51–60 of 88 posts
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…
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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...
From what I understand, they are pushing the boundaries on the hardware front, i.e. relatively recent, typical Linux computers onboard, and just relying on having a few redundant ones and short flight times, rather than very radiation hardened systems like those used in satellites or real-time operating systems. However on the SpaceX software side I think they’re fairly conservative and “boring”, so I’d guess C and s…
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They don’t reach the stations orbital velocity immediately after launch though. What they do is launch into a lower orbit behind the station. Lower orbits have a shorter orbital period, so they gradually catch up and raise their orbit as they get closer. If the went into a ballistic trajectory directly at the station, there is a risk of debris from the launch, such as paint flecks, scraps of metal, etc hitting the st…
Technically they do reach the stations velocity. In fact they exceed it. The lower orbit is slightly faster. Total energy is lower, but they are moving faster than the station. A counterintuitive part of spaceflight is that often you have to first accellerate in order to slow down.
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From what I understand, they are pushing the boundaries on the hardware front, i.e. relatively recent, typical Linux computers onboard, and just relying on having a few redundant ones and short flight times, rather than very radiation hardened systems like those used in satellites or real-time operating systems. However on the SpaceX software side I think they’re fairly conservative and “boring”, so I’d guess C and s…
I'd be surprised if they were able to be human flight certified without all the redundancy and hardening that any other manned spacecraft has, though.
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.
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…
I have no idea how it is actually done. But my guess is that lots and lots of automated testing. It is the only way to make sure that any changes you make do no break some other critical parts.
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…
>>In fact, I really cannot comprehend how something like this can be successfully done, given how so many things could go wrong. I have no idea how it is actually done. But my guess is that lots and lots of automated testing. It is the only way to make sure that any changes you make do no break some other critical parts.
Sadly, not as automated as you would hope/think.
The industry is working toward fuller automated testing, but it is much harder to do with “real hardware” in the loop.
Part of the reason why space has [historically] been expensive is exactly because you have to have specialized humans doing a ton of tests.
One reason Elon has been able to lower costs by reusable rockets is exactly because you don’t have to do as much testing per launch.
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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.
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...
[0] https://www.reddit.com/r/IAmA/comments/1853ap/we_are_spacex_...
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_...
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…
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.
That isn't to say they haven't been doing interesting things from a technical perspective (they're landing rockets on barges, after all), but the real secret to their success has been taking proven technology and doing it better/more efficiently (for instance, the fundamental design of their rocket engine, the Merlin, dates back to 50's).