They use many different types of processors and they use C++ and Linux.
I'll say it again. They _won't_ be switching to rad hardened processors, not now, not anywhere in the near future. We'll see who gets to tell who "I told you so" when they send spacecraft to Mars.
Quote from: A_M_Swallow on 11/19/2012 02:59 pmQuote from: mlindner on 11/19/2012 07:26 am{snip}All of this implies that going forward in the future this is their development philosophy. You don't 180 your philosophy suddenly for small reasons, you continue to make your philosophy work with the new environment. If the reliability they have now isn't good enough for deep space then they add more redundancy until you get enough. I think this is a pretty strong point to them to continue this way of designing. They won't be switching to rad hardened components.SpX-2 is unlikely to have rad hardened computers in it. SpX-3 could.No that was not what was said. He said its ingrained in how they get developers. They use many different types of processors and they use C++ and Linux. It they get rad-hardened hardware then that suddenly means the hardware (and software to interact with it) is non standard. They now have workforce issues and they need specialized people with knowledge of that hardware.I'll say it again. They _won't_ be switching to rad hardened processors, not now, not anywhere in the near future. We'll see who gets to tell who "I told you so" when they send spacecraft to Mars.
Quote from: mlindner on 11/19/2012 07:26 am{snip}All of this implies that going forward in the future this is their development philosophy. You don't 180 your philosophy suddenly for small reasons, you continue to make your philosophy work with the new environment. If the reliability they have now isn't good enough for deep space then they add more redundancy until you get enough. I think this is a pretty strong point to them to continue this way of designing. They won't be switching to rad hardened components.SpX-2 is unlikely to have rad hardened computers in it. SpX-3 could.
{snip}All of this implies that going forward in the future this is their development philosophy. You don't 180 your philosophy suddenly for small reasons, you continue to make your philosophy work with the new environment. If the reliability they have now isn't good enough for deep space then they add more redundancy until you get enough. I think this is a pretty strong point to them to continue this way of designing. They won't be switching to rad hardened components.
So do we know what time of day this mission will launch?
Quote from: manboy on 11/19/2012 05:08 pmSo do we know what time of day this mission will launch?Chill out, we don't even know with any certainty yet what date this will launch.
Not sure if I found the right split point, but I've created a CRS-1 software rad issue thread to give this one as "general"...http://forum.nasaspaceflight.com/index.php?topic=30184.75Can't get over the incredible volume of posts on these SpaceX sections/threads. So keep it valuable, keep it worthwhile, or I can see this turning into a restrictive posting area.
Quote from: baldusi on 11/16/2012 05:54 pmThe article also mentioned that they decided not to resynch the computer, because they didn't felt it was necessary, but the fact that it got out of the loop doesn't means it had permanent damage.I suspect, if I'm forced to make a guess, that the radiation event might have generated some non recoverable latch up. But instead of trying to get it back, they kept it down so they could analyze it later when it returned.SpaceX wanted to resynch the computer, but Nasa was not in favor of doing that while it was attached to station, so they didn't. If it had been free flying SpaceX would have issued the resynch command. Moving forward SpaceX plans on making resynching automatic. Also to note is that SpaceX's expectations for radiation induced electronics trouble were higher than what they actually observed for the mission.source: talk given by SpaceX employee (senior GNC engineer)
The article also mentioned that they decided not to resynch the computer, because they didn't felt it was necessary, but the fact that it got out of the loop doesn't means it had permanent damage.I suspect, if I'm forced to make a guess, that the radiation event might have generated some non recoverable latch up. But instead of trying to get it back, they kept it down so they could analyze it later when it returned.
Quote from: LegendCJS on 11/16/2012 06:17 pmQuote from: baldusi on 11/16/2012 05:54 pmThe article also mentioned that they decided not to resynch the computer, because they didn't felt it was necessary, but the fact that it got out of the loop doesn't means it had permanent damage.I suspect, if I'm forced to make a guess, that the radiation event might have generated some non recoverable latch up. But instead of trying to get it back, they kept it down so they could analyze it later when it returned.SpaceX wanted to resynch the computer, but Nasa was not in favor of doing that while it was attached to station, so they didn't. If it had been free flying SpaceX would have issued the resynch command. Moving forward SpaceX plans on making resynching automatic. Also to note is that SpaceX's expectations for radiation induced electronics trouble were higher than what they actually observed for the mission.source: talk given by SpaceX employee (senior GNC engineer)Absolutely, positively 100% false. NASA thought it was a good idea to resync but mainly wanted to make sure they and SpaceX understood the process. SpaceX's plan changed a lot which did not give a clear indication that the resync was well understood. NASA just asked for caution and many felt if it was not well understood and not truly critical, then don't push it. Also not sure if by your last sentence you mean SpaceX expected less problems from the rad environment or more than then saw. From the beginning they dismissed radiation hits and NASA had to repeatedly pushed for more evidence. In the end a waiver was granted but we were expecting problems.
I have found a forum in which someone claims to have read that the Falcon 9 rocket has already been transported to the launch site, can anyone confirm this? http://www.spacextalk.com/viewtopic.php?f=18&t=13
From the beginning they dismissed radiation hits and NASA had to repeatedly pushed for more evidence. In the end a waiver was granted but we were expecting problems.
Quote from: erioladastra on 11/24/2012 06:04 pmFrom the beginning they dismissed radiation hits and NASA had to repeatedly pushed for more evidence. In the end a waiver was granted but we were expecting problems. Source? And who is "we"?
Can you give a source? This is significantly different than what was quoted direclty from a SpaceX engineer.
Jurvetson (SpaceX investor) posted a flickr image of the current state of the CRS2 Dragon - currently under construction in a clean room at Hawthorne:http://www.flickr.com/photos/jurvetson/8234369578/in/photostream (picture takes two days ago)
