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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 exagg

• akiselev 13y ago
  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)
  • mturmon 13y ago
    Regarding your (2), I think you may not be aware of the vast scope of Earth observing missions (http://science.nasa.gov/earth-science/missions/ http://science.nasa.gov/earth-science/missions/). 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.
    • akiselev 13y ago
      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.