SpaceX Tuesday...
Discussion
London424 said:
When they crack this the cost of launches becomes very very cheap. Cost of fuel and general servicing.
It's not as straightforward as that. The Shuttle showed that designing spacecraft for reuse that are strong but light enough and with powerful enough rocket motors can be extremely costly.The Shuttle's main engines were designed to be used over and over again. It turned out that they needed to be almost completely re-manufactured between missions. When envisaged, they hoped they could have Shuttle ready to go again in 14 days. it turned out to be more like 9 months. In the end, getting a Shuttle sorted for its next flight cost more than using an expendable rocket due to the man-hours involved in fixing it each time.
The engines on the Falcon are less complex (and far less powerful) than those of the Shuttle - and they run off kerosene and liquid oxygen (as opposed to liquid hydrogen and liquid oxygen). Therefore, the amount of refurbishing between uses may be less than the Shuttles - but I bet they will still need a fair amount of work to get them safely operational again.
It'll be interesting to see how it progresses once they get them landed. Refurbishment cost will be key but they're working with a much simpler machine than the shuttle to start with. I'd imagine they'll soon have a good idea of how economical it'll be compared to a non-recoverable version.
I am sure getting this stage refurbed for another launch will be a LOT simpler and cheaper to do than the Shuttle. But getting the thing back is the first part of the equation. Once they do recover one safely, THEN they can examine the state of the stage and see what work needs to be done to make it flight worthy again.
A few days ago, I was looking at some artist impressions from the mid 1970s of unmanned launcher concepts using Shuttle technology.
One interesting set up was a cluster of FOUR liquid fueled boosters arranged around a Shuttle External Tank. The boosters were designed to be recovered and re-used. The plan was to parachute the boosters into the ocean after burn-out, To protect the liquid fuelled motors, nozzles etc from salt water and impact damage, the bottom of each had a pair of clamshell doors which closed over the bottom of the rocket, effectively sealing the motors from water ingress.
I wonder if there is any mileage in trying that approach?
A few days ago, I was looking at some artist impressions from the mid 1970s of unmanned launcher concepts using Shuttle technology.
One interesting set up was a cluster of FOUR liquid fueled boosters arranged around a Shuttle External Tank. The boosters were designed to be recovered and re-used. The plan was to parachute the boosters into the ocean after burn-out, To protect the liquid fuelled motors, nozzles etc from salt water and impact damage, the bottom of each had a pair of clamshell doors which closed over the bottom of the rocket, effectively sealing the motors from water ingress.
I wonder if there is any mileage in trying that approach?
The Falcon 9 design and launch procedure seems to be built around detecting and tolerating failure. The standard pre-launch static fire of the 1st stage should help to identify any problems with a reused engine. Also, having 9 engines gives you a good degree of fault tolerance - as long as the failed engine doesn't explode taking out the others.
Due to weight problems with the shuttle, the SSMEs ended up having to be very high performance for their size. To do this they need to run at very high turbopump and chamber pressures. If you were choosing a car engine for re usability with minimum refurbishment you probably wouldn't opt for the one with the highest specific output, but that's the situation the shuttle ended up with. One of the many compromises brought about by the need to bring down development costs despite the impact on operating costs.
Due to weight problems with the shuttle, the SSMEs ended up having to be very high performance for their size. To do this they need to run at very high turbopump and chamber pressures. If you were choosing a car engine for re usability with minimum refurbishment you probably wouldn't opt for the one with the highest specific output, but that's the situation the shuttle ended up with. One of the many compromises brought about by the need to bring down development costs despite the impact on operating costs.
Agreed. For a first stage you need plenty of "oomph" to get the whole weighty stack up and running (just like the F1s on the Saturn V). Once you've got everything motoring along nicely and up to a decent altitude, then the sporty engines can take over.
The Shuttle had sporty engines doing part of the heavy duty lifting.
Ironically, so will the SLS.
The Shuttle had sporty engines doing part of the heavy duty lifting.
Ironically, so will the SLS.
Eric Mc said:
The plan was to parachute the boosters into the ocean after burn-out, To protect the liquid fuelled motors, nozzles etc from salt water and impact damage, the bottom of each had a pair of clamshell doors which closed over the bottom of the rocket, effectively sealing the motors from water ingress.
I wonder if there is any mileage in trying that approach?
So far as I am led to believe (so discount if it's nonsense), the ocean landings are only intended as a proof of concept, once they are landing reliably they can be allowed to land on solid ground, and so much closer to their facilities.I wonder if there is any mileage in trying that approach?
If after a few successful recoveries it ends up being more expensive for refurbishment and other recovery methods may be more economical, I'd probably expect them to try them, rather than sticking with trying to prove a flawed concept as correct.
Ian974 said:
So far as I am led to believe (so discount if it's nonsense), the ocean landings are only intended as a proof of concept, once they are landing reliably they can be allowed to land on solid ground, and so much closer to their facilities.
They are already looking at building a landing pad at the former Atlas launch Complex LC-13 at Canaveral in anticipation of successful barge landings. http://www.parabolicarc.com/2015/01/12/draft-envir...
Edited by MartG on Sunday 18th January 11:45
MartG said:
They are already looking at building a landing pad at the former Atlas launch Complex LC-13 at Canaveral in anticipation of successful barge landings. http://www.parabolicarc.com/2015/01/12/draft-envir...
Those contingency pads marked would possibly help for an error of margin Edited by MartG on Sunday 18th January 11:45
Next Falcon launch has slipped to Feb 9th at the earliest
http://www.spaceflightinsider.com/organizations/na...
http://www.spaceflightinsider.com/organizations/na...
Eric Mc said:
I think they are pretty open minded about various ideas. This is their preferred option and they will keep trying. If, in the end, they can't get it to work, they may try something different.
As you can see, there are alternatives.
I'm pretty sure if you can get it back something will be reusable economically, if nothing else the first stage is a big ticket item at the local recycling depot :-)As you can see, there are alternatives.
Perhaps if you can reliably get it back there are further refinements that could be made to the first stage to make it more-reusable and/or more easily serviced?
I wonder if the first payload to fly on a refurbed rocket gets a discount?
scubadude said:
I'm pretty sure if you can get it back something will be reusable economically, if nothing else the first stage is a big ticket item at the local recycling depot :-)
Perhaps if you can reliably get it back there are further refinements that could be made to the first stage to make it more-reusable and/or more easily serviced?
I wonder if the first payload to fly on a refurbed rocket gets a discount?
I think they want to make its profitable. After all, it's hoped to be an economic proposition. At the moment it probably isn't that profitable so cutting costs would be better at reducing the current losses rather than offering discounts.Perhaps if you can reliably get it back there are further refinements that could be made to the first stage to make it more-reusable and/or more easily serviced?
I wonder if the first payload to fly on a refurbed rocket gets a discount?
It's main customer at the moment is still the US taxpayer (in the form of NASA).
Just some info I found while wandering round their site
http://www.spacex.com/about/capabilities
Also found this which puts some of his cost figures into perspective...the reality of course may be very different.
http://www.zmescience.com/space/spacex-reusable-ro...
http://www.spacex.com/about/capabilities
Also found this which puts some of his cost figures into perspective...the reality of course may be very different.
http://www.zmescience.com/space/spacex-reusable-ro...
London424 said:
I like the picture showing the Falcon 9 Heavy's 3 boosters all with legs. That would be fun landing 3 stages at the same time at the same site!Caruso said:
London424 said:
I like the picture showing the Falcon 9 Heavy's 3 boosters all with legs. That would be fun landing 3 stages at the same time at the same site!Looks like Google are getting in on the act
http://arstechnica.com/business/2015/01/google-mig...
That would make things very very interesting
http://arstechnica.com/business/2015/01/google-mig...
That would make things very very interesting
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