29mm GPS trackers...

GrouchoDuke said:

Cris can't do the assembly because of FCC rules. If he did, he'd have to get it stamped by them. It's completely fine to have a 3rd party assemble it though.

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Yes, thanks I read that on Chris's assembly thread, once I knew where it was.

rocketsam2016 said:

I've tried to make it up by buying more(I'm at 3 quantum's and an eggfinder TX and LCD) and letting other folks know how much I really have enjoyed building and using them in addition to Cris's outstanding support. I hadn't soldered in a decade and my experience was very very limited, but I had a blast and the assembly error was just me being dumb rather than some intrinsic gnarly challenge.

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For me it been 20 years for me except for a relay based launch controller I built a year ago. It is the surface mounts that give me pause. This a perfect type of thing for a how to video I'm sure it would save Chris buckets of support time. Cover the required tools and supplies then step by step assembly.

cerving said:

I would recommend that you take a look at the product page on our website, eggtimerrocketry.com, and take a look at the assembly and user guides too (under the Support section for the particular product you're looking for, i.e. Eggfinder Support). The FAQ's are helpful too. Similarly, you should do the same with other products that you're considering, so you can educate yourself on their strengths and weaknesses. Yes, this may take some time, but it's really the best way to choose something like this; when I evaluate hardware/software for my day job I usually end up downloading tons of documentation and going through it before I recommend a solution to the guys that write the checks.

In the case of the assembly vs ready-to-fly question, if you're not experienced with electronic assembly of this type I would recommend that you have it built for you. Connor does a decent job, and really doesn't charge that much considering his time. (Except for the LCD case... I think he just doesn't like to do them.) You will still save a significant amount of money vs the other GPS options out there. We sell a number of different products of varying degrees of assembly difficulty. If you want to get your feet wet, you can start with an Eggtimer Classic altimeter, then go to a Quark or Quantum to get some experience with surface mount assembly, then once you're comfortable with that you can try building your own Eggfinder TX kit. When you've really mastered things you can try a TRS. Once you've built a few of these kits, it gets much easier, just like building rockets.

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Thanks Chris, Sounds like people have fun building them. My chief concerns are receiving a component that is bad and surface mounts. If have Connor build it, the later is covered and in fact his experience would be beneficial in determining what any bad components(s) were too, but how would that work. Would you send him replacement(s) or would you have to send to me and them me to him? One of the reason I'd buy your product is the financial feasibility of purchasing multiples, but all the back and forth would be a hassle. I'd rather just purchase and assemble myself. Is there not some assembly videos that cover tools, techniques, and assembly?

cerving said:

I would recommend that you take a look at the product page on our website, eggtimerrocketry.com, and take a look at the assembly and user guides too (under the Support section for the particular product you're looking for, i.e. Eggfinder Support). The FAQ's are helpful too. Similarly, you should do the same with other products that you're considering, so you can educate yourself on their strengths and weaknesses. Yes, this may take some time, but it's really the best way to choose something like this; when I evaluate hardware/software for my day job I usually end up downloading tons of documentation and going through it before I recommend a solution to the guys that write the checks.

In the case of the assembly vs ready-to-fly question, if you're not experienced with electronic assembly of this type I would recommend that you have it built for you. Connor does a decent job, and really doesn't charge that much considering his time. (Except for the LCD case... I think he just doesn't like to do them.) You will still save a significant amount of money vs the other GPS options out there. We sell a number of different products of varying degrees of assembly difficulty. If you want to get your feet wet, you can start with an Eggtimer Classic altimeter, then go to a Quark or Quantum to get some experience with surface mount assembly, then once you're comfortable with that you can try building your own Eggfinder TX kit. When you've really mastered things you can try a TRS. Once you've built a few of these kits, it gets much easier, just like building rockets.

Click to expand...

Do a search on some of the threads and advice. Many have posted what it takes to assemble. I use a cheap 15 watt pencil with a bunch of replacement tips, magnification, good lighting and a square pyrex disk to assemble in. The dish will contain the parts better if you accidentally flip one.

Getting the LCD case cut nicely so it looks good is a job and I don't blame Connors asking price. It takes time. The EggFinder v2 is easier than the v1 kit to get together.

When it comes to "micro" sized GPS trackers I recall Robert DeHate did one many years ago and flew it. I remember seeing it on a website he had.
The solution to the problem of "small" leads to compromises specifically decreased Rf power output and decreased GPS performance due to having to use
a small GPS receiving antenna and a "small" transmitter with decreased Rf output. Making a powerful "small" GPS tracker that requires a large capacity
battery (ie. spell that heavy) sort of defeats the purpose.

I had played around with a Sparkfun, large postage stamp sized GPS receiver one had to plug into a USB serial board. Yeah it worked but the chip sized GPS antenna compromised the number of satellites it could track reliably and one would need a serial interface and a transmitter to connect to it so it was no longer
"micro-sized".

The EggFinders will do just that, find ones rocket. It is not a telemetry system that will give one "every single position". One doesn't need every single position to find a rocket though. There are ways to increase the reliability of packet decoding but it just takes a few positions on descent to get one to the ground footprint of the tracker. Once the main chute comes out and the descent slows a bit it increases the successful decoding of the positions.

All my totally sight unseen EggFinder/TRS flights were tracked successfully and found by me. They would have been lost otherwise as there was no way to tell where the rockets were headed.

The smallest sized GPS tracker is like Keith showed the Tele-GPS. It is a bit more compact than an EggFinder but of course requires a Technician's license to operate.

Kurt

jahall4 said:

That sounds awful tight. Do you have pictures? Pictures would also be nice to help understand what parts and pieces are required at a minimum to have a working system as it looks like there are several options.

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No 29mm pics, sorry. Regarding system choices and options, RTx comes in 2 basic flavors:

- Standard System / requires a 3rd party GPS enabled device for waypoint navigation to the rocket.
- Navigator System / RTx directs you to the rocket waypoint autonomously.

There is a standalone recording-only "logger" version without a radio, but I don't think that's what you're looking for. LCD and Bluetooth options are the most popular display options for the base, but I have also sold systems that pump NMEA stream via the USB module to a PC as a fixed base station and data logger via the uCenter app.

There's an RTx thread in this section that has been a running history of test and setup from a number of users that may assist your option questions as well.

jahall4 said:

That sounds awful tight. Do you have pictures? Pictures would also be nice to help understand what parts and pieces are required at a minimum to have a working system as it looks like there are several options.

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Go to the site an peruse the photos there: https://www.missileworks.com/products/
It can be interfaced to one of their altimeters or I believe it can be standalone. Look at the instructions and the spec sheet to see if it would fit for your purposes. Kurt

ksaves2 said:

I use a cheap 15 watt pencil with a bunch of replacement tips, magnification, good lighting and a square pyrex disk to assemble in.... The EggFinder v2 is easier than the v1 kit to get together.

Once the main chute comes out and the descent slows a bit it increases the successful decoding of the positions.

All my totally sight unseen EggFinder/TRS flights were tracked successfully and found by me. They would have been lost otherwise as there was no way to tell where the rockets were headed.

Click to expand...

Thanks Kurt, good info...

Your comment "once the main chute" comes out... Are you suggesting the EggFinder may be no help in finding rocket (or its "crater") in a ballistic "recovery" scenario?

MWC said:

No 29mm pics, sorry. Regarding system choices and options, RTx comes in 2 basic flavors:

- Standard System / requires a 3rd party GPS enabled device for waypoint navigation to the rocket.
- Navigator System / RTx directs you to the rocket waypoint autonomously.

There is a standalone recording-only "logger" version without a radio, but I don't think that's what you're looking for. LCD and Bluetooth options are the most popular display options for the base, but I have also sold systems that pump NMEA stream via the USB module to a PC as a fixed base station and data logger via the uCenter app.

There's an RTx thread in this section that has been a running history of test and setup from a number of users that may assist your option questions as well.

Click to expand...

So there are 3 pieces that are absolutely required? 1) Logger (has the GPS) 2) transmitter 3) receiver that some how connects to my PC or Android phone? I've looked at your website but the number of connectivity options discussed w/o any diagrams leaves me guessing. So put another way... what is the entry cost (least expensive configuration) that will communicate the last few GPS cords so I can punch them into my phone and find the rocket or its crater.

Got to remember Jim I have never done this before. So what is obvious to others in this forum may not be to me. The lack of simple block diagram is a problem across the whole industry. Not just picking on you.

thx

jahall4 said:

So there are 3 pieces that are absolutely required? 1) Logger (has the GPS) 2) transmitter 3) receiver that some how connects to my PC or Android phone? I've looked at your website but the number of connectivity options discussed w/o any diagrams leaves me guessing. So put another way... what is the entry cost (least expensive configuration) that will communicate the last few GPS cords so I can punch them into my phone and find the rocket or its crater.

Got to remember Jim I have never done this before. So what is obvious to others in this forum may not be to me. The lack of simple block diagram is a problem across the whole industry. Not just picking on you.

thx

Click to expand...

The standard RTX and navigator RTX consist of two pieces which are basically identical to each other. Each piece is both a GPS and radio transceiver. One is configured for the rocket and the other is configured to be the base station. For the base station you also need some kind of interface. In my instance I bought the LCDT.

The logger Jim mentioned would be an RTX without a transceiver; not what you're looking for.

Steve Shannon said:

The standard RTX and navigator RTX consist of two pieces which are basically identical to each other. Each piece is both a GPS and radio transceiver. One is configured for the rocket and the other is configured to be the base station. For the base station you also need some kind of interface. In my instance I bought the LCDT.

The logger Jim mentioned would be an RTX without a transceiver; not what you're looking for.

Click to expand...

See... this is why I was confused why would one need a GPS on the receiving base station? Why would they both need to be transceivers? Does that not drive up the cost?

jahall4 said:

Thanks Kurt, good info...

Your comment "once the main chute" comes out... Are you suggesting the EggFinder may be no help in finding rocket (or its "crater") in a ballistic "recovery" scenario?

Click to expand...

Um. No and No. A tumbling rocket at high speed leads to different positions of the GPS antenna and the tracker transmit antenna. The signal coming off the 900Mhz tracking antenna is "polarized" depending on the
antenna geometry. I'll ignore "circularly polarized" antennas to keep this simple but it boils down to this: For optimal receiving of a signal, if the little straight vertical antenna on your tracking transmitter
is in a "vertical" position ie. up and down, that's the position you want your receive antenna to be in. If the antenna is horizontal ie. sideways that's the position one would like their receive antenna to be in
for optimal reception.

Now with a rocket flight, the rocket may be flopping around after apogee deployment of a dual deploy. The antenna orientation may be rapidly changing and if the rocket is far away, the ability to pick up the signal is degraded
due to the power output of the tracker and the less than optimal position of the receive/transmit antennas. Packet reception may be intermittent especially with the 900Mhz trackers. Once the main chute is deployed with a nosecone mounted tracker
the antenna may be in the up/down or down/up position which is pretty optimal for reception with a vertically oriented receiver antenna. If the antenna is pointing down, the reception would technically be lousy right underneath the rocket but that is likely not going to happen. The rocket is going to still be up pretty high with a slower descent rate, in a good geometry for reception and increased chances of position decoding. A few hundred feet in the air
improves your chances for receiving. Do a ground test with the EggFinder lying horizontally on the ground and you'll notice that the ground footprint is not as good as the "in air" footprint. Hence I generally use a higher main
deployment so I can to improve my chances of getting positions for developing a trend line for drift.

Now a few other variables are the 1000 knot speed limit on GPS reception as all the commercially available chipsets will lock out if that is exceeded. Decoding returns once the speed drops back down plus the fact that the doppler effect at high speeds
may degrade the performance of the onboard GPS chipset. There's a 60,000 foot altitude limit too but some GPS chipsets will work above that altitude as long as the speed limit isn't exceeded. The efficiency of the antenna system on the receiving end can
have a big effect. You may see people with multi-element antennas (Yagis) pointing them skyward and rotating them in different positions. They're trying to optimize positioning of the antenna systems to see if they can increase the ability to get reception from a sight unseen rocket. A Yagi is a directional antenna with increased sensitivity in the direction they are pointed hence they can improve decoding ability. Only problem with 900Mhz is the width of the beam is narrow which makes pointing a Yagi on that band at a sight unseen rocket very hard to achieve reliably. At 144Mhz, 220Mhz and 420Mhz ranges the beamwidth of the Yagi is wide enough so that antenna is workable on those bands. That's what those folks are using when you see them tracking. (As an aside, I've used a multi-element Yagi antenna on the 900Mhz band to go after the rocket once it is on the ground. The orientation is not likely changing that quickly and I've proven the ground footprint is improved substantially. This might be helpful with a project that lands several miles away from you. Not necessary for most sport fliers. Ummmm, there is an antenna type
that is called a patch antenna that can increase the reception range a bit and has a wide enough beamwidth to be workable on 900Mhz. I've tried one and it works. I use a live map so I was able to keep it pointed
in the direction of the sight unseen rocket) Example: A patch antenna has polarity too and is usually marked on the back!

Lastly, more horsepower trumps everything. A high powered transmitter is decodeable from longer ranges no matter what the antenna positioning is. That's a no brainer of course.
With hobby rockety, there's a limit to tracker size and battery capacity so everything is a tradeoff.

Ballistic flight? I had an Eggfinder lead me to a rocket with the fincan sticking out of the ground. Only received two positions but it was just before the rocket hit ballistic. It was an H motor in a fiberglass rocket that was totally sight unseen. I wouldn't have known where to look but walked out to the position on the map and there it was. Sure if the rocket gets knocked side ways and goes off ballistic at a 45 degree angle away from you, you
probably won't receive anything before it hits but if it's closer, relatively speaking you stand a chance to find the crash site with the EggFinder as I did. The tracker gave up its life but I got a flyable rocket back after replacing the nosecone I cracked trying to get it out of the ground. If it was RDF tracking, one might not be able to get a reliable bearing before the rocket hits because the tracker usually dies in that instance.

That's GPS tracking in a nutshell. Kurt

jahall4 said:

See... this is why I was confused why would one need a GPS on the receiving base station? Why would they both need to be transceivers? Does that not drive up the cost?

Click to expand...

1. In order to know where the rocket is in relation to you, you need both locations, the rockets and yours. The RTx in the rocket knows the rocket's location. It sends that information to the base RTx. The base RTx then knows both locations.
2. In any intelligent conversation both sides have to be able to talk and listen, thus requiring transceivers rather than just a transmitter on one end and receiver on the other. I don't know the details but I assume that Missileworks system has a bidirectional protocol that allows the two units to identify themselves to each other
3. That also allows Missileworks to kit and build one board instead of two different boards.




Steve Shannon

jahall4 said:

See... this is why I was confused why would one need a GPS on the receiving base station? Why would they both need to be transceivers? Does that not drive up the cost?

Click to expand...

Ahhhh, don't be discouraged here. If all you want to do is GPS track you need a transmitter and a receiver period. Systems like Mr. Jim Amos Missileworks tracker and the Eggfinder TRS have the ability to send commands to the tracker/altimeter device
for remote programming. You don't need to be concerned with this if all's you need is a tracker. You can keep track of your position with a handheld GPS either a dedicated unit or a phone that has
that capability. The Missileworks device can be had with a GPS receiver at the receive station so an arrow can point you in the right direction. If you are adept at inputting the last known position into a GPS or phone, you can get
to the last known position with a good chance of either finding the rocket or being within the ground foot print of the tracker to get a new position.

Look at this thread to see what's possible with software tracking programs: https://www.rocketryforum.com/showthread.php?137555-Eggfinder-Map-tracks&p=1643420#post1643420

A GPS receiver is in the computer tablet so live tracking/plotting is doable. I'll tell you, it's pretty cool. Kurt

ksaves2 said:

Um. No and No.

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Wow Kurt, lots of real good info, thanks for taking the time to write the post!

Steve Shannon said:

1. In order to know where the rocket is in relation to you, you need both locations, the rockets and yours. The RTx in the rocket knows the rocket's location. It sends that information to the base RTx. The base RTx then knows both locations.
2. In any intelligent conversation both sides have to be able to talk and listen, thus requiring transceivers rather than just a transmitter on one end and receiver on the other. I don't know the details but I assume that Missileworks system has a bidirectional protocol that allows the two units to identify themselves to each other
3. That also allows Missileworks to kit and build one board instead of two different boards.




Steve Shannon

Click to expand...

Obviously you can receive w/o transmitting, but certainly the system would be more flexible with bidirectional communications. Regarding #1... Why do I need to know where is is in relation to me if I have the the coordinates.

ksaves2 said:

Ahhhh, don't be discouraged here. Not If all you want to do is GPS track you need a transmitter and a receiver period. Systems like Mr. Jim Amos Missileworks tracker and the Eggfinder TRS have the ability to send commands to the tracker/altimeter device
for remote programming. You don't need to be concerned with this if all's you need is a tracker. You can keep track of your position with a handheld GPS either a dedicated unit or a phone that has
that capability. The Missileworks device can be had with a GPS receiver at the receive station so an arrow can point you in the right direction. If you are adept at inputting the last known position into a GPS or phone, you can get
to the last known position with a good chance of either finding the rocket or being within the ground foot print of the tracker to get a new position.

Look at this thread to see what's possible with software tracking programs: https://www.rocketryforum.com/showthread.php?137555-Eggfinder-Map-tracks&p=1643420#post1643420

A GPS receiver is in the computer tablet so live tracking/plotting is doable. I'll tell you, it's pretty cool. Kurt

Click to expand...

Does sound cool. Nice to know it has that capability.

Not discouraged just a little annoyed that I can't get some direct answers to direct question, but you have nailed it exactly.

For my first foray into a tracking system I just want to keep it simple and inexpensive. And what you describe is exactly what I'll do... once I stop receiving coordinates I'll pull my phone out and enter as many coordinates as I need (or have) to determine a track and start walking. I have used a product for years called Backcoutry navigator that, of course, allows me to enter waypoints and record tracks. Perfect for this type of thing. If you are unfamiliar here's the link and I won't even ask you to google it :wink: https://backcountrynavigator.com/

So it looks like the best option as an entry point is the Standard EggFinder and pay Conor to assemble it?

jahall4 said:

Obviously you can receive w/o transmitting, but certainly the system would be more flexible with bidirectional communications. Regarding #1... Why do I need to know where is is in relation to me if I have the the coordinates.

Click to expand...

It's a self contained system. You don't have to have a separate gps to plug the coordinates into.

You can receive without transmitting, but in that case the data stream that's being transmitted is always the same data. In a bidirectional protocol (and depending on the protocol of course) you can request certain information, ask for information to be repeated, send commands, etc. Again, I have no knowledge of what Missileworks' system can do, but every protocol I've ever worked with has evolved over time. I like the benefits that offers. If I can carry one small box into the field with me that tells me where to go to get my rocket that's a good thing.


Steve Shannon

Steve Shannon said:

It's a self contained system. You don't have to have a separate gps to plug the coordinates into.

You can receive without transmitting, but in that case the data stream that's being transmitted is always the same data. In a bidirectional protocol (and depending on the protocol of course) you can request certain information, ask for information to be repeated, send commands, etc. Again, I have no knowledge of what Missileworks' system can do, but every protocol I've ever worked with has evolved over time. I like the benefits that offers. If I can carry one small box into the field with me that tells me where to go to get my rocket that's a good thing.


Steve Shannon

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Seems sort of "old school" to have it point you to the rocket particularly when I have already invested in tablets and phones and software. Certainly not the least expensive option and with more to go wrong when all you want are some GPS cords to find the rocket. Remember we are talking about a 29mm rocket. I can buy a backup or two of eggfinders. But you're exactly right If I wanted full telemetry and remote control it would be a good way to go.

jahall4 said:

Seems sort of "old school" to have it point you to the rocket particularly when I have already invested in tablets and phones and software. Certainly not the least expensive option and with more to go wrong when all you want are some GPS cords to find the rocket. Remember we are talking about a 29mm rocket. I can buy a backup or two of eggfinders. But you're exactly right If I wanted full telemetry and remote control it would be a good way to go.

Click to expand...

Yep, I drive to my rockets. If the launch site doesn't have Google Maps, I'm not flying.

Our launch site has a 46,000' AGL COA, with a five mile radius that we fully use. It's mostly hill and dale with prohibited off-road vehicle travel. In the valleys cell service is nonexistent. We just have different conditions.


Steve Shannon

Steve Shannon said:

Our launch site has a 46,000' AGL COA, with a five mile radius that we fully use. It's mostly hill and dale with prohibited off-road vehicle travel. In the valleys cell service is nonexistent. We just have different conditions

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Check out https://backcountrynavigator.com/ as it allows you to download the maps. No Internet connection required during use.

BTW... how do you guys have 46,000' wavier? The FAA capped those to 18,000' to keep them under Class A airspace. Now you have to have a wavier for each flight above 18,000 do you not?

jahall4 said:

Check out https://backcountrynavigator.com/ as it allows you to download the maps. No Internet connection required during use.

BTW... how do you guys have 46,000' wavier? The FAA capped those to 18,000' to keep them under Class A airspace. Now you have to have a wavier for each flight above 18,000 do you not?

Click to expand...

Probably depends on just how busy the Class A airspace is above your site. We have a 50k' waiver near Phoenix with no call-ins, but we're in a MOA.

jahall4 said:

Check out https://backcountrynavigator.com/ as it allows you to download the maps. No Internet connection required during use.

BTW... how do you guys have 46,000' wavier? The FAA capped those to 18,000' to keep them under Class A airspace. Now you have to have a wavier for each flight above 18,000 do you not?

Click to expand...

No. Your information is incorrect. Several clubs have COAs that exceed 18k. We've had ours for years. Class 3 rockets require separate paperwork per flight, but not Class 2.

Thanks for information about backcountrynavigator. Have you looked at Magellan's TRX app?


Steve Shannon

This all makes me want to solder up the Eggfinder I got last month...and go fly rockets in Phoenix. I may have to make the drive from Vegas.

GrouchoDuke said:

This all makes me want to solder up the Eggfinder I got last month...and go fly rockets in Phoenix. I may have to make the drive from Vegas.

Click to expand...

I did the first real HPR Eggfinder test out at Eagle Eye, along with a beta tester. If you don't have a good tracker there, you don't get your rocket back. We drove right up to both rockets...

Steve Shannon said:

No. Your information is incorrect. Several clubs have COAs that exceed 18k. We've had ours for years. Class 3 rockets require separate paperwork per flight, but not Class 2.

Click to expand...

This was directly from our club officer that handles waivers. Have you renewed yet?

Just a FYI, I have been working with the FAA for our waiver for the upcoming flying season. There has been a change in Washington that lowered the highest altitude for all waivers from 25,000 msl to 18,000 msl. (Roughly 17,400 feet above our field). This was done at the national level to standardize the airspace which matches FAA airspace classifications (Class A goes from 18,000 to 60,000 MSL).

We can get higher launch windows into Class A airspace but they will have to done in 45 days in advance, for each rocket, and specific date and times which will go to Washington for approval.

We will be operating on our current wiaver till it expires, then we go to the new one.

So 64K what the heck if 25K was the limit?

I turned in my renewal a few weeks ago. I've been notified they're working on it and that they'll call if they have any questions. Mine always goes through AST anyway because it surpasses the 25k limit.


Steve Shannon

Steve Shannon said:

I turned in my renewal a few weeks ago. I've been notified they're working on it and that they'll call if they have any questions. Mine always goes through AST anyway because it surpasses the 25k limit.


Steve Shannon

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That makes more sense now, but don't they regulate only commercial flights?

I think you're probably referring to the seven requirements fulfilling FAR 101.29. That's been in place since 2008 and can easily be misinterpreted to mean information on each rocket, when the wording is actually "each type of rocket". Information on each rocket is simply not possible for most launches.
The 45 day requirement has been in place for years.


Steve Shannon

Steve Shannon said:

I think you're probably referring to the seven requirements fulfilling FAR 101.29. That's been in place since 2008 and can easily be misinterpreted to mean information on each rocket, when the wording is actually "each type of rocket". Information on each rocket is simply not possible for most launches.
The 45 day requirement has been in place for years.

Click to expand...

So.... how does that change the altitude of the standing wavier? Are you saying you request waivers for every launch 45 days in advance so you can fly some of the rockets above 18K?