I've not understood why you would want to land at sea. Like you said, the movement of the barge would seem problematic at best. I would think landing at remote location on land would be more suitable.
Blue Origin has test and landed their rocket out in the desert of west Texas. Of course this is a tourist rocket but you can see from the video that they bring it back to land out in the middle of nowhere. (I grew up about an hour from here so I can attest there's not a lot out there)
I've not understood why you would want to land at sea.
In order to launch payloads with a given rocket requiring more energy than is available from a land return.
no return: Max payload combined with orbital insertion velocity
down range return: reduced payload, velocity
launch site return: considerably more reduced payload, velocity
Of course, were there an island conveniently located in the right place down range, that would be nice. There is not, however.
These are not small differences, either. While reuse is a nifty idea, it comes with a huge price. Shuttle could not launch nearly the combination of payload, velocity as could a comparably sized or comparably priced single-use rocket. Only the hope for cost reduction through reuse gave any hope of breaking even, let alone reaching the substantial saving that was the program goal.
Falcon 9 pays prices differing from those for shuttle. But there is appreciable extra hardware, and therefore launch mass, dedicated to the return function. Actually using the return function means foregoing a great deal of orbital insertion payload, velocity.
As discussed propelling over land has it's hazards to those that live beneath and the K.E. to orbit differs by ~ 200 GJ one way vs the other, that being nearly equivalent to payload doubling. Or it may be a choice, for certain payloads, between low Earth orbit ( circular) vs geosynchronous transfer orbit ( elliptical ). The Blue Origin trajectories are vertical up and down : they are not orbital trajectories ( grossly insufficient available energy by two orders or magnitude ). Energy is everything here plus the requirement to determine orbital plane by initial vectors. The ultimate orbital plane for the payload is also a choice of downrange direction for first stage recovery. Changing orbital plane significantly when you're up there is equivalent to another tank of fuel ....
.... in fact according to this page for a cool 61M $USD ( this year ) spends either as 5000kg to GTO or 13000kg tonnes to LEO. Those are maxima : for which you'd have to toss the first stage completely, no recovery. For recovery you have to reduce payload, the Earth will always ask for approx 8 km/sec tangential if you don't want to splat dirt.
Now for the Heavy, multiply performances times four .... but 'only' 50% more cost ( as presently projected ). In any event his current demonstrated delivery ( minus one payload ) is a bargain, but I reckon he is probably loss leading for now.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
As discussed propelling over land has it's hazards to those that live beneath and the K.E. to orbit differs by ~ 200 GJ one way vs the other, that being nearly equivalent to payload doubling. Or it may be a choice, for certain payloads, between low Earth orbit ( circular) vs geosynchronous transfer orbit ( elliptical ). The Blue Origin trajectories are vertical up and down : they are not orbital trajectories ( grossly insufficient available energy by two orders or magnitude ). Energy is everything here plus the requirement to determine orbital plane by initial vectors. The ultimate orbital plane for the payload is also a choice of downrange direction for first stage recovery. Changing orbital plane significantly when you're up there is equivalent to another tank of fuel ....
.... in fact according to this page for a cool 61M $USD ( this year ) spends either as 5000kg to GTO or 13000kg tonnes to LEO. Those are maxima : for which you'd have to toss the first stage completely, no recovery. For recovery you have to reduce payload, the Earth will always ask for approx 8 km/sec tangential if you don't want to splat dirt.
Now for the Heavy, multiply performances times four .... but 'only' 50% more cost ( as presently projected ). In any event his current demonstrated delivery ( minus one payload ) is a bargain, but I reckon he is probably loss leading for now.
Cheers, Mike.
That's what I was thinking too...if you want to send up a lighter payload then they will use the return and reuse option, making your costs cheaper, but if you want to send up a heavier payload, beyond the range the thing can land and reuse, then your costs go up because of it. Or you could take your chances on being the last one to use the parts before they are scrapped as not being safe for any more launches after yours. Depends on how fast you want the thing in the sky, if you can wait it could be cheaper. Of course if something fails again and they have to build a new one instead of you being the last one to use it your chances at cost reduction go out the window, or your time line is shot to hell.
The ultimate orbital plane for the payload is also a choice of downrange direction for first stage recovery
Not exactly, only in generality. This graphic seems to indicate that the first stage moves out of the plane of the second stage progression :
... where the first stage after separation is clearly marked as doing a right hand turn, as it were, to land on the drone ship. So that is an interesting boost back burn, or have they been doing that all along for downrange retrievals ?
BTW : the blue curve to the right of the second stage position is a projection of where it would go if it became ballistic ( thrust lost to zero ). So that is the splat into the planet bit if you don't get orbital velocity. Again I say, energy is everything and that has to come from inside the fuel tank at the time. The fuel at any moment arrived there because of the prior burning of other fuel. Unburnt fuel is ( temporary ) payload .... and has to be shoved around, at an energy cost, just like the nominated final payload.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Ice build up may have caused SpaceX landing to fail.
"The lockout collet on one of the rocket's four legs didn't latch, leading to the mishap, SpaceX CEO Elon Musk wrote in a post on Twitter and Instagram."
and
"Root cause may have been ice buildup due to condensation from heavy fog at liftoff," he (Musk) said.
The fog was very heavy, in fact I urge you to watch the non-hosted version where the beast emerges out of the mist, plus you can directly hear all the noises. There is a bit of control room voice-over, but the rocket's sounds in the last minute especially are cool with the rapid transition from quiescence to full power. What a machine ! :-)
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Per SpaceX stats site the next launch is Feb 6, of a 5+ tonne communications satellite ie. GTO insertion. There is also a rumor of the first Falcon Heavy launch in April/May !! :-)
Cheers, Mike.
( edit ) It is not the first time ice has caused catastrophe. A bit anti-intuitive really but one can have ice forming and staying so only a few meters from a rocket exhaust.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
I've not understood why you
)
I've not understood why you would want to land at sea. Like you said, the movement of the barge would seem problematic at best. I would think landing at remote location on land would be more suitable.
Blue Origin has test and landed their rocket out in the desert of west Texas. Of course this is a tourist rocket but you can see from the video that they bring it back to land out in the middle of nowhere. (I grew up about an hour from here so I can attest there's not a lot out there)
https://www.youtube.com/watch?v=9pillaOxGCo
ps, yes I know part of the video is animated but it's the end where it lands that's important.
RE: I've not understood why
)
In order to launch payloads with a given rocket requiring more energy than is available from a land return.
no return: Max payload combined with orbital insertion velocity
down range return: reduced payload, velocity
launch site return: considerably more reduced payload, velocity
Of course, were there an island conveniently located in the right place down range, that would be nice. There is not, however.
These are not small differences, either. While reuse is a nifty idea, it comes with a huge price. Shuttle could not launch nearly the combination of payload, velocity as could a comparably sized or comparably priced single-use rocket. Only the hope for cost reduction through reuse gave any hope of breaking even, let alone reaching the substantial saving that was the program goal.
Falcon 9 pays prices differing from those for shuttle. But there is appreciable extra hardware, and therefore launch mass, dedicated to the return function. Actually using the return function means foregoing a great deal of orbital insertion payload, velocity.
As discussed propelling over
)
As discussed propelling over land has it's hazards to those that live beneath and the K.E. to orbit differs by ~ 200 GJ one way vs the other, that being nearly equivalent to payload doubling. Or it may be a choice, for certain payloads, between low Earth orbit ( circular) vs geosynchronous transfer orbit ( elliptical ). The Blue Origin trajectories are vertical up and down : they are not orbital trajectories ( grossly insufficient available energy by two orders or magnitude ). Energy is everything here plus the requirement to determine orbital plane by initial vectors. The ultimate orbital plane for the payload is also a choice of downrange direction for first stage recovery. Changing orbital plane significantly when you're up there is equivalent to another tank of fuel ....
.... in fact according to this page for a cool 61M $USD ( this year ) spends either as 5000kg to GTO or 13000kg tonnes to LEO. Those are maxima : for which you'd have to toss the first stage completely, no recovery. For recovery you have to reduce payload, the Earth will always ask for approx 8 km/sec tangential if you don't want to splat dirt.
Now for the Heavy, multiply performances times four .... but 'only' 50% more cost ( as presently projected ). In any event his current demonstrated delivery ( minus one payload ) is a bargain, but I reckon he is probably loss leading for now.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
RE: As discussed propelling
)
That's what I was thinking too...if you want to send up a lighter payload then they will use the return and reuse option, making your costs cheaper, but if you want to send up a heavier payload, beyond the range the thing can land and reuse, then your costs go up because of it. Or you could take your chances on being the last one to use the parts before they are scrapped as not being safe for any more launches after yours. Depends on how fast you want the thing in the sky, if you can wait it could be cheaper. Of course if something fails again and they have to build a new one instead of you being the last one to use it your chances at cost reduction go out the window, or your time line is shot to hell.
RE: The ultimate orbital
)
Not exactly, only in generality. This graphic seems to indicate that the first stage moves out of the plane of the second stage progression :
... where the first stage after separation is clearly marked as doing a right hand turn, as it were, to land on the drone ship. So that is an interesting boost back burn, or have they been doing that all along for downrange retrievals ?
BTW : the blue curve to the right of the second stage position is a projection of where it would go if it became ballistic ( thrust lost to zero ). So that is the splat into the planet bit if you don't get orbital velocity. Again I say, energy is everything and that has to come from inside the fuel tank at the time. The fuel at any moment arrived there because of the prior burning of other fuel. Unburnt fuel is ( temporary ) payload .... and has to be shoved around, at an energy cost, just like the nominated final payload.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Ice build up may have caused
)
Ice build up may have caused SpaceX landing to fail.
"The lockout collet on one of the rocket's four legs didn't latch, leading to the mishap, SpaceX CEO Elon Musk wrote in a post on Twitter and Instagram."
and
"Root cause may have been ice buildup due to condensation from heavy fog at liftoff," he (Musk) said.
I wonder if there were say
)
I wonder if there were say five or six legs instead of four, a failure of one leg might not be catastrophic.
Of course that's extra weight but four seems, an odd number [sic] for stability.
The fog was very heavy, in
)
The fog was very heavy, in fact I urge you to watch the non-hosted version where the beast emerges out of the mist, plus you can directly hear all the noises. There is a bit of control room voice-over, but the rocket's sounds in the last minute especially are cool with the rapid transition from quiescence to full power. What a machine ! :-)
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
RE: What a machine ! A
)
A beast. 500+ tons - ~30 seconds later, 200mph vertically.
Per SpaceX stats site the
)
Per SpaceX stats site the next launch is Feb 6, of a 5+ tonne communications satellite ie. GTO insertion. There is also a rumor of the first Falcon Heavy launch in April/May !! :-)
Cheers, Mike.
( edit ) It is not the first time ice has caused catastrophe. A bit anti-intuitive really but one can have ice forming and staying so only a few meters from a rocket exhaust.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal