SpaceX Crew Demo-1 Mission [video] • Hacker News Board

Re: SpaceX Crew Demo-1 Mission [video]

#71

Post by joezydeco » Sat, Mar 02, 2019, 7:33 PM UTC

JshWright wrote: post #60

mandeepj wrote: post #37

Earlier quoted context omitted.

To help you with not feeling overwhelmed - they are doing it since May 6, 2002. It has taken a lot of time, of a lot of people to get here. There was a lot of failures also, along the way.

A lot of what they are doing dates back a lot further than that. The innovations SpaceX has brought to the industry are more process related than technical. SpaceX has done a great job of setting a streamlined vertical integration for their production processes, which has allowed them to iterate a lot faster than others in the industry. That isn't to say they haven't been doing interesting things from a technical per…

So, out of curiosity, was there one person responsible for SpaceX operating in this manner? Was it Musk, or someone else?

Unless they accomplished a miracle by building a world-class engineering team from zero, there must have been a catalyst.

Re: SpaceX Crew Demo-1 Mission [video]

#72

Post by aboutruby » Sat, Mar 02, 2019, 7:35 PM UTC

Symmetry wrote: post #48

From Eric Berger's twitter[1] > If the first stage lands tonight, SpaceX will have successfully landed 35 of its 69 launches, meaning that MORE THAN HALF of its rocket launches will have safely returned. [1] https://twitter.com/SciGuySpace/status/1101752352317628416

Same thing happened to NASA, started at 43.6% success rate for 1950s then 85.1% for 1960s, etc. etc. https://space.stackexchange.com/questions/1659/what-is-the-s...

Re: SpaceX Crew Demo-1 Mission [video]

#73

Post by JshWright » Sat, Mar 02, 2019, 7:56 PM UTC

joezydeco wrote: post #71

JshWright wrote: post #60

Earlier quoted context omitted.

A lot of what they are doing dates back a lot further than that. The innovations SpaceX has brought to the industry are more process related than technical. SpaceX has done a great job of setting a streamlined vertical integration for their production processes, which has allowed them to iterate a lot faster than others in the industry. That isn't to say they haven't been doing interesting things from a technical per…

So, out of curiosity, was there one person responsible for SpaceX operating in this manner? Was it Musk, or someone else? Unless they accomplished a miracle by building a world-class engineering team from zero, there must have been a catalyst.

Elon Musk definitely deserves a huge share of the credit for SpaceX's success, but there have definitely been other folks who have made (and continue to make) critical contributions.

Just a couple examples would include Tom Mueller, who was responsible for most of the design of the propulsion systems SpaceX currently uses (including the Merlin and Draco engines), and Gwynne Shotwell, SpaceX's President and COO. SpaceX absolutely owes its existence to Shotwell, both its commercial success, and the fact that it didn't die (a number of times) are directly due to her.

From an outsider's perspective (_very_ outside), it seems like it's really the "synergy" of Elon and Gwynne that have made SpaceX what it is today.

Re: SpaceX Crew Demo-1 Mission [video]

#74

Post by raptorraver » Sat, Mar 02, 2019, 8:02 PM UTC

elteto wrote: post #58

bsaul wrote: post #41

Earlier quoted context omitted.

I remember reading here a document about C programming guidelines for military / space software ( basically no dynamic memory allocation ever), but that was set a long time ago. I wonder if spaceX reinvented some parts of the software stack, or if they went along the traditional way. I don’t expect seing rust code in the shuttle, but maybe formal proof with custom functionnal languages...

The flight software team did a reddit AMA a while back [0]. They use C++ for writing the flight software (what flies falcon, dragon, etc) running on a customized RT Linux. [0] https://www.reddit.com/r/IAmA/comments/1853ap/we_are_spacex_...

Thanks for this! ”We’re looking to start crew trials as early as 2015.” :)

Re: SpaceX Crew Demo-1 Mission [video]

#75

Post by 420codebro » Sat, Mar 02, 2019, 8:19 PM UTC

JshWright wrote: post #60

mandeepj wrote: post #37

Earlier quoted context omitted.

To help you with not feeling overwhelmed - they are doing it since May 6, 2002. It has taken a lot of time, of a lot of people to get here. There was a lot of failures also, along the way.

A lot of what they are doing dates back a lot further than that. The innovations SpaceX has brought to the industry are more process related than technical. SpaceX has done a great job of setting a streamlined vertical integration for their production processes, which has allowed them to iterate a lot faster than others in the industry. That isn't to say they haven't been doing interesting things from a technical per…

The resulting cost savings they (SpaceX) are bringing to the launch market is really amazing. United Launch Alliance (ULA) made a fortune on over-charging the United States Government for their National Security launches. SpaceX is now competing for those launches with a price between 1/4 to 1/3 of what ULA is charging.

Re: SpaceX Crew Demo-1 Mission [video]

#76

Post by 420codebro » Sat, Mar 02, 2019, 8:23 PM UTC

aboutruby wrote: post #72

Symmetry wrote: post #48

From Eric Berger's twitter[1] > If the first stage lands tonight, SpaceX will have successfully landed 35 of its 69 launches, meaning that MORE THAN HALF of its rocket launches will have safely returned. [1] https://twitter.com/SciGuySpace/status/1101752352317628416

Same thing happened to NASA, started at 43.6% success rate for 1950s then 85.1% for 1960s, etc. etc. https://space.stackexchange.com/questions/1659/what-is-the-s...

Remember the SpaceX statistic is counting number of returned, versus the NASA one is number of successes getting into orbit. I know I'm glossing over the fact that SpaceX benefits from the work NASA did for the past 60+ years, but just wanted to point that out (as it speaks kudos to SpaceX for mastering such a brand-new thing so quickly, on a budget).

Re: SpaceX Crew Demo-1 Mission [video]

#77

Post by JshWright » Sat, Mar 02, 2019, 8:28 PM UTC

420codebro wrote: post #75

JshWright wrote: post #60

Earlier quoted context omitted.

A lot of what they are doing dates back a lot further than that. The innovations SpaceX has brought to the industry are more process related than technical. SpaceX has done a great job of setting a streamlined vertical integration for their production processes, which has allowed them to iterate a lot faster than others in the industry. That isn't to say they haven't been doing interesting things from a technical per…

The resulting cost savings they (SpaceX) are bringing to the launch market is really amazing. United Launch Alliance (ULA) made a fortune on over-charging the United States Government for their National Security launches. SpaceX is now competing for those launches with a price between 1/4 to 1/3 of what ULA is charging.

Part of that also comes from the pricing model. ULA has often done cost-plus contracts, which incentivize inflating the cost. When SpaceX joined the party, most of the contracts became fixed price (i.e. the government is going to pay $X, and it's up to the launch provider to build their profit into that, and any cost overruns are the provider's problem).

Re: SpaceX Crew Demo-1 Mission [video]

#78

Post by Gravityloss » Sat, Mar 02, 2019, 9:07 PM UTC

the8472 wrote: post #65

Gravityloss wrote: post #49

Earlier quoted context omitted.

Computer engineering is new. We're still at the phase where bridges collapse and ships sink regularly.

It's a matter of tradeoffs. If your webapp is unusable 2 days a year people will just do something else in the meantime. If your flight control software fails for two days a year planes might come crashing down. The former is tolerable even if unpleasant from a customer perspective, thus they don't pay for flight control levels of reliability. And it's not like this is unique to software. It's the difference between…

Yes, I agree. I was wildly exaggerating.

Life sustaining equipment is regulated and has a lot of resources spent on it to make it reliable. And toy software doesn't matter if it falls down.

I guess medium level services fall in between. Still causing inconvenience and monetary losses when they fail.

Re: SpaceX Crew Demo-1 Mission [video]

#79

Post by solarkraft » Sat, Mar 02, 2019, 9:40 PM UTC

avmich wrote: post #68

monocasa wrote: post #59

Earlier quoted context omitted.

And FreeRTOS. RTLinux is only barely soft realtime.

> RTLinux is only barely soft realtime. Linux used to run as a non-privileged process in hard real-time kernel, which taken together was guaranteeing responses in nanoseconds range. If this is still the case (along with what Wikipedia states) , the whole system is by definition hard real-time.

But only the underlying kernel part is actually real-time, the Linux process wouldn't be, right? That leads me to the question: Shouldn't all things in a rocket be real time? Are they "post-poning" stuff like telemetry and other communications?

Re: SpaceX Crew Demo-1 Mission [video]

#80

Post by oconnor663 » Sat, Mar 02, 2019, 9:41 PM UTC

Gravityloss wrote: post #49

primordialsoup wrote: post #31

I am an engineer who builds with a computer. And when I see such things as this, I sometimes spend a minute or so marveling and thinking about the complexity of building and orchestrating such a launch. In fact, I really cannot comprehend how something like this can be successfully done, given how so many things could go wrong. Yes, I understand the idea of redundancy, I understand gravity, I understand that physics…

Computer engineering is new. We're still at the phase where bridges collapse and ships sink regularly.

To be fair, a big portion of high profile computer engineering failures involve attackers actively searching for vulnerabilities, which bridges and ships don't need to deal with as much.