Aethon

Blue Origin Thread (merged)

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Launch date: Dec 16. Elon shared some pics with us. Grid fins confirmed.

Sorry for being brief - I'm stuck using a tablet.

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Edited by Airlock

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I can't wait. It'll be something historical if he pulls it off. The procedure once it's down would be interesting.

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Are they actually putting a payload into orbit or is his solely just a demonstration? Because I can't imagine SpaceX waiting on good sea conditions. Because they practicality never are... The sea is rough 90% of the time so are they really going to wait for calm seas before the launch? If so that Dec16 date has a good chance of being delayed...

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Granted the barge is unmanned or at least minimally manned, so more than likely there will be a boat close by that will have a crew on that will board the barge and tie down the rocket in some fashion for transport to shore.

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Are they actually putting a payload into orbit or is his solely just a demonstration? Because I can't imagine SpaceX waiting on good sea conditions. Because they practicality never are... The sea is rough 90% of the time so are they really going to wait for calm seas before the launch? If so that Dec16 date has a good chance of being delayed...

The barge is equipped with stabilizing thrusters to keep it in place with an error of only 3 meters. It's designed from the same technology drilling barges and oil platforms use to keep in place. It'll be rough, but it's a pretty big barge and it will definitely keep stay where it needs to be. How flat it will be depends on just how bad the weather is on the launch day. They are launching CRS-5 if I remember correctly which is the 5th resupply mission to the ISS.

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Also the barge has been confirmed to have some sort of wave damping system on it, which i bet can decrease the apparent wave height by ~2m

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Also the barge has been confirmed to have some sort of wave damping system on it, which i bet can decrease the apparent wave height by ~2m

I didn't think about it but that seems about right.

Oil rig transfer boats(I think it was these) and other yachts have pretty cool systems that dampen waves. I forget exactly how it works, it's been awhile since I've read about it, but they can make 5foot swells seem like perfectly calm. It's pretty amazing. It works by moving ballast around I think, I could be completely wrong though.

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2m? Wow.. I suppose the hope then is for no excessively rough seas. I hope we get good footage. It'll be quite the sight.

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Now THIS should be interesting. I hope they will have an aircraft around or a boat that can take HD video of the descent.

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Also the barge has been confirmed to have some sort of wave damping system on it, which i bet can decrease the apparent wave height by ~2m

I can't think of a way to "reduce the apparent wave height" without pumping water ballast back and forth in floating pontoons to increase/decrease their buoyancy as the waves pass. SpaceX's barge appears to have only one hull so this wouldnt be an option. At best, they could stabilize how much the barge rolls and pitches due to the waves while floating up and down in them and holding position to within 3 metres.The amount of up/down motion would then depend on the wave length (i.e. short wavelength waves that are freshly being churned up or are running against a current vs. long rollers left over from a distant storm.)

As for conditions at sea, you can view them online on NOAA's marine forecast web page. The forecasts and current conditions are updated a couple of times a day. I've posted an example below. Florida is in the lower left, the UK is in the upper right. Contours are the mean significant wave height in metres. Mean significant wave height is the average of the largest third of waves. That means that ~83% of waves are smaller than the given height while ~17% are bigger.

PJAA99.gif

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Not the WHOLE rocket... just the flyback stage. They land it, put 5 bucks in the tank, and it flys back to the launchpad

Still though that's incredible. Is that really cheaper then just tugging the barge back to shore? Itd be quicker that's for sure... And time is money I suppose.

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PakledHostage you can dampen out the motion by using vertical motors, hydraulically lifting and lowering the deck, having extendable fins like on cruise ships, partially submerging the hull to reduce the freeboard, etc. There are a bunch of differernt ways all with their own drawbacks

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Still though that's incredible. Is that really cheaper then just tugging the barge back to shore? Itd be quicker that's for sure... And time is money I suppose.

Main problem with an relaunch is reliability and chance of fail during the return flight, it would not cost much outside that.

Problem with towing the barge is that you expose the rocket of sea spray.

I thought that flyback would be interesting for Russia as they fly over land, you can have an small base for the rocket to land, here you could do an better inspection than on the barge, rocket would also be to large to transport cheaply on roads.

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you can dampen out the motion by using vertical motors, hydraulically lifting and lowering the deck, having extendable fins like on cruise ships, partially submerging the hull to reduce the freeboard, etc.

Right, but I really doubt vanes are used or are even practical in this case. The vanes on cruise ships work because the ship moves through the water. They work like wings to apply a righting force that ramps out roll. The SpaceX platform is stationary.

The deck may have hydraulic actuators to lift and lower it (that's a good thought BTW), but it isn't clear from the limited info we have that it has that capability.

My point stands. You can relatively "easily" damp out pitch and roll oscillations, but vertical motion is much harder on a monohulled barge.

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Not the WHOLE rocket... just the flyback stage. They land it, put 5 bucks in the tank, and it flys back to the launchpad

Oh, no no no, I understand that (although I can envision a sea-launch architecture for future BFR/MCT flights).

I'm just concerned flying first stages back from the barge will cut down on the number of times they can be reused.

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They really want to land on barges as a long-term solution? I thought they were only going to do this until they convinced the powers-that-be that they are able to reliably plop the stage down onto a chosen landing spot. In which case I wouldn't think it would even matter (for that purpose) if the stage fell over later due to the shifting deck.

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They really want to land on barges as a long-term solution? I thought they were only going to do this until they convinced the powers-that-be that they are able to reliably plop the stage down onto a chosen landing spot. In which case I wouldn't think it would even matter (for that purpose) if the stage fell over later due to the shifting deck.

I assume they're still planning to RTLS eventually. However, landing on a platform at sea may allow for larger payloads on the F9, as well as FH central core recovery.

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I think it's more a matter of "The goverment is making us use a barge at the beginning... what can we use a barge for later on?" and building the barge from the outset for still hypothetical advanced missions.

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If this was going to be for anything but the short term, wouldn't it make more sense to build a semi submersible?

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I always assumed the Orion was meant to be docked with transit modules, such as a centrifuge or a torpor compartment.

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I always assumed the Orion was meant to be docked with transit modules, such as a centrifuge or a torpor compartment.

No idea where you picked that up from. NASA isn't building any transit modules because Congress isn't funding any expedition missions. And centrifuges and "torpor" modules belong in science fiction.

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