... that really shows the gimbal aspect into the 50+ knot wind ie. the thrust is near vertical while the barrel is offset by the windage. So it won't land on all four legs simultaneously, hence the hop translation to leftwards when the barrel swings to vertical, and then the remaining legs contact the barge to stop that lateral movement.
Cheers, Mike.
I see surrounding engine bells so is this landing utilizing only one engine?
It "looks" so simple/elegant but there is a lot going on there.
I see surrounding engine bells so is this landing utilizing only one engine?
Yup.
Quote:
It "looks" so simple/elegant but there is a lot going on there.
Yup. I'm aware that I keep raving on, but the degree of power/finesse required to so aggressively manipulate that mass of hardware on such short time scales is quite unprecedented. For the booster : on the up they create several hundred GigaJoules of kinetic energy at height, on the way down they spend that again plus the grav-pot without a wreck and near perfect timing to pinpoint location. SpaceX is defining a new class of rocketry that will take many years for others to match - even if no one gets to Mars.
Cheers, Mike.
( edit ) Here is footage from 2014 of a three engine version of the current Falcon 9 configuration clearly demonstrating the engine gimballing with vane use to steer. This is a spin-off of SpaceX's agribusiness division ( the cattle herding test program ). I've also read that because of the heat issues on 2+ km/s re-entry SpaceX may consider constructing the vanes in-house using an alloy of unobtainium.
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
The sea landing showed SpaceX can recover boosters intact from some of its most challenging launches, but the rocket’s searing return from space took a toll.
CEO Elon Musk indicated the rocket stage may not be in shape to launch again, but will help the company assess the flight-worthiness of boosters recovered in the future.
David
Miserable old git
Patiently waiting for the asteroid with my name on it.
An April 29th post over at NASASpaceflight.com asserted that the next scheduled F9 launch was for the Thaicom-8 satellite, scheduled for a launch window of 17:40 through to 19:19 Eastern time on May 26. A couple of more recent sources affirm that date, at least approximately, though no confirmation of the time of day.
This will be another comsat going to geosynchronus orbit. It is lighter than some (near 3100 kg), so should be a candidate for barge recovery. They may try to tweak the parameters to get a bit less roasting. As the landing itself looked downright gentle, it appears that the max damage mentioned in the post by David S was probably thermal damage at atmospheric re-entry.
The most obvious ways to get less thermal damage require more delta-V in the braking burn before re-entry, but that could involve paring back margins for remaining fuel at touchdown, converting from 3-engine burn to 1-engine burn later in the landing sequence, and operating at a higher fraction of max throttle during all portions of the landing burn. Just maybe there is room to chill the propellants a bit more, or to tweak ascent parameters to get the required release point using a trifle less fuel.
"How lucky do you feel today?" It is an awkward exercise in dealing with severely nonlinear and asymmetric loss functions. Some places you would borrow fuel from will hurt not at all right up to very close to the point where they give catastrophic loss. The heating damage variation is a little more gradual.
The sea landing showed SpaceX can recover boosters intact from some of its most challenging launches, but the rocket’s searing return from space took a toll.
CEO Elon Musk indicated the rocket stage may not be in shape to launch again, but will help the company assess the flight-worthiness of boosters recovered in the future.
Interesting article. I was not aware that this last launch incurred stresses that might make it unusable. Its all part of the learning curve.
Those vanes were toasted for sure. Depending upon how modular their design/production is : how much of the booster is re-usable ? The hint seems to be that the JCSAT-14 booster was pretty close to non-recovery.
So roughly for GSTO ( current config including deep cryo for fuel ) : 5200kg is beyond recovery ( SES-9 ) and 4700kg is approximately at the limit of recovery but maybe not re-use ( JCSAT-14 ). Thus Thaicom-8 at 3100kg should be a doddle ? Or will they give that payload the max KE available and use a similiar margin for booster return ? Hmmmm ....
Quote:
Its all part of the learning curve.
Yup, they'll either succeed or find out why they can't in terms of physical limits. This goes way back to Elon's analysis of why leaving Earth via rocketry is a marginal proposition eg. the payload delivered to Mars surface will be ~ 0.7 % of the launch mass and that's with multiple launches to LEO, assembly and then boost off to Mars.
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
Those vanes were toasted for sure. Depending upon how modular their design/production is : how much of the booster is re-usable ? The hint seems to be that the JCSAT-14 booster was pretty close to non-recovery.
So roughly for GSTO ( current config including deep cryo for fuel ) : 5200kg is beyond recovery ( SES-9 ) and 4700kg is approximately at the limit of recovery but maybe not re-use ( JCSAT-14 ). Thus Thaicom-8 at 3100kg should be a doddle ? Or will they give that payload the max KE available and use a similiar margin for booster return ? Hmmmm ....
Quote:
Its all part of the learning curve.
Yup, they'll either succeed or find out why they can't in terms of physical limits. This goes way back to Elon's analysis of why leaving Earth via rocketry is a marginal proposition eg. the payload delivered to Mars surface will be ~ 0.7 % of the launch mass and that's with multiple launches to LEO, assembly and then boost off to Mars.
Cheers, Mike.
I wonder how many times he will try to land elsewhere, ie the Moon, before heading to actual Mars? Or will he just go for the Gold and just head for the Mars landing with no external Earth attempts? It seems to me there are lots of variables with Mars landings, especially the way he is trying it, that some kind of try on something else, even something passing by, could make sense. And if he could soft land on something passing by it could be another money making proposition for any Scientists wishing to put something on there to gather tons of data.
Still looks good for Thursday. It's funny how neither SpaceX nor Thaicom websites mention this .... seems the source is Kennedy Space Center who ought know I guess.
Quote:
... try to land elsewhere ...
The Moon is an obvious punt but this now depends on your timescale. To be meaningful the Moon adds another 20 years to development, but with the huge advantage of possibly LOX could be sourced there. On the Moon H2/LOX looks a better proposition with 1/6th of terrestrial gravity. But now we need another Elon to continue when the current one expires. Sad but true. These ambitions require multi-generational intent/focus, best of luck with that ! :-)
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
These ambitions require multi-generational intent/focus
Cheers, Mike.
Elon also recognizes this I am sure. That why I believe that he will get SpaceX on Mars during his time. It probably won't be a man but it will be some sort of SpaceX creation. And that will be something to look forward to.
RE: I found this one for
)
I see surrounding engine bells so is this landing utilizing only one engine?
It "looks" so simple/elegant but there is a lot going on there.
RE: I see surrounding
)
Yup.
Yup. I'm aware that I keep raving on, but the degree of power/finesse required to so aggressively manipulate that mass of hardware on such short time scales is quite unprecedented. For the booster : on the up they create several hundred GigaJoules of kinetic energy at height, on the way down they spend that again plus the grav-pot without a wreck and near perfect timing to pinpoint location. SpaceX is defining a new class of rocketry that will take many years for others to match - even if no one gets to Mars.
Cheers, Mike.
( edit ) Here is footage from 2014 of a three engine version of the current Falcon 9 configuration clearly demonstrating the engine gimballing with vane use to steer. This is a spin-off of SpaceX's agribusiness division ( the cattle herding test program ). I've also read that because of the heat issues on 2+ km/s re-entry SpaceX may consider constructing the vanes in-house using an alloy of unobtainium.
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
Falcon suffered 'max'
)
Falcon suffered 'max' damage
David
Miserable old git
Patiently waiting for the asteroid with my name on it.
An April 29th post over at
)
An April 29th post over at NASASpaceflight.com asserted that the next scheduled F9 launch was for the Thaicom-8 satellite, scheduled for a launch window of 17:40 through to 19:19 Eastern time on May 26. A couple of more recent sources affirm that date, at least approximately, though no confirmation of the time of day.
This will be another comsat going to geosynchronus orbit. It is lighter than some (near 3100 kg), so should be a candidate for barge recovery. They may try to tweak the parameters to get a bit less roasting. As the landing itself looked downright gentle, it appears that the max damage mentioned in the post by David S was probably thermal damage at atmospheric re-entry.
The most obvious ways to get less thermal damage require more delta-V in the braking burn before re-entry, but that could involve paring back margins for remaining fuel at touchdown, converting from 3-engine burn to 1-engine burn later in the landing sequence, and operating at a higher fraction of max throttle during all portions of the landing burn. Just maybe there is room to chill the propellants a bit more, or to tweak ascent parameters to get the required release point using a trifle less fuel.
"How lucky do you feel today?" It is an awkward exercise in dealing with severely nonlinear and asymmetric loss functions. Some places you would borrow fuel from will hurt not at all right up to very close to the point where they give catastrophic loss. The heating damage variation is a little more gradual.
RE: Falcon suffered 'max'
)
Interesting article. I was not aware that this last launch incurred stresses that might make it unusable. Its all part of the learning curve.
May 26th is the next
)
May 26th is the next scheduled launch.
Those vanes were toasted for
)
Those vanes were toasted for sure. Depending upon how modular their design/production is : how much of the booster is re-usable ? The hint seems to be that the JCSAT-14 booster was pretty close to non-recovery.
So roughly for GSTO ( current config including deep cryo for fuel ) : 5200kg is beyond recovery ( SES-9 ) and 4700kg is approximately at the limit of recovery but maybe not re-use ( JCSAT-14 ). Thus Thaicom-8 at 3100kg should be a doddle ? Or will they give that payload the max KE available and use a similiar margin for booster return ? Hmmmm ....
Yup, they'll either succeed or find out why they can't in terms of physical limits. This goes way back to Elon's analysis of why leaving Earth via rocketry is a marginal proposition eg. the payload delivered to Mars surface will be ~ 0.7 % of the launch mass and that's with multiple launches to LEO, assembly and then boost off to Mars.
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: Those vanes were
)
I wonder how many times he will try to land elsewhere, ie the Moon, before heading to actual Mars? Or will he just go for the Gold and just head for the Mars landing with no external Earth attempts? It seems to me there are lots of variables with Mars landings, especially the way he is trying it, that some kind of try on something else, even something passing by, could make sense. And if he could soft land on something passing by it could be another money making proposition for any Scientists wishing to put something on there to gather tons of data.
Still looks good for
)
Still looks good for Thursday. It's funny how neither SpaceX nor Thaicom websites mention this .... seems the source is Kennedy Space Center who ought know I guess.
The Moon is an obvious punt but this now depends on your timescale. To be meaningful the Moon adds another 20 years to development, but with the huge advantage of possibly LOX could be sourced there. On the Moon H2/LOX looks a better proposition with 1/6th of terrestrial gravity. But now we need another Elon to continue when the current one expires. Sad but true. These ambitions require multi-generational intent/focus, best of luck with that ! :-)
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: These ambitions
)
Elon also recognizes this I am sure. That why I believe that he will get SpaceX on Mars during his time. It probably won't be a man but it will be some sort of SpaceX creation. And that will be something to look forward to.