A kerosene-fueled X-33 as a single stage to orbit vehicle.
in [Physics]
|
Prev: JSH:Twin primes probability correlation
Next: SpaceX says Falcon 9 rocket test fire is a success
From: Pat Flannery on 12 Apr 2010 10:54 On 4/12/2010 5:20 AM, Pat Flannery wrote: > The fact that it ignited at a lower temperature than aluminum alloy that > was in its near vicinity in the presence of atomic oxygen came as quite > a surprise for the Columbia Accident Investigation Board in their final > report. If you want to read up on the CAIB's surprise about the burning titanium on Columbia, start at page 157 of this PDF: http://www.nasa.gov/pdf/298870main_SP-2008-565.pdf Section 2.1.6.7 "Thermal analysis – x-links" and continue on to page 166. The titanium was burning at a temperature only around 1/10th as high as predicted for its ignition. The titanium on the upper fuselage windows and the burned titanium rollers (with photos and drawings) also gets discussed on pages 253-258. Pat
From: J. Clarke on 12 Apr 2010 12:05 On 4/12/2010 10:54 AM, Pat Flannery wrote: > On 4/12/2010 5:20 AM, Pat Flannery wrote: > >> The fact that it ignited at a lower temperature than aluminum alloy that >> was in its near vicinity in the presence of atomic oxygen came as quite >> a surprise for the Columbia Accident Investigation Board in their final >> report. > > If you want to read up on the CAIB's surprise about the burning titanium > on Columbia, start at page 157 of this PDF: > http://www.nasa.gov/pdf/298870main_SP-2008-565.pdf > Section 2.1.6.7 "Thermal analysis – x-links" > and continue on to page 166. > The titanium was burning at a temperature only around 1/10th as high as > predicted for its ignition. > The titanium on the upper fuselage windows and the burned titanium > rollers (with photos and drawings) also gets discussed on pages 253-258. So who on the board had ever worked with titanium?
From: Matt on 13 Apr 2010 01:43 On Sun, 11 Apr 2010 18:34:10 -0400, J. Clarke wrote: >On 4/11/2010 3:21 PM, Matt wrote: >> On Sun, 11 Apr 2010 14:57:00 -0400, J. Clarke wrote: >> >>> On 4/11/2010 1:59 PM, Matt wrote: >>>> On Sun, 11 Apr 2010 10:28:48 -0700 (PDT), hcobb wrote: >>>> >>>>> On Apr 10, 8:29 am, Robert Clark<rgregorycl...(a)yahoo.com> wrote: >>>>>> Note also that use of the rocket thrust from the X-33 would also allow >>>>>> you to reach higher speeds say Mach 3+ before release. This would >>>>>> allow greater payload, since less delta-V would need to be supplied by >>>>>> the X-33 after release. The extra rocket propellant for the X-33 >>>>>> required for firing during the linked portion of the trip would be >>>>>> carried in the carrier craft fuselage. >>>>>> >>>>>> Bob Clark >>>>> >>>>> Since you need to reach Mach 25+ to orbit this saves you only 12% of >>>>> the speed requirement while imposing a requirement for an airframe >>>>> that can at least sustain that ground velocity while climbing. >>>>> >>>>> A much better result can be had from a balloon-assisted launch system >>>>> where the objective is to start the rocket with as much altitude as >>>>> possible rather than speed. >>>>> >>>>> http://academy.grc.nasa.gov/y2008/group-project/proposal-for-a-balloon-assisted-launch-system >>>> >>>> This is a proposal from 2008. Was it approved? >>> >>> That's not a "proposal", it's a student exercise. Google "Glenn Academy". >> >> http://academy.grc.nasa.gov/y2007/research-projects/group-project-proposal >> Goals in Project Choice >> + Useful to NASA >> >> It would appear that NASA approved the choice of the project topic. > >Just as any teacher approves the choice of the topic of term papers and >other student projects. I don't know about you, but it wasn't a requirement for my senior project that it be "useful to the university." >> Did the "proposal" not receive some level of review within NASA? > >The same review that any educational project gets. > >> Else it was simply a time-wasting exercise. > >By that logic all education is "a time wasting exercise". The purpose >of education is not to come up with wonderful new ways of doing things, >it's to teach students what we already know. All of education isn't geared toward evaluating technology for potential application. Does research assistance done by university students *never* help "to come up with wonderful new ways of doing things?" Did you do intern work in college? If so, did the company you worked for not want results they could use? >> Perhaps consistent with the >> environment, but that's another issue. > >The environment is a summer training program for college students. It's an elite program. Students who achieve entry deserve better than to be taught how to spin their wheels on a project that no one cares about. If no one cared about it, then "proposal" was just so much NASA-speak. If some one did care about it, then it received some level of consideration beyond what was given to my senior project.
From: J. Clarke on 13 Apr 2010 10:57 On 4/13/2010 1:43 AM, Matt wrote: > On Sun, 11 Apr 2010 18:34:10 -0400, J. Clarke wrote: > >> On 4/11/2010 3:21 PM, Matt wrote: >>> On Sun, 11 Apr 2010 14:57:00 -0400, J. Clarke wrote: >>> >>>> On 4/11/2010 1:59 PM, Matt wrote: >>>>> On Sun, 11 Apr 2010 10:28:48 -0700 (PDT), hcobb wrote: >>>>> >>>>>> On Apr 10, 8:29 am, Robert Clark<rgregorycl...(a)yahoo.com> wrote: >>>>>>> Note also that use of the rocket thrust from the X-33 would also allow >>>>>>> you to reach higher speeds say Mach 3+ before release. This would >>>>>>> allow greater payload, since less delta-V would need to be supplied by >>>>>>> the X-33 after release. The extra rocket propellant for the X-33 >>>>>>> required for firing during the linked portion of the trip would be >>>>>>> carried in the carrier craft fuselage. >>>>>>> >>>>>>> Bob Clark >>>>>> >>>>>> Since you need to reach Mach 25+ to orbit this saves you only 12% of >>>>>> the speed requirement while imposing a requirement for an airframe >>>>>> that can at least sustain that ground velocity while climbing. >>>>>> >>>>>> A much better result can be had from a balloon-assisted launch system >>>>>> where the objective is to start the rocket with as much altitude as >>>>>> possible rather than speed. >>>>>> >>>>>> http://academy.grc.nasa.gov/y2008/group-project/proposal-for-a-balloon-assisted-launch-system >>>>> >>>>> This is a proposal from 2008. Was it approved? >>>> >>>> That's not a "proposal", it's a student exercise. Google "Glenn Academy". >>> >>> http://academy.grc.nasa.gov/y2007/research-projects/group-project-proposal >>> Goals in Project Choice >>> + Useful to NASA >>> >>> It would appear that NASA approved the choice of the project topic. >> >> Just as any teacher approves the choice of the topic of term papers and >> other student projects. > > I don't know about you, but it wasn't a requirement for my senior > project that it be "useful to the university." > > >>> Did the "proposal" not receive some level of review within NASA? >> >> The same review that any educational project gets. >> >>> Else it was simply a time-wasting exercise. >> >> By that logic all education is "a time wasting exercise". The purpose >> of education is not to come up with wonderful new ways of doing things, >> it's to teach students what we already know. > > All of education isn't geared toward evaluating technology for > potential application. So what? We aren't talking about "all education", we are talking about one specific exercise. > Does research assistance done by university > students *never* help "to come up with wonderful new ways of doing > things?" Whether it helps or not, its purpose is to teach the student. > Did you do intern work in college? If so, did the company you worked > for not want results they could use? When one does "intern work" one is working for an employer, one is not engaging in a training exercise. You don't seem to grasp the concept of "exercise". >>> Perhaps consistent with the >>> environment, but that's another issue. >> >> The environment is a summer training program for college students. > > It's an elite program. Students who achieve entry deserve better than > to be taught how to spin their wheels on a project that no one cares > about. So what should they do, be put right to work as engineers on something that will kill people when it crashes? > If no one cared about it, then "proposal" was just so much NASA-speak. > If some one did care about it, then it received some level of > consideration beyond what was given to my senior project. It was an exercise in proposal-writing. Geez.
From: Matt on 14 Apr 2010 02:22
On Tue, 13 Apr 2010 10:57:59 -0400, J. Clarke wrote: >On 4/13/2010 1:43 AM, Matt wrote: >> On Sun, 11 Apr 2010 18:34:10 -0400, J. Clarke wrote: >> >>> On 4/11/2010 3:21 PM, Matt wrote: >>>> On Sun, 11 Apr 2010 14:57:00 -0400, J. Clarke wrote: >>>> >>>>> On 4/11/2010 1:59 PM, Matt wrote: >>>>>> On Sun, 11 Apr 2010 10:28:48 -0700 (PDT), hcobb wrote: >>>>>> >>>>>>> On Apr 10, 8:29 am, Robert Clark<rgregorycl...(a)yahoo.com> wrote: >>>>>>>> Note also that use of the rocket thrust from the X-33 would also allow >>>>>>>> you to reach higher speeds say Mach 3+ before release. This would >>>>>>>> allow greater payload, since less delta-V would need to be supplied by >>>>>>>> the X-33 after release. The extra rocket propellant for the X-33 >>>>>>>> required for firing during the linked portion of the trip would be >>>>>>>> carried in the carrier craft fuselage. >>>>>>>> >>>>>>>> Bob Clark >>>>>>> >>>>>>> Since you need to reach Mach 25+ to orbit this saves you only 12% of >>>>>>> the speed requirement while imposing a requirement for an airframe >>>>>>> that can at least sustain that ground velocity while climbing. >>>>>>> >>>>>>> A much better result can be had from a balloon-assisted launch system >>>>>>> where the objective is to start the rocket with as much altitude as >>>>>>> possible rather than speed. >>>>>>> >>>>>>> http://academy.grc.nasa.gov/y2008/group-project/proposal-for-a-balloon-assisted-launch-system >>>>>> >>>>>> This is a proposal from 2008. Was it approved? >>>>> >>>>> That's not a "proposal", it's a student exercise. Google "Glenn Academy". >>>> >>>> http://academy.grc.nasa.gov/y2007/research-projects/group-project-proposal >>>> Goals in Project Choice >>>> + Useful to NASA >>>> >>>> It would appear that NASA approved the choice of the project topic. >>> >>> Just as any teacher approves the choice of the topic of term papers and >>> other student projects. >> >> I don't know about you, but it wasn't a requirement for my senior >> project that it be "useful to the university." >> >> >>>> Did the "proposal" not receive some level of review within NASA? >>> >>> The same review that any educational project gets. >>> >>>> Else it was simply a time-wasting exercise. >>> >>> By that logic all education is "a time wasting exercise". The purpose >>> of education is not to come up with wonderful new ways of doing things, >>> it's to teach students what we already know. >> >> All of education isn't geared toward evaluating technology for >> potential application. > >So what? We aren't talking about "all education", we are talking about >one specific exercise. Actually, we were talking about a concept. Someone put a "proposal" label on it. You seem convinced that it was merely an exercise. I think the program is poorly conceived if that's all it was. >> Does research assistance done by university >> students *never* help "to come up with wonderful new ways of doing >> things?" > >Whether it helps or not, its purpose is to teach the student. Can a task not have more than one purpose? >> Did you do intern work in college? If so, did the company you worked >> for not want results they could use? > >When one does "intern work" one is working for an employer, one is not >engaging in a training exercise. In my experience, it was both. >You don't seem to grasp the concept of "exercise". I understand what an exercise is. I also know what it is to enter fully-charged from college into a not-as-advertised intern environment. It can be demoralizing to a college student. >>>> Perhaps consistent with the >>>> environment, but that's another issue. >>> >>> The environment is a summer training program for college students. >> >> It's an elite program. Students who achieve entry deserve better than >> to be taught how to spin their wheels on a project that no one cares >> about. > >So what should they do, be put right to work as engineers on something >that will kill people when it crashes? Isn't that what an apprentice aircraft mechanic does? Why *when* it crashes? Give the students some credit. They actually do know a thing or two. Do you assume that they are incapable of designing something that works? >> If no one cared about it, then "proposal" was just so much NASA-speak. >> If some one did care about it, then it received some level of >> consideration beyond what was given to my senior project. > >It was an exercise in proposal-writing. Geez. Is that NASA's product? Proposals? Or maybe it was more. http://academy.grc.nasa.gov/archives/535 The high altitude launch of their group project (a balloon assisted launch system) is scheduled for August 30, 2008 with StratoStar LLC in Indiana. If it was only an exercise in writing proposals, why did they plan to launch anything? http://academy.grc.nasa.gov/main/mission-statement Its primary objectives are to: 1. Provide upper level undergraduate/first-second year graduate students cutting-edge research opportunities with NASA scientists, engineers, and educators. "The vision of the Academy as described by its founder, Dr. Gerald Soffen is 'To give possible leaders a view into how NASA, the university community, and the private sector function, set their priorities, and contribute to the success of the aerospace program.'" I merely asked what happened to a "proposal" cited as a reference for a "better" way to launch objects. It got a "Duh!" response from you. Perhaps that was amiss. |