(or specific impulse) and actual exhaust velocity of a rocket you're working on? Gimme some details, I understand that stuff, 'couse I make my own rockets (well solid fuel ones, of course). Also what system of units do they use? long live metric system.

Trust_in_Thrust1 karma

ISP is around 420s - hydrogen makes it go :)

We actually use both, mostly metric though. Some parts are cheaper in imperial, so yeah

Oinikis1 karma

Glad to hear that. You use expander or staged combustion cycle? And are there plans for these rockets to be reusable? Also what are intentions for these rockets? Orbital launch vehicles? If so what type of staging? Personally I think 2 stage with boosters is the most efficient one.

Trust_in_Thrust1 karma

Vinci, the upper stage is an expander cycle. We have worked on staged combustion in the past, but there is no active project. Mostly launcher engines, so first and upper stage. Small thrusters are also being developed, monoprop, biprop and electric. These are used for ARCS and satellites.

We don't perform system analysis of the launcher, so I can't tell you what staging for what mission is best

heathbar241 karma

I'm going to college for Physics. Is it possible to get a job like yours or would a more specific degree be required?

Trust_in_Thrust2 karma

Probably not in my department, but in System Analysis or Modelling you might have more luck. If you can't do engineering or fluid dynamics it's rare. Some of my colleagues in electronics or optics have a Physics degree. So space science is definitely possible

00000000i1 karma

my good question deleted by a wideass mod. so i will change it's shape and ask again. which one in these tree space agencies you want to choose and say why you chose it?

  • esa
  • nasa
  • jaxa

Trust_in_Thrust2 karma

I guess you mean which one is the best. Simple - NASA, they are only governed by one country and they actually did stuff.

Not ESA because they're a bit too complex and less ambitious. Not JAXA, because they do even less.

All answers deeply subjective :)

00000000i1 karma

is doing-stuff means going moon? sending vehicle to mars? or what? but others doing stuff too. for instance this or this. ESA look like more scientific though.

i think NASA doing more cause it's $17 billion budget.

Trust_in_Thrust2 karma

The space shuttle was dominating the space age, just think of that. ESA has some way to go. JAXA only launches twice a year and that rocket isn't finished yet ;)

randomderpydude1 karma

Hi and thanks for doing this AMA! I have always wondered do rocket engines have stuff in common with "normal" engines (the ones you see in cars) do they have similar parts or the same way of working?

Trust_in_Thrust1 karma

Well, they have spark plugs. We use them to light the igniters for ground tested engines, but flying ones don't have any of the same parts you would expect

TPave961 karma

Do you think rocket power or some type of ballistic trajectory/rocket like technology will ever be used for day-to-day human transport?

Trust_in_Thrust1 karma

At some point maybe, but it's way too expensive for now

Kinetik_Inferno1 karma

This is exactly what I was hoping to go into, I love math and engineering.

What was your education prior to this? Ie: did you study much chemistry or was it mostly physics and calculus?

Do you play Kerbal Space Program?

Trust_in_Thrust1 karma

It was mostly physics and calculus, the chemisty was voluntary and I chose to specialize a bit on it during my studies

WonTheGame1 karma

Do you play kerbal space program?

Trust_in_Thrust1 karma

Yes...a lot :)

brokenheels0 karma

Sooo, what's the speed velocity if an airbus on slow motion?

Trust_in_Thrust1 karma

No idea, I'm guessing around 100m/s