I'd like to know exactly what is required for man-rating a rocket. Does it involve extra testing? Or is redesigning required to accommodate added redundancy? Let's hear from the experts. Ted
Whoa... you're wading in where angels fear to tread... LOL
I'm not going to pretend to be an expert, but I've been reading up on this for over 4 years on nasaspaceflight.com, which I HIGHLY recommend (REAL rocket scientists hang out there and literally you can learn more there than you ever dreamed... I know I have!) so here's what I've learned...
Manrating involves, first of all, designing everything to at least a 1.4 "fundamental of safety" (safety level) in the rocket... in other words, everything should be able to tolerate at least 40% over the "normal, expected" loads encountered without failing, IE tanks should be able to take 40% more than the expected pressure without rupturing, etc. Manrating also involves monitoring the 'health' and performance of various components, avionics, the rocket engine turbopumps, thrust, TVC, etc. and have the capability of safe shut down (for liquid engines anyway) and automatic abort if necessary. The trajectory has to stay outside of 'black zones' which would impose loads or conditions which would make an abort impossible or extremely risky to a crew of being successfully performed.
There are a TON of other factors and requirements that play into all this, and I won't pretend to go into it, but if you're REALLY interested there ARE a lot of resources in the forums on nasaspaceflight.com that are available. There's also the L2 forum (for a monthly fee) where you can look at the ACTUAL TECHNICAL DOCUMENTS of the space program, requirements, capabilities, studies, etc...
Here's the deal... Prior to Columbia, the "planned" shuttle replacement (eventually maybe someday-- kinda like X-33, X-38, NASP, etc.) was supposed to be the "OSP" (Orbital Space Plane) which was sort of a winged lifting body used to ferry astronauts to space and maybe small cargo. OSP was supposed to launch on an EELV (Delta IV, Atlas V) which were then deemed capable of being SAFE ENOUGH FOR A MANNED LAUNCHER (with mods). After Columbia demonstrated the need for shuttle retirement and the CEV proposals started to be floated for a shuttle follow on (back when the arguments between a small spaceplane (ala OSP), capsule, biconic, orbital module/capsule (soyuz-like) design, etc. were being hashed out) NASA Administrator O'Keefe and Admiral Steidle's plans were to use EELV to launch the CEV, and then follow on with an EELV Phase II/III heavy lift vehicle (HLV) for cargo launches (moon landers, habs, fuel depots, Mars trans-habs, tankers, etc). Shuttle would be flown out and then shut down.
Now, the thing is, NASA learned that one of the weaknesses that Apollo suffered was that it's production/use was focussed in only a few areas, IE California, Alabama, Louisiana, Florida, Texas, and a few others, which meant that it's POLITICAL SUPPORT in Congress wasn't widespread enough to fend off cancellation once the moon landing was accomplished, especially for such a big, highly visible, and expensive program. When NASA got the shuttle program, they decided not to repeat that mistake again, so they made the STS program as "wide-spread" as possible to garner the maximum amount of political support (who can vote against shuttle if it means that the vendor in their district will be shut down, and local jobs back home will be lost-- why they're likely not to re-elect the guy!) and this widespread support served shuttle pretty well through a lot of storms here and there... but it's also a double edged sword-- when it became apparent that shuttle needed replacing, it ALSO meant that, if STS were shut down, those politicians would face the wrath of an angry electorate back home who lost their jobs when shuttle was shut down. SO, there was ENORMOUS political pressure to replace shuttle with something that would keep those jobs *more or less* in place and uninterrupted to the extent possible... thus "shuttle derived" was born-- SDLV. O'Keefe and Steidle were out, EELV was out, and SDLV was in, along with Mike Griffin and his cohorts who had thier own ideas of SDLV, primarily a proposal called "the Stick" which became Ares I. To quell the substantial fight that the EELV proponents were putting up and make SDLV a 'shoo-in', the decision was made to make CEV (Orion) a 5.5 meter capsule-- "too big" to fit on an EELV. There was also a big "FUD" campaign to smear EELV's as "unsafe" due to blackzones (which could be overcome by a trajectory change, and was, but the red herring remained), that EELV would require a new expensive upper stage development and qualification program (like Ares didn't... in fact Ares requires TWO-- one for Ares I and another for Ares V EDS) and that it would cost MORE to manrate EELV than Ares I would cost to develop (patently rediculous). The ESAS study was done to "confirm" the architecture based on a so called "one and a half" launch solution was "best", which relied on the launch of a small crew launcher, followed by the launch of a cargo rocket carrying the hardware needed. The small size/capability of the crew launcher would require a HUGE cargo rocket to carry all the needed mission hardware, fuel, consumables, equipment, etc. Thus was born Ares V. Other SDLV advocates said it was the wrong choice-- designing, building, and operating TWO different rockets, one small and one gigantic, launching TWO times per mission, would be FAR more expensive than designing ONE "medium sized" SDLV that could be built as identical units, launched TWICE for each mission, one for crew and some cargo, the other for only cargo, would be much cheaper. As Ares I strayed further and further from it's initial ESAS design, requiring a new first stage SRB, new upperstage engine, and still was having serious underperformance issues, it grew more and more different from the shuttle derived components from which is was supposed to be built, and as Orion got heavier and Ares I required more equipment be installed for vibration mitigation, among other things, more and more weight and capabilities were being required of Ares V, making it grow more and more huge to make up for Ares I inadequacy. This caused it to grow SO huge that it had virtually NOTHING in common with shuttle, from which it was supposedly derived. It also got to be less and less compatible with it's brother Ares I, which would drive costs through the roof.
Now here we are five years and 9 billion dollars later, and guess what?? Ares I and V ARE too expensive, are too far out to save the shuttle workforce from massive layoffs, EELV is cheaper and CAN be made to work safely, and developing and launching a SINGLE SDLV rocket twice for exploration missions IS cheaper and better than the "little and big" Ares solution... Just what everybody but Griffin and his cadre were saying all along... now that STS is winding down and the pink slips are fixing to go out, with an unpopular president and his party facing a drubbing in the upcoming elections, there is a LOT of pressure to prevent those layoffs, and with the budget getting creamed (and soon the country by inflation) the pressure is on for a more affordable, more quickly available SDLV solution, and for commercial interests to take up ISS deliveries... SDLV in SOME flavor is required to prevent the job losses, and commercial is the best bet for quick results to close the gap.
THAT's why we are where we are... OL JR
