The gunshot-sounding pop could easily have been the sound of the first thing to fail inside the rocket
Not when you have multiple videos for triangulation, as well as internal sensors which are sensitive enough to - as in the case of CRS-7 - not only detect an impact, but internally triangulate where in the spacecraft it occurred based on how long it took to get to the individual sensors.
The ULA has a lot to lose by trying to sabotage their competitors in a blatantly illegal way. It's the last thing they would do
I fully agree.
It could have been an employee acting on their own (perhaps someone with mental health problems), but what are the odds that the ULA has such an employee combined with the odds that that employee could have successfully smuggled a rifle all the way to the top of the building?
You tell me. Do employees have to walk through metal detectors on the way into work? No? Then pretty damned high.
I don't know if you've watched news coming out of America lately, but "armed people with grudges shooting at things" aren't exactly a rare situation. People involved in spaceflight are no exception. Wasn't that long ago when an astronaut - one of the most highly screened/profiled individuals in any employment field on Earth - went off her rocker and tried to kidnap the girlfriend of another astronaut.
The gunshot theory only becomes probable if they find hard evidence, like bullet fragments, or tell-tale damage to the wreckage.
And your knowledge that they haven't is?
This "visit" came two weeks after the explosion. They almost certainly had gathered the debris by that point and gone through the second stage components where the explosion started. And they still felt the need to go visit ULA. So you tell me what that means.
I can't tell you what they've found. Maybe there's a COPV that's basically shredded to fiber and they think it might have been shot which caused it to disintegrate. Or maybe they have a COPV with a nice bullet shaped hole in its side, aligned with the building in question. I can't tell you what they have. Before we insist either that it surely was shot, or surely wasn't shot, we should wait to see what evidence was actually found.
Why are you pretending that there were only the technologies that you hand-picked available, when the table actually listed numerous options with a wide range of masses? Why are you pretending that a neutron shield must be inert mass used for nothing other than shielding, and that increased distance between crew and propulsion isn't likewise an option? Why are you pretending that the table doesn't already list conversion efficiency? How close attention did you actually pay to what you were reading?
"Simple" is the last word I would choose to preface "nuclear thermal rocket".;) ISPs on nuclear thermal aren't that great, and variable-impulse ion propulsion is much more mission profile flexible. And again: he calls for engineering high power nuclear reactors anyway, shipping them to Mars anyway, for things like ISRU - so why not use such a reactor en route, if you're going through the effort to develop one regardless? And contrary to your "before he personally dies of old age" statement, we're much closer to high powered ion-propulsion than we are to nuclear thermal rockets.
Don't get me wrong, VASIMR isn't my preferred approach... honestly, I'd love to see more effort going into dusty / foggy fission fragment reactors. But I can certainly see how it would be useful for a wide range of missions, and how developing high power sources for space applications is something we need to do regardless.
There's a nice breakdown here for different technologies, table 1. Keep in mind that they cite things in kg/kW, not kW/kg; you have to have an energy source, energy conversion, and heat rejection mechanism - and if it's manned, a neutron shield (although there's a variety of possibilities beyond a dedicated shield, such as shielding with cargo, propellant, significant distances, etc); and that the conversion efficiency must be accounted for.
It's a stupid comparison that's not to Zubrin's credit. The reason that no powerful space nuclear reactors have been developed is because there hasn't been any demand for them. Nuclear reactor power to weight ratios don't scale up linearly, they scale up vastly higher than linearly. Figures of 1000W/kg aren't just some sort of out-of-a-hat fantasy numbers, they're based on the very real work in the field. More to the point, even solar is already in the low hundreds of watts per kilogram, so again, Zubrin's acting like 10W/kg is the state of the art and 50W/kg overoptimistic is beyond absurd.
We know how Zubrin feels about VASIMR. There's also good reason to disagree with him. For example, his nuclear reactor criticism? He himself proposes building a powerful nuclear reactor to power colonies on Mars, so he's not self-consistent. His power density figures aren't anywhere close to realistic. He talks like 50W/kg is some sort of unachievably optimistic goal, when in reality ATK Ultraflex solar arrays already get 150W/kg (and MegaFlex 200W/kg), figures that have been going up significantly with time; high power nuclear designs for future space missions are measured in kilowatts per kilogram. His complaints about the funding that's gone to VASIMR versus other things are unfair, as VASIMR hasn't received all that much funding - certainly not enough to develop a nuclear reactor as he mentions. And nobody is going to develop a power system for VASIMR without having first validated the propulsion system (something Zubrin apparently doesn't want them to do). He tries to portray its various ion drive competitors as better, without mentioning that the primary reason for choosing VASIMR is its high peak thrust levels. Lastly, Zubrin's dismissal of the dangers of in-transit radiation is not shared by most researchers.
Thanks for chiming in and linking the paper, and my apologies for exposing yourself to the comment environment here, which has become rather toxic concerning space issues of late. The fact that the press coverage comes across as "hype-y" doesn't help any.
While I think your premise of using space junk is... let's say "optimistic", in the anywhere-close-to-near-term timeframe.... the engine concept itself seems quite sound and interesting. I can't read the paper (not going to shell out $30 for it... not your fault I know, the publishing world is terrible), but - how sensitive is it to the geometry of the cathode? Is your concept that things would be melted down and cast (or extruded, or any other mechanism) into your desired geometry? I assume that at present you're doing something like feeding in wire off a spool to act as the cathode?
Any bullet striking the LOX tank would immediately turn into an incendiary bullet - even ignoring the hot/molten aluminum it would spray into the tank (which most definitely burns). Long-range bullets are going to be either copper or steel jacketed, commonly with a steel penetrator, lead core. While the lead is iffy, both copper and steel will ignite in LOX under high shock conditions (and if there's anything that's a high shock condition, it's a bullet impact).
I really doubt that they've considered everything. For instance possible ignition sources should include static electricity from high atmospheric charge driven by enhanced solar wind conditions (coronal hole influence). They're smart enough not to launch in a thunderstorm, yet surprisingly don't seem to avoid a related condition.
You mean, on the rocket sitting between four separate lightning towers? Our are you talking about some other situation?
What is the dark spot on the video supposed to have to do with anything? I can't believe Slashdot even linked that thing. SpaceX is investigating seeing a shadow and white flash on a ULA building in a video that they have.
I think the concept that ULA itself would have hired a sniper to shoot out a SpaceX rocket to be beyond absurdity. However, the concept that a ULA employee might happen to be a bit unhinged, as well as good with a gun? Not nearly so much.
It would of course depend on how good ULA's security procedures are. Do their employees need to go through a metal detector or anything that could have stopped them from taking a gun to work? Honestly, I doubt it, but if so it'd hinder that possibility.
It's interesting that this event happened 2 weeks after the explosion. They had almost certainly recovered most of the debris by that point and looked over the most obvious culprits; it's not like they did this the day after the explosion. This would imply that - at least based on what they could see two weeks into the investigation - the damage could be consistent with a bullet. That, of course, doesn't mean that it couldn't be consistent with anything else - only that it's at least considered a possibility. What I wouldn't give to see what they've found so far.... a COPV with a big round hole in its side for example would be pretty damning.
Amazing how Slashdot can include a video about conspiracy theories not being investigated, and by doing so imply that this is actually the core of the investigation.
The "UFO" has nothing to do with anything being investigated. The only thing present in that particular video under investigation was a sound heard shortly before the explosion. A different video (not public) showed a shadow and white flash on the roof of a ULA building.
They've cleared the struts of any responsibility. Nor would that make any sense, as - being on the ground - there would be little force on the struts. Due to how buoyancy works, the more the G forces there are on the rocket, the more the helium tanks try to rise in the LOX, and the more load there is on the struts keeping them in place.
Note that the strength of the struts has nothing to do with the "helium tanks" (COPVs)
I doubt that they would consider this theory if there was any sort of other obvious explanation for the damage that they're seeing. Every failure requires an explanation, a way to reproduce the results.
Indeed. I would be utterly shocked if ULA, as a company, made a decision to do this. Even moreso if it were done in a way that could lead back to them. On the other hand, a random angry employee with a gun? Gee, Americans shooting at entities that they're angry about, never heard of that happening before;)
More to the point, as a general rule a second stage would be easier to penetrate, as they're usually built lighter (not sure the thickness on SpaceX's stages, but in general it works like that).
Strangely, Al-Li alloys are more resistant to impact ignition with LOX than pure Al. That said, the LOX will have burned up part of the aluminum. *That* said, I still would expect them to "most likely" recover a penetration hole if one existed.
One of the things SpaceX had been investigating from the beginning was a bang heard in distance before the explosion.
I really doubt this is what happened. But if it did... my god, this would be one of the biggest scandals in the entire history of spaceflight. Even if it was an employee acting on their own.
Even ignoring the issue of whether a shock can make LOX react with aluminum (it can) or composites (it can very easily), the failure was in the helium system. The high pressure helium system, which stores all of the pressurant for the launch. Yes, if you shoot a pressurized COPV, it most definitely will release its pressurant in very short order.
That's not to back up this shooting hypothesis. But concerning whether a bullet could have caused the failure if present, I don't think there's any question about it. I don't think it should come as a surprise to anyone, but in case it does: shooting at fueled, pressurized rockets is a bad idea.
Since it's not clear from your post, have you actually played NMS?
The reason that most people essentially max out tech on their first planet isn't because they're "completionists", it's because there's so little content in the game. NMS is an "everything can be found everywhere in bulk" sort of game. Including tech blueprints.
So how do you imagine that miners on Mars will be competitive without actually having mining equipment
It's not a comparison of mining equipment or no mining equipment - it's a comparison of A) automated, self-maintaining, may-not-get-damaged-or-it's-lost-forever mining equipment or B) human-controlled, human-maintained, human-salveagable mining equipment. In an environment where the premise is that humans already are.
The robots that are outcompeting them are on Mars, and orbiting Jupiter taking pictures, oh, and orbiting the earth transmitting signoals around and doing science and stuff.
Because there are no humans there. What about this is hard for you to understand? I'll repeat: there is precisely one place in the solar system where humans exist outside of Earth: ISS. Do robots outcompete them there - yes or no?
The best numbers I could find is that the annual cost of the ISS
Red herring. We're comparing to a scenario where humans are on Mars either way. Talking about the cost of putting people on Mars, keeping them alive, etc, is irrelevant because that is planned either way. The question at hand is, is it cheaper to use their already present labour, or send robots? And it's a no contest comparison.
Do these [abc.net.au] look like Mar's rovers to you?
No, and:
1)... nor would you have the payload capacity to send something like that 2)... nor would something like that survive the Martian environment (dust, radiation, cold, pressures low enough for outgassing, difficulty with radiating excessive heat, etc) 3)... nor can you use that sort of power source on Mars 4)... nor do you have people there to do the (extreme) sort of maintenance such a vehicle requires 5)... nor do they do the most complex operations, only doing the (proportionally very simple) ferrying operations 6)... nor do they have to avoid risk at all cost due to the lack of people there to fix it if it goes awry and hits something 6)... nor do they have to avoid risk at all cost due to the lack of people there to fix *whatever it might run into* if it goes awry and hits something.... and about fifty other things.
The ISS is just floating there doing nothing.
Deflection. The question was, in construction and research on ISS, do they use the available human labour, or do they send robots to do it? Of course robots are used where there aren't humans, but that's not the topic of discussion; we're talking about a world where there's a human settlement on Mars. You're arguing that robots outcompete humans in a space environment where humans are. Well, we have precisely one space environment where humans are - ISS. Where are all of the robots outcompeting them?
I'll reiterate:
It's certainly an arguable point as to whether it's worth the cost sending humans in the first place - but once they're there, there's no debate at all about whether it's cheaper to use their labour or to engineer, build, and send robots to do the same task.
Surely this is a joke. How can you possibly have any tech blueprints left to find, 120 hours into the game? Most people essentially max out on their first planet.
You have a serious tolerance for grind. I don't know whether I should congratulate or feel bad for you.;)
ASCII? You spoiled child, back in my day our games graphics were displayed with blinking readout lights on a board. Old Flashey, we used to call that board. A game of "Hit The Button At The Right Time" used to cost a dime, which was two hours wages at the time, but oh, how I sunk so many dimes into Old Flashey...
Slashdot Mirror
Not when you have multiple videos for triangulation, as well as internal sensors which are sensitive enough to - as in the case of CRS-7 - not only detect an impact, but internally triangulate where in the spacecraft it occurred based on how long it took to get to the individual sensors.
I fully agree.
You tell me. Do employees have to walk through metal detectors on the way into work? No? Then pretty damned high.
I don't know if you've watched news coming out of America lately, but "armed people with grudges shooting at things" aren't exactly a rare situation. People involved in spaceflight are no exception. Wasn't that long ago when an astronaut - one of the most highly screened/profiled individuals in any employment field on Earth - went off her rocker and tried to kidnap the girlfriend of another astronaut.
And your knowledge that they haven't is?
This "visit" came two weeks after the explosion. They almost certainly had gathered the debris by that point and gone through the second stage components where the explosion started. And they still felt the need to go visit ULA. So you tell me what that means.
I can't tell you what they've found. Maybe there's a COPV that's basically shredded to fiber and they think it might have been shot which caused it to disintegrate. Or maybe they have a COPV with a nice bullet shaped hole in its side, aligned with the building in question. I can't tell you what they have. Before we insist either that it surely was shot, or surely wasn't shot, we should wait to see what evidence was actually found.
Why are you pretending that there were only the technologies that you hand-picked available, when the table actually listed numerous options with a wide range of masses? Why are you pretending that a neutron shield must be inert mass used for nothing other than shielding, and that increased distance between crew and propulsion isn't likewise an option? Why are you pretending that the table doesn't already list conversion efficiency? How close attention did you actually pay to what you were reading?
"Simple" is the last word I would choose to preface "nuclear thermal rocket". ;) ISPs on nuclear thermal aren't that great, and variable-impulse ion propulsion is much more mission profile flexible. And again: he calls for engineering high power nuclear reactors anyway, shipping them to Mars anyway, for things like ISRU - so why not use such a reactor en route, if you're going through the effort to develop one regardless? And contrary to your "before he personally dies of old age" statement, we're much closer to high powered ion-propulsion than we are to nuclear thermal rockets.
Don't get me wrong, VASIMR isn't my preferred approach... honestly, I'd love to see more effort going into dusty / foggy fission fragment reactors. But I can certainly see how it would be useful for a wide range of missions, and how developing high power sources for space applications is something we need to do regardless.
There's a nice breakdown here for different technologies, table 1. Keep in mind that they cite things in kg/kW, not kW/kg; you have to have an energy source, energy conversion, and heat rejection mechanism - and if it's manned, a neutron shield (although there's a variety of possibilities beyond a dedicated shield, such as shielding with cargo, propellant, significant distances, etc); and that the conversion efficiency must be accounted for.
It's a stupid comparison that's not to Zubrin's credit. The reason that no powerful space nuclear reactors have been developed is because there hasn't been any demand for them. Nuclear reactor power to weight ratios don't scale up linearly, they scale up vastly higher than linearly. Figures of 1000W/kg aren't just some sort of out-of-a-hat fantasy numbers, they're based on the very real work in the field. More to the point, even solar is already in the low hundreds of watts per kilogram, so again, Zubrin's acting like 10W/kg is the state of the art and 50W/kg overoptimistic is beyond absurd.
We know how Zubrin feels about VASIMR. There's also good reason to disagree with him. For example, his nuclear reactor criticism? He himself proposes building a powerful nuclear reactor to power colonies on Mars, so he's not self-consistent. His power density figures aren't anywhere close to realistic. He talks like 50W/kg is some sort of unachievably optimistic goal, when in reality ATK Ultraflex solar arrays already get 150W/kg (and MegaFlex 200W/kg), figures that have been going up significantly with time; high power nuclear designs for future space missions are measured in kilowatts per kilogram. His complaints about the funding that's gone to VASIMR versus other things are unfair, as VASIMR hasn't received all that much funding - certainly not enough to develop a nuclear reactor as he mentions. And nobody is going to develop a power system for VASIMR without having first validated the propulsion system (something Zubrin apparently doesn't want them to do). He tries to portray its various ion drive competitors as better, without mentioning that the primary reason for choosing VASIMR is its high peak thrust levels. Lastly, Zubrin's dismissal of the dangers of in-transit radiation is not shared by most researchers.
Thanks for chiming in and linking the paper, and my apologies for exposing yourself to the comment environment here, which has become rather toxic concerning space issues of late. The fact that the press coverage comes across as "hype-y" doesn't help any.
While I think your premise of using space junk is... let's say "optimistic", in the anywhere-close-to-near-term timeframe.... the engine concept itself seems quite sound and interesting. I can't read the paper (not going to shell out $30 for it... not your fault I know, the publishing world is terrible), but - how sensitive is it to the geometry of the cathode? Is your concept that things would be melted down and cast (or extruded, or any other mechanism) into your desired geometry? I assume that at present you're doing something like feeding in wire off a spool to act as the cathode?
Any bullet striking the LOX tank would immediately turn into an incendiary bullet - even ignoring the hot/molten aluminum it would spray into the tank (which most definitely burns). Long-range bullets are going to be either copper or steel jacketed, commonly with a steel penetrator, lead core. While the lead is iffy, both copper and steel will ignite in LOX under high shock conditions (and if there's anything that's a high shock condition, it's a bullet impact).
I really doubt that they've considered everything. For instance possible ignition sources should include static electricity from high atmospheric charge driven by enhanced solar wind conditions (coronal hole influence). They're smart enough not to launch in a thunderstorm, yet surprisingly don't seem to avoid a related condition.
You mean, on the rocket sitting between four separate lightning towers? Our are you talking about some other situation?
What is the dark spot on the video supposed to have to do with anything? I can't believe Slashdot even linked that thing. SpaceX is investigating seeing a shadow and white flash on a ULA building in a video that they have.
I think the concept that ULA itself would have hired a sniper to shoot out a SpaceX rocket to be beyond absurdity. However, the concept that a ULA employee might happen to be a bit unhinged, as well as good with a gun? Not nearly so much.
It would of course depend on how good ULA's security procedures are. Do their employees need to go through a metal detector or anything that could have stopped them from taking a gun to work? Honestly, I doubt it, but if so it'd hinder that possibility.
It's interesting that this event happened 2 weeks after the explosion. They had almost certainly recovered most of the debris by that point and looked over the most obvious culprits; it's not like they did this the day after the explosion. This would imply that - at least based on what they could see two weeks into the investigation - the damage could be consistent with a bullet. That, of course, doesn't mean that it couldn't be consistent with anything else - only that it's at least considered a possibility. What I wouldn't give to see what they've found so far.... a COPV with a big round hole in its side for example would be pretty damning.
Amazing how Slashdot can include a video about conspiracy theories not being investigated, and by doing so imply that this is actually the core of the investigation.
The "UFO" has nothing to do with anything being investigated. The only thing present in that particular video under investigation was a sound heard shortly before the explosion. A different video (not public) showed a shadow and white flash on the roof of a ULA building.
They've cleared the struts of any responsibility. Nor would that make any sense, as - being on the ground - there would be little force on the struts. Due to how buoyancy works, the more the G forces there are on the rocket, the more the helium tanks try to rise in the LOX, and the more load there is on the struts keeping them in place.
Note that the strength of the struts has nothing to do with the "helium tanks" (COPVs)
I doubt that they would consider this theory if there was any sort of other obvious explanation for the damage that they're seeing. Every failure requires an explanation, a way to reproduce the results.
Indeed. I would be utterly shocked if ULA, as a company, made a decision to do this. Even moreso if it were done in a way that could lead back to them. On the other hand, a random angry employee with a gun? Gee, Americans shooting at entities that they're angry about, never heard of that happening before ;)
Break out the popcorn...
I think you're a bit confused as to how rockets work (hint: they don't need air to burn)
More to the point, as a general rule a second stage would be easier to penetrate, as they're usually built lighter (not sure the thickness on SpaceX's stages, but in general it works like that).
Strangely, Al-Li alloys are more resistant to impact ignition with LOX than pure Al. That said, the LOX will have burned up part of the aluminum. *That* said, I still would expect them to "most likely" recover a penetration hole if one existed.
One of the things SpaceX had been investigating from the beginning was a bang heard in distance before the explosion.
I really doubt this is what happened. But if it did... my god, this would be one of the biggest scandals in the entire history of spaceflight. Even if it was an employee acting on their own.
Even ignoring the issue of whether a shock can make LOX react with aluminum (it can) or composites (it can very easily), the failure was in the helium system. The high pressure helium system, which stores all of the pressurant for the launch. Yes, if you shoot a pressurized COPV, it most definitely will release its pressurant in very short order.
That's not to back up this shooting hypothesis. But concerning whether a bullet could have caused the failure if present, I don't think there's any question about it. I don't think it should come as a surprise to anyone, but in case it does: shooting at fueled, pressurized rockets is a bad idea.
Love that analogy!
Since it's not clear from your post, have you actually played NMS?
The reason that most people essentially max out tech on their first planet isn't because they're "completionists", it's because there's so little content in the game. NMS is an "everything can be found everywhere in bulk" sort of game. Including tech blueprints.
It's not a comparison of mining equipment or no mining equipment - it's a comparison of A) automated, self-maintaining, may-not-get-damaged-or-it's-lost-forever mining equipment or B) human-controlled, human-maintained, human-salveagable mining equipment. In an environment where the premise is that humans already are.
Because there are no humans there. What about this is hard for you to understand? I'll repeat: there is precisely one place in the solar system where humans exist outside of Earth: ISS. Do robots outcompete them there - yes or no?
Red herring. We're comparing to a scenario where humans are on Mars either way. Talking about the cost of putting people on Mars, keeping them alive, etc, is irrelevant because that is planned either way. The question at hand is, is it cheaper to use their already present labour, or send robots? And it's a no contest comparison.
No, and:
1) ... nor would you have the payload capacity to send something like that ... nor would something like that survive the Martian environment (dust, radiation, cold, pressures low enough for outgassing, difficulty with radiating excessive heat, etc) ... nor can you use that sort of power source on Mars ... nor do you have people there to do the (extreme) sort of maintenance such a vehicle requires ... nor do they do the most complex operations, only doing the (proportionally very simple) ferrying operations ... nor do they have to avoid risk at all cost due to the lack of people there to fix it if it goes awry and hits something ... nor do they have to avoid risk at all cost due to the lack of people there to fix *whatever it might run into* if it goes awry and hits something. ... and about fifty other things.
2)
3)
4)
5)
6)
6)
Deflection. The question was, in construction and research on ISS, do they use the available human labour, or do they send robots to do it? Of course robots are used where there aren't humans, but that's not the topic of discussion; we're talking about a world where there's a human settlement on Mars. You're arguing that robots outcompete humans in a space environment where humans are. Well, we have precisely one space environment where humans are - ISS. Where are all of the robots outcompeting them?
I'll reiterate:
Surely this is a joke. How can you possibly have any tech blueprints left to find, 120 hours into the game? Most people essentially max out on their first planet.
You have a serious tolerance for grind. I don't know whether I should congratulate or feel bad for you. ;)
ASCII? You spoiled child, back in my day our games graphics were displayed with blinking readout lights on a board. Old Flashey, we used to call that board. A game of "Hit The Button At The Right Time" used to cost a dime, which was two hours wages at the time, but oh, how I sunk so many dimes into Old Flashey...