Re: [PSAS] $5000 prize for 100,000 foot flight
humm, spec the solid motors to put the rocket in the range of 105k to 110k and use an upward-facing RCS system + some software foo to take that back down to exactly 100k... sounds plausible to me -d On Mon, Feb 28, 2011 at 11:14 PM, Josh Triplett wrote: > On Mon, Feb 28, 2011 at 10:14:21PM -0800, Nathan Bergey wrote: >> 100,000 feet is a pretty number. Maybe >> when I get the Trajectory Optimizer working we can do an optimal mass >> problem with it and see just how big it would have to be. Maybe with dart? >> Anyway I wasn't suggesting we go for it just wanted to know what people >> thought about it so I don't sound stupid tomorrow on the air. > > Now you're giving me a crazy idea. Once we have working control, how > closely could we put the apogee to 100k feet, plus or minus? Or any > arbitrary number roughly in the proper range for the engine size? > > - Josh Triplett > > ___ > psas-team mailing list > psas-team@lists.psas.pdx.edu > http://lists.psas.pdx.edu/mailman/listinfo/psas-team > > This list's membership is automatically generated from the memberships of the > psas-airframe, psas-avionics, and psas-general mail lists. Visit > http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from > these lists. > ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
On Mon, Feb 28, 2011 at 10:14:21PM -0800, Nathan Bergey wrote: > 100,000 feet is a pretty number. Maybe > when I get the Trajectory Optimizer working we can do an optimal mass > problem with it and see just how big it would have to be. Maybe with dart? > Anyway I wasn't suggesting we go for it just wanted to know what people > thought about it so I don't sound stupid tomorrow on the air. Now you're giving me a crazy idea. Once we have working control, how closely could we put the apogee to 100k feet, plus or minus? Or any arbitrary number roughly in the proper range for the engine size? - Josh Triplett ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
On Mon, 28 Feb 2011 22:14:21 -0800, Nathan Bergey wrote: > From what I gathered in the list this is a competition to get people working > on reasonable goals. I think they're tired of seeing pie-in-the-sky plans > that don't get off the ground. Baby steps. Just get to 100,000 feet without > blowing anything up and record GPS (proof of not being an idiot about flight > electronics) and recover safely then share what you did with the world. > Sounds pretty great actually. There have been a few amateur groups who have beat 100k'. Might be fun to see how small a rocket we could get to go that high. I'm currently building an airframe that flies on a single L and sims to 10km. I don't know if anyone has gotten to 100k' (a bit more than 30km) with less than an N total impulse. I might be able to convince the Skytraq guys to provide a tweaked firmware image for their GPS chips for a university project like this. All of the GPS systems I know of that will report reasonable data during ascent are much larger and heavier than TeleMetrum. -- keith.pack...@intel.com pgpr2E0LL5AHC.pgp Description: PGP signature ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
> > Hey, now that you mention it, we *do* have the code and public data > sources to simulate down to the correlator level if we want to. :-) Ha, no cheating! Too bad we don't have the time or money to do this though because it would be a fun project. 100,000 feet is a pretty number. Maybe when I get the Trajectory Optimizer working we can do an optimal mass problem with it and see just how big it would have to be. Maybe with dart? Anyway I wasn't suggesting we go for it just wanted to know what people thought about it so I don't sound stupid tomorrow on the air. I'm pretty sure the tracking loop is causing the GPS to lose lock. Yes, as I remember it we agreed this was a problem. I have seen other people suggest this as a likely problem over 4 g's and fixable with GPS/INS type solutions. >From what I gathered in the list this is a competition to get people working on reasonable goals. I think they're tired of seeing pie-in-the-sky plans that don't get off the ground. Baby steps. Just get to 100,000 feet without blowing anything up and record GPS (proof of not being an idiot about flight electronics) and recover safely then share what you did with the world. Sounds pretty great actually. -Nathan On Mon, Feb 28, 2011 at 9:27 PM, Jamey Sharp wrote: > On Mon, Feb 28, 2011 at 8:54 PM, I wrote: > > So... if this is a height competition, I would think that the sponsor > would > > provide the GPS... Mostly because folks like us can produce a GPS log > that > > clearly indicates 100,000 ft from my Liberty 4 ;) In fact, I'd bet Dave > can > > do it with 2 lines of PERL. > > Hey, now that you mention it, we *do* have the code and public data > sources to simulate down to the correlator level if we want to. :-) > > Jamey > > ___ > psas-team mailing list > psas-team@lists.psas.pdx.edu > http://lists.psas.pdx.edu/mailman/listinfo/psas-team > > This list's membership is automatically generated from the memberships of > the psas-airframe, psas-avionics, and psas-general mail lists. Visit > http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself > from these lists. > ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
On Mon, Feb 28, 2011 at 8:54 PM, I wrote: > So... if this is a height competition, I would think that the sponsor would > provide the GPS... Mostly because folks like us can produce a GPS log that > clearly indicates 100,000 ft from my Liberty 4 ;) In fact, I'd bet Dave can > do it with 2 lines of PERL. Hey, now that you mention it, we *do* have the code and public data sources to simulate down to the correlator level if we want to. :-) Jamey ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
Quoting Keith Packard : On Mon, 28 Feb 2011 15:05:37 -0800, I wrote: Quoting Nathan Bergey : > Yes, I think the main goal is to get people to think about GPS on rockets. > Even if we don't make an attempt this should be fun to watch. > > More (selfishly) importantly I've been invited on the Evadot podcast > tomorrow morning to be an "expert" pundit of sorts about the contest and > what is hard about it, what's easy, etc. > > Anyone have thoughts about it? Is it a good idea? Is it easy? It's not trivial, but it can be done. The hard part is tracking the *rate* that the Doppler-affected satellite signal frequency changes. If you build a GPS that can track (the frequency change) that fast, it becomes susceptible to noise. This can be greatly alleviated by tightly coupling the GPS and INS sensors (+ details). > How long will > it take for someone to win? GPS units capable of high dynamics already exist. If someone that has one knows a rocket guy, problem solved. Tracking the max altitude doesn't require high dynamic response; rockets tend to have low acceleration outside of the boost phase. There are lots of commercial GPS units capable of accurately tracking rocket position during coast, apogee and descent. The Trimble units are often used for this altitude. In fact, the new TRA altitude record rules for flights above 40k' require use of one of these in place of a barometric altimeter. I guess that's true... re-reading the challenge, the point is the 100,000 ft, not the GPS tracking. OEM's have a tracking loop (google Costas loop) typically with a 1Hz bandwidth (source: a GPS INS book I have. It's at home at the moment). Some OEM units can change the loop bandwidth to something higher, but with poorer accuracy and greater likelihood of loosing the satellite lock. The result is this: if the GPS accelerates (relative to the satellite) above a certain rate (some GPS OEMs advertise 4 g's) the correlator cannot change the carrier tracking frequency fast enough to keep up, so the signal lock is lost. Right, you lose the signal during boost, but rapidly re-acquire it after the motor burns out. The GPS in TeleMetrum loses lock under boost, but usually re-locks within a few seconds of motor burnout. It's problem is not the tracking loop low-pass filter, but the Kalman filter post-processing the raw GPS coordinates into the displayed values. That shows a huge lag, which you'd expect if the model error co-variance values were very small. I'd be happy enough to be able to change the Kalman filter values and not mess with the tracking loop filter; I'm not trying to steer. Huh? I'm pretty sure the tracking loop is causing the GPS to lose lock. Especially in your rockets (with your more-reasonable-than-PSAS mass fractions)! I'd agree that one could build a KF to track position during that time, but from what I've read on tracking correlators, IMHO the loop filter is never going to keep up with your 20+g rockets on boost. So... if this is a height competition, I would think that the sponsor would provide the GPS... Mostly because folks like us can produce a GPS log that clearly indicates 100,000 ft from my Liberty 4 ;) In fact, I'd bet Dave can do it with 2 lines of PERL. This is actually doable. Too bad we're broke... ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
On Mon, 28 Feb 2011 15:05:37 -0800, I wrote: > > Quoting Nathan Bergey : > > > Yes, I think the main goal is to get people to think about GPS on rockets. > > Even if we don't make an attempt this should be fun to watch. > > > > More (selfishly) importantly I've been invited on the Evadot podcast > > tomorrow morning to be an "expert" pundit of sorts about the contest and > > what is hard about it, what's easy, etc. > > > > Anyone have thoughts about it? Is it a good idea? Is it easy? > > It's not trivial, but it can be done. The hard part is tracking the > *rate* that the Doppler-affected satellite signal frequency changes. > If you build a GPS that can track (the frequency change) that fast, it > becomes susceptible to noise. This can be greatly alleviated by > tightly coupling the GPS and INS sensors (+ details). > > > How long will > > it take for someone to win? > > GPS units capable of high dynamics already exist. If someone that has > one knows a rocket guy, problem solved. Tracking the max altitude doesn't require high dynamic response; rockets tend to have low acceleration outside of the boost phase. There are lots of commercial GPS units capable of accurately tracking rocket position during coast, apogee and descent. The Trimble units are often used for this altitude. In fact, the new TRA altitude record rules for flights above 40k' require use of one of these in place of a barometric altimeter. > OEM's have a tracking loop (google Costas loop) typically with a 1Hz > bandwidth (source: a GPS INS book I have. It's at home at the moment). > Some OEM units can change the loop bandwidth to something higher, but > with poorer accuracy and greater likelihood of loosing the satellite > lock. The result is this: if the GPS accelerates (relative to the > satellite) above a certain rate (some GPS OEMs advertise 4 g's) the > correlator cannot change the carrier tracking frequency fast enough to > keep up, so the signal lock is lost. Right, you lose the signal during boost, but rapidly re-acquire it after the motor burns out. The GPS in TeleMetrum loses lock under boost, but usually re-locks within a few seconds of motor burnout. It's problem is not the tracking loop low-pass filter, but the Kalman filter post-processing the raw GPS coordinates into the displayed values. That shows a huge lag, which you'd expect if the model error co-variance values were very small. I'd be happy enough to be able to change the Kalman filter values and not mess with the tracking loop filter; I'm not trying to steer. -- keith.pack...@intel.com pgpvePRyq7zqg.pgp Description: PGP signature ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
On Mon, Feb 28, 2011 at 03:05:37PM -0800, I wrote: > Quoting Nathan Bergey : > OEM's have a tracking loop (google Costas loop) typically with a 1Hz > bandwidth (source: a GPS INS book I have. It's at home at the > moment). Some OEM units can change the loop bandwidth to something > higher, but with poorer accuracy and greater likelihood of loosing > the satellite lock. The result is this: if the GPS accelerates > (relative to the satellite) above a certain rate (some GPS OEMs > advertise 4 g's) the correlator cannot change the carrier tracking > frequency fast enough to keep up, so the signal lock is lost. > > Another approach is to adapt the rocket to work with the GPS. This > would get you the tracking, but not necessarily the altitude unless > you can unlock the GPS (ITAR restriction). The OS GPS or GPL/GPS > could really shine here. > > I'd say one could do this with a 2 stage rocket using a slow first > stage, a slow second stage, and long launch rail. The key is to keep > the OEM GPS acceleration under 4 G's the whole way. Hybrids might > have an advantage here with long slow burns. Note that they don't say you need continuous GPS tracking, just that you need at least one GPS measurement above the altitude threshold. So, as long as the GPS recovers during the coast phase, before apogee, that should suffice. Of course, independently from their criteria we *want* a GPS unit that works continuously through the flight. - Josh Triplett ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
Quoting Nathan Bergey : Yes, I think the main goal is to get people to think about GPS on rockets. Even if we don't make an attempt this should be fun to watch. More (selfishly) importantly I've been invited on the Evadot podcast tomorrow morning to be an "expert" pundit of sorts about the contest and what is hard about it, what's easy, etc. Anyone have thoughts about it? Is it a good idea? Is it easy? It's not trivial, but it can be done. The hard part is tracking the *rate* that the Doppler-affected satellite signal frequency changes. If you build a GPS that can track (the frequency change) that fast, it becomes susceptible to noise. This can be greatly alleviated by tightly coupling the GPS and INS sensors (+ details). How long will it take for someone to win? GPS units capable of high dynamics already exist. If someone that has one knows a rocket guy, problem solved. Hopefully I have my facts straight about GPS (yes I know about the ITAR or vs and in the cutoff conditions). Anything else relevant? Why not just fly an OEM board? OEM's have a tracking loop (google Costas loop) typically with a 1Hz bandwidth (source: a GPS INS book I have. It's at home at the moment). Some OEM units can change the loop bandwidth to something higher, but with poorer accuracy and greater likelihood of loosing the satellite lock. The result is this: if the GPS accelerates (relative to the satellite) above a certain rate (some GPS OEMs advertise 4 g's) the correlator cannot change the carrier tracking frequency fast enough to keep up, so the signal lock is lost. Another approach is to adapt the rocket to work with the GPS. This would get you the tracking, but not necessarily the altitude unless you can unlock the GPS (ITAR restriction). The OS GPS or GPL/GPS could really shine here. I'd say one could do this with a 2 stage rocket using a slow first stage, a slow second stage, and long launch rail. The key is to keep the OEM GPS acceleration under 4 G's the whole way. Hybrids might have an advantage here with long slow burns. I'm getting on the aRocket list now. Super annoying that it's closed. -Nathan On Mon, Feb 28, 2011 at 12:05 PM, Jamey Sharp wrote: On Mon, Feb 28, 2011 at 9:57 AM, Nathan Bergey wrote: > http://www.rocketryplanet.com/index.php?option=com_content&task=view&id=3542&Itemid=29 > 100,000 ft is not even space, only a mere 30 km. Note the requirement of > having GPS. Something we should already know how to do. Note the requirement amounts to "still getting data from the GPS receiver above 100k feet." ITAR limits export of GPS receivers "designed for producing navigation results above 60,000 feet altitude and at 1,000 knots velocity or greater", but as I recall, PSAS found that 1) American GPS makers don't want to build commercial receivers that they can't export, and 2) they treat the restriction as an "or". So maybe the real point of this challenge is to demonstrate an amateur GPS receiver that works well above 60k feet? I wish the "arocket" list archives weren't closed. I'd like to see the original challenge without having to subscribe. Also note the prize is now almost meme-compliant, at $9000. Somebody should throw in another dollar. Jamey ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
> > We've been assured by skytraq that they treat the ITAR limits as AND, not > OR. So, that chip should 'just work', aside from issues of kalman filter > lag. Thanks Keith. Now that I'm on the aRocket l can read the thread (but it's kind of long). Interesting snips here: > if you succeed and write up the experience for the benefit of others, I’ll > donate $5k to your project. I am not going to bankroll any attempt, because I don’t expect you to succeed. Offering cash for a task that seems trivial (successful 100,000’ flight) compared to the primary task being discussed (two stage rockoon flight to 400 miles, not to mention orbit) and watching it go unclaimed is a demonstration that the primary task being discussed was wildly unrealistic. I live in a bit of a glass house here -- everyone involved in the X-Prize except Scaled were wildly unrealistic, including Armadillo. I don’t think it is a noble effort to make grandiose plans and squander resources on a project with an infinitesimal chance of success. In the abstract, it is good for the “gene pool” to have some of those long shot attempts, but I feel sorry for the concrete examples I see. I don’t want you to have spent your $160k and time on something that turns out to be a complete failure. The bottom line is that you aren’t going to put something in orbit if you aren’t a millionaire, and you should just get over it. Getting something to space (100km) is a much more credible goal for an amateur effort, and still highly (but not wildly) optimistic with funding at this level. I would be happy to see more discussion on aRocket of practical issues with high altitude flights, even well below 100km. It is clearly still far from routine, and there is much to learn. John Carmack On Mon, Feb 28, 2011 at 2:03 PM, Keith Packard wrote: > On Mon, 28 Feb 2011 13:53:51 -0800, Nathan Bergey > wrote: > > > Yes, I think the main goal is to get people to think about GPS on > rockets. > > Even if we don't make an attempt this should be fun to watch. > > > > More (selfishly) importantly I've been invited on the Evadot podcast > > tomorrow morning to be an "expert" pundit of sorts about the contest and > > what is hard about it, what's easy, etc. > > > > Anyone have thoughts about it? Is it a good idea? Is it easy? How long > will > > it take for someone to win? Hopefully I have my facts straight about GPS > > (yes I know about the ITAR or vs and in the cutoff > > conditions). Anything else relevant? Why not just fly and OEM board? > > We've been assured by skytraq that they treat the ITAR limits as AND, > not OR. So, that chip should 'just work', aside from issues of kalman > filter lag. > > -- > keith.pack...@intel.com > ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
On Mon, 28 Feb 2011 13:53:51 -0800, Nathan Bergey wrote: > Yes, I think the main goal is to get people to think about GPS on rockets. > Even if we don't make an attempt this should be fun to watch. > > More (selfishly) importantly I've been invited on the Evadot podcast > tomorrow morning to be an "expert" pundit of sorts about the contest and > what is hard about it, what's easy, etc. > > Anyone have thoughts about it? Is it a good idea? Is it easy? How long will > it take for someone to win? Hopefully I have my facts straight about GPS > (yes I know about the ITAR or vs and in the cutoff > conditions). Anything else relevant? Why not just fly and OEM board? We've been assured by skytraq that they treat the ITAR limits as AND, not OR. So, that chip should 'just work', aside from issues of kalman filter lag. -- keith.pack...@intel.com pgpPK0261BBHQ.pgp Description: PGP signature ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
Yes, I think the main goal is to get people to think about GPS on rockets. Even if we don't make an attempt this should be fun to watch. More (selfishly) importantly I've been invited on the Evadot podcast tomorrow morning to be an "expert" pundit of sorts about the contest and what is hard about it, what's easy, etc. Anyone have thoughts about it? Is it a good idea? Is it easy? How long will it take for someone to win? Hopefully I have my facts straight about GPS (yes I know about the ITAR or vs and in the cutoff conditions). Anything else relevant? Why not just fly and OEM board? I'm getting on the aRocket list now. Super annoying that it's closed. -Nathan On Mon, Feb 28, 2011 at 12:05 PM, Jamey Sharp wrote: > On Mon, Feb 28, 2011 at 9:57 AM, Nathan Bergey > wrote: > > > http://www.rocketryplanet.com/index.php?option=com_content&task=view&id=3542&Itemid=29 > > 100,000 ft is not even space, only a mere 30 km. Note the requirement of > > having GPS. Something we should already know how to do. > > Note the requirement amounts to "still getting data from the GPS > receiver above 100k feet." ITAR limits export of GPS receivers > "designed for producing navigation results above 60,000 feet altitude > and at 1,000 knots velocity or greater", but as I recall, PSAS found > that 1) American GPS makers don't want to build commercial receivers > that they can't export, and 2) they treat the restriction as an "or". > So maybe the real point of this challenge is to demonstrate an amateur > GPS receiver that works well above 60k feet? > > I wish the "arocket" list archives weren't closed. I'd like to see the > original challenge without having to subscribe. > > Also note the prize is now almost meme-compliant, at $9000. Somebody > should throw in another dollar. > > Jamey > ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
Re: [PSAS] $5000 prize for 100,000 foot flight
On Mon, Feb 28, 2011 at 9:57 AM, Nathan Bergey wrote: > http://www.rocketryplanet.com/index.php?option=com_content&task=view&id=3542&Itemid=29 > 100,000 ft is not even space, only a mere 30 km. Note the requirement of > having GPS. Something we should already know how to do. Note the requirement amounts to "still getting data from the GPS receiver above 100k feet." ITAR limits export of GPS receivers "designed for producing navigation results above 60,000 feet altitude and at 1,000 knots velocity or greater", but as I recall, PSAS found that 1) American GPS makers don't want to build commercial receivers that they can't export, and 2) they treat the restriction as an "or". So maybe the real point of this challenge is to demonstrate an amateur GPS receiver that works well above 60k feet? I wish the "arocket" list archives weren't closed. I'd like to see the original challenge without having to subscribe. Also note the prize is now almost meme-compliant, at $9000. Somebody should throw in another dollar. Jamey ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
[PSAS] $5000 prize for 100,000 foot flight
FYI http://www.rocketryplanet.com/index.php?option=com_content&task=view&id=3542&Itemid=29 100,000 ft is not even space, only a mere 30 km. Note the requirement of having GPS. Something we should already know how to do. ___ psas-team mailing list psas-team@lists.psas.pdx.edu http://lists.psas.pdx.edu/mailman/listinfo/psas-team This list's membership is automatically generated from the memberships of the psas-airframe, psas-avionics, and psas-general mail lists. Visit http://lists.psas.pdx.edu to individually subscribe/unsubscribe yourself from these lists.
