I had one person telling me on another board because a SpaceX mission was originally proposed to lift off in February but was re-scheduled to a later date in the year for (whatever reason) that means the mission was late.
This thread is not without merit.... But when I start seeing scrubs of hot fires, then I think it has gone too far.The same goes for delays months in advance which shifts the launch date.How about limiting it to scrubs/delays of actual launch attempts, only within a few days of the first launch attempt? In other words, any delay or scrub AFTER the hot fire.
Quote from: brovane on 01/07/2015 12:38 amI had one person telling me on another board because a SpaceX mission was originally proposed to lift off in February but was re-scheduled to a later date in the year for (whatever reason) that means the mission was late. http://www.nasa.gov/home/hqnews/2012/jul/HQ_C12-029_RSLP-20_Launch_Services.html
Thanks Jim for that link. That is a great example. Obviously this mission didn't lift off in December 2014. It is slated for lift off the end of March 2015 currently from VAFB. Lets assume that in March Jason-3 lift's off and there are no scrubs, issues with static fire etc. Do we call that a on-time launch? The launch itself is several months late from when it was originally procured.
What I'm wondering is, in this particular abort, why was the hold called by the operator and not the vehicle software immediately. The statement George Diller (BTW, didn't he retire from launch commentary?) made at the time was that it would have caused an automatic abort anyway. So what's the point of deferring that decision if the slew check was done somewhere around T-4:30 ?It's as if there's another check done later, specifically for the drift as opposed to just being able to cover the entire test slew envelope (one not necessarily excluding the other)?
Quote from: brovane on 01/07/2015 02:07 pmThanks Jim for that link. That is a great example. Obviously this mission didn't lift off in December 2014. It is slated for lift off the end of March 2015 currently from VAFB. Lets assume that in March Jason-3 lift's off and there are no scrubs, issues with static fire etc. Do we call that a on-time launch? The launch itself is several months late from when it was originally procured. It is now June.
Quote from: nimbostratus on 01/07/2015 05:08 amI get no specific infornation, but there is a simple reason, engines optimized for vacuum have problems with firing at sea level.And how the thrust vectoring problem was detected for this attempt is a mystery.They slew the engine during the countdown
I get no specific infornation, but there is a simple reason, engines optimized for vacuum have problems with firing at sea level.And how the thrust vectoring problem was detected for this attempt is a mystery.
No mystery if they power on the second stage engine for the status check.
What follows does not include weather scrubs. Only scrubs for technical issues. Also, IMHO... and I am a fan boy not a rocket scientist.My background is software and I've learned that you never get the last bug out of complex systems. There was an academic effort to devise methods to prove programs correct. It fizzled. Any large complex software package always has bugs, IMHO. You fix them as you find them and your goal is to introduce less new bugs than you fix. Over time older code gets more and more robust (but since the large complex software package is having new features bolted on, it may or may not be getting buggier overall)I'm not bothered by scrubs, per se.What would bother me is if the scrubs were due to the same exact problem over and over. My expectation is that over time, the scrubs/launch ratio will decline, and that the nature of the problems that caused scrubs would become more and more esoteric and more and more edge case related.
@cartman -- I'm assuming you're deliberately not including the delay from early December (12/7 I think) caused by cargo reshuffle after the Orbital incident?