Though there are many factors leading up to the failure listed in the article, I think the most serious one was not testing the system under the expected flight conditions. It seems like such a big oversight that I wouldn't be surprised if there were other bugs lurking in the system that had also gone undetected.
Maybe someone more knowledgeable about these things can answer this for me: when they say that this resulted in the loss of $370 million, is that number the entire mission cost or simply the actual rocket plus Cluster cost? I imagine the r&d cost far outweighs the cost of the actual build. I've been wondering at the same time why we don't send another one or two rovers to mars based on the design of curiosity seeing how it worked, as how expensive would the entire build be to replicate considering there's no more r&d costs?
I think it is physical materiel and fuel costs. The R&D efforts leading up to the launch were certainly not a waste, as the Ariane V flew again after the accident, so it doesn't make sense to include them in the loss.
Modern space programs operate on a skewed risk tolerance mostly for public relations purposes. Given a billion dollar program with a $250 million final build and launch cost, NASA and ESA will chose to spend $750 million on R&D and launch one mission with a 95% success chance instead of $500 million on R&D and two missions with a 80-90% success chance (money spent on R&D has rapid diminishing returns on the success rate of satellites, whether you're talking about CubeSats or billion dollar satellite arrays, and two launches at 80% has a 96% success chance). NASA knows that most projects (Mars Science Lab excluded) can be done such that the budget pays for two launches instead of one by spending money on cheaper components (a single CPU made specifically for high radiation environments is like $1mil+) but when it comes to public perception, 2 failed launches sounds better than 3 or 4 (despite the fact that the latter would mean 6-7 successful launches versus 3-4 for the former).
The $370 million was probably the cost of the four satellites and the rocket + operations. It might include R&D but not most of the scientific operations part of the grant (there is tons of science to do before and after a scientific mission like this).
You're making some broad-brush proclamations here that are wrong. I think you have a point regarding the risk tolerance of some NASA missions, but you're exaggerating too much, and your comment can't be taken seriously as a result.
I don't want to thoroughly engage all the problems with your comment, but I'll point out two: (1) Launching two spacecraft is not a cure for poor system reliability. Systems fail after launch for all kinds of reasons; a 1-in-2 launch success rate and 2 launches does not guarantee a successful mission. You can't build systems that are half reliable and half not. (2) Some things really have to work on the first try: Earth and sun-observing systems that need data continuity with failing earlier systems, planetary missions with narrow launch windows, systems with standing armies of on-ground analysis personnel who can't be put on hold while a replacement is built and launched.
1) I'm not talking about stripping the budget willy-nilly but relaxing the risk-tolerance that goes into making the calculations for the reliability budget across the board. A trivial example from my own experience is in working on a Cubesat thermal system. There were a lot of trade offs that we had to make like whether to use cheap thermal tape or use some expensive quartz reflective panels or whether to just slap a heat sink on something or use a peltier cooler. Each trade off could drastically change the cost of the final build and the cost of R&D time and equipment. For a Cubesat, the added up differences wouldn't cover the cost of a second launch but I would expect there to be major trade offs to be made that wouldn't totally compromise the mission in larger projects.
2) I fully agree, and there are many missions that are just so important that we should strive for success on the first try (MSL, some extremely better telescope like NuStar, and probably the satellites in this article), but NASA's/ESA's budget is much bigger than just those missions and I would argue many of them could have afforded second launches without drastically compromising reliability (i.e. without becoming half reliable and half not as you say)
Many of these are monitoring missions with data continuity constraints. For example, solar irradiance monitors are hard to calibrate, so missions need to overlap.
Also, they have a set of scientists that do calibration, who can't be told to go away and do something else for two years while a replacement is built. This kind of happened with OCO, and it was a bummer.
You're right, I do not, and I admit I thought little about how important data continuity is. Everything below is speculative and clarification would be greatly appreciated:
I just read up on the OCO and that really does suck. In this case I doubt $280 mil would have paid for 2 launches without making it half-reliable but perhaps a spread on risk across multiple similar missions would work. If (and this is a big if) there are enough missions that need roughly the same payload volume/size, orbit, etc. they can split the cost of a third rocket and both build a carbon copy backup, or if a backup would be too expensive invest in maintaining the staff and tooling for the most expensive instrumentation for a faster, cheaper backup build later on. If one of the mission fails, they have a third backup launch and a realistic shot of having/making a second satellite. If they both succeed, the launch is sold for profit to someone who really really needs the launch window or donated to civilian and less critical mission satellites.
This is of course stretching into changing NASA bureaucracy and would have tons of unforeseen consequences but would have the interesting side-effect of providing more low-cost or even free piggy back launch opportunities, especially for CubeSats. Also, talking to an engineer at Orbital, the increased volume could really help lower costs for everyone Also, in the case of critical staff for calibration, operation, etc., how the cost/opportunity cost of having them just sit there while the mission rebuilds versus losing them to other projects?
My thought isn't to passively set aside part of the budget for backups but to actively use the resources to create a smart risk management system that (and I'm making a big assumption) looks at the satellite and launch hardware as far more expendable than it is now, in exchange for more overall throughput. Thinking about the OCO, it's difficult to tell if it's an example of why it wouldn't work or if the delay in what (I would think) would be a critical data source on our impact on our planet is an argument for a shift in philosophy. It would be like going from "Once in a while, the launch will fail but it's rare so let's focus on making the satellite stay up as long as possible" to "Rockets blow up all the time so let's make sure we're not the ones stuck without a backup for what is already a ten to hundred million range dollar project." With the rapid progression of everything from electronics to materials to information technology, it might be beneficial to start thinking on shorter mission time lines for Earth orbiting missions.
Rereading your comments though, it seems that I am under the delusion that a larger portion of NASA's mission are exploratory and more flexible versus missions that support critical infrastructure or carry instruments for data that is far too valuable. Or maybe the bureaucracy carries more overhead than I think it does and the days of NASA taking risks like the explorers of the Old and New world are behind it.
It's a long road to space-qualify a new technology, and because system failure is a logical OR of subsystem failures, you can't put too much new tech or new science into a mission. You'll try a bunch of stuff and one thing will fail, and you won't learn much.
Multiple launches of unreliable systems are not a particularly good way to reduce risk. That's not doing engineering, that's throwing darts.
Can someone tell me why this article spends 90% of its wordcount talking about the rocket used to launch the spacecraft rather than the spacecraft itself?
You should probably write a letter to the editor of Wikipedia with your question/complaint, and perhaps threaten to cancel your subscription if their writing doesn't improve to cover what you think it should cover.
Currently, "Ariane 5 Flight 501" redirects to this article. There is a category for launch failures (http://en.wikipedia.org/wiki/Category:Satellite_launch_failu...), and looking at that I guess the Wikipedia convention is to name launch failure articles after the satellite that would have been launched.
That's industry tradition. It's not common to number or name launches, but rather to refer to the primary payload, e.g. “The MSL launch”.
EDIT: I'm sure that the launch provider has some naming scheme referencing the rocket itself, but usage of that is almost universally confined to internal communications. Human spaceflight is perhaps the exception (STS-125, not Hubble Servicing Mission #4).
That one's bad enough, but my favorite is the $420M "Glory" satellite that fell into the Pacific ... after the payload faring separation failed ... just like it did for the previous, Orbiting Carbon Observatory launch.
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[ 3.1 ms ] story [ 44.7 ms ] threadhttps://www.youtube.com/watch?v=kYUrqdUyEpI
The $370 million was probably the cost of the four satellites and the rocket + operations. It might include R&D but not most of the scientific operations part of the grant (there is tons of science to do before and after a scientific mission like this).
I don't want to thoroughly engage all the problems with your comment, but I'll point out two: (1) Launching two spacecraft is not a cure for poor system reliability. Systems fail after launch for all kinds of reasons; a 1-in-2 launch success rate and 2 launches does not guarantee a successful mission. You can't build systems that are half reliable and half not. (2) Some things really have to work on the first try: Earth and sun-observing systems that need data continuity with failing earlier systems, planetary missions with narrow launch windows, systems with standing armies of on-ground analysis personnel who can't be put on hold while a replacement is built and launched.
2) I fully agree, and there are many missions that are just so important that we should strive for success on the first try (MSL, some extremely better telescope like NuStar, and probably the satellites in this article), but NASA's/ESA's budget is much bigger than just those missions and I would argue many of them could have afforded second launches without drastically compromising reliability (i.e. without becoming half reliable and half not as you say)
Many of these are monitoring missions with data continuity constraints. For example, solar irradiance monitors are hard to calibrate, so missions need to overlap.
Also, they have a set of scientists that do calibration, who can't be told to go away and do something else for two years while a replacement is built. This kind of happened with OCO, and it was a bummer.
I just read up on the OCO and that really does suck. In this case I doubt $280 mil would have paid for 2 launches without making it half-reliable but perhaps a spread on risk across multiple similar missions would work. If (and this is a big if) there are enough missions that need roughly the same payload volume/size, orbit, etc. they can split the cost of a third rocket and both build a carbon copy backup, or if a backup would be too expensive invest in maintaining the staff and tooling for the most expensive instrumentation for a faster, cheaper backup build later on. If one of the mission fails, they have a third backup launch and a realistic shot of having/making a second satellite. If they both succeed, the launch is sold for profit to someone who really really needs the launch window or donated to civilian and less critical mission satellites.
This is of course stretching into changing NASA bureaucracy and would have tons of unforeseen consequences but would have the interesting side-effect of providing more low-cost or even free piggy back launch opportunities, especially for CubeSats. Also, talking to an engineer at Orbital, the increased volume could really help lower costs for everyone Also, in the case of critical staff for calibration, operation, etc., how the cost/opportunity cost of having them just sit there while the mission rebuilds versus losing them to other projects?
My thought isn't to passively set aside part of the budget for backups but to actively use the resources to create a smart risk management system that (and I'm making a big assumption) looks at the satellite and launch hardware as far more expendable than it is now, in exchange for more overall throughput. Thinking about the OCO, it's difficult to tell if it's an example of why it wouldn't work or if the delay in what (I would think) would be a critical data source on our impact on our planet is an argument for a shift in philosophy. It would be like going from "Once in a while, the launch will fail but it's rare so let's focus on making the satellite stay up as long as possible" to "Rockets blow up all the time so let's make sure we're not the ones stuck without a backup for what is already a ten to hundred million range dollar project." With the rapid progression of everything from electronics to materials to information technology, it might be beneficial to start thinking on shorter mission time lines for Earth orbiting missions.
Rereading your comments though, it seems that I am under the delusion that a larger portion of NASA's mission are exploratory and more flexible versus missions that support critical infrastructure or carry instruments for data that is far too valuable. Or maybe the bureaucracy carries more overhead than I think it does and the days of NASA taking risks like the explorers of the Old and New world are behind it.
A starting point is http://nmp.nasa.gov/ which is a series of missions that specifically accept risk to develop selected new technologies. There are also opportunities for higher-risk science-investigations (http://science.nasa.gov/about-us/smd-programs/earth-system-s...). There is also a pathway through airborne systems, to develop new mission concepts (e.g., http://lidar.jpl.nasa.gov/co2las.html)
It's a long road to space-qualify a new technology, and because system failure is a logical OR of subsystem failures, you can't put too much new tech or new science into a mission. You'll try a bunch of stuff and one thing will fail, and you won't learn much.
Multiple launches of unreliable systems are not a particularly good way to reduce risk. That's not doing engineering, that's throwing darts.
EDIT: I'm sure that the launch provider has some naming scheme referencing the rocket itself, but usage of that is almost universally confined to internal communications. Human spaceflight is perhaps the exception (STS-125, not Hubble Servicing Mission #4).
https://en.wikipedia.org/wiki/Glory_%28spacecraft%29