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SpaceX Grasshopper Flies High

universetoday.com

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Re: SpaceX Grasshopper Flies High

#191

Post by lutorm »

Game_Ender wrote: post #189
lutorm wrote: post #188

This is probably a good place to point out: The SpaceX flight software team is looking for skilled software engineers! There are openings from anything from front-end RoR stuff to flight software and simulations infrastructure. If you want to help making stuff like this video run, check out some of these: https://jobs.github.com/positions/bd54ba2a-a930-11e2-9c0e-5c... http://www.spacex.com/careers.php?jvi=oarEWfwV,Jo…

What are the upsides to living in LA?

Depends on where you live now, I guess. Let's just say living in LA is not the reason I work here... though it isn't nearly as bad as I had feared.

Re: SpaceX Grasshopper Flies High

#192

Post by lutorm »

luke_s wrote: post #183
slackpad wrote: post #128

Earlier quoted context omitted.

I've been on the Flight Software team at SpaceX for a little over three years. It feels a lot like a startup. The team is still relatively small and people are pretty passionate about what they are working on. The project variety is wide as well. Personally, I've gotten to work on low-level drivers and OS stuff, application code that runs on the vehicles and ground systems, Dragon's fault-tolerant platform, internal…

Would you guys consider remote work? I would love to work for SpaceX but I can't really justify uprooting my family and moving to the other side of the world for it :-\

I think the general rule is not, but there exist exceptions. Foreigners (without greencards), however, are extremely difficult to hire due to export regulations (http://pmddtc.state.gov/regulations_laws/itar_official.html)

Re: SpaceX Grasshopper Flies High

#193

Post by bdonlan »

deepblueocean wrote: post #25
jessriedel wrote: post #21

For those of you who haven't seen it, here is SpaceX's fantastic animation of their ultimate goal for Falcon 9 (complete with soundtrack by Muse): http://www.youtube.com/watch?v=sWFFiubtC3c This will give you an idea of how grasshopper fits into the full flight plan.

I find this confusing. It's awesome, that's for sure. But it seems like lifting all the fuel needed to do a soft landing is inherently a tradeoff for less payload capacity. What is the benefit, then? Is it just so much cheaper to be able to re-use the first two stages?

According to http://www.popularmechanics.com/science/space/rockets/elon-m... :

> "The payload penalty for full and fast reusability versus an expendable version is roughly 40 percent," Musk says. "[But] propellant cost is less than 0.4 percent of the total flight cost. Even taking into account the payload reduction for reusability, the improvement is therefore theoretically over a hundred times."

Re: SpaceX Grasshopper Flies High

#194

Post by slackpad »

elteto wrote: post #139
slackpad wrote: post #128

Earlier quoted context omitted.

I've been on the Flight Software team at SpaceX for a little over three years. It feels a lot like a startup. The team is still relatively small and people are pretty passionate about what they are working on. The project variety is wide as well. Personally, I've gotten to work on low-level drivers and OS stuff, application code that runs on the vehicles and ground systems, Dragon's fault-tolerant platform, internal…

Hey! Can you spare some career advice for an aspiring aero engineer that wants to work on the software side of the rocket? If you could share what you would consider is a good path to follow to get to where you are right now, I would really appreciate it. I am a programmer at heart but even that could not pull me away from my love of space ;) so I decided to study aerospace engineering first.

It's hard to say what works best since we have so many different backgrounds on the team. I think having an interesting portfolio of projects (professional or side / hobby type stuff) is important - make sure you've done some awesome stuff that you can map onto what you might do here. Also, hone your communication skills. A big part of success at SpaceX is being able to work with others in a team and quickly get ideas across. Getting an internship is definitely a good way to go - we usually give interns pretty meaty projects that are a good taste of what full-time work might be like. Good luck!

Re: SpaceX Grasshopper Flies High

#195

Post by Someone »

Florin_Andrei wrote: post #165
jordan0day wrote: post #75

Earlier quoted context omitted.

I imagine there's a lot less fuel required to land than is required to take off. That is, on launch, the rocket is probably (eventually) reaching speeds of several thousand miles per hour. Upon landing, the atmosphere does most of the slowing-down for you, so you only need enough fuel to reduce the speed from terminal velocity (not sure what this would be for a rocket, probably several hundred miles an hour, at least…

> I imagine there's a lot less fuel required to land than is required to take off. Right. At take off, the delta vee is the escape velocity PLUS all the losses due to friction, which are tremendous. At landing, the delta vee is only equal to terminal velocity. EDIT: Okay, plus some flying time on top of the landing point.

Another way to state this: at launch, air resistance is your enemy. When landing, it's your friend.

Re: SpaceX Grasshopper Flies High

#196

Post by simonh »

747facts wrote: post #186
wiredfool wrote: post #98

Earlier quoted context omitted.

Another perspective is that the Falcon9 carries about as much kerosene as a 747.

I decided to fact check you. 57,285 U.S. gallons in a fully loaded 747. Jet-A is 6.84 lb/US gal. That's about 196 tons. Looks like stage 1 of the Falcon 9 is estimated to use 239 tons of RP-1 and stage 2 49 tons. http://www.boeing.com/boeing/commercial/747family/pf/pf_400_... http://www.spacelaunchreport.com/falcon9.html

Cool, so they're well within an order of magnitude of each other.

Re: SpaceX Grasshopper Flies High

#197

Post by noselasd »

BaconJuice wrote: post #90
JshWright wrote: post #86

Earlier quoted context omitted.

Even buying something off the shelf, that's not an absurdly expensive 'toy' ( If you build it yourself, you could put together a video platform like that for under $1k (including the gyro stabilized camera gimbal).

Hey JshWright, I recently got very interested in creating one of these and you seem to be pretty knowledgeable about this. Can you please give me advice on where a newbie can start with this? I would like to learn how to build one on my own from scratch. Thank you.

* http://www.diydrones.com/

Re: SpaceX Grasshopper Flies High

#198

Post by someperson »

luke_s wrote: post #181
nkoren wrote: post #67

Earlier quoted context omitted.

I second that recommendation. This is the successor to a site called "Hobbyspace" which was the best clearinghouse for all commercial space news since the mid-1990s. Although it was just a hobbyist's website, I have reason to believe that its comprehensive reporting and very clear-headed analysis actually bears some of the credit for catalysing the entire Newspace movement (eg., Elon Musk was a following and commenti…

Oh wow - is there any way to find his old posts. It would be really interesting to see some of his comments and thoughts given everything that has happened since.

Yeah if somebody digs up his comments I'll be REALLY interested to read them :)

Re: SpaceX Grasshopper Flies High

#199

Post by tomelders »

nanofortnight wrote: post #125
nawitus wrote: post #108

Earlier quoted context omitted.

Are you saying it should be single-stage-to-orbit? That's currently technologically nearly impossible, even if the rocket doesn't need to land back to Earth.

Not as technologically impossible as you might think: http://www.reactionengines.co.uk/space_skylon.html

I really don't understand why Skylon isn't getting more coverage.

Re: SpaceX Grasshopper Flies High

#200

Post by rbanffy »

samstave wrote: post #176
InclinedPlane wrote: post #58

Earlier quoted context omitted.

Almost the entirety of the cost of an orbital launch is in manufacturing and operational costs. Cost of fuel is basically just noise. If you can reduce operational turnaround time and operational complexity, even at a cost of payload, then you'll save so much money it'll be worth it in the long term. SpaceX is aiming for a re-assemble, gas up and go workflow. If they can pull it off it might reduce their per flight l…

Also, the first stage put up the second and third stage units. What if you have a payload container that was the size and weight limits of the second and third stage, which was put up into LEO by the first stage. The payload would then be picked up by vehicles already in orbit, and the first stage unit returns to earth. Assuming that the payloads are simply building materials, to be assembled by bots in orbit....

The first sage alone won't take your payload to LEO - you'd still need a second stage. However, orbital tugs with electric engines could take your payload from LEO to other orbits with less reaction mass than a chemical rocket could.

You'd still have to refuel their reaction mass, unless we are talking solar or magnetic sails.

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