Are the "Marco Polo" recovery devices functional?

[gsanders]

I am wondering if the "Marco Polo" Advanced Recovery devices are worth the money? Does anyone have any experience or feedback on these items in regards to rockertry.

Thanks in advance.

 

[ksaves2]

Get a Missile works T3 if you're antsy or wait for the Featherweight offering. I did a quick read of the website and they state it is a 900 megahertz ISM band rdf tracker. They say it's good for 2 mile range and is touted as a drone tracker. I would venture a guess that the ground footprint is not very good. The missile Works T3 is cheaper and if you pay a little more for the featherweight GPS tracker that is on the cusp of being offered for sale, I would think you'd be better satisfied.
I discounted the egg timer GPS tracker because it sounds like you're not a builder of electronic devices. If you can build then you can get a 100 mw GPS tracker on fhe ISM BAND for a lot cheaper than this Marco Polo thing. I will state the disclaimer that I do not own one of these devices and only speak of what I have read on their website. Kurt

 

[woferry]

I haven't used it myself, but there's a HP flyer in my groups (LUNAR/TCC) that has been using it and really liked it so far. I don't think he's on this forum however.

 

[ksaves2]

It being purely RDF on 900Mhz, if one's rocket gets out to the 2 mile limit and there is a wind shift to another direction, the rocket could conceivably drift out of the "ground footprint" down low and one is blindly following an arrow in the wrong direction.

Patronize the folks who offer tracking solutions for rocketry for the reasons I present
below. Don't get me going on GSM stuff and by golly if you got cell service at your
site, fine. But if your GPS antenna is facing the "dirt" after the rocket is down when you call it, kiss it good-bye if it doesn't give you an accurate position and went "sight unseen" during the flight.

If one receives GPS coordinates with a GPS tracker (not this Marco Polo device) near the position where LOS (Loss of signal) occurs, they stand a better chance of getting within the ground footprint of the tracker. If one live tracks on a map, which is getting pretty doable these days, one can see the drift trend down low and will know what direction to proceed to get within the ground footprint of the tracker, especially if the rocket is not there when they get to the last known position while the rocket was in the "air". Grab a 900Mhz Yagi antenna on the receiver end once the rocket is down and one will definitely increase the ground footprint of the tracker. Might be a lifesaver on a difficult recovery.

When I say "live track" I mean a device that puts bread crumb positions on a map for
one to peruse. Radio Hams have been doing this for many years and it's possible to do
with the non-licensed required 900Mhz GPS Android based trackers using GPS Rocket Locator: https://rocketlocator.com/?i=1 The photomaps (Google maps) are gone but the OSM
(Open Source Maps) are serviceable.

I've tracked rockets at altitude using Ham Beeline GPS (https://www.bigredbee.com/BeeLineGPS.htm) trackers and more often than not the rockets can drift in directions that have absolutely no relation to the ground wind direction. I've directed the peanut gallery to look 180 degrees of where they "thought" the rocket went to where the expected main chute event is supposed to occur.

Then again, if the rocket is small enough, the main event isn't seen because it's too far away. What's too small? Well a 38mm MD, DD rocket with a 36 inch parachute (fluorescent mind you) is invisible at 1.25 miles even if all the events occur in a nominal fashion with a main deployment set for 800 feet. (Cripes, shoulda used 1000 feet!)

With the Ham trackers RDF or otherwise on 70cm, 1.25 meter and 2 meter bands. If Rf is emitted from the tracker, it can be DF'd with a yagi antenna and an attenuator with a signal strength meter on the radio. Say a GPS tracker loses lock on the satellites, as long as it's emitting Rf (and it can be garbage actually with just a station ID) if one can hear it with a radio, one can home in with RDF equipment. I have velcro on a Yagi beam so I can take off the Tele-BT receive station and can plug in an electronic attenuator for RDF within seconds. With the Beeline Ham band stuff, I have the attenuator on the Yagi with it set for "pass-through", that is it just passes the signal on to the radio for GPS positioning. If the recovery gets difficult I have the option to switch to RDF with an attenuator but in 10 years, I've not had to do that with a GPS Ham band tracker. I usually find the rocket at the position on the map. I do have to disqualify myself as I've not had a rocket land 3 miles away but I believe with these strategies I and anyone else would be ready to optimize their chance at finding their or others rockets.

If one's rockets stay within the limitation of the Marco Polo device, then it should give one some insurance for recovery. One should keep in mind that with Rf tracking, altitude can be ones friend. Ham radio operators put up antennas on towers to gain an edge and when one is flying a rocket, the rocket is up in the air and gives line-of-sight to the receive station.

Increase the sensitivity of the receive station and one will be able to receive a signal
from a rocket that's higher up and down low and at a distance. In fact with a 100 Mw, 900 Mhz GPS tracker the ground footprint is likely less than 1/2 mile. If the rocket lands in a depression, it's even less. Hence if one can track with a live map on a device, it will give them an edge to a successful recovery..

I'll again stress that due to the limited beamwidth of a Yagi antenna on 900Mhz it should be considered unreliable for "in-flight" tracking. One can't keep the effective receiving parameters of Yagi antenna pointed at a "sight unseen" rocket reliably. The little vertical dipole or simply a stock vertical antenna is optimal for in flight tracking. If one wants to
increase the sensitivity of the ground station a patch antenna is the option there and to be
"really optimal" use circularly polarized antennas. Now that's getting way out there.

A patch antenna looks like this:


I have it up on a pole of course and the patch antenna does give one some "gain" if facing the rocket in flight as it has a wider beam width than a Yagi. The antenna has "polarity" and I point it accordingly to the rocket based on presumed antenna position of the rocket in flight.
You say, "wtf". I say if interested study and take a Ham test and one will learn about this stuff. Radio ain't rocket science and books are out there to make it simple and easy to pass
a Ham Technician test. You'll have a better understanding of Rf for tracking no matter which
systems you use. RDF, GPS NMEA trackers on 900? No problem for you as you'll be able to optimize your setup to your capabilities.

If one's rockets are going to be landing within a mile then a "pointing" device on 900Mhz
might be serviceable. Remember, they tout this Marco Polo for "drones" and if the flier of the drone gets a runaway that goes out of range, kiss it goodbye. If they are running a live
camera on 5.8Mhz I doubt they'll have live vision unless they have a powerful and large
drone and receive station. Put it on a small drone with no visual telemetry and better not
fly out of sight. I will remind one that "out of sight" is where a lot of our rockets go and if "we" don't use a positive tracking paradigm, our rockets will become fodder for combines.
(At least in the Midwest on the farms that a lot of us use for flight ranges.)

Kurt KC9LDH

 

[BSNW]

Lordy I think the Marco-Polo would work just fine! Most people I see who track are looking for a rocket in crops...means flat ground..and you simply need to find it in the plants. If the darn thing works for lost and fly away drones it will find a rocket. Go to YouTube and see other people's demonstrations. For the money you can't beat it! I am saving up for one. No need to get a HAM licence no pricey radio AND yagi antenna yada yada yada......
If the drone and airplane folks like it....I would be pretty sure it will be okay for us. Now if your one of those who go miles high with those big fancy rockets you may need something else..I bet for most people it just fine

 

[BSNW]

I also launch with a HP club where folks routinely launch very high.....I have often seen both GPS and the folks waiving yagi antennas lose rockets one a field that is miles of flat ground for miles in every direction. I like watching them argue as who's system is the best. I went to another field in Indiana and watched a guy land in ten foot corn. He took his Marco Polo and disappeared into the corn only to emerge from the corn ten min later with his rocket. Good enough for me! That's what sold me!

 

[ksaves2]

I also launch with a HP club where folks routinely launch very high.....I have often seen both GPS and the folks waiving yagi antennas lose rockets one a field that is miles of flat ground for miles in every direction. I like watching them argue as who's system is the best. I went to another field in Indiana and watched a guy land in ten foot corn. He took his Marco Polo and disappeared into the corn only to emerge from the corn ten min later with his rocket. Good enough for me! That's what sold me!

"A man's got to know his limitations." If your rockets are coming down within 2 miles and you have a screamer/beeper on your harness, sure you'll find it. You fly more aggressively and that Marco Polo thing isn't going to be worth squat and by God don't take it out on the playa unless you're going to use it in a modroc that is likely going to come down within sight.

If your rocket gets out of range and takes a sharp turn on the descent while it is out of range, you'll likely be walking a line to "no where" as you'll hopelessly being going the wrong direction to get within the ground footprint of the M.P. device. I doubt it's 1/4 to 1/2 mile. Stuck in a corn row in a depression the range is shorter.

So, the take home is if you can't see your rocket at all, you have to blindly walk the line and pray you'll stumble within the ground footprint of the tracker to get the final bearing,
If not, it will be lost unless someone stumbles upon it blindly.

Now you say, the folks with RDF are essentially doing the same thing! Ah, well they are using trackers on the 1,25 meter, 2 meter and 70cm bands that have a heck of a lot
better propagation than 900 Mhz so they get a better bearing lock at farther range. Hence LOS (loss of signal) occurs closer to the ground and they can receive the signal and if they hold that bearing have a better chance of reacquiring a new bearing and home in the rocket.

Gentlemen, fly the MP within it's limitations and it should work for you. Stuff it in a small rocket that goes above 3000 feet in windy weather and I'll bet a regular RDF tracker or
GPS tracker of any type will have a better chance of finding the rocket that goes completely sight unseen than that Marco Polo thingie. Personally I think it's a toy for
hobby drones that don't fly anything like a high performance rocket. Study is good, if one stays ignorant and uses lesser tracking technology in a $500.00 rocket
the risk of losing it is a lot higher than using something already proven. (Unless they use motors that keep it within sight!)

Don't bother to fly it out on the playa. The salts absorb the Rf signal once the rocket is on the ground. People who fly RDF devices out there can lose them more readily in aggressive projects because even with a commercial RDF unit, the can't hold a bearing and get within the very small ground footprint of the tracker.

I've had folks say that out there, GPS tracking is mandatory with one or two GPS trackers preferably. Kurt

 

[BSNW]

"A man's got to know his limitations." If your rockets are coming down within 2 miles and you have a screamer/beeper on your harness, sure you'll find it. You fly more aggressively and that Marco Polo thing isn't going to be worth squat and by God don't take it out on the playa unless you're going to use it in a modroc that is likely going to come down within sight.

If your rocket gets out of range and takes a sharp turn on the descent while it is out of range, you'll likely be walking a line to "no where" as you'll hopelessly being going the wrong direction to get within the ground footprint of the M.P. device. I doubt it's 1/4 to 1/2 mile. Stuck in a corn row in a depression the range is shorter.

So, the take home is if you can't see your rocket at all, you have to blindly walk the line and pray you'll stumble within the ground footprint of the tracker to get the final bearing,
If not, it will be lost unless someone stumbles upon it blindly.

Now you say, the folks with RDF are essentially doing the same thing! Ah, well they are using trackers on the 1,25 meter, 2 meter and 70cm bands that have a heck of a lot
better propagation than 900 Mhz so they get a better bearing lock at farther range. Hence LOS (loss of signal) occurs closer to the ground and they can receive the signal and if they hold that bearing have a better chance of reacquiring a new bearing and home in the rocket.

Gentlemen, fly the MP within it's limitations and it should work for you. Stuff it in a small rocket that goes above 3000 feet in windy weather and I'll bet a regular RDF tracker or
GPS tracker of any type will have a better chance of finding the rocket that goes completely sight unseen than that Marco Polo thingie. Personally I think it's a toy for
hobby drones that don't fly anything like a high performance rocket. Study is good, if one stays ignorant and uses lesser tracking technology in a $500.00 rocket
the risk of losing it is a lot higher than using something already proven. (Unless they use motors that keep it within sight!)

Don't bother to fly it out on the playa. The salts absorb the Rf signal once the rocket is on the ground. People who fly RDF devices out there can lose them more readily in aggressive projects because even with a commercial RDF unit, the can't hold a bearing and get within the very small ground footprint of the tracker.

I've had folks say that out there, GPS tracking is mandatory with one or two GPS trackers preferably. Kurt

Yea...well said! but how many guys go to "The Playa" when considering the entire rocketry community and why does every product have to compare to the super duper high performance guys? I saw my friend drive around for an hour at LDRS looking for a signal when he was using a $600 GPS. I also saw a club member completely lose a rocket when he had the radio with yagi antenna in a flat field of at least 5 square miles. LIMITATIONS? it looks like all options have them and when actually considering the average rocket flyer I think ALL options are good. MOST people do not go to the "desert of the gods" to launch rockets. To call the Marco Polo a "toy" is a cheap shot. If I have to walk around a little bit to get my signal back...WHO CARES! The transmitter on the MP transmits for a month. If I am looking in the crops for a rocket and know I have to be within 1/2 mile I think my odds are pretty good I will get it back. I also dont need to get a HAM or spend a fortune. I think it comes down to to the folks who have the "super duper expensive set up" being a tad upset that the average person can get a complete tracking system for under $250.00 and be out at the launch field finding rockets along side of them. the take home for me is that for MOST of us...the darn thing works!

Either way, I have personally seen the MP system work in rolling fields of corn with its dips and valleys while I have also seen a GPS lose signal in wide open spaces and even set off an altimeter charge on the pad b/c of its 2W transmission. I have also seen a number of guys lose signal with their $350 HAM radio. I am also sure some guy has also had a bad experience with the MP....Based on my observation they all are not a sure thing! So which is best in the end? Who knows...but I wont spend more than $235 plus free shipping to find out!

 

[ksaves2]

There is no best and one just has to take care to optimize their system and not go outside of the design parameters.

Use metallic paint on a rocket that shields Rf? Sure could lose it if one doesn't do an adequate ground test.

Blast a 16mW GPS tracker to 60k? Well, might be better off with a 100mw 70cm tracker or a 1 watt GPS tracker on an APRS band with deployment electronics
that are proven immune to the higher Rf field. I witnessed a ballistic flight of a 2 watt dog tracker too that shut down the deployment electronics in flight.
Deployment on the pad at least results in less damage and possible repair/remedy. Kurt

 

[lowga]

Marco Polo sells a crush-proof, polycarbonate enclosure for the transmitter that can be attached using wire ties. Attaching the tracker to the outside of a rocket would be very similar to mounting a keychain camera at that point. You can also attach their mount using screws into the airframe.

While I do wish that the receiver had the option to attach an external antenna, I see no reason why this tracker wouldn't meet the needs of about 90% of HP launches. Most of our launches are restricted to H-I motors to stay under the waiver, and I imagine that applies to a lot of folks. It has the advantage of being a very simple system to set up (KISS is still a good rule of thumb) and license free.

The tracker you fly is always better than the tracker at home on the work bench.

 

[kuririn]

I think the takeaway is, match the system to the rocket and how you're flying. A high power rocket that goes out of sight and winds up thousands of yards downrange will not benefit from the more limited tracking solutions, obviously. On the other hand, why invest hundreds of dollars if all you are flying is a low/mid power rocket that may get lost in an adjacent corn field or tall grass? A sonic beeper will pinpoint your rocket's location for much less than the MP, in this case. Another solution would be a small tracking device linked to a smartphone app/Bluetooth, like TrackR or Tile. Ring the chime, head for the sound. Plus, I understand TrackR now has led lights. That could be useful in low light conditions.The MP might be useful in a scenario between the two aforementioned, where it is lost at a distance further than earshot, but still within its' footprint. Buy for what you need, no need to overspend.

 

[ksaves2]

I think the takeaway is, match the system to the rocket and how you're flying. A high power rocket that goes out of sight and winds up thousands of yards downrange will not benefit from the more limited tracking solutions, obviously. On the other hand, why invest hundreds of dollars if all you are flying is a low/mid power rocket that may get lost in an adjacent corn field or tall grass? A sonic beeper will pinpoint your rocket's location for much less than the MP, in this case. Another solution would be a small tracking device linked to a smartphone app/Bluetooth, like TrackR or Tile. Ring the chime, head for the sound. Plus, I understand TrackR now has led lights. That could be useful in low light conditions.The MP might be useful in a scenario between the two aforementioned, where it is lost at a distance further than earshot, but still within its' footprint. Buy for what you need, no need to overspend.

Well said................. The problem is the temptation to use it in something that's too aggressive to ensure a reliable recovery.

I tell you, there is nothing worse than having a totally sight unseen flight and not having a freaking idea where it went. That feeling got worse after I flew tracked sight unseen flights at altitude with larger rockets (with successful recoveries) and went back to flying modrocs up high. Yeah they're cheap (relatively) but I still hate losing them!
Especially if I was stupid enough to use an RMS case in 'em. Won't do that again. Modroc RMS I save for projects that are going to be coming in under sight or with some
kind of tracker! Kurt

 

[gsanders]

Does anyone know if the Missle Works featherweight unit is available yet? If so, does anyone have the URL and any input.

Thanks

Get a Missile works T3 if you're antsy or wait for the Featherweight offering. I did a quick read of the website and they state it is a 900 megahertz ISM band rdf tracker. They say it's good for 2 mile range and is touted as a drone tracker. I would venture a guess that the ground footprint is not very good. The missile Works T3 is cheaper and if you pay a little more for the featherweight GPS tracker that is on the cusp of being offered for sale, I would think you'd be better satisfied.
I discounted the egg timer GPS tracker because it sounds like you're not a builder of electronic devices. If you can build then you can get a 100 mw GPS tracker on fhe ISM BAND for a lot cheaper than this Marco Polo thing. I will state the disclaimer that I do not own one of these devices and only speak of what I have read on their website. Kurt

 

[LithosphereRocketry]

Does anyone know if the Missle Works featherweight unit is available yet? If so, does anyone have the URL and any input.

Thanks

MissileWorks and Featherweight are two different things.

MissileWorks (MWC on the forum IIRC) makes 2 trackers, the RTx and the T3- I haven't used either, but they've been available for a while.
https://www.missileworks.com/rtx/
https://www.missileworks.com/t3/

Featherweight (Adrian A on the forum) is currently developing a tracker. It is not available yet.
https://www.featherweightaltimeters.com/featherweight-gps-tracker.html

As ksaves2 mentioned, Eggtimer Rocketry (cerving on the forum) sells DIY GPS tracker kits for considerably less than the other options, if you're willing to solder small parts.

 

[gsanders]

Hello:

Does anyone know how to get in touch with Featherweight Altimeters? I filled out the "contact form" on their website late last week and no one has responded to me yet.

TIA.

MissileWorks and Featherweight are two different things.

MissileWorks (MWC on the forum IIRC) makes 2 trackers, the RTx and the T3- I haven't used either, but they've been available for a while.
https://www.missileworks.com/rtx/
https://www.missileworks.com/t3/

Featherweight (Adrian A on the forum) is currently developing a tracker. It is not available yet.
https://www.featherweightaltimeters.com/featherweight-gps-tracker.html

As ksaves2 mentioned, Eggtimer Rocketry (cerving on the forum) sells DIY GPS tracker kits for considerably less than the other options, if you're willing to solder small parts.