Showing posts with label Annoyances. Show all posts
Showing posts with label Annoyances. Show all posts

Sunday, October 9, 2011

SpaceX Has A Pipedream

Spaceflight Now has a recent article [Reprinted from CBS Space] on SpaceX's vision of making their boosters reusable. The simulation video is sharp. The stated intention is for direct descent and landing under rocket thrust. Sounds simple enough on the face of it but I immediately saw some flaws in the plans.

First Stage; Slant range puts the booster a long way from the launch site and variable target orbits increase possible descent points over a large arc, typically well out over the Atlantic. The sheer height of the Falcon 9 booster makes me want to install much larger landing legs [and more of them]. This is why all flyback booster designs thusfar have wings, wheeled landing gear and sometimes jet engines.

Second stage, This might actually be a bit easier than the first stage. Because the 2nd stage is itself orbital [or nearly so], one can pick the reentry point and bring it down where desired. A reentry heat shield adds a lot of weight though. At least 2 motor restarts are needed, but restarts are not that uncommon here. Need a lot of spare fuel for both the deorbit and the landing. Second stage motor nozzles are typically optimized for high altitude/vacuum operations and will be inefficient back at sea level.
I believe it was NRL that was ground testing a booster 20 or so years ago that was low-pressure [no turbo pumps] and had a variable expansion thrust bell, kinda like the "turkey feathers" on a fighter jet engine nozzle. This allowed inflight expansion ratio optimization for any altitude.

Capsule and boosters are shown returning on thrust alone. Even with thrust for landing, parachute systems would still be more economical and probably lighter for slowing and stabilizing the vehicles in an upright position instead of relying on attitude thrusters and the mains alone. Parachutes would also add some safety in case of motor failure, or at least reduce the splat.

>>>>>>
"We'll see if this works," Musk said. "But it's going to be certainly an exciting journey. And if it does work, it'll be pretty huge. If you look at the cost of a Falcon 9 ... it's about $50 (million) to $60 million. But the cost of the fuel and oxygen and so forth is only about $200,000. So obviously, if we can reuse the rocket, say, a thousand times, then that would make the capital cost of the rocket for launch only about $50,000. ... It would allow about a hundred-fold reduction in launch costs."
<<<<<<

Was Mr Musk reading that off a script???
Nobody's gonna get 1000 uses out of any booster, even if there is that large a backlog of flight contracts. Divide flight contracts by; payload production rates, vehicle refurbishment rate, available ground support, optimal launch windows... I'm sorry but I would've scoffed at 100 flights per booster. How about 10 flights each on a 5-10 booster fleet. By then; if the economics are sound, you'll be building a few replacements and/or an improved new fleet anyway.
Note that Elon says a 1000 fold reduction in booster cost relates to only a 100 fold reduction in overall launch costs. That sounds reasonable as other costs go up drastically. Additional flight systems complication, booster retransport, refurbishment, range comm/nav systems, additional facilities...manpower, manpower, manpower.

I have great respect for SpaceX and what they have accomplished. In fact I'd like to work for them, and I can't say that about most of the aerospace industry or NASA itself.

http://spaceflightnow.com/news/n1109/30spacexflyback/

Upgraded PC At Last

Hooraw!
My friend Steve recently replaced my PC tower with a much newer one. Not precisely cutting edge as it was assembled from hand-me-down components, but it's a lot more advanced than my old one which I had for over 11 years.

There's a helluva lot of work to do yet, software and tools to transfer or download, and gigs of folders to transfer. Wherever practical, I'm downloading fresh copies or newer versions of software and tools just to be sure they're clean and up to date. Normally I cringe and start to break out in hives every time I'm faced with "Updated" or "Improved" software. Most of the time it has compatability issues or unresolved glitches, or will no longer do what I needed it to do beforehand [Quicktime comes to mind on that score]. Naturally, I totally object to automated updates and block them always. The learning curve is pretty steep, principally changing from Win 98 to XP, and Bobcad 17 to 21.xx. After using dialup all those years, having a hi-speed internet connection sure is nice too.

Steve is a computer professional and I cannot recommend him enough. You can reach him through the following link; pcmaverick.org
Thanks Steve.

Sunday, October 2, 2011

Don't Forget the Cheese!!!

One of the things I like best about living in south Texas is Mexican food. To be more accurate; Tex-Mex food. I aint talkin' about Taco Hell here. Above all else I love breakfast, I'll have breakfast for dinner even, this includes breakfast tacos. I usually ask for cheese on my breakfast tacos and from time to time the cooks forget to do so. Happens to burgers sometimes too. Over the last 30+ years this has added up to quite a bit of lost cheese. Brings a tear to my eye.

Today I was trying out a new restaraunt, ordered myself some coffee and two tacos; bacon, egg & cheese and chorizo, egg & cheese. When the order was ready the manager brought it out because my server was busy elsewhere. The tacos were large but they looked a bit thin, I peaked under the flaps and there was plenty of cheese but nothing else! No eggs, no porky bits. Without some grilling time, these weren't exactly quesadillas yet either. The manager was all apologetic but I had to laugh out loud, disturb the whole place loud. That was funny!

The Wheel of Cheese Turns Full Circle.

Sunday, June 19, 2011

Blog Annoyance

The previous blogpost has the wrong date.
It should've read June, not January.
The reason why is smart software that is dumber than I would've thought.
Instead of using the date when it was actually posted, the software used the date from when the post was first created and saved as a draft, this despite extensive editing and additions the day I actually posted it. While the draft date might be useful information to me in a nagging sort of way, it is totally useless to the reader.
There are a couple other drafts scattered in my Edit Posts section, and if I decide to use them eventually, I'll now have to remember to paste them into a new post rather than risk them posting with the wrong date, or worse, being inserted amidst older posts outright. I would consider that to be an example of revisionist history, albeit minor and unintended. Rereading my old posts, I've run across quite a bit of stuff that could use reediting, but most are of the typesetting or spelling variety plus a few phrases that could've been done better. Just not worth the effort. If I found some gross errors, that might be a different story
People can rip pages from books, but that leaves evidence of the fact. People can burn books, but there are always more books. Be wary of the web, because computer editing and manipulation are very hard, or impossible to detect, especially text. Anyone can post to, or reedit a Wiki entry.

Tuesday, October 12, 2010

Back in the Saddle, NOT!

I had high hopes for upping my post rate this fall
here at the Lab, but such is not going to be the case.

In late September my landline was disconnected and
I about refuse to pay a further autodebited dime to
ATT/yahoo for their klugey [sp?] email that I have to
constantly wait for advertising to load on. I expect
advertising on Yahoo free sites, but not on something
costing me over $17/mo and is slower than ever already.
GRRRRR!
When the email software switched over, the previously
full featured address book lost everything except the
names and email addresses. All the phone numbers, all
the USPS addresses, all the aliases and side notes. ALL
GONE! DOUBLE GA-ERRRRR!!!
Of course this means my access is limited at the moment,
and I'm losing all my old email files and peoples addresses.

So my friends & relations who read this, please email me
at; kur.kzak@gmail.com
I tried changing my blog personal data to the new email
address and was denied. WTF?
If I can't resolve that issue I'll have to change emails again.
Gee, Google Blog and Google Email together sounded like a
Good idea at the time.

I also aquired a cell phone again after doing without one for
about 7 years and not missing it most of the time.
Thanks K&S.

Monday, January 18, 2010

Basically, I'm Annoyed!

Here's a rare picture free post.
This is just words, about words.

It's not uncommon for fad words to come and go in daily use in our culture. Some words stick around, some peak and then decline rapidly, some not fast enough. The word; "Problematic" thankfully has faded away. It's not a bad word in itself, but so few people used it correctly,
it would set my teeth on edge every time by reflex.

What has me growling this time is the word; "Basically".
What really set me off was an American reporter in Haiti being interviewed by another reporter over a live feed right after the recent earthquake. This guy said "Basically" at least six times, but never kept it basic. That's as bad as a hippy saying "Like" and/or "Y'know" every sentence. This guy was educated and experienced though, how embarrassing. I hope his colleagues make a blooper disc of it. I wouldn't mind "Basically" so much if it didn't precede the LONG version of an explanation so often. It should be followed by one or two concise sentences of explanation tops, otherwise it's not basic is it?

After listening to enough people say "Basically", I realized that a lot of the time it's thrown in while they're collecting their thoughts or composing the next sentence before launching into an explanation, thusly it takes the place of dead air or the more honest; "Uhhh" or "Um".
No excuse!
After a few times though, it has a negative effect on one's appearance of intelligence.

OK, I wrote; "Basically" 5 times, [including this time] but only USED it once, in the title. There it was used correctly and concisely, IF you don't bother to read the post.