What is the benefit of landing the boosters to parachuting them back to earth as I NASA did with their solid boosters? .
My thoughts exactly when I watched it happen on the live stream. Those two boosters were like high tech ballet dancers dropping down onto the landing pads. I started out on a crappy PBS live feed and jumped to the CNN feed mid flight.It was god damn beautiful.
I glanced at the PBS live feed too but just watched the two official streams from spacex.com (youtube one channel, two cams).. my understanding was that the rest of the IRC community did the same.My thoughts exactly when I watched it happen on the live stream. Those two boosters were like high tech ballet dancers dropping down onto the landing pads. I started out on a crappy PBS live feed and jumped to the CNN feed mid flight.
What is the benefit of landing the boosters to parachuting them back to earth as I NASA did with their solid boosters? I'd think keeping enough fuel, that has to go up and then to return and land wouldn't be the most efficient.
If you go through the R&D costs of developing a reusable launch vehicle, the opportunity costs (in terms of fuel used for return and the lost revenue opportunity for more payload to orbit) of returning the launcher to the first stage, and the costs of refurbishment between flights, generally accepted practice shows that you have to re-use the booster or launch the vehicle 5–10 times before you make your money back if you account for all the costs.
Many papers have been written on this topic and this is a well established ‘rule of thumb’. This doesn’t even account for the price reduction that many customers flying on a ‘used’ first stage will likely demand.
Thus I am thinking that very few, if any, of the SpaceX Falcon 9 first stages are going to be re-used for more than 3 or so flights and that SpaceX will therefore not break even on the reusability portion of the equation.
Why then would SpaceX want to have a landing reusable rocket? Two reasons.
First, this is an obvious Mars landing technology and if this is one of SpaceX’s goals (as I believe it is since this was the main reason that the company was started), the landing system development costs can be counted against a number of other accounts not related to reusability.
Secondly, and I think that this is the dominant answer, reusability allows a marked increase in flight rates. Reverse engineered financial models of SpaceX show that to reach a good strong positive cash flow, they need more than the traditional 10–12 launches per year that sized rocket has demonstrated. Reusability should easily double the amount of flights possible from a mere production and logistics standpoint.
With reusability, 20–25 flights a year puts SpaceX into a much more positive cash flow position and thus I believe that this is a very important driver. I believe that the first stage has been identified as one of the bottle necks to flying more often mainly due to its production, transport and attendant infrastructure. Reusability is a great brand image generator, but, more importantly, it enables SpaceX to double their flight rate and make more money, all the while preparing for Mars landings with the reusability technology.
What is the benefit of landing the boosters to parachuting them back to earth as I NASA did with their solid boosters? I'd think keeping enough fuel, that has to go up and then to return and land wouldn't be the most efficient.
Excellent question. Here is the answer I googled.
https://www.forbes.com/sites/quora/...save-by-reusing-a-falcon-rocket/#3da8130724d7
The design of the falcon 9 and their launch process helps reduce the cost to up mass.
They do what’s called a load and go. They load the ultra cold LOX right before launch so it remains “densified”. Which gives them enough performance to try and land the first stage(s).
For launches where the trajectory, vehicle mass, and delta V requirements require lesser amounts of propellant they will try and land the first stage on land.
For heavier missions or missions that require more delta V they will float the drone barge out there so the first stage only needs enough propellant to kill its forward velocity and land on the barge instead of flying all the way back.
If neither is possible they treat the Falcon as any other expendable launcher.
To further reduce propellant usage the 1st stage has “grid fins” to help control aerodynamics without using propellant.
The reason to avoid parachuting into the ocean is salt water contamination is a huge cost to design and to refurbish the first stage.
The shuttle SRBs were just hollow tubes. The Falcon 9 1st stage is full of sensitive parts like tanks, valves and turbo pumps. They don’t like salt water.
I watched an interview with their director and her reasoning is that they are moving beyond low earth orbit vehicles which is allowing companies like SpaceX the opportunity to fill the void.Question: why isn't NASA developing a more economical rocket? Not an expert on the SLS but it seems like it will be expensive compared to what SpaceX is doing.
I watched an interview with their director and her reasoning is that they are moving beyond low earth orbit vehicles which is allowing companies like SpaceX the opportunity to fill the void.
Question: why isn't NASA developing a more economical rocket? Not an expert on the SLS but it seems like it will be expensive compared to what SpaceX is doing.
Huh?This doesn't explain why they're developing such an expensive system that isn't reusable.
The design of the falcon 9 and their launch process helps reduce the cost to up mass.
They do what’s called a load and go. They load the ultra cold LOX right before launch so it remains “densified”. Which gives them enough performance to try and land the first stage(s).
For launches where the trajectory, vehicle mass, and delta V requirements require lesser amounts of propellant they will try and land the first stage on land.
For heavier missions or missions that require more delta V they will float the drone barge out there so the first stage only needs enough propellant to kill its forward velocity and land on the barge instead of flying all the way back.
If neither is possible they treat the Falcon as any other expendable launcher.
To further reduce propellant usage the 1st stage has “grid fins” to help control aerodynamics without using propellant.
The reason to avoid parachuting into the ocean is salt water contamination is a huge cost to design and to refurbish the first stage.
The shuttle SRBs were just hollow tubes. The Falcon 9 1st stage is full of sensitive parts like tanks, valves and turbo pumps. They don’t like salt water.
Huh?
Oh I misunderstood you. The SLS is probably sacrificing that for payload.I'm talking about NASA's Space Launch System and comparing it to what SpaceX is doing. The SLS will not be reusable.
https://en.wikipedia.org/wiki/Space_Launch_System