That is a cool picture
Posted on 06/25/2002 1:20:24 PM PDT by GeneD
That is a cool picture
Just in case anyone thought I was serious, I wasn't. I don't believe in the shuttle/earthquake thing. I was just making a joke. I used to subscribe to Skeptical Inquirer, so that should tell you something.
NASA is correct to ground the fleet. However, this will impart millions of dollars of penalties on ISS operations and jeopardizes the safety of the crew on ISS if Soyuz can not effectively be replaced.
It must be a lonely feeling on ISS right now. The only solace is that Soyuz capsule. If the old capsule fails, they're dead!
FYI. Hydrogen is not hypergolic in this situation. The hydrogen-oxygen mixture requires an ignition source. In the gas generators and main chamber of the SSME this is is accomplished with an augmented spark igntion (ASI) system.
Allow me to clarify what should have been the main facts in the article:
The three main engines gimbal, remember. So the fuel lines contain bellows which allow for the movement. The "flow liners" are inside these bellows at the interfaces between the orbiter and the engines.
From space.com:
The cracks were found on metal liners that fit inside the engine plumbing and helps supercold propellant move past accordion-shaped bellows, which are built into the pipes to make them flexible.The liners don't hold pressure so a cracked liner doesn't mean any liquid hydrogen or liquid oxygen is leaking, said NASA spokesman James Hartsfield. But there is concern that any debris from a crack could work its way into a firing engine, which could lead to disaster.
The cracks are not in the propellant lines themselves, Hartsfield said.
If you look at all the stuff govt. spends money on, these two efforts are probably the least worthless of them all. Aid to Israel and Egypt is about 6 billion a year, how much did we spend on Nato and european defense when they should have been doing it themselves ? Welfare, food stamps, medicaid, congressional salaries, jobs for monica, etc. If we are to waste money (and I think about half of the 1.8 trillion a year budget is a waste) I don't mind wasting a few billion a year on nasa.
What about:
NOAA geostationary weather and polar-orbiting environmental satellites (built and launched by NASA)
the Solar and Heliospheric Observatory (SOHO)
the Mars missions (these are only the current missions)
the Landsat 7 mission (and also the previous Landsat missions)
and that's just a few. Not to mention all the aeronautics research that they do that improves aircraft efficiency; numerous technological spinoffs, such as better medical imaging; and a host of scientific research efforts.
NASA is far more than the three "highlights" you mentioned. They can't shut down the floating pork project in space (the ISS) unfortunately, but NASA does a lot of things quite well - and unnoticed in the public mind.
The next time that there's a better and more accurate hurricane forecast that allows evacuations in time to save hundreds of lives -- NASA provided the data and instruments to improve that forecast.
Excellent post. One of the primary difficulties of "selling" much of what NASA does is that it comes under the heading of basic research. Basic research means unguided research with no application-oriented goal: it simply means doing research to find out what is not yet known. But in doing that, much of the spinoff is due to the necessity to develop more sophisticated tools to answer such basic questions. These sophisticated tools frequently are used in subsequent work for unexpected and highly important applications. Hurricane forecasting (as I mentioned earlier) is a good example. One of the first main goals of civilian remote sensing was improved weather observations. But in pushing the boundaries of what can be learned about the oceans and atmosphere, new technologies offer much better ways to detect circulation patterns that can lead to hurricanes even before the characteristic cloud patterns have developed. Such advances are hard to value, but if someone survives a hurricane due to a better forecast, they are invaluable.
You are correct regarding the problems with SSME HPFTP longevity. The nation hasn't invested in propulsion technology for 20 - 30 years. Let's face it...It's been 30 years since the last major innovation in materials science and engineering of engines for high speed aerospace applications. SSME's were designed on paper and pencil and predate the 8086!
The space shuttle program was originally spec'ed to be reusable. What resulted is best termed as "rebuildable." That goes double for the SSMEs.
For propulsion and operations research, the shuttle is great. As a practical system to low earth orbit, it is a failure.
Every device requires maintainance and the shuttle and it's engines are no different. Name any other invention with any sophistication that was completely reusable out of the gate. OK, so maybe a paper clip.
For propulsion and operations research, the shuttle is great. As a practical system to low earth orbit, it is a failure.
I blame any lack of practicality on NASA. The contractors pushed the technical limits as far as they could and then NASA micromanaged it into a Rube Goldberg. It is the first in a series of steps in the evolutionary process of creating a fully reusable launch vehicle. Certainly there is no current market for such a capability, but at least NASA demonstrated enough vision to attempt it and thus paved the way for what is to come. Manned and cheap/practical are incompatible at this stage of evolution.
Great comeback!
Scottie, make it one to beam out of this thread. I've gotta get back to work.
The SSME does not mark the invention of the rocket engine. In fact, it is fairly far along the maturity curve. Maintenance and operating costs simply were not driving factors in its design; wringing the last bit of ISP out of H2/LOX was.
Manned and cheap/practical are incompatible at this stage of evolution.
I believe that has become a self-fulfilling prophecy. Because of the chicken and egg problem with regards to market, no one but NASA has any viable interest in space transportation and NASA has a real vested interest in making space transportation as expensive and labor intensive as possible. (Not a purposeful sabotage, that is just what bureaucratic agencies do by nature.)
Plenty of real engineers believe they could come up with reasonable transportation to LEO. The problem is that no accountants want to try, largely based on NASA's ham-handed attempts.
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