Astroprof's Page

Well, I finally did it.  I got my own domain name.  I've staked out my little piece of the internet.  Now, I just have to build something there.  I will be moving astroprof's page there.  I'll try to bring the postings already here over to the new site.  Now, this will likely take a while for me to get things over there like I want them.  So, I may not be doing much posting this next week or so.

When things are fully running, I'll post a note here with a link here telling you where to find me.  I am looking forward to this.  It ought to be fun.  If anyone has any suggestions about what might be good to have for the new location, let me know.  I don't know if I'll be able to work out everything (or even if I want to!), but I'll gladly consider any suggestions.

-Astroprof

Not too long ago, I posted an entry about the new Ares Rockets that NASA is designing. I mentioned that portions of the new rockets are based on Shuttle technology, in particular the exteranal tank. Well, that includes the problamatic foam. There was an article in the local paper here today about just that. As with most of the news in the local paper, local reporters didn't come up with it. This was an AP story. The reporter pointed out that this is the same foam that keeps flaking off, and that a piece of foam falling off on liftoff was what did the damage to the Columbia that ultimately proved fatal to that craft. However, the report also goes on to say that this should not be a problem. Well, I thought that I might expand on that.

Foam has been flaking off of the Shuttle external tank since the early days of the Space Shuttle in the 1980's. At first, engineers correcty were concerned. However, as time passed without a major incident relating to the foam problems, their concerns were put on the back burner. Then, in the 1990's, the manufacturing process for the external tanks changed to use a new, more environmentally friendly way of applying foam to the tanks. I am all for saving the environment. But, folks, we need to be reasonable. The problem with the new method was that the foam was even more likely to flake off than before. Concerns about this went unheeded. Even when a particularly large chunk of foam fell off and seriously damaged a support brace holding the solid rocket boosters to the external tank on the STS-112 mission, higher ups didn't take the matter seriously. Not, until the loss of the Columbia on mission STS-107, that is.

So, can foam flaking be dangerous with this new design? Well, yes. But, not nearly as dangerous as with the Shuttle program. First of all, the biggest concern that NASA has with foam flaking is that the foam flaking off might damage the orbiter's heat shield. The heat shield is composed of rather delicate porous ceramic tiles that are easy to damage. Hitting them hard enough can break or scour them. Even more fragile are the tiles on certain parts of the orbiter, like on the leading surfaces of the wings, where the heat load is greatest. These tiles are much more brittle, and they are easier to damage. A foam strike on the leading edge of the Columbia's port wing is what is believed to have doomed the craft.

However, the new CEV won't have that problem. This new craft rides atop the rockets. So, any foam shedding will not be able to strike the crew vehicle. Furthermore, it is expected that foam shedding should not strike anything important. The Ares I, which will be used to lift the astronauts into space in their CEV will not even have fins to damage. This rocket is steered with gimballed rocket motor nozzles. There is a faring around the base of the rocket, but foam should actually have moved away from the rocket body enough by the time that it reaches the faring that impact is unlikely, and if impact did occur, serious damage is also unlikely. In theory, that is. A worse case scenario would be if foam near the top of the rocket peeled off, and that exposed more foam to aerodynamic stresses that cause it to peel off, and so forth. One could imagine foam breaking away from an entire side of the rocket. This could, in theory, lead to handling problems. I don't think that any problems of this sort would bring down the rocket, but then it would be unwise not to consider every possibility, however remote. And, this is, indeed, an exceedingly remote possibility. Such a cascading foam peeling has never happened, and I don't think that it can even happen without a whole lot of things going wrong with rocket manufacture, foam composition, foam application, rocket handling after fabrication, etc. It would take a remarkable series of failures to even lead to such a foam cascade, which would unlikely have a disastrous result even if it did occur.

However, the Ares V is another story. This is the heavy lift vehicle. It will be the rocket to lift the major heavy components of Lunar and Martian missions into space. It will be used for future major launches of space station components. And, it is more susceptable to damage. This is because it is composed of a central core with two solid rockets strapped to the side. Despite the fact that Atlantis safely completed the STS-112 mission, there was serious damage caused by foam shedding to a strut holding one of the solid rockets onto the external tank. The strut held. However, in only just held. Had the damage happened earlier in the flight, had the damage been slightly more severe, had the damage happened closer to the end of the strut, then the solid rocket might have torn away from the external tank. Well, actually, only part of the solid rocket would have torn away. The other part would have torn off part of the external tank, resulting in a repeat of the sort of even that destroyed the Challenger. This is still a danger. And this danger would still exist with the Ares V rocket. It is a remote possibility, but then so is the possibility of damage such as that which downed Columbia. Again, ignoring it is dumb. However, even a loss of an Ares V, while bad, and disastrous for the completion of a mission, would not result in loss of life (unless, of course, the debris fell on someone). The astronauts will be riding into space aboard an Ares I, which is unlikely to suffer horrible damage from any foam shedding.

So, there you have more on the Ares rockets.

Oh, and I am still looking to move my blog. I'll post a forwarding address when that happens. Interestingly, this new thing that they've put into effect here actually seems to work better with Firefox than it does with Internet Explorer. Imagine that. A Microsoft product that doesn't work well with other Microsoft things. Still, not all features work, and I don't like it. So, I am looking to move.

-Astroprof

We are getting near the end of the summer.  There are just under three weeks left of summer school.  I've been teaching a summer-long class (not those silly 5 week long classes that so many places do for summer school).  Anyway, now the questions are coming.  A couple of students who had been scoring in the 30's on exams, and not much better on labs and homework have figured out that they are not passing and have dropped.  Some have been in the 80's on exams, and 90's on homework and labs, and they realize that they have a shot at an A if they work hard.  Others are looking at a C, and they feel that they'll be happy with that.  At least one is thinking that a D will be the best that he can hope for, and so he is going to try to get his rear in gear to at least pass the class.  These are students who are figuring it out on their own. 

Then, one comes to me and asks, "Is there any hope of my passing this class?" 

"Well," I say, "There's always hope.  But you need to really concnetrate on the class.  You won't pass if you keep going the way that you are going.  You need to actually show up, do the work, and turn things in to be graded.  You need to spend the time on the class, and you need to decide if passing the class is a priority or not.  What means more, passing the class or the rest of your life?  You clearly are smart enough, and you clearly have the math background, the problem solving skills, and so forth to do well in the class.  However, you are not putting the effort into it that is needed." 

So, he went away to think about that.

He really can pass.  He does show in class (when he bothers to be there) that he can grasp what we are doing.  When I set up a problem on the blackboard, and then pose a question to the class on what step we should do next, he frequently comes up with a correct approach, especially if the best next step is a derivative, integral, or some other procedure using calculus.  He can do this.  The problem is that he is trying to do too much.  He is trying to work full time this summer and take a difficult class.  He works some distance away, and he has to commute.   That is why he misses class and almost always drags in late, he says.  Working all day and taking an evening class leaves no time to study or do homework, which is why he says that he is doing poorly and not turning things in.  Well, not doing the homework is why he is doing poorly, for sure.  If they will just do the homework problems, then they'll be ready for the exams.  That's how this class works.  I fully sympathize with the whole thing of life interfering with studies.  I've had that problem, too.  You need to work to pay the bills, including tuition.  But, you need time to do the classwork.  In the summer, the students also try to run around with friends who are not taking classes in the summer, and that takes time away from studies.  Taking a physics class, or any other time intensive class in the summer is hard, even with my summer long class.  It is still accelerated from the regular semester.  But, what is the solution?

I honestly don't know.  The system isn't set up to further the aims of non-traditional students.  I went to college after high school.  My parents paid for the university's tuition, with the help of a scholarship and student loans.  I had to pay off the student loans myself.  I did get a small job on campus for a while, but it was working with one of the professors in one of the research labs, so it was directly related to the field.  The same with summer jobs.  I didn't do summer school.  Graduate school, though, I had a teaching assistantship, like most of the other graduate students.  That took more time, but it was still part time, and it was directly related to what I was doing.  Also, there were more student loans. 

Students today, though, try to juggle full time jobs and college.  When I was a student, full time college was full time.  I spent most of my time outside of class studying, doing homework problems, lab write-ups, papers, etc.  I spent untold hours in the library, reading, researching, studying.  Yeah, there was some play time, but it was mostly study.  I didn't have time for a job then!  Yet, almost all of my students work.  Some work part time, but many try to work full time.  They have to.  Tuition is astronomical.  Textbook prices are beyond astronomical.  Most of my students pay far more for textbooks than they do tuition.  I occasionally teach a class over at the big private university across town, and a single semester there costs as much as my entire 4 year degree did.  Parents simply can not afford to foot the bills.  Scholarships and grants don't provide near enough support.  Nearly 75% of the students are on some sort of financial aid.  Most of that is student loans.  Some students are graduating college now with student loan debt that approximates a mortgage.  To keep that down, they work while going to school.  But, they still have to go full time, otherwise they don't qualify for any student loans at all, and worse, they have to start paying back the ones that they already have if they are not full time students.  Many also try to remain full time students so that they can get affordable health insurance.  But, working gives them little time to be students.

Then, even worse, they are programmed by the public schools to think that they don't need to work outside of class.  Most of the schools here give very little homework, and they use class time to work on the homework (isn't that classwork rather than homework?).  So, students get used to the idea that they can learn all that they need in class.  They don't realize that they need to spend hours outside of class each day.  They don't realize that college in-class  time is just setting the stage for them to learn!  So, they try to work and go to school.  Worse, many of my students went and did something else for a few years between high school and college.  Among those other things, all too often, were getting married and having kids.  So, now they try to add family time to a full time college schedule and full time work.  Something has to give.  But what?

Do we assign less work to accomodate these new type of students?  But, wouldn't that mean less learning?  Yeah, I know that some faculty are doing just that.  They are cutting material out of the classes to make them easier.  But doesn't that devalue the class, and ultimately the college degree?  Surely that isn't the answer.  What if students took fewer classes so that they could manage the time?  Well, they can't.  If they took fewer classes, then they don't qualify for financial aid, insurance, and a host of other things.  Here in Texas, there are even penalties for taking longer than four years to get an undergraduate degree, so that is an added incentive to sign up for a full load (and the legislature has been talking of making those penalties far stiffer). 

I just don't know.  I don't really see how my students manage.  It looks like getting through college is just getting tougher and tougher.  I sort of wonder how I'd do it if I were a student today.

-Astroprof

..
What the @$&# ?  Does my blog look as different to everyone else as it does to me?  Last night, I logged on to work on an entry while my students were doing a lab exercise, and the entire thing was screwed up.  The format was messed up, the usual options were gone, and it was unbelievably SLOW loading up.  In fact, the panes didn't even fit on the screen!  I couldn't do anything!  Then, aferwards, I tried from my office, and it was still different, but at least things fit on the screen and some options worked.  The same at home.  I guess that this is Microsoft's new "improvement" to their Spaces.  Well, as usual, they took something that worked adequately, though not well, and made it worse in the name of improvement.  I figured out that probably the reason that it is totally unusable from the lab was that the computer there is using an older version of Internet Explorer.  My office uses a newer version, and at home I use a new version of Firefox.  So, in typical microsoft fashion, you have to get the latest product to do anything.  The latest product doesn't always work on older computers.  Also, the lab computers are protected so that students can't download and install things on them, and that means that I also can't do anything.  I have to get someone to do that.  Tell me that this is better?  They are apparently raving about how the new features are so much better.  Well, I don't even see much in the way of new features (other than an icon for the blog owner, is that important?) .  In fact, many of the old things that I used no longer work.  Wow.  I'll have to try to figure out if I can adapt this thing.  If not, I may be moving my blog.  I have thought about that now and then, since this never was something that worked quite like I had wanted.  But, it was here, and this is where I started the blog, and it did work for at least posting stuff, so I just kept it since people had gotten used to finding me here. 

Oh, and as if to make things even more confusing, they changed the URL on me once again.  Why can't they leave things alone?  What about all the pointers to this little spot on the internet?  Yeah, yeah, they apparently went and automatically fixed pointers within their system so that other blogs pointing here were corrected.  That is only blogs pointing here from within their own system.  As usual, they forgot that there is an entire world out there that is not doing everything under microsoft.

So, I will see if I can get the new features (if I can find them) working, see if I like them, and if not ...
It wold just be a hassle to move.  Still, it is a hassle to stay and have everything change every now and then.  That is just like moving.  Does anyone out there have suggestions for favorite places to host a blog?  I realize there are several, and the best one for me might not be the most popular.

-Astroprof