Quote from: yg1968 on 10/08/2009 06:15 pmQuote from: kkattula on 10/08/2009 06:14 pmQuote from: Ben the Space Brit on 10/08/2009 06:05 pm...FWIW, I agree with Bo about seperate 'mission' and 'archetecture' safety assessment is necessary. How safe any given mission would be must be necessarily affected by the suitability and reliability of the vehicle. That said, safety is really on roughly equal footing with cost, IMHO. It doesn't matter if your rocket has a 1:1400 LOC rate if you can't afford it, after all....NASA put their launch vehicle requirement at 1:1000 or better. If the other factors in a mission give an overall rating of 1:100 or 1:20, then it makes no significant difference whether the LV is 1:1100 or 1:2000 or 1:10000000000. The effect on the mission rating is lost in the noise.Yes but a lot of these risks increase because we have not done it often and the more missions we fly to the moon, the less risky it becomes. It's also a matter of how many times, we have done it and not just the fact that we are going further into space.And its a whole lot easier to do so if you aren't blowing $40B on making a vehicle that in the best perfect theoretical world only improves mission crew safety by 0.1%.~Jon
Quote from: kkattula on 10/08/2009 06:14 pmQuote from: Ben the Space Brit on 10/08/2009 06:05 pm...FWIW, I agree with Bo about seperate 'mission' and 'archetecture' safety assessment is necessary. How safe any given mission would be must be necessarily affected by the suitability and reliability of the vehicle. That said, safety is really on roughly equal footing with cost, IMHO. It doesn't matter if your rocket has a 1:1400 LOC rate if you can't afford it, after all....NASA put their launch vehicle requirement at 1:1000 or better. If the other factors in a mission give an overall rating of 1:100 or 1:20, then it makes no significant difference whether the LV is 1:1100 or 1:2000 or 1:10000000000. The effect on the mission rating is lost in the noise.Yes but a lot of these risks increase because we have not done it often and the more missions we fly to the moon, the less risky it becomes. It's also a matter of how many times, we have done it and not just the fact that we are going further into space.
Quote from: Ben the Space Brit on 10/08/2009 06:05 pm...FWIW, I agree with Bo about seperate 'mission' and 'archetecture' safety assessment is necessary. How safe any given mission would be must be necessarily affected by the suitability and reliability of the vehicle. That said, safety is really on roughly equal footing with cost, IMHO. It doesn't matter if your rocket has a 1:1400 LOC rate if you can't afford it, after all....NASA put their launch vehicle requirement at 1:1000 or better. If the other factors in a mission give an overall rating of 1:100 or 1:20, then it makes no significant difference whether the LV is 1:1100 or 1:2000 or 1:10000000000. The effect on the mission rating is lost in the noise.
...FWIW, I agree with Bo about seperate 'mission' and 'archetecture' safety assessment is necessary. How safe any given mission would be must be necessarily affected by the suitability and reliability of the vehicle. That said, safety is really on roughly equal footing with cost, IMHO. It doesn't matter if your rocket has a 1:1400 LOC rate if you can't afford it, after all....
The problem is that NASA is staring itself blind on the whole "crew separate from cargo". It is a policy that will ultimately result in the death of NASA spaceflight - for budget reasons.
Quote from: Lars_J on 10/08/2009 11:04 pmThe problem is that NASA is staring itself blind on the whole "crew separate from cargo". It is a policy that will ultimately result in the death of NASA spaceflight - for budget reasons. Cargo is define as mass not related to mission, ie a comsat. Another manned spacecraft (lunar lander) or some important ISS logistics are not "cargo". But ISS logistics items such Tang, toilet paper and tee shirt (low value) are included as "cargo",
I agree... but Ares I appears to be specifically designed to do absolutely minimal 'cargo'. (or logistics) It is taking the "crew separate from cargo" to the extreme - which is the core belief behind the "1.5 launch" philosophy/fallacy.
Quote from: Jim on 10/09/2009 12:01 amQuote from: Lars_J on 10/08/2009 11:04 pmThe problem is that NASA is staring itself blind on the whole "crew separate from cargo". It is a policy that will ultimately result in the death of NASA spaceflight - for budget reasons. Cargo is define as mass not related to mission, ie a comsat. Another manned spacecraft (lunar lander) or some important ISS logistics are not "cargo". But ISS logistics items such Tang, toilet paper and tee shirt (low value) are included as "cargo", I agree... but Ares I appears to be specifically designed to do absolutely minimal 'cargo'. (or logistics) It is taking the "crew separate from cargo" to the extreme - which is the core belief behind the "1.5 launch" philosophy/fallacy.
Show me one lift vehicle other than the Shuttle that is human rated and exists anywhere but on paper. The term "paper rocket" is meaningless.
Bingo, that is the whole crux of the matter. Ares I (32 billion) is not worth the 0.1%
But wasn't it the point to seperate crew from cargo that resulted in Ares-1?
And you said that Ares-1 is so bad. Do you really think NASA managment is totally incompetent not seeing the *as you say* amazing DIRECT design???
NASA has gone public with all it's (big and small) problems since Columbia. Seeing this, i can't beleave that NASA is closing her eyes regarding nothing else than the future of human space flight.
Even Mr. Augustine thinks that there are better ways than DIRECT. (flexible Path....)
Quote from: Jim on 10/09/2009 12:03 amBingo, that is the whole crux of the matter. Ares I (32 billion) is not worth the 0.1% And that is the reason we all love Jim"I am sorry mam, your son can not have the 5 million dollar surgery to save his life. If he lives 80 more years and makes 50k a year, he will never earn enough to pay it back" , reaches over, unplugs the cord, sips his coffee, and walks out of the room.
But they figure that these issues can be fixed with enough time and money which is a fair assesment in my opinion.
Just 2 things you have missed: the 6-crew requirement was never required for lunar missions.
1) I might be wrong, but I think that the six-crew requirement originates from a Mars crew return mission profile. 2) An Orion with one pilot is launched to rendezvous with a returning MTV beyond LEO to recover the crew of five. 3) Hence you have the six-seat requirement. Once again, we were reminded that Ares-I and Ares-V were originally intended for Dr. Griffin's vision of a Mars HSF program.4) IMHO, six crew is a nice round number for general LEO orbital maintenance missions. You thus have two two-man EVA teams that you can rotate during the mission, plus a pilot and a flight engineer (the latter to operate the RMS). 5)You could also theoretically use Orion as a one-vehicle lifeboat for a full six-man ISS crew. I'm pretty sure that this latter requirement is what is driving Roscosmos to specify six crew for their Soyuz replacement.
At times during the public hearings he seems to have been doing nothing but fighting the PoR's corner against all-comers.
Quote from: Matthew Raymond on 10/08/2009 09:39 pmI just don't see there being enough payloads to justify the development costs.That's my point - If you're going to develop the JUS anyway, you should be able to get the smaller-diameter ACES stage much cheaper than if you had to develop it from scratch. Which is apparently something ULA wants to do anyway, but can't quite justify based on current markets... The JUS contract could tip the balance. After all, the ACES-41 would be a far better EELV upper stage than the Centaur or DHCUS, and once you've got it, you've got it.In addition, if a JUS-based depot needs filling, you could use an ACES-71 to do that...
I just don't see there being enough payloads to justify the development costs.
Quote from: Matthew Raymond on 10/08/2009 09:24 pmShow me one lift vehicle other than the Shuttle that is human rated and exists anywhere but on paper. The term "paper rocket" is meaningless.Most any of the operational launchers are "human rated". The term "human rated" is meaningless.
Not so. First of all, manned launch vehicles need instrumentation on all systems for two reasons:1) NASA needs a steady stream of data for mission operations, and later for mission analysis to see what worked and what needs to be changed.2) The LAS needs to know when something has gone wrong to trigger an emergency auto-abort.Secondly, systems need to be specifically designed with crew safety in mind. Excessive G forces and thrust oscillations are examples of things you want to be sure you design out of your rocket before you put people on it.3. Just because there isn't literally an official "rating" for human space flight doesn't mean that there aren't certain things that need to be done to prepare a lift vehicle for manned missions. I personally think that NASA should create a set of official "human rating" guidelines so that we can put this silly argument to rest.