Quote from: edkyle99 on 02/08/2014 04:22 pmAtlas 5's 43 launch flight record makes it possible to predict with high confidence that it should have a better than 96% reliability rate - ranking only behind Soyuz and Delta 2. Falcon 9 v1.1's 3-launch record only makes it possible to say with confidence that it should do better than 80%. Falcon 9 v1.1 would have to score 20 consecutive initial successes to get to a proven high-confidence 95% reliability. Atlas 5 has a big head start in this regard. - Ed KyleYes, but SpaceX's rocket certainly has the /potential/ of equal or even better reliability. Atlas V relies on booster rockets for larger payloads (i.e. CST-100 and the like) which don't have engine-out capability, neither do the two upper stage engines. Falcon 9 has engine-out capability on the multi-engine first stage and the fewest feasible number of stages (2) and just a single upper stage engine....
Atlas 5's 43 launch flight record makes it possible to predict with high confidence that it should have a better than 96% reliability rate - ranking only behind Soyuz and Delta 2. Falcon 9 v1.1's 3-launch record only makes it possible to say with confidence that it should do better than 80%. Falcon 9 v1.1 would have to score 20 consecutive initial successes to get to a proven high-confidence 95% reliability. Atlas 5 has a big head start in this regard. - Ed Kyle
The line of reasoning that goes "we've invested in all these vehicles, so we should find a way to use them all" is a form of the Sunk Cost Fallacy.http://en.wikipedia.org/wiki/Sunk_cost_fallacy#Loss_aversion_and_the_sunk_cost_fallacyBoth safety and cost of a particular vehicle improve with each additional flight. Eventually, you get diminishing returns to the point where additional flights don't improve things much. But the foreseeable flight rates of these vehicles are very far from reaching the point of diminishing returns. Hence splitting the limited number of flights among more vehicles means overall costs are much higher and safety much lower.It isn't necessarily a waste to invest in several development programs even knowing you're going to cancel some of them. That's because you don't know which of the development programs will do best. By investing in several and then choosing one, you can potentially get a better expected outcome per dollar spent than with any other way of spending those dollars.
I'm just wondering what happens to these companies in the non-alternate universe, that have invested a lot of resources in crew transport when the ISS gets de-orbited in the mid 2020's or so.Without a robust manned program in place by then, such as a replacement station or such (seems unlikely) how will four, or three or even one of these companies be able to afford to maintain the infrastructure to produce crew-carrying spacecraft.Space-X and Orbital, yes. they have the satellite launch market angle but CST-100 or (in particular) DreamChaser...once the ISS is gone won't those companies have a tough, if not impossible, time maintaining those capabilities with a greatly reduced need for crew transport missions?Even though the Russians or especially the Chinese will/could likely maintain a continuous manned presence in space they're not going to contract private American firms for crew launch. Likewies ESA or JAXA...nowhere to send crews to.
Quote from: ApolloStarbuck on 02/09/2014 04:55 amI'm just wondering what happens to these companies in the non-alternate universe, that have invested a lot of resources in crew transport when the ISS gets de-orbited in the mid 2020's or so.Without a robust manned program in place by then, such as a replacement station or such (seems unlikely) how will four, or three or even one of these companies be able to afford to maintain the infrastructure to produce crew-carrying spacecraft.Space-X and Orbital, yes. they have the satellite launch market angle but CST-100 or (in particular) DreamChaser...once the ISS is gone won't those companies have a tough, if not impossible, time maintaining those capabilities with a greatly reduced need for crew transport missions?Even though the Russians or especially the Chinese will/could likely maintain a continuous manned presence in space they're not going to contract private American firms for crew launch. Likewies ESA or JAXA...nowhere to send crews to.What about private space stations? Bigelow is collaborating with Boeing to develop the CST-100, and two years ago they announced a partnership with SpaceX. "What Bigelow offers Boeing, SpaceX, and other vehicle developers is the promise of a sustained, large market for space transportation services."
Quote from: ChrisWilson68 on 02/09/2014 06:13 amThe line of reasoning that goes "we've invested in all these vehicles, so we should find a way to use them all" is a form of the Sunk Cost Fallacy.http://en.wikipedia.org/wiki/Sunk_cost_fallacy#Loss_aversion_and_the_sunk_cost_fallacyBoth safety and cost of a particular vehicle improve with each additional flight. Eventually, you get diminishing returns to the point where additional flights don't improve things much. But the foreseeable flight rates of these vehicles are very far from reaching the point of diminishing returns. Hence splitting the limited number of flights among more vehicles means overall costs are much higher and safety much lower.It isn't necessarily a waste to invest in several development programs even knowing you're going to cancel some of them. That's because you don't know which of the development programs will do best. By investing in several and then choosing one, you can potentially get a better expected outcome per dollar spent than with any other way of spending those dollars....so what why not allow them to become part of the U.S. spacecraft inventory upon full orbital operation? If they fail due to poor business decisions or another circumstance then is on them... As I said when I started this thread it is an “Alternate Universe” where we didn’t spend twenty plus Billion to sell the scrapper for pennies on the million...
Quote from: Rocket Science on 02/09/2014 12:37 pmQuote from: ChrisWilson68 on 02/09/2014 06:13 amThe line of reasoning that goes "we've invested in all these vehicles, so we should find a way to use them all" is a form of the Sunk Cost Fallacy.http://en.wikipedia.org/wiki/Sunk_cost_fallacy#Loss_aversion_and_the_sunk_cost_fallacyBoth safety and cost of a particular vehicle improve with each additional flight. Eventually, you get diminishing returns to the point where additional flights don't improve things much. But the foreseeable flight rates of these vehicles are very far from reaching the point of diminishing returns. Hence splitting the limited number of flights among more vehicles means overall costs are much higher and safety much lower.It isn't necessarily a waste to invest in several development programs even knowing you're going to cancel some of them. That's because you don't know which of the development programs will do best. By investing in several and then choosing one, you can potentially get a better expected outcome per dollar spent than with any other way of spending those dollars....so what why not allow them to become part of the U.S. spacecraft inventory upon full orbital operation? If they fail due to poor business decisions or another circumstance then is on them... As I said when I started this thread it is an “Alternate Universe” where we didn’t spend twenty plus Billion to sell the scrapper for pennies on the million...The ideal universe result you actually need is to have one or maybe two winners on ISS missions and all other entrants go on to thrive in their own market segments with new customers. Conflating US spacecraft with government spacecraft is confusing. Dream Chaser is investigating options towards this goal I believe.As a layman I thought the goal of the program always was to leverage NASA experience and knowledge into stimulating a self perpetuating industry that it could then go back to when required.