Here's onboard video from the abort test. That is a 6+ gee punch out !
I definitely reckon the trunk section is being briefly kept as a debris shield. That high initial gee could well dramatically reduce the relatively velocity to any fragmenting components, thus hopefully deflect off rather than gouge through.
I am reminded of the discussions after the Challenger disaster. One ( ex-NASA ) commentator pointed out - and was heavily criticised for what was obviously an honestly held concern - the intrinsic high danger of such enterprises. His main worry was not so much the specifics of mis-adventures in space programs but rather that civilians would totally misunderstand it. Especially if they came from quite unrelated backgrounds and were passengers in such craft. So he put the question as to whether someone like Christa McAuliffe could have truly understood the mortal risk she took, which was sadly fulfilled. Needless to say that query was harshly dealt with by many at that time ie. how dare you ask that ? Culturally the idea of a "clueless hero" is very distasteful, especially if someone is very loved. Since then it has become evident that NASA was very much eating it's own BS back in 1986, and was still in that same habit* when Columbia came down in 2003.
Hence if you are going to send people to Mars in the fashion as envisaged by Mr Musk ( ? $500K+ per person ) then this has to be talked about in my opinion. Quite specifically it ought be examined as to how open and honest SpaceX could be to it's non technically literate customers. Then again, maybe the greatest degree of risk miscalculation would come from the likes of myself - who think they know what is going on but actually don't. Would the other side of the table care if the cheque comes across either way ? What pressure could be upon a SpaceX employee when giving advice ? In my view the stance should at least be :
Quote:
Many people will die doing this. Assume it is going to be you. Why are you really doing this ?
I just luv Richard Feynman's quip : the easiest person to fool is yourself. :-)
Cheers, Mike.
* For those not up with that narrative : by 1986 there was clear evidence of risk with the SRB O-ring burn through. This was formally raised within NASA and ignored at high level. In 2003 there was clear evidence of risk with shuttle heat shield tile knock off at launch. This was also formally raised within NASA and ignored at high level. On both occasions the logic that prevailed was 'so far so good' rather like a player of Russian roulette, except that unlike Russian roulette the bullet was well studied/located and could have been removed. I believe that is a legitimate precis.
( edit ) NB The issue I've raised is independent of any actual risk. I'm inspecting the degree of insight that people should/would/could have when they sign up for space travel. I reckon armed service personnel ( I include civilian police here ) would have a very valuable viewpoint, particularly combat veterans.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
I, personally, despise the "zero defects" mentality. Let's all cheer together as we say we are trying so hard that surely our efforts have produced a perfect, or at least near-perfect result.
I much prefer the cold-hearted numbers game I found at Bell Labs when I first worked there as a summer Co-op student in 1969. None of the parts we are using work all the time, so let us measure failure rates of components until we are blue in the face, and construe various design aggregations of those components which soldier on in the face of many (but not all) failures, and compare the computed system level failure rates against very specific (not zero, but stunningly ambitious) goals. If not met, try again, if met, build it.
This approach was used to build telephone switches (a building full of hardware which connects tens of thousands of local phones to each other and to the larger network), against a reliability specification of two hours of downtime per 40 years of operation--and met it, using an assortment of relay-ish hardware of 1930's provenance which lesser men would have trouble making work for a few hours (Number 5 crossbar--the definitive urban switch of the pre-electronic era). They even met the goal with No. 1 ESS, their first production switch using these new-fangled (and rather unreliable) transistor thingies.
NASA never even tried to do an honest failure probability calculation for the shuttle system until after the Challenger event. The results were stunningly worse than what most folks had thought likely.
I think their own calculations called for loss of crew and vehicle once every not many hundred flights at the end of operational flights, after many, many billions had been spent on reliability upgrades. The next disaster was just a question of time--maybe the next flight, maybe a few years, but not lots of years.
Just to balance things a little, much as I like Elon's contribution to the mix, I seriously doubt SpaceX has much of an idea of what the real loss of crew and vehicle odds of their vehicle are likely to be. It is not easy at all to get close to the right answer. The first requirement is actually to want to know, and the second to be willing to spend serious money getting somewhat close to the right answer.
Agreed. I think SpaceX has a far better approach than most, judging by their design redundancies. A great example here is that the Dragon can eject right up to and including orbit. This is an historic first and there need to be more like it. It's a long way home from Mars .... assuming you get there of course. I have read that Elon's initial idea was to send mice to Mars, which is not as silly as it sounds ! :-)
The commentator I mentioned ( I'm sorry that I can't locate him exactly in my memory ) also chided the American public for being apparently so naive as to expect literally no failures of significance. I'd be confident in saying that if the Challenger crew were purely professional astronauts ( ex-test pilots etc ) then the hammering NASA got wouldn't have been as harsh. You are simply not allowed to kill Motherhood & Apple Pie. The deeper concern is closure of the discussion because comments like the previous sentence have been dis-allowed in the past.
There can be rebound though. Occasionally I'm called upon to advise people about some Syndrome X - usually they've read about it on the Internet ie. Dr. Google - and they don't realise their biggest risk ( if any & by a huge margin ) was coming along to consult with me. Everyday risks of say, road trauma, far outweigh the imaginative health constructs I examine. A wee bit of truth and a great lump of pump .... to service some commercial end typically. One has to be aware of the base risk of life : you will die.
Cheers, Mike.
( edit ) One largely unavoidable and unpredictable risk of transit to/from Mars would be a coronal mass ejection ( the Sun ). The radiation would absolutely toast anything biological and you need mountains of material and/or a planetary magnetic field to avoid that.
( edit ) I just keep watching that punch out. That's a serious device. A quick back-of-the-envelope calculation gives the mass of that Dragon + trunk at ~ 8.25 metric tonnes.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Agreed. I think SpaceX has a far better approach than most, judging by their design redundancies. A great example here is that the Dragon can eject right up to and including orbit. This is an historic first and there need to be more like it. It's a long way home from Mars .... assuming you get there of course. I have read that Elon's initial idea was to send mice to Mars, which is not as silly as it sounds ! :-)
The commentator I mentioned ( I'm sorry that I can't locate him exactly in my memory ) also chided the American public for being apparently so naive as to expect literally no failures of significance. I'd be confident in saying that if the Challenger crew were purely professional astronauts ( ex-test pilots etc ) then the hammering NASA got wouldn't have been as harsh. You are simply not allowed to kill Motherhood & Apple Pie. The deeper concern is closure of the discussion because comments like the previous sentence have been dis-allowed in the past.
To me as a kid growing up as a military brat watching the launches and walks etc it always seemed as the NASA guys were 'the smartest guys in the room' and therefore logically would have done the calculations on accidents and how to avoid them. In hindsight that was rather naive of me, and probably millions of others. Now that I have actually met some Scientists I understand they can be absolutely brilliant in their field of expertise, but also 'dumb as dirt' about many other things. It makes sense NOW, someone simply doesn't have the time to learn everything about everything, so people tend to focus on the areas they are good at, some REALLY good at, and let someone else take care of the 'other stuff'. NASA's problem seems to be that they didn't bring in enough 'other stuff' people to handle the 'what if it fails stuff'.
I was watching a show on the History Channel the other day and they were talking about Oppenheimer and the atomic bomb and what was taking them so long to make it work. One General came in and asked Oppenheimer what the holdup was and he said 'oh it works now with a failure rate of about 1 in a thousand, but I am shooting for 1 in a million, until then it isn't ready!' The General went back to the President and said "it's ready now", and they moved the resources into place and dropped them.
To me as a kid growing up as a military brat watching the launches and walks etc it always seemed as the NASA guys were 'the smartest guys in the room' and therefore logically would have done the calculations on accidents and how to avoid them. In hindsight that was rather naive of me, and probably millions of others. Now that I have actually met some Scientists I understand they can be absolutely brilliant in their field of expertise, but also 'dumb as dirt' about many other things. It makes sense NOW, someone simply doesn't have the time to learn everything about everything, so people tend to focus on the areas they are good at, some REALLY good at, and let someone else take care of the 'other stuff'. NASA's problem seems to be that they didn't bring in enough 'other stuff' people to handle the 'what if it fails stuff'.
My understanding of NASA's culture was that the boffins were quite ready to look at risk and when such was disclosed were ignored by the non-technically trained management - who would certainly prefer the narrative of "technical error" to be taken as the one history remembers ( compare with a "willful ignorance" story ). I am also reminded of Igor Sikorski's approach to testing : the test pilot is the chief engineer !
In generality the best advisors for executive roles have not been "yes-men". When LBJ was managing the Vietnam war he had daily briefings. He lambasted those who brought him bad news, so after a while the news bringers stopped passing on true facts. It didn't take long for his decisions to reflect that ignorance, even his enemies started to wonder about the quality of his knowledge ( not that they minded, because that typically worked to their advantage ).
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
The next launch is 26 Jun 2015 03:09:00 UTC - it has a Dragon plus a satellite payload, first time for that combo I believe.
Aside : the 6.6g nett upward acceleration is achieved in under a second. It's not too often that the rate of change of acceleration is looked at ie. the third derivative of distance with time. Often the word 'jerk' is used to denote this, which has the nice property of sounding like it feels. I was just researching about acceleration injuries to humans - internal organ rupture - and this level ought be fine. The data is necessarily sparse ( as we don't experiment ) and is estimated by some authors to require several tens of g/sec to get into the nasty zone, for instance tearing the spleen. Lady Diana Spencer lost the attachment of her lungs to her heart and that was more than likely > 200 g/sec.
Cheers, Mike.
( edit ) To be exact the spleen isn't torn, but the soft tissue pedicle which only loosely holds it in situ rips. Thus the artery within that pedicle ....
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Mike, that is a really great picture. When I look at the windows on the capsule they reflect the "fire" from the engines, making it appear as if there is a fire within the capsule. That is just too much of an E-ticket ride for me. Hopefully they will never have to use it but I am sure that for those who fly its nice to know its there.
Mike, that is a really great picture. When I look at the windows on the capsule they reflect the "fire" from the engines, making it appear as if there is a fire within the capsule. That is just too much of an E-ticket ride for me. Hopefully they will never have to use it but I am sure that for those who fly its nice to know its there.
It's competitors certainly wouldn't credit it but SpaceX is making alot of technical breakthroughs. No new physics but smarter engineering. One important aspect of the SpaceX program is to keep as much as possible in-house which has one advantage at least : that reduces "crossover" type problems eg. mistaking Imperial for Metric thrust specifications say ( see Mars Climate Orbiter ), or one part of telescope not actually suitable for another part ( see Hubble ), or 100% over-pressured O2 plus an in-swinging door ( White/Chaffee/Grissom pad test ).
Cheers, Mike.
( edit ) FWIW I thinks there may have been internal lighting :
Quote:
During today's test, Crew Dragon carried a test dummy equipped with sensors in order to gather all the data necessary to help ensure a safe environment for future crew ....
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Not a Dragon or SpaceX matter per se but one of the two Soyuz return modules parked at the ISS today had a wee spot of trouble. According to an article posted by the Guardian (known to most of us by a former name including Manchester) during a test of the docking system there was an unexpected engine firing of the Soyuz. Since it was attached to ISS, ISS got a bit of an orbital adjustment.
I too saw that article. That is just scary especially when coupled with the launch failure of the last resupply mission. There apparently are two Soyuz modules at the space station with one getting ready to return some astronauts to earth. They did not/would not say if the one scheduled to supply transportation was the one that misfired. Would not give me a warm fuzzy. I hope the Russian are not becoming complacent with all of their successful launches to realize that every mission is a "first launch".
Here's onboard video from the
)
Here's onboard video from the abort test. That is a 6+ gee punch out !
I definitely reckon the trunk section is being briefly kept as a debris shield. That high initial gee could well dramatically reduce the relatively velocity to any fragmenting components, thus hopefully deflect off rather than gouge through.
I am reminded of the discussions after the Challenger disaster. One ( ex-NASA ) commentator pointed out - and was heavily criticised for what was obviously an honestly held concern - the intrinsic high danger of such enterprises. His main worry was not so much the specifics of mis-adventures in space programs but rather that civilians would totally misunderstand it. Especially if they came from quite unrelated backgrounds and were passengers in such craft. So he put the question as to whether someone like Christa McAuliffe could have truly understood the mortal risk she took, which was sadly fulfilled. Needless to say that query was harshly dealt with by many at that time ie. how dare you ask that ? Culturally the idea of a "clueless hero" is very distasteful, especially if someone is very loved. Since then it has become evident that NASA was very much eating it's own BS back in 1986, and was still in that same habit* when Columbia came down in 2003.
Hence if you are going to send people to Mars in the fashion as envisaged by Mr Musk ( ? $500K+ per person ) then this has to be talked about in my opinion. Quite specifically it ought be examined as to how open and honest SpaceX could be to it's non technically literate customers. Then again, maybe the greatest degree of risk miscalculation would come from the likes of myself - who think they know what is going on but actually don't. Would the other side of the table care if the cheque comes across either way ? What pressure could be upon a SpaceX employee when giving advice ? In my view the stance should at least be :
I just luv Richard Feynman's quip : the easiest person to fool is yourself. :-)
Cheers, Mike.
* For those not up with that narrative : by 1986 there was clear evidence of risk with the SRB O-ring burn through. This was formally raised within NASA and ignored at high level. In 2003 there was clear evidence of risk with shuttle heat shield tile knock off at launch. This was also formally raised within NASA and ignored at high level. On both occasions the logic that prevailed was 'so far so good' rather like a player of Russian roulette, except that unlike Russian roulette the bullet was well studied/located and could have been removed. I believe that is a legitimate precis.
( edit ) NB The issue I've raised is independent of any actual risk. I'm inspecting the degree of insight that people should/would/could have when they sign up for space travel. I reckon armed service personnel ( I include civilian police here ) would have a very valuable viewpoint, particularly combat veterans.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
I, personally, despise the
)
I, personally, despise the "zero defects" mentality. Let's all cheer together as we say we are trying so hard that surely our efforts have produced a perfect, or at least near-perfect result.
I much prefer the cold-hearted numbers game I found at Bell Labs when I first worked there as a summer Co-op student in 1969. None of the parts we are using work all the time, so let us measure failure rates of components until we are blue in the face, and construe various design aggregations of those components which soldier on in the face of many (but not all) failures, and compare the computed system level failure rates against very specific (not zero, but stunningly ambitious) goals. If not met, try again, if met, build it.
This approach was used to build telephone switches (a building full of hardware which connects tens of thousands of local phones to each other and to the larger network), against a reliability specification of two hours of downtime per 40 years of operation--and met it, using an assortment of relay-ish hardware of 1930's provenance which lesser men would have trouble making work for a few hours (Number 5 crossbar--the definitive urban switch of the pre-electronic era). They even met the goal with No. 1 ESS, their first production switch using these new-fangled (and rather unreliable) transistor thingies.
NASA never even tried to do an honest failure probability calculation for the shuttle system until after the Challenger event. The results were stunningly worse than what most folks had thought likely.
I think their own calculations called for loss of crew and vehicle once every not many hundred flights at the end of operational flights, after many, many billions had been spent on reliability upgrades. The next disaster was just a question of time--maybe the next flight, maybe a few years, but not lots of years.
Just to balance things a little, much as I like Elon's contribution to the mix, I seriously doubt SpaceX has much of an idea of what the real loss of crew and vehicle odds of their vehicle are likely to be. It is not easy at all to get close to the right answer. The first requirement is actually to want to know, and the second to be willing to spend serious money getting somewhat close to the right answer.
Agreed. I think SpaceX has a
)
Agreed. I think SpaceX has a far better approach than most, judging by their design redundancies. A great example here is that the Dragon can eject right up to and including orbit. This is an historic first and there need to be more like it. It's a long way home from Mars .... assuming you get there of course. I have read that Elon's initial idea was to send mice to Mars, which is not as silly as it sounds ! :-)
The commentator I mentioned ( I'm sorry that I can't locate him exactly in my memory ) also chided the American public for being apparently so naive as to expect literally no failures of significance. I'd be confident in saying that if the Challenger crew were purely professional astronauts ( ex-test pilots etc ) then the hammering NASA got wouldn't have been as harsh. You are simply not allowed to kill Motherhood & Apple Pie. The deeper concern is closure of the discussion because comments like the previous sentence have been dis-allowed in the past.
There can be rebound though. Occasionally I'm called upon to advise people about some Syndrome X - usually they've read about it on the Internet ie. Dr. Google - and they don't realise their biggest risk ( if any & by a huge margin ) was coming along to consult with me. Everyday risks of say, road trauma, far outweigh the imaginative health constructs I examine. A wee bit of truth and a great lump of pump .... to service some commercial end typically. One has to be aware of the base risk of life : you will die.
Cheers, Mike.
( edit ) One largely unavoidable and unpredictable risk of transit to/from Mars would be a coronal mass ejection ( the Sun ). The radiation would absolutely toast anything biological and you need mountains of material and/or a planetary magnetic field to avoid that.
( edit ) I just keep watching that punch out. That's a serious device. A quick back-of-the-envelope calculation gives the mass of that Dragon + trunk at ~ 8.25 metric tonnes.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
RE: Agreed. I think SpaceX
)
To me as a kid growing up as a military brat watching the launches and walks etc it always seemed as the NASA guys were 'the smartest guys in the room' and therefore logically would have done the calculations on accidents and how to avoid them. In hindsight that was rather naive of me, and probably millions of others. Now that I have actually met some Scientists I understand they can be absolutely brilliant in their field of expertise, but also 'dumb as dirt' about many other things. It makes sense NOW, someone simply doesn't have the time to learn everything about everything, so people tend to focus on the areas they are good at, some REALLY good at, and let someone else take care of the 'other stuff'. NASA's problem seems to be that they didn't bring in enough 'other stuff' people to handle the 'what if it fails stuff'.
I was watching a show on the History Channel the other day and they were talking about Oppenheimer and the atomic bomb and what was taking them so long to make it work. One General came in and asked Oppenheimer what the holdup was and he said 'oh it works now with a failure rate of about 1 in a thousand, but I am shooting for 1 in a million, until then it isn't ready!' The General went back to the President and said "it's ready now", and they moved the resources into place and dropped them.
RE: To me as a kid growing
)
My understanding of NASA's culture was that the boffins were quite ready to look at risk and when such was disclosed were ignored by the non-technically trained management - who would certainly prefer the narrative of "technical error" to be taken as the one history remembers ( compare with a "willful ignorance" story ). I am also reminded of Igor Sikorski's approach to testing : the test pilot is the chief engineer !
In generality the best advisors for executive roles have not been "yes-men". When LBJ was managing the Vietnam war he had daily briefings. He lambasted those who brought him bad news, so after a while the news bringers stopped passing on true facts. It didn't take long for his decisions to reflect that ignorance, even his enemies started to wonder about the quality of his knowledge ( not that they minded, because that typically worked to their advantage ).
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
This is rocketry
)
This is rocketry :
Awesome ! :-)
The next launch is 26 Jun 2015 03:09:00 UTC - it has a Dragon plus a satellite payload, first time for that combo I believe.
Aside : the 6.6g nett upward acceleration is achieved in under a second. It's not too often that the rate of change of acceleration is looked at ie. the third derivative of distance with time. Often the word 'jerk' is used to denote this, which has the nice property of sounding like it feels. I was just researching about acceleration injuries to humans - internal organ rupture - and this level ought be fine. The data is necessarily sparse ( as we don't experiment ) and is estimated by some authors to require several tens of g/sec to get into the nasty zone, for instance tearing the spleen. Lady Diana Spencer lost the attachment of her lungs to her heart and that was more than likely > 200 g/sec.
Cheers, Mike.
( edit ) To be exact the spleen isn't torn, but the soft tissue pedicle which only loosely holds it in situ rips. Thus the artery within that pedicle ....
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Mike, that is a really great
)
Mike, that is a really great picture. When I look at the windows on the capsule they reflect the "fire" from the engines, making it appear as if there is a fire within the capsule. That is just too much of an E-ticket ride for me. Hopefully they will never have to use it but I am sure that for those who fly its nice to know its there.
RE: Mike, that is a really
)
It's competitors certainly wouldn't credit it but SpaceX is making alot of technical breakthroughs. No new physics but smarter engineering. One important aspect of the SpaceX program is to keep as much as possible in-house which has one advantage at least : that reduces "crossover" type problems eg. mistaking Imperial for Metric thrust specifications say ( see Mars Climate Orbiter ), or one part of telescope not actually suitable for another part ( see Hubble ), or 100% over-pressured O2 plus an in-swinging door ( White/Chaffee/Grissom pad test ).
Cheers, Mike.
( edit ) FWIW I thinks there may have been internal lighting :
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Not a Dragon or SpaceX matter
)
Not a Dragon or SpaceX matter per se but one of the two Soyuz return modules parked at the ISS today had a wee spot of trouble. According to an article posted by the Guardian (known to most of us by a former name including Manchester) during a test of the docking system there was an unexpected engine firing of the Soyuz. Since it was attached to ISS, ISS got a bit of an orbital adjustment.
I too saw that article. That
)
I too saw that article. That is just scary especially when coupled with the launch failure of the last resupply mission. There apparently are two Soyuz modules at the space station with one getting ready to return some astronauts to earth. They did not/would not say if the one scheduled to supply transportation was the one that misfired. Would not give me a warm fuzzy. I hope the Russian are not becoming complacent with all of their successful launches to realize that every mission is a "first launch".