On Sat, 09 Apr 2016 08:50:58 -0400
Post by Mike YettoSo it is writ, so mote it be....
Post by Big Bad BobPost by Big Bad Bobhttp://www.theregister.co.uk/2016/04/08/spacex_successfully_shoots_off_a_supply_mission/
worth a round of applause. It's a first, yeah.
science fiction becoming science fact - the rockets that land on
their tails. Well, just the first stage, but still...
oops I posted this to the wrong newsgroup, sorry - crossposting
correctly. still cool.
Perhaps not the wrong group. Was the computer that landed the
first stage running Windows 10 or Linux?
Mike "asking for a friend" Yetto
ELC: SpaceX lessons learned
By Jake Edge
March 6, 2013
On day two of the 2013 Embedded Linux Conference, Robert Rose of SpaceX
spoke about the "Lessons Learned Developing Software for Space
Vehicles". In his talk, he discussed how SpaceX develops its
Linux-based software for a wide variety of tasks needed to put
spacecraft into orbit—and eventually beyond. Linux runs everywhere at
SpaceX, he said, on everything from desktops to spacecraft.
Cut!
His team does not use "off-the-shelf distro kernels". Instead, they
spend a lot of time evaluating kernels for their needs. One of the
areas they focus on is scheduler performance. They do not have hard
realtime requirements, but do care about wakeup latencies, he said.
There are tests they use to quantify the performance of the scheduler
under different scenarios, such as while stressing the network. Once a
kernel is chosen, "we try not to change it".
The development tools they use are "embarrassingly non-sophisticated",
Rose said. They use GCC and gdb, while "everyone does their own thing"
in terms of editors and development environments. Development has
always targeted Linux, but it was not always the desktop used by
developers, so they have also developed a lot of their own POSIX-based
tools. The main reason for switching to Linux desktops was because of
the development tools that "you get out of the box", such as ftrace,
gdb (which can be directly attached to debug your target platform),
netfilter, and iptables.
Rose provided an interesting view inside the software development for a
large and complex embedded Linux environment. In addition, his talk was
more open than a previous SpaceX talk we covered, which was nice to
see. Many of the techniques used by the company will sound familiar to
most programmers, which makes it clear that the process of creating
code for spacecraft is not exactly rocket science.
http://lwn.net/Articles/540368/