@falstro all my figures are eps :)

@casey Kind of a random question, but could a rocket be useful in atmospheric research? Say if, for example, it could carry a 100lb payload to 60,000ft for a relatively low cost?

@casey handwritten of course? ;)

There's a union meeting right outside my window, megaphones and everything. The noise is irritating. Their message is so naive it's making me want to punch a hole in the wall. I'd like to see speakers open with telling everyone what kind of money they get for proclaiming that people aren't getting enough money.

did I say something inappropriate in my comment that the guy decided to delete answer AND account? aviation.stackexchange.com/a/5043/1467

not that I saw...

yey! @voretaq7 BlueJays slid into first place in the AL east last night. :)

@falstro I do occasionally hand edit the bounding boxes :)

@JayCarr not sure. The only thing we routinely send up that high (and actually quite higher) are weather balloons but I dont think the instrumentation would sample properly at the speeds a rocket would fly at. The only rockets I know of that are routinely used are the ones to launch our satellites into orbit.

@casey - More what I was thinking was that the rocket could drop something into a storm cell from above, or something like that. Though I suppose it would need more than a 12 mile range for that.

I was kind of thinking like those little model rockets, only bigger. So a chute would be deployed that dropped the payload into the area to be studied.

Not going to be as cheap as a balloon, I will admit, but could it be useful?

It seems like it might be nice in a windy situation where using a balloon would probably just cast the payload adrift.

a thunderstorm with tops to 60,000 ft would destroy an amateur rocket

likewise dropsondes with chutes are not suitable for thunderstorms

Assuming it would actually be useful, what kind of forces would it need to withstand to be able to deploy something useful? (Bear in mind, this is not your normal amatuer rocket).

look at what the hurricane hunters drop into hurricanes

Mmmm

Ah, there we go. I can start there.

@JayCarr if you are near the updraft, you can be looking at vertical speeds in excess of 100 mph. Nearby there you will find large hail, encounter freezing temperatures and ice accretion, lightning discharges, and either lots of rime icing or lots and lots of rain.

weather balloons don't get launched into convection, they don't survive long

So trying to put something into strong convection would be an interesting technical challenge, if nothing else, correct?

@JayCarr thats how balloons measure winds aloft, we track their drift

@JayCarr it can be done as the hurricane dropsondes are done, but the difficulty is operational. A thunderstorm is transient and even a strong supercell may only live a few hours. Having a research aircraft equipped and ready, dispatched and flown to a target cell takes a lot of time. Hurricanes exist for days or weeks and are much easier to target.

@JayCarr I provided nowcasting support for the DC3 project where we have a DC8, a GV and a Falcon sampling very near thunderstorms.

Hmm, this makes me wonder how hard/easy it might be to haul around a large rocket wit ha storm hunting team... And have that rocket be large enough and strong enough to place something inside of a thunderstorm.

We would fly those aircraft out to an area with no storms and have them wait in clear air for a storm we forecasted to happen so they would be in position for an intercept

expensive and requires a lot of support

I still think a rocket is going to alter its near environment such that sampling from it won't really do any good

Even if the rocket were to seperate in the storm and release something that would move away from the rocket body?

(Preferably over an unpopulated area since rocket parts falling from the sky tend to be dangerous)

I suppose the package would need to be slowed down significantly though, correct?

An object going 600knots wouldn't be terribly useful.

@JayCarr it'll be hard. Consider most people chasing storms are targeting tornadic storms. Road networks tend to not cooperate with intercepting storms and storms can be moving as fast as 70 mph or nearly stationary. Its hard enough to get on some storms let along setup and launch a rocket

plus I have to now carry equipment to receive telemetry and data back from the rocket and what it drops, and hopefully recover the instrument package

its a lot of work

How much would a useful telemetry package weight?

depends on what you are intending to observe

And I recognize this is difficult to the point of maybe being silly, I'm just looking for a long term target. My brother and I are just getting into building liquid fueled rockets, and I like having a purpose in things.

lol, anything that can be observed with a 30lbs payload perhaps? I really am not sure what people would want to monitor in a thunderstorm. I just think it would be fun to try and put a rocket in one.

a traditional radiosonde is only about 1/4 kg

That makes this all seem a lot easier suddenly.

I was figuring to be useful the rocket would need to deliver at least a 30lbs payload or something...

what people would really like to capture is in-situ drop growth, drop size distributions, ice growth, learn more about the riming, accretion, collision and coalescence processes, etc

but I don't think a rocket is going to be a useful platform for that

but dunno

@JayCarr those .25 kg payloads are not launched into convection

even on VORTEX2 our balloon teams did not launch into convection

they launched ahead if of by 10-20 km, and around it, but not into it

Well, two things then. What is the general weight of something like that (because it's the factor I'm working on right now) and do you have a write up on what kinds of forces we can expect to see in a thunderstorm... In detail, preferably. Even if I have to learn some math.

Yeah, going into convection and doing something useful sounds like an interesting (if perhaps slightly unreasonable) goal to work towards.

We live in the mid-west so helping with super-cell research kind of hits home as well...

@JayCarr I don't have a reference for that handy, but the forces are enough to bring down airplanes or significantly damage them

Mmm, I'll do some searching then.

Though I suppose if I'm really interested in this information I could trying building a rocket with some some really good acceleromators to send into a storm. That would probably give me some idea of the forces involved.

Your best bet would to contact some of the university departments that are doing in-situ thunderstorm obs and see what they can tell you

they'll know better what instrumentation is needed and where it needs to be

Do you know of any good programs off hand?

The farthest I've gotten into this is, "casey makes it sound like getting data from a thunderstorm is hard, I wonder if a rocket could do it." Which is what prompted the question last night.

I'm pretty, shall we say, naive on the subject.

Texas Tech does ground in-situ obs with sitcknets, but nothing airborne. U Colorado flies a UAS to get near-surface in-situ obs and ground based drop disdrometers. NSSL does balloon obs. OU / NSSL and CSWR do vehicle based in-situ surface / 2m obs. Everyone else samples with various radars (OU, TT, CSWR, NSSL, UMASS, Navy postgrad school)

vortex2.org/instruments

thats not everyone who does stuff, but most of the big names

the radars are where a lot of the research is going. cloud-scale wavelengths with dual-polarization and dual/triple doppler with other trucks. The Navy radar had fancy electric beam steering.

Fun! Though I doubt I'll be putting a radar array on a rocket... Still, that's a good start. Thanks casey, you've given me a lot to think about :)

has anyone here been an Air Force pilot at some point in their career?

I scored 1790 on the SAT, and I only scored 540 in the math section. Do you think I should try to become a USAF pilot or choose another career?

put another way, do I have much of a chance of scoring well on the AFOQT?

Maybe if you asked a recruiter they would have access to a practice test you can take?

ok

but isn't the AFOQT taken after college?

or is the content stuff a highschooler would know?

I really am not sure, gotta be honest. My only test I ever studied for was the LSAT (law school). All I remember is that me, and all my friends who were trying to go to various kinds of grad schools, often studied by finding practice tests.

So I figure, if you want to know how hard it will be, that would be the best choice.

If nothing else, it would give you some idea of what you need to study in college to be ready to take the test.

Also, a recruiter would know of some Air Force pilots you could talk to in order to get some of these questions answered.

Granted, it's probably a good idea to take a recruiters help with a grain of salt, but they can be a good resource for things like this.

yeah

a recruiter is going to contact me sometime soon to set up a meeting

I was just wondering if there were any air force pilots here who could speak from personal experience. ;)

It's the right place to start. Just keep in mind, they always tell you "sure, we can make you a xxx, it'll be hard, but we can get that done."

At least that's what they always said to me.

lol

ah ok

Sorry, I guess that's not me ;)

ah ok

They really need to get a military stack exchange going.

Questions like that would be really good on there....

yep

man, i hope I can become a USAF pilot...

It would be pretty cool, I'll admit.

And these days it is pretty safe...well, at least for the pilot.

I'd considered it with the idea that I would eventually become an astronaut or a test pilot.

But then I found out there aren't a lot of test pilot positions in the AF these days, and astronauts these days all seem to be scientists.... If only I were that smart.

yeah

but I would be content flying around C-130's to tell you the truth

That will definitely make it a bit easier to get a seat I would think. If you don't mind taking the boring missions.

i don't

but a pilot needs to have 25 points min in the Pilot section, and 10 points in the Navigator section

which I guess I could do if I studied hard

If you want it, work for it, life isn't know for just handing things to people...

yep

definitely gonna work for it

i am planning on enlisting in the AF reserves, then go to college for an aviation degree, then become an officer in the USAF, and then become a pilot

came up with that plan after talking to a few USAF pilots at the airshow

and doing some research

well, gtg now

Best of luck!

@flyingfisch about the only military recruitment advice I can offer is "Get everything in writing, and make sure your AFSC on the enlistment form is the right one."

Kind of impressive that a tweet about the new instrument procedures handbook was the #11 "government tweet" yesterday.

@voretaq7 were you in the Air Force?

@flyingfisch Nope. The US Military didn't want me.

ah ok. why?

@flyingfisch Something about telling the persistent Navy recruiter that wouldn't leave me alone my senior year of high school that his uniform did nothing for me but I would very much enjoy seeing him out of it.

ah

(I figured I had nothing to lose: Best case I get laid, worst case at least they'll stop calling me!)

((For the record, I didn't get laid. Story of my life.))

they wouldn't take you after that?

@flyingfisch This was back in the "Don't-Ask-Don't-Tell" days, and seeing as how I told...

ah

military aviation was probably harder to get into then too?

(plus I totally camped it up because my real goal was to get them to quit calling. I don't mind being a DoD contractor on occasion, but line military service is not my cup of bullets.)

Military aviation is still pretty competitive from what I understand - at least flying jobs.

ah

do you get paid to fly?

me personally? No. And the lousy pay for airline first officers generally discourages me from changing careers.

what is your career?

IT

ah

well, i guess I'll talk to the recruiter and see what happens

@flyingfisch Like I said the big thing is to make sure that your recruitment paperwork classifies you appropriately - it's still not a guarantee (everything is "subject to the requirements of the service), but it's better than finding out you got coded as "missile maintenance" or something when you were looking for a flying job :)

before or after college?

I plan on going to college and being in the Air Force reserves at the same time

@flyingfisch Either - your enlistment paperwork usually includes something about your specialty/designation.

oh ok

@flyingfisch that's actually not a bad deal (unless we wind up going to war :/)

the way I look at it is best case scenario, in 5 or 6 years I will be an Air Force pilot. Worst case, I would have gotten an aviation degree for free, as well as a pilot's license with through the aviation program.

huh. so, Open Airplane is now nearby and i'm thinking about getting checked out in something with 4 seats, and I noticed... they offer gift certificates.

How does that work with the FAA's pro-rata share of costs regulation?

if somebody buys you a $200 gift certificate, and you use that to rent an airplane, aren't they paying 100% of the costs?

@flyingfisch Depending on where you are consider coast guard or Air National Guard.

why?

is it less competetive?

@egid I imagine you can't carry the person who bought you the gift certificate under those circumstances :)

@flyingfisch it can be. Also slightly lower chance of getting shipped off to be shot at :)

"Not likely to be shot at" is one of the checklist items for my job-hunting process :)

@flyingfisch also you're arguably doing more good. :)

@egid @flyingfisch and the coast guard has those cool helicopters. (Ugly paint scheme though.)

@egid with the coast guard?

@voretaq7 helicopters. yuck. i want to fly fixed wing

@JayCarr compared to the air force? yes.

and how am I doing more good out of the Air Force?

coast guard does lots of civilian SAR

oh

@egid Oh, I'd agree, I was just wondering if that's what you were referencing.

@egid I wondered if you were referencing IT.

@flyingfisch What, you have a problem with an aircraft that's doing it's level best to tear itself to bits? :-P

air force is causing collateral damage

haha no

@egid At which point I'd disagree ;)

@voretaq7 1,000,000 parts flying in formation

@voretaq7 indeed.

@egid "loose formation" :-)

depends on when it last went in for a phase check

and metal fatigue waiting to happen

I personally prefer "A rotating mass of metal fatigue, surrounded by an oil leak, in search of a zip code in which to have an NTSB investigation."

Am I sensing some jealousy around here or something? I mean, I prefer fixed wing, but what's wrong with a helicopter. We have to have some way to deliver rock stars to concerts, right?

@JayCarr Two words: Ground Resonance.

@voretaq7 And now you have to explain physics to me again.

@voretaq7 What's that?

@JayCarr i'm just mad about how much it costs to rent a helicopter

I can make some downright HEINOUS landings in a fixed-wing aircraft and it won't literally fall apart because of it

don't mind me

@egid yeah there's that too - I can rent a twin for about what a little trainer chopper costs :)

@JayCarr there's also this video:

@JayCarr what ever happened to autogiros?

@voretaq7 But a helicopter can nearly fall apart taking off from the top of a building, where fixed wing planes generally need a runway of some kind to do that

@fooot That's OK - I don't mind runways. They're nice, long, obstacle-free areas where I don't generally need to worry about clipping a power line or something :-)

@voretaq7 To be fair, McGyver built that helicopter out of gum, a paperclip, an old Chevy and 3 bottles of Pabst Blue Ribbon.

@voretaq7 unless you take off in the wrong direction

@JayCarr Nonsense. The turbine required at least a Coors Light can :-)

@ratchetfreak the runway itself is still free of power lines -- what happens after the departure end threshold is your problem :-P

There are some days when I really really wish I could pick more than one correct answer for a question.

Here, the answer by federico is very good, and easily followed, but the answer by Peter Kampf is more detailed though harder to follow. Both of them were very useful. I doubt I would have really understood Peter's answer without federicos but... Which one do I select as being correct?

Any thoughts on which should be marked correct? I really am unsure. @BretCopeland When do we get to start marking more than one answer as correct, eh? ;)

I think the votes bear out the overall "better answer". Peter has a good answer, but Federico does a good job breaking down your questions and answering each one, and the photos help a lot to explain the ideas (for me at least).

@JayCarr Yeah, you have a point there.

give it a day then

That's definitely my first step at the moment...