Author Topic: Reused Falcons + Dragons for ISS resupply missions?  (Read 11648 times)

Online Robotbeat

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #20 on: 08/01/2014 07:59 pm »
This may change. SpaceX may get competition. And actually, imagine a large module, like an MPLM with Cygnus as the spacecraft bus launched on an Atlas V or a beefed up Antares or something. It'd be 5-10 tons of non-volume-constrained cargo, possibly even full ISS racks. Could give SpaceX a run for their money and a reason to reduce price to NASA.
« Last Edit: 08/01/2014 08:04 pm by Robotbeat »
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Offline moralec

Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #21 on: 08/01/2014 08:00 pm »
Would it be logical in the future transporting such things with the cheapest way: with reused Falcons + Dragons? It shouldn't cost more than $50 million pro flight (guess), with 3,300 kg of cargo.
SpaceX is already the cheapest, there is no (economical) reason for them to lower the price for NASA.
There are several.
First, it is their goal to use reusable rockets/spacecraft, and the pricing will have to reflect reusability for it to make sense from a customer (NASA) perspective.
Secondly, their (i.e. Elon's) goal is to lower the cost of access to Space. They want to put that into practice sooner rather than later. CRS and crew transport to ISS are logical contracts for them to push their combined business+ideology model.
The above two points will play a pivotal role in allowing them to convince future customers.
You guys understood me wrong. I was talking about price, not cost.

Of course there are reasons for lowering costs of accessing to space. Just not any reason to reduce the price of services to NASA.

Currently NASA does not care if the rocket is recovered or not. NASA wants a fixed price per upload and download mass. And SpaceX is currently offering the cheapest price.

No misunderstanding from my part. SpaceX may be interested in lowering prices if that means winning in another way, for example by securing a multi-year contract from Nasa and thus reducing uncertainty about future income flows.
 


Offline MTom

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #22 on: 08/01/2014 08:03 pm »
If only talking about "low value" things like water and consumables to the ISS, then maybe NASA should consider switching their contracting to just pay for mass delivered instead of a per launch fee.  i.e. every ton delivered = $X.  SpaceX can choose to send them up however they want.  If they are confident that they can get them up there using reusable rockets, they can take the risk of payload loss against the potential cost savings.  This system incentivizes lower launch costs but does potentially increase the risks.

Seems to be a good idea.

There could be an other problem: the risk is not only about the loss of the payload but the delay on the delivery.
To avoid this, could it launched weeks earlier and "parking" on orbit? In case of a loss there will be enough time for a second launch of an other rocket.
(And full payment only in case of in time delivery... )

Offline MTom

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #23 on: 08/01/2014 08:18 pm »
Would it be logical in the future transporting such things with the cheapest way: with reused Falcons + Dragons? It shouldn't cost more than $50 million pro flight (guess), with 3,300 kg of cargo.
SpaceX is already the cheapest, there is no (economical) reason for them to lower the price for NASA.
There are several.
First, it is their goal to use reusable rockets/spacecraft, and the pricing will have to reflect reusability for it to make sense from a customer (NASA) perspective.
Secondly, their (i.e. Elon's) goal is to lower the cost of access to Space. They want to put that into practice sooner rather than later. CRS and crew transport to ISS are logical contracts for them to push their combined business+ideology model.
The above two points will play a pivotal role in allowing them to convince future customers.
You guys understood me wrong. I was talking about price, not cost.

Of course there are reasons for lowering costs of accessing to space. Just not any reason to reduce the price of services to NASA.

Currently NASA does not care if the rocket is recovered or not. NASA wants a fixed price per upload and download mass. And SpaceX is currently offering the cheapest price.

If NASA could get more cargo to ISS and SpaceX could practicing with recovered hardware for the same amount of money , this would be a win-win situation. (e.g: 2 new Falcon+Dragon--> 1 new + 2 or 3 recovered Falcon+Dragon for the same price).

P.S: only in case if NASA really increases the resupply rate. Unless SpaceX gets less money in a year.
« Last Edit: 08/01/2014 08:46 pm by MTom »

Offline MP99

Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #24 on: 08/01/2014 09:28 pm »


Would it be logical in the future transporting such things with the cheapest way: with reused Falcons + Dragons? It shouldn't cost more than $50 million pro flight (guess), with 3,300 kg of cargo.
SpaceX is already the cheapest, there is no (economical) reason for them to lower the price for NASA.
There are several.
First, it is their goal to use reusable rockets/spacecraft, and the pricing will have to reflect reusability for it to make sense from a customer (NASA) perspective.
Secondly, their (i.e. Elon's) goal is to lower the cost of access to Space. They want to put that into practice sooner rather than later. CRS and crew transport to ISS are logical contracts for them to push their combined business+ideology model.
The above two points will play a pivotal role in allowing them to convince future customers.
You guys understood me wrong. I was talking about price, not cost.

Of course there are reasons for lowering costs of accessing to space. Just not any reason to reduce the price of services to NASA.

Currently NASA does not care if the rocket is recovered or not. NASA wants a fixed price per upload and download mass. And SpaceX is currently offering the cheapest price.

No misunderstanding from my part. SpaceX may be interested in lowering prices if that means winning in another way, for example by securing a multi-year contract from Nasa and thus reducing uncertainty about future income flows.

If SpaceX's price is low enough, this may leave room for another player to also provide services.

This may be a benefit to SpaceX if they feel customers won't sign up for service from them until there is also an alternative supplier.

Or, they may find it easier to close their business case if they're flying multiple times per year.

I suspect both have elements, but they need a "backup" supplier to grow the market.

Cheers, Martin

Offline aero

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #25 on: 08/05/2014 01:26 am »
It'll never work until SpaceX gets the recovery right, like NASA does it. See!!   ;D

http://forum.nasaspaceflight.com/index.php?topic=31078.msg1238864#new
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Offline AJW

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #26 on: 08/05/2014 02:37 am »
I thought that CRS was about kg to ISS for $.  Do the contracts also specify that only new vehicles can be used or can SpX deliver the cargo and pocket any additional savings?

Online The_Ronin

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #27 on: 08/05/2014 06:57 pm »
I believe NASA contracted new Dragons for each flight.  Elon made a reference to it before how they could be saving NASA more money if they only let them recycle the Dragons.

Offline Elmar Moelzer

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #28 on: 08/05/2014 07:03 pm »
I believe NASA contracted new Dragons for each flight.  Elon made a reference to it before how they could be saving NASA more money if they only let them recycle the Dragons.
IIRC, the thing was that back then SpaceX could not give NASA an accurate quote for reused Dragons, which is why NASA decided to simply buy a new one every time.

Offline JasonAW3

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #29 on: 08/05/2014 07:45 pm »
I believe NASA contracted new Dragons for each flight.  Elon made a reference to it before how they could be saving NASA more money if they only let them recycle the Dragons.
IIRC, the thing was that back then SpaceX could not give NASA an accurate quote for reused Dragons, which is why NASA decided to simply buy a new one every time.

Makes sense.

     SpaceX couldn't give NASA a good price on reused Dragon Capsules until they found out what was going to be needed in refurbishing them for reuse.

     Now that they've recovered a number of them, they could now give NASA a realistic cost per reused capsule.
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Offline JasonAW3

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #30 on: 08/05/2014 07:50 pm »
Dragon isn't built to be a tanker, so the water/fuel idea is a non-starter.

AFAIK water is transported up in bags, and Dragon has 11 cubic metre of internal volume - one cubic metre of water equals 1,000kg (1mt), so Dragon is not volume constrained for carrying water, but weight constrained (total launch payload mass = 6,000kg).

Cygnus has far more internal volume (27 cubic metre), but can only carry 1,800kg of mass.

Quote
(Cygnus is great.)

I think it could be instrumental in expanding humanity into and beyond LEO.

I think Cygnus, Bigelow's inflatable habitat and the Dragon/Falcons are going to be the driving force for future long range space exploration.
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Offline Lee Jay

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #31 on: 08/05/2014 07:51 pm »
I believe NASA contracted new Dragons for each flight.  Elon made a reference to it before how they could be saving NASA more money if they only let them recycle the Dragons.
IIRC, the thing was that back then SpaceX could not give NASA an accurate quote for reused Dragons, which is why NASA decided to simply buy a new one every time.

Makes sense.

     SpaceX couldn't give NASA a good price on reused Dragon Capsules until they found out what was going to be needed in refurbishing them for reuse.

     Now that they've recovered a number of them, they could now give NASA a realistic cost per reused capsule.

Which might be higher than previously believed since they seem to have a tendency to fill with sea water after splashdown.

Offline AncientU

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #32 on: 08/05/2014 08:59 pm »
I believe NASA contracted new Dragons for each flight.  Elon made a reference to it before how they could be saving NASA more money if they only let them recycle the Dragons.
IIRC, the thing was that back then SpaceX could not give NASA an accurate quote for reused Dragons, which is why NASA decided to simply buy a new one every time.

Makes sense.

     SpaceX couldn't give NASA a good price on reused Dragon Capsules until they found out what was going to be needed in refurbishing them for reuse.

     Now that they've recovered a number of them, they could now give NASA a realistic cost per reused capsule.

Which might be higher than previously believed since they seem to have a tendency to fill with sea water after splashdown.

Can be solved with land landing, which might be the gateway to reusable CRS flights and manned flights too.
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Offline Jarnis

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #33 on: 08/06/2014 05:50 am »
I believe NASA contracted new Dragons for each flight.  Elon made a reference to it before how they could be saving NASA more money if they only let them recycle the Dragons.
IIRC, the thing was that back then SpaceX could not give NASA an accurate quote for reused Dragons, which is why NASA decided to simply buy a new one every time.

Makes sense.

     SpaceX couldn't give NASA a good price on reused Dragon Capsules until they found out what was going to be needed in refurbishing them for reuse.

     Now that they've recovered a number of them, they could now give NASA a realistic cost per reused capsule.

Who knows, maybe second commercial resupply contract will have a bid "with reused dragons" and "with new dragons" and NASA gets to pick...

Offline MTom

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #34 on: 08/06/2014 06:46 pm »
I believe NASA contracted new Dragons for each flight.  Elon made a reference to it before how they could be saving NASA more money if they only let them recycle the Dragons.
IIRC, the thing was that back then SpaceX could not give NASA an accurate quote for reused Dragons, which is why NASA decided to simply buy a new one every time.

Makes sense.

     SpaceX couldn't give NASA a good price on reused Dragon Capsules until they found out what was going to be needed in refurbishing them for reuse.

     Now that they've recovered a number of them, they could now give NASA a realistic cost per reused capsule.

Who knows, maybe second commercial resupply contract will have a bid "with reused dragons" and "with new dragons" and NASA gets to pick...

Or both, as I mentioned earlier: splitting the low-value / less time-critical and high-value / time-critical cargo...
« Last Edit: 08/06/2014 06:50 pm by MTom »

Offline arachnitect

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #35 on: 08/08/2014 05:51 am »
I believe NASA contracted new Dragons for each flight.  Elon made a reference to it before how they could be saving NASA more money if they only let them recycle the Dragons.
IIRC, the thing was that back then SpaceX could not give NASA an accurate quote for reused Dragons, which is why NASA decided to simply buy a new one every time.

Makes sense.

     SpaceX couldn't give NASA a good price on reused Dragon Capsules until they found out what was going to be needed in refurbishing them for reuse.

     Now that they've recovered a number of them, they could now give NASA a realistic cost per reused capsule.

Who knows, maybe second commercial resupply contract will have a bid "with reused dragons" and "with new dragons" and NASA gets to pick...

Or both, as I mentioned earlier: splitting the low-value / less time-critical and high-value / time-critical cargo...

I really don't see NASA establishing a two tier setup on an ongoing basis; just getting a mission to launch is such pain that NASA is going to want to maximize the chance of success. Splitting supplies up into more launches causes conflicts at the range and in orbit at station.

However: I could see it happening once or maybe twice the first time someone flies a refurbished cargo capsule. The cargo on the first Dragon and Cygnus missions was nice to have on station but I recall NASA saying they wouldn't lose any sleep about the cargo itself if it ended up in the ocean. So if Spacex wants to demo a refurbished Dragon, maybe NASA puts together a manifest of less valuable stuff for that one mission. Once it's been demonstrated, I think NASA is going to expect it to work.

The commercial crew contenders want to reuse/refurb their spacecraft and they're subject to the highest standards for both "payload" safety and on time performance.

Offline MTom

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #36 on: 08/11/2014 08:37 pm »

Who knows, maybe second commercial resupply contract will have a bid "with reused dragons" and "with new dragons" and NASA gets to pick...

Or both, as I mentioned earlier: splitting the low-value / less time-critical and high-value / time-critical cargo...

I really don't see NASA establishing a two tier setup on an ongoing basis; just getting a mission to launch is such pain that NASA is going to want to maximize the chance of success. Splitting supplies up into more launches causes conflicts at the range and in orbit at station.


Maximisimg the succes [of launches] is only a partial solution for the problem.
The system-problem is that there is a bottleneck at ISS and there are variations at the launch timing. Without buffering between them every day of slipping is a loss for the whole system (effect of variations in a JIT system).

See Goldratt's Theory of constraints:
Quote
The JIT philosophy holds a minimum inventory between each work-center, typically only one. When there is a blockage in the flow line and Murphy ‘strikes’, the line stops and plant output is effected.
...
Drum-Buffer-Rope enhances JIT by protecting the weakest link in the system, and therefore the system as a whole, against process dependency and variation and thus maximises the systems’ overall effectiveness.

About he bottleneck (system's constraint):

Quote
When there is an internal constraint, there are very few resources (people, machines, equipment, materials) dictating the output of the system. The most limiting resource is referred to as the ‘Drum’ as it determines the pace or ‘beat’ of the entire system. 
Following Step 2 - Decide how to Exploit the System’s Constraint(s), the constraint resource cannot be allowed to waste one moment of its capacity. This means that it should never be stopped waiting for parts and should not use capacity producing anything other than the parts required to fulfill sales orders. To ensure this we finitely schedule the Drum creating a Drum Schedule. The Drum schedule should maximise the Throughput of the Constraint and provide a detailed plan for just this one area. The Drum Schedule must be derived from the Shipping Schedule.

and for the rest of the system:

Quote
Following step 3 - Subordinate everything else to the above decisions, there are a number of actions that have to be met by the non-constraints in the system in order to meet the Drum Schedule and ultimately the shipping schedule. As discussed earlier, variation and Murphy cause, from time to time, pieces of plant to break down. Understanding that we have to protect the constraint from lost capacity due to these breakdowns, a Buffer of time is used.
...

http://www.goldratt.co.uk/resources/drum_buffer_rope/


The question is if a significantly cheaper logistic chain (using re used hardware) could allow a "better" supply chain, with a buffer before the bottleneck to prevent it: in this case spacecrafts on orbit waiting for docking - with the opportuinity of rearrange a sequence between them (not always the same sequence as they were launched). This would need more launches and also an other arrangement of the payloads between the spacecrafts.

P.S: I know there are 100's of answers why this couldn't be done. The question is: how could it be possible in the future. Unless the system-problem remains.

Offline Bob Shaw

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Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #37 on: 08/11/2014 10:35 pm »
I think they'll use refurbed Dragons for demo flights initially, or for missions which might not otherwise get the thumbs up and where a re-used spacecraft could lower the financial bar. Obvious examples are the Max-Q abort demo (or have they specified a D2 with it's SuperDracos for that, can't recall), DragonLab and Red Mars. As for Bigelow missions, presumably they'd all have to be D2 vehicles so that they could dock rather than be berthed - but used D2s will be about by the time Bigelow flies another space station.

Offline CuddlyRocket

Re: Reused Falcons + Dragons for ISS resupply missions?
« Reply #38 on: 08/12/2014 09:51 am »
I think they'll use refurbed Dragons for demo flights initially, or for missions which might not otherwise get the thumbs up and where a re-used spacecraft could lower the financial bar. Obvious examples are the Max-Q abort demo (or have they specified a D2 with it's SuperDracos for that, can't recall), DragonLab and Red Mars.

Yes, it is a SuperDraco equipped Dragon that is being tested in the abort demo because they are testing the abort system of which the SuperDracos are the significant component! Red Mars also needs the SuperDracos for landing on the planet. Dragonlab could potentially be done with a refurbished existing Dragon though.

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