Launching at sea

[BDB]

This is my random thought of the day....The Navy launches lots of rockets from ships and submarines, Copenhagen Suborbitals launches from a barge, and, of course, SpaceX lands rockets on a barge, but has anyone in hobby rocketry ever seriously pursued launching from a raft (or maybe a low-altitude rockoon tethered to a boat) at sea? It would obviously add lots of complexity to both the launch and recovery, but those could be fun problems to solve. If possible, it could also be a cool way for those of us who are not close to Black Rock to try some extreme stuff.

 

[fyrwrxz]

Just a thought, you still have to check with the FAA for flight paths.

 

[Incongruent]

Brace yourself. Long comment incoming.

The reason that most space rockets launch, land, fly, stage, and/or disintegrate over the ocean is safety- The ocean is big and mostly devoid of humans and property. The missiles launch there because it's once again, big and you can move around. (Note: not all resons covered) Most of the benefits of launching space rockets and missiles are in some part detrimental to (small) model rockets. The vast expanse and currents move rockets around, so you can't say that you searched an area already. Lack of solid land makes it harder to move around. Cardboard motor cases swell up in water and get stuck.

Larger rockets get more benefits and are better suited for water launches.


Or:

The pros:
No breakage from the shock of landing
No property is good for high power rockets
No need for a flame deflector, just cut a hole in the boat; nonflammable material
No trees
No tall grass
No power lines
Flat
Water and sky are the same color
Can be engineered to point vertically if chuffed off rod.
Drag under water slows down lawn dart but doesn't break rocket as easily.
Bragging rights (this one of the most important ones, anyone can launch from *pfff* land.)
GPS will be there anyways.

The cons:
Waves
Hard to find
Need to waterproof rocket and electronics, deployment electronics must be separate from open tube.
Salt water (oceans only) corrodes things.
No paper or water dissolvable things can be used.
Water reflects light
Longer searching, harder to recover
The entire rocket has to float for ease of sighting- requires sealed off compartments of air for buoyancy (water can seep in between gaps) or inflatable balloons (Think space capsule)
Currents could carry rocket away easily in open space.
The possible legal concerns (above post)
Remains of propellant or building supplies dissolving or washing off into water.
If the rocket sinks, It's gone forever. Visibility beneath water is a few feet and a blurry, foggy view makes sea grass look like rocket.

If the rocket is buoyant enough, skimming the water like after an oil spill might get the rocket in low visibility or high glare.
Lakes better than seas
Rocket needs to be built with extra precautions
Barge needs to self level.
More suited for HPR, though that's what your comment seemed to be geered to anyways.
Due to the flatness, a large rocket would be easy to track if you kept your eyes on the rocket until splashdown. No hills to hide behind.
It would be interesting to have, say, a helium balloon attatched to a mylar streamer get pushed out at ejection and act as a beacon after landing.

(Most) Anything is possible (with the right budget), but think about benefits and limitations to determine feasibility.
There are many benefits, but just as many complications that could make it not work.
Some are easily solved but make sure you know the risks of launching this way. Not just economic and safety, but also check to see if the materials you build with can contaminate the water and whether that can be solved.


I think it's a great concept with lots of potential and I'd love to help turn it into reality.



-Tony

 

[BDB]

You are right. It would be incredibly challenging. Plus, I'd need to buy a boat, and that would kill my rocket motor budget.

 

[Incongruent]

But for high power, it could be really useful. Consider $200 or so (I can't remember) as possibly free since you (or I) can write an apogee newsletter. Or more, if there are multiple parts.
No need for the boat, unless you actually want the rocket back. Some barrels and wood, pvc can make a barge, plus some (maybe folding) legs for stability.

There are limitations, but if your club offers a reward for a flying field...
Getting a normal field is hard enough, but since lakes have less potential for housing, etc. It'll be more long lasting.
Sod farms, pastures, farms, fields- these are all flammable. How long has it been since you've launched or seen a launch of a sparky? (please live somewhere hot and dry...)
The only field that doesn't burn is a lake bed. And those aren't too nice on hard landings, or so I've heard.

You know how someone has "we both like lakes, she likes hers wet and I like mine dry?"
Well now we can settle the dispute.

If you have a launch pad on the shore or the dock angles so the rocket recovers in the lake or on the shore, that would eliminate the need for a barge and still might not need a blast deflector.
Being on a dock could take care of some of the safety benefits of water launches, as long as the rod is angles away and the rocket on the lake side of the rod. (I think)

Get some friend who like boating or kayaking and have them play "Get the rocket"
Recovery solved. For certain distances.

I think it's a great idea. There's even a beach for the less rocketry inclined family members. A suitable flying field for HPR could be hours away for some, but a lake that could be one might be less than 30 minutes away.

It would be challenging as getting high power certified can be challenging, new techniques, different situations, emptier wallet. But you got L1 certified, I'm assuming because it opened up new possibilities: new motors, rockets, and mortgages. Water launches will too.
And you said it nicely in the first post, these would be fun problems to solve.


I'll think about it this weekend and try to find a cheap way, then continue trying to persuade you.
I want it to happen too. (Even though I can't get HP certified or Jr. certified to launch from it)

Think of it this way, If you had launched HPR from water your whole life and knew the benefits, would you want to launch from land, with the power lines, trees, tall grass, dangers from chuffing off the rod, and so forth?




-Tony

 

[blackbrandt]

I've seriously considered this. I actually have plans drawn up for one. Basically it would activate a balloon on landing that would act as a beacon. Full fiberglass rocket, and accelerometer based deployment so no vent holes.

 

[K'Tesh]

Early in my current BAR period, I remember frequently seeing a video on YouTube of a guy launching an Estes Phoenix Missile (with onboard camera) off of a small ?barge? ?Raft?

I found the video. Audio from various real launches of actual rockets or missiles, including Apollo 13.

[video=youtube;58RdTBpLCGo]https://www.youtube.com/watch?v=58RdTBpLCGo[/video]

[video=youtube;9OCTvYy1qiI]https://www.youtube.com/watch?v=9OCTvYy1qiI[/video]

 

[Incongruent]

You can have vent holes, just there's the canister and there's a diaphragm inside that makes up one of the walls for the altimeter (loaded in and sealed from the other side)

 

[BDB]

I've seriously considered this. I actually have plans drawn up for one. Basically it would activate a balloon on landing that would act as a beacon. Full fiberglass rocket, and accelerometer based deployment so no vent holes.

Matt and I are thinking alike on this one. Maybe we need to establish a mid-Atlantic TRA prefectorate. And I mean MID-Atlantic, in the truest sense of the term.

 

[Getmore]

Back in the day of my low power fun I launched off the bow of my boat in the river here. It was a lot of fun chasing it down before it landed in the water.

 

[Incongruent]

Water launching small models is a good demonstration, but parks easily offer enough space to fly them. Launching from a lake really shines through for high power/ high altitude rockets, where the vast, flat expanse offers a large landing and recovery area.
(Among the other aforementioned pros, but mostly recovery)

Don't get me wrong, the small model is cool, I'm just saying it's not practical. Though that model seems neutrally stable or near neutrally stable. (At first) So good thing it launched on water, too.
Like the 4x chad staged alphas- (fly to the side, then cruise missile, "dropping spent motors as it goes")

 

[Incongruent]

Matt and I are thinking alike on this one. Maybe we need to establish a mid-Atlantic TRA prefectorate. And I mean MID-Atlantic, in the truest sense of the term.

Lakes are better because salt water (I've read) dissolves aluminum through galvanic corrosion.

I just google searched... correct me if I'm wrong.

I've thought about launching over water too, before this, but until I listed the pros and cons I never realized how good the idea could be.

 

[RocketFeller]

I've got the perfect chase vehicle - when do we start?

 

[Incongruent]

Together we'll develop a launch system and rocket that'll launch and land into the water successfully. A small scale mid power rocket first, improve on the design, then do a full scale high power test. Either you (and your club) can build it per our designs since you have the boat, or we could build different parts of it and send them to you. Standard launch system angled towards the lake, maybe?

To answer your question, ASAP.

 

[boatgeek]

Lakes are better because salt water (I've read) dissolves aluminum through galvanic corrosion.

I just google searched... correct me if I'm wrong.

I've thought about launching over water too, before this, but until I listed the pros and cons I never realized how good the idea could be.

Salt water isn't too bad on aluminum as long as you don't have stray currents running through it and you don't leave it there for a long time. If you find your rocket, the casing will probably be OK. On the other hand, salt water is absolute murder on electronics.

 

[blackbrandt]

Which is why you could use an accelerometer. This would allow you to have a hermetically sealed electronics bay.

 

[Incongruent]

Which is why you could use an accelerometer. This would allow you to have a hermetically sealed electronics bay.

You can have a hermetically sealed electronics bay and record altitude as well with a diaphragm. Redundancy is good with electronics. Both would work, I'm just suggesting a way to use an altimeter as well.

How fast would ocean currents carry the rocket and how fast would the wind above the ocean carry the rocket?
(Once it lands in the water, since the chute is deployed, the currents will have more tug on the rocket.)
The water *might* seep in through the nozzle and slosh inside, if you have large freshwater lakes nearby it's a much lower risk since it's not corrosive (maybe a little?) and higher there's a higher chance for recovery as it's for the most part contained and there should be less wind since there's a smaller area.

You will almost certainly want a GPS tracker for large rockets, even with the balloon beacon. Otherwise, the balloon will eventually deflate, and the rocket will be pretty much gone.
Will the GPS tracker antennae need to be outside the rocket? If so, maybe some 316 (I think, it's for marine environments with corrosion) stainless steel rods along or around the body tube somewhere.

Will the salt water corrosion from a week of salt water sloshing have more or less damage than filling up the casing a quarter up with nails and shaking it like a can of paint?

Will the solid combustion products in the motor after launch dissolve into the water? Will they be in any way contaminate the aquatic ecosystems or water?

Fiberglass is a good choice. Everything on the outside surface after ejection has to be waterproof.

What about salt water on steel eyebolts or quick links? Galvanized steel? Stainless steel? (Problably going to be 304 stainless)

Remember that each way and each solution has it's own pros and cons.

 

[Danh]

This is my random thought of the day....The Navy launches lots of rockets from ships and submarines, Copenhagen Suborbitals launches from a barge, and, of course, SpaceX lands rockets on a barge, but has anyone in hobby rocketry ever seriously pursued launching from a raft (or maybe a low-altitude rockoon tethered to a boat) at sea? It would obviously add lots of complexity to both the launch and recovery, but those could be fun problems to solve. If possible, it would be could also be a cool way for those of us who are not close to Black Rock to try some extreme stuff.

There was an article in either sport rocketry or apogee newsletter that discussed someone launching on a lake


Here in Michigan we go out 3-4 miles to catch walleye in the winter I always wondered what kind of waiver you could get in the middle of the bay.

 

[Rex R]

to answer your question, yes.
Rex

 

[boatgeek]

You can have a hermetically sealed electronics bay and record altitude as well with a diaphragm. Redundancy is good with electronics. Both would work, I'm just suggesting a way to use an altimeter as well.

How fast would ocean currents carry the rocket and how fast would the wind above the ocean carry the rocket?
(Once it lands in the water, since the chute is deployed, the currents will have more tug on the rocket.)
The water *might* seep in through the nozzle and slosh inside, if you have large freshwater lakes nearby it's a much lower risk since it's not corrosive (maybe a little?) and higher there's a higher chance for recovery as it's for the most part contained and there should be less wind since there's a smaller area.

You will almost certainly want a GPS tracker for large rockets, even with the balloon beacon. Otherwise, the balloon will eventually deflate, and the rocket will be pretty much gone.
Will the GPS tracker antennae need to be outside the rocket? If so, maybe some 316 (I think, it's for marine environments with corrosion) stainless steel rods along or around the body tube somewhere.

Will the salt water corrosion from a week of salt water sloshing have more or less damage than filling up the casing a quarter up with nails and shaking it like a can of paint?

Will the solid combustion products in the motor after launch dissolve into the water? Will they be in any way contaminate the aquatic ecosystems or water?

Fiberglass is a good choice. Everything on the outside surface after ejection has to be waterproof.

What about salt water on steel eyebolts or quick links? Galvanized steel? Stainless steel? (Problably going to be 304 stainless)

Remember that each way and each solution has it's own pros and cons.

This is all assuming it's salt water. Ocean currents are 0-4 MPH depending on where you are in open ocean, and near-shore tidal currents can get very fast if you're not at slack current. With no balloon, you'll need to be within tens of yards to see the rocket. If you have a tower on your boat, you might get that up to 100 in ideal conditions. With a brightly colored balloon (preferably with a radar reflector and GPS units), you might get to a mile or so. Assuming ~20-mile range for GPS units, you're looking at about 2-5 hours maximum to find your rocket before it's gone and headed to one of the oceanic garbage patches. If there's any wave action beyond ripples, your chances of finding things without the balloon/radar beacon are nearly nil. In 1-2 foot waves, it is very hard to spot a person's head above water, let alone something that is entirely in the water.

Water will get in the nozzle and anywhere else that isn't hermetically sealed, and maybe some places that are. Murphy will direct the water to where you least want it to be. You could probably increase chances of the GPS working by having it in a sealed compartment that rides up near the balloon to get it higher off the surface. I don't think it would need any special antenna on the outside since it can transmit through fiberglass. I assume that the GPS signals won't go through water worth a damn, so it can't be far below the surface regardless.

Since you only have a few hours to find the rocket, corrosion shouldn't be that bad as long as all the parts get a fresh water rinse when you find them. Stainless would be nice, 316 if you can get it. If not, 304 is fine, and galvanized will work.

I'm not 100% sure what's in the combustion products left behind, but if it's cardboard and soot, that's not going to harm the marine environment. It would be friendly not to use green motors and others with heavy metals in the propellant.

 

[Incongruent]

That's why I would prefer lakes. Less waves, no garbage patches to be whisked away to, and freshwater.

Having to rinse out the saltwater covered rocket with freshwater could get complicating if one boat has to pick out all the rockets. Maybe.

The lake (or ocean) idea is geared (I at least I think) to large composite powered rockets due to the lack of large flying fields. If anyone is in good terms with Aerotech or Cessorani or Loki or Gorilla Works... you get the idea... and can ask for a MSDS, that'll be really helpful.The balloon will problably be a normal round one elongated with a wrap of string at the middle or (preferably) some tube that slides out the BT at mains deployment. A long silver Mylar streamer will connect it to the rocket, with Kevlar down the middle for strength and possibly a wire for an antennae. The cardboard tube can be covered with Mylar tape (if it reflects radar) or something. If the rocket uses dual deployment, it should easily be able to land in a decont sized lake- near me, depending on wind direction, over 20km of lake can be used. (Look up Dallas on google maps and zoom out a bit. Lots Of Lakes!
I agree on the green motors, which would have barium, but I've heard that perchlorates are found in quite high concentrations after firework shows in local bodies of water, and that's without the fireworks even entering the water.
Composite model rocket motors use Ammonium Perchlorate, aluminium powder, a binder such as HTPB, CTPB, or PBAN, and various flame effect additives and catalysts. Slag formed by the combustion of larger Aluminium particles is a problem, but not one we can easily solve with pre made motors.

Quick MSDS and stuff search reveals:

Ammonium Perchlorate releases oxides of nitrogen (but not N2O) HCl, and ammonia when burned. According to a Harvard paper, these are "environmentally friendly". There is also a NASA article trying to reduce HCl released because it damages the atmosphere and causes acid rain.

Aluminium is well tolerated by plants and animals, and oxidizes into corundum, which appears (impure) in nature as sapphire and ruby.

HTPB is a customized mixture different depending on application. (Read: dang it!) Negligable solubility in water. Burns releasing CO2, CO, "other toxic vapors" and Butadine. Low concentrations may cause irritation.
CTPB itself can be irritating to the respiratory tract, and you should "avoid release into the environment". "Runoff may cause pollution. I haven't found oxidation products yet.
PBAN has lower toxicity than HTPB. Also no oxidation products found.

Too many flame and burn additives, better to see if we can get MSDS or a list of ingredients (not the percentages) from the motor manufacturer.

Maybe a GPS with the antennae on the balloon beacon and a GPS with the antennae on the rocket body.

I'm not sure how an accelerometer can be used for dual deploy. I think that having the balloon deploy with mains simplifies the process, but I have absolutely no experience in HPR, so I might have overlooked something.

The motor case will have to be well washed with clean water to avoid possible corrosion. It would be hard, but not impossible, for saltwater environments, to have a swinging plug or something that seals the nozzle end. Black powder motors have you soak in water to destroy and dispose in an "outside trash reciprocal".


Rex R, that's a really cool design, how the saucer lands as a boat.

 

[tomsteve]

freeze the lake and get a snowmobile for recovery.

 

[BDB]

So this is why I love TRF....

Not quite 24 hrs ago I posted a random idea. Now I have 2 pages of brainstorming and someone offered me a boat!

I'm not ready for a challenge like this just yet (need to get my L2 next month first). But this might be a super cool project to tackle in a couple years.

Keep it coming! If anyone else has legit ideas or experience with launching HPR-type rockets at sea (for me, it would have to be the North Atlantic), I'd love to hear it.

 

[Incongruent]

There was a piece in the old NAR Model Rocketry magazine around 1972 about a guy that launched a model rocket from an R/C submarine. It was pretty interesting all the things he had to do to make it work. Wish I still had the issue...

Does anyone have the issues from that time?

Pulled from this thread

 

[rstaff3]

Just Google 'underwater launched model rocket' and you'll get a bunch-o-hits.

 

[Incongruent]

Just Google 'underwater launched model rocket' and you'll get a bunch-o-hits.

The goal isn't an underwater launch, it's using a lake or ocean as a flying and recovery field, since large flat areas of land big enough for HPR are hard to come by (and easy to be taken away for development). I'm not sure about the submarine, it problably is an underwater launch but it could have some solutions to our problems too.

 

[rstaff3]

I suspect many of the underwater launches could help just as much as the submarine one. Waterproofing is a clear area of interest. Anyway, I offered this as an alternative to an arcane magazine the likely won't surface.

 

[rstaff3]

Found a Rockets for Schools article in the April 1999 issue of HPR Magazine. They describe some of the attributes of one of the water recovery designs: body was cardboard with 3 layers of glass; G10 fins; sealed payload sections to protect contents and provide buoyancy; added the inner tubes from CO2 inflatable life jackets to the chutes with the cartridges being actuated when the shock tether extended. It had tracking transmitters and 2 of the 3 parts were recovered by the Coast Guard. There were problems with the life jacket stuff tangling the chutes.

The launch was run by TRA prefectures from Wisconsin and Chicago. If they have websites maybe ya'll could contact them to see if there are experienced members still hanging around?

 

[Rex R]

ya mean these folks? https://www.tripoliwisconsin.org/
Rex

 

[blackjack2564]

Nope...these check out video show launching over water and boat recovery.

This one : https://www.rockets4schools.org/

Have worked event 5 times.

When using altimeters just a few inches of aquarium plastic hose coiled 2 times and inserted into vent holes. Other open end just flops around inside bay.
Acts like P-trap....when in flight samples air just fine, upon landing in water, water will enter first coil, not second...no water in bay.

Many guys just fly and get wet....no big deal. dry off after remove battery on car dash or low heat. Done & fly again.

You guys are WAY overthinking this, been done for many, many years. :wink: