Amateur rocket launch reaches 121,000 feet • Hacker News Board

Re: Amateur rocket launch reaches 121,000 feet

#51

Post by cjdavis » Thu, Oct 20, 2011, 7:44 PM UTC

Pyrodogg wrote: post #47

jgrahamc wrote: post #15

Earlier quoted context omitted.

Build something else. Whatever it is that you build you end up with that awesome "I built that" feeling. Last night I hacked to 0230 on turning a set of 50 GE Color Effects Christmas lights into a 7x7 color display. No one around me really understands why this was worth staying up half the night for, but when I finally got control of the serial bus protocol for programming the lights and saw my display work under my…

At Twin Cities Maker a few of our members are undergoing a project to turn these into a large color changing glass block wall. It's been a pretty cool project to watch. http://www.tcmaker.org/wiki/doku.php?id=projects:led_signboa... http://www.flickr.com/photos/eagletusk/6259626384/

We used shiftbrites in our 7x8 window at Hive13 adnd it worked out very nicely. Last week we got it working with OSC and Processing - http://www.hive13.org/?p=527 - which should make connecting to it with a wide variety of software pretty easy.

Re: Amateur rocket launch reaches 121,000 feet

#52

Post by jholman » Thu, Oct 20, 2011, 7:52 PM UTC

imd wrote: post #40

If GPS failed before 100,000 ft (and it looks like any commercial GPS would), what about the altitude charts on the project's homepage?[0] How were they generated? Can that data-gathering method qualify it for the Carmack challenge? 0: http://ddeville.com/derek/Qu8k.html

As to how they were generated, the charts are labelled. The first shows raw acceleration data, plus the first and second integrals of that data. The second shows data from a _simulation_, which was tweaked after the flight to approximate more closely data that they do have.

Re: Amateur rocket launch reaches 121,000 feet

#53

Post by achristoffersen » Thu, Oct 20, 2011, 8:23 PM UTC

Related; Copenhagen Suborbitals - homegrown opensource _manned_ rocket: http://www.copenhagensuborbitals.com/ - Peter Madsen (one of the two guys building this thing) also built a submarine..

Edit: June launch attempt http://www.youtube.com/watch?feature=player_embedded&v=K... http://www.copenhagensuborbitals.com/contentgfx/Rocket-2011_... http://en.wikipedia.org/wiki/Copenhagen_suborbitals

Re: Amateur rocket launch reaches 121,000 feet

#54

Post by iwwr » Thu, Oct 20, 2011, 10:58 PM UTC

alphadog wrote: post #24

121,000 feet = 36.88 km From Wikipedia: The Kármán line lies at an altitude of 100 kilometres (62 mi) above the Earth's sea level, and is commonly used to define the boundary between the Earth's atmosphere and outer space. That's not space. Though it's an amazing feat nonetheless.

It's not an artificial boundary. It's the approximate maximum altitude at which winged vehicles have to move faster than the orbital velocity (at that altitude) in order to attain lift (where lift is depending on the pressure at that altitude). A wing moving below orbital velocity and above that altitude will not get lift at any angle of attack, just drag.

Re: Amateur rocket launch reaches 121,000 feet

#55

Post by iwwr » Thu, Oct 20, 2011, 11:06 PM UTC

TylerE wrote: post #20

Pretty impressive, but that ain't space.

It's above more than 99% of the atmosphere, very nearly space.

The pressure is around the same you'd find on Mars (on the ground), incidentally.

Re: Amateur rocket launch reaches 121,000 feet

#56

Post by Loic » Fri, Oct 21, 2011, 6:37 AM UTC

willyt wrote: post #11

If you look at the cut open V2 rocket in the Imperial War museum in London you can see about 1/3 of the innards is the control system; gyro's, inertial guidance etc. Today you can buy that on a chips from digi-key, farnell, sparkfun or wherever for say $50 or even just root your smartphone and use it as the control system. It always surprises me that there is very little precision rocketry or ROV proliferation amongs…

For the cut, you can take a look here: http://en.wikipedia.org/wiki/File:Esquema_de_la_V-2.jpg and the corresponding Wikipedia article: http://en.wikipedia.org/wiki/V-2

Technologically impressive, but a weapon...

Re: Amateur rocket launch reaches 121,000 feet

#57

Post by derobert » Fri, Oct 21, 2011, 5:40 PM UTC

tibbon wrote: post #7

jcapote wrote: post #4

"As the GPS devices on Qu8k failed to log readings above 100,000 feet, the attempt is likely disqualified." would love to know what happened

Went higher than the GPS satellites could see?

Two things:

First, GPS satellites are in orbit ~20,000 km altitude, so this rocket is nowhere near too high. The beamwidth is pretty wide (it covers the entire half of the Earth, after all). Some quick research shows that below 3–4000km, there isn't much difference. http://emergentspace.com/gps_pubs/SSVP-v1.07-2column.pdf.

You should be able to get exact orbits (to the centimeter!) from the NGS (http://www.ngs.noaa.gov/orbits/), if you're interested.

Second, its the receiver that sees the GPS satellites, not the other way around. The satellites transmit, the receiver does not.

Re: Amateur rocket launch reaches 121,000 feet

#58

Post by JabavuAdams » Sat, Oct 22, 2011, 1:52 AM UTC

tzs wrote: post #50

JabavuAdams wrote: post #35

Earlier quoted context omitted.

It all depends whether you're using that metric, though -- it's all fairly arbitrary. X15 pilots were considered astronauts for exceeding 100k ft.

The threshold was 50 miles for X-15 pilots to be considered astronauts, which is 264k feet.

I knew I should have looked that up. Fuck! Thanks.