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Thread: AeroStat/TARS Balloon Found Near Cudjoe Key Florida - Fs98

  1. Thumbs up AeroStat/TARS Balloon Found Near Cudjoe Key Florida - Fs98

    N24* 41.80' W81* 30.94' Altitude 14,000 Feet.

    The Tethered Aerostat Radar System (TARS) is an American low-level airborne ground surveillance system that uses aerostats (moored balloons) as radar platforms. Similar systems include the EL/M-2083 and JLENS.

    The aerostats are large fabric envelopes filled with helium, and can rise up to an altitude of 15,000 feet (4,600 m) while tethered by a single cable. The largest lifts a 1000 kg payload to an operating altitude providing low-level, downward-looking radar coverage. The aerostat consists of four major parts or assemblies: the hull and fin, windscreen and radar platform, airborne power generator, and rigging, and tether; they are kite balloons obtaining aerodynamic lift from relative wind as well as buoyancy from being lighter than air.

    The hull of the aerostat contains two parts separated by a gas-tight fabric partition. The upper chamber is filled with helium and provides the aerostat's lifting capability. The lower chamber of the hull is a pressurized air compartment. The hull is constructed of a lightweight polyurethane-coated Tedlar fabric. An airborne engine drives the generator, supplied by a 100-gallon diesel fuel tank.
    Beginning in the late 1990s, the aerostat sites were equipped with Lockheed Martin 420K aerostats. This blimp carries the Lockheed Martin L-88 as its primary payload, a surveillance radar with a range of 370 km (200 nm). The 420K's envelope shape, fin design, and cable attachment points are further optimized for high aerodynamic stability and easy ground handling. While Lockheed Martin is the prime contractor for the 420K aerostats, the envelopes are built by ILC Dover.
    As of 2004, all TARS sites except one were equipped with the 420K aerostats. The exception is Cudjoe Key, which uses two smaller, but otherwise similar, Lockheed Martin 275K blimps. One carries the L-88(V)3, a light-weight L-88 derivative, while the other is used to transmit the Radio y Televisión Martí TV program into Cuba.

    I saved the modes and the print screens too!


  2. #2
    Join Date
    Feb 2014
    Klammath Falls, OR


    I worked on the TARS site in Yuma, Az. from the first night it was inflated with the TCOM 71Meter system.
    I started as an E-Tech II, moved up 6 months later the the E-Tech III position, ie the lead E-Tech. When Lockheed took over, they forced me to move to Flight Director, or loose my job, a position I disliked intensely. Originally, they did away with the Lead E-Tech position, forcing my move, then quickly re-instated it. In other words, they lied to me. I worked there for over 15 years before being forced to retire due to medical reasons.

    It had a powered tether system, with the 3-phase power wires run up through the center of the tether, which allowed a MUCH longer flight time, weather permitting, than Lockheed's silly generator. Yuma holds the TARS record for time aloft at just over 31 days. A record which will never be broken with the absurd Lockheed system. The generator must be recovered every 3-4 days for refuel and maintenance.
    The powered tether was also MUCH stronger, being made out of Kevlar. The rediculous Lockheed (I wish there were a way to express the incredible scorn I feel for that company), tether, if you can call it that, is a large, nylon rope CORE, no sheath, just the core, with cheap heat-shrink over it. Much weaker. Much cheaper, and I mean that in every sense of the word "cheap". One of the ways Lockheed managed to get the contract. They claimed a less expensive system. It's actually cheaper, not just less expensive.

    At Yuma, they kept the envelope (balloon), radar, and mooring system, and added their pitiful mods. Completely replaced the Equipment Rack, slung under the envelope forward of the Windscreen which houses the Westinghouse radar.

    By the way, if you think the balloon can fly for any length of time at 15,000' AGL, you're wrong. 10,000' to 12,000' is about the working limit, realistically. Depending on the Helium fill, or amount of Helium gas in the balloon, and thus, it's lifting ability, the tuning of the generator, and so on.

    lower chamber of the hull is a pressurized air compartment
    is actually known as the ballonet. It's there to keep the hull's shape as altitude changes. As the ballon rises, the pressure in the hull increases. The reverse is obviously true. Since you don't want to vent Helium as you rise, and there is no realistic way to add more as you lower, the ballonet provides a way to maintain the hull's internal pressure, and thus shape, within realistic values. You vent air from the ballonet as you rise, pump air into it as you come down, thus compensating. If you were continue to rise after the ballonet is empty, about 12,000', the pressure increase in the Helium compartment will eventually rip a seam, venting the Helium, and you'll loose the balloon.

    Actually, there is a Helium Vent valve, and if the pressure in the hull rises high enough to be a danger to the envelope, it opens. If the balloon is rising too rapidly, however, and the valve is incapable of venting fast enough, RIIIIP goes the hull, and down she comes.

    By the way, the fins are air filled, not Helium. The exception is the sites that receive snow. They can add Helium to the fins to help hold the balloon off the ground, when the balloon is moored. A grounded balloon is a dead balloon, to paraphrase the famous Dr. Pol. If there is enough snow, the crew is dispatched to sweep it off. Yes, they can walk around the top of the envelope. Perfectly safe. They wear fall prevention harnesses, and are tethered to a safety line run along the top of the balloon. They must check their shoes for rocks before they get on the balloon, though. A rock caught in the tread is liable to tear a hole in the top, or Helium compartment. Bad scene for both the balloon, AND the crewman it happens to. If you fall into the Helium bag, you suffocate in the Helium. A crew is standing by for rescue whenever ANYONE is on top of the balloon, with breathing equipment.

    Again, a balancing act. When the snow stops, or melts away, the Helium in the fins is removed, and replaced with air again to maintain proper balance during flight.

    All this to say that if there is enough Helium to lift the system to 15,000', chances are there isn't enough ballonet volume to allow the system to rise that high without venting Helium, thus removing the lift needed. Conditions would have to be perfect to get there. Odds of everything being perfectly aligned to achieve 15,000' MSL are very small.

    As a side note, the pressures for the Aerostat systems are measured in Inches of Water Gauge. A very small unit of pressure. An IWG is about 0.035 PSI. 3.5 100ths of a PSI. Atmospheric pressure at sea level is 14.7 PSI. Think about it
    It only takes about 7 IWG internal Hull Pressure to rip the hull open.

    they are kite balloons obtaining aerodynamic lift from relative wind as well as buoyancy from being lighter than air.
    A very careful balancing act is needed there. Yes, they get lift from the wind. OK, you can rise higher the the Helium alone permits. What happens now when, not if, when, the wind decreases? Suddenly, you DON'T have enough lift. Slack tether. Or worse, you lay tether on the ground. Catch a gust aloft now, or the wind just returns to what it was, the tether will probably break when it suddenly tensions up again. Especially if you start to inhaul the tether to get the tension back. If you lay tether, ANYthing that it catches on will probably cause it to break. If you're inhauling at the time it lays, you'll probably catch on something and break the tether. A rock, the Mooring System, heck, it will probably jump the Flying Sheave, the large pulley at the end of the mooring system the tether runs through. It does, it breaks.

    The winch system is designed to operate with a certain amount of tension on the tether. Imagine a fishing reel. Ever tried to wind line on, or off, of one? It needs tension on the line, or you get what they call a bird's nest. The line gets all messed up, and doesn't reel on OR off any longer. Picture that, on a much larger scale.

    A little wind is acceptable, providing you don't RELY on it for lift. Too much wind, and the tether can over-tension, and break, too little, well, see above.

    The balloon can't fly in rain, snow, or any other adverse weather, by the way. In Ft. Huachuca, Az and Deming, NM, snow is a real problem. In Yuma, thunderstorms. I'm sure every site had it's own, unique, weather problems.

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    A nice picture of the Yuma Site, before Lockheed got ahold of it.

    Any questions, please feel free to ask. I will try to answer as best I can...

    Had a thought...then there was the smell of something burning, and sparks, and then a big fire, and then the lights went out! I guess I better not do that again!
    Sgt, USMC, 10 years proud service, Inactive reserve now

  3. Thumbs up

    I'm using my Windows Vista Laptop to run Fs98. I had shut off the User Access Control and use WinXP compatibilty Mode. Fs2002 Croaked on me, Fs2002 reboots my WinXP desktop and shows bad graphics under Vista! I'm the process of recording ALL the landmarks in Fs98, both natural and Man made!!


  4. Default

    Thanks for your summary on TARS.
    Very informative.

  5. #5
    Join Date
    Feb 2014
    Klammath Falls, OR


    Glad to help

    What I wonder is why they included the TV Marti (marTEE) balloon, and not the Yuma, Deming, or Ft. Huachuca balloons. There was even one in the mid-east, in Kuwait, that was destroyed during one of their little wars. Took them a week of shooting holes in the bag before it lost enough Helium to settle down. I hate to think what the radar looked like, though <shudder>
    It did it's job of warning them of the invasion, though, give it that.

    Even ONE of them would have been really nice.

    Ah, well, I'm off to take a look at the one they did.
    Have fun all!

    Had a thought...then there was the smell of something burning, and sparks, and then a big fire, and then the lights went out! I guess I better not do that again!
    Sgt, USMC, 10 years proud service, Inactive reserve now

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