Low-cost Launch Vehicle Concept

[sgt_flyer]

We will be able to see a part of the iss undocking / docking process soon on nasaTV -

There's Progress 52 undocking +iss live on february 3rd, and progress 54 launch, docking and iss live the 5th

http://www.nasa.gov/multimedia/nasatv/MM_NTV_Breaking.html#.UueHYplPe0c

[shynung]

It's not even chamber walls. I'm more worried about LOX being used to cool the nozzle bell. These are small channels at high temperatures that are going to carry one of the most corrosive substances possible?

On the other hand, I see no reason why LOX and LH2 can't be simply switched here.

I suppose that explains why the rocket would go boom 1/3 of the time.

I noticed that they plan to use the GH2 as cold-gas thrusters when the LH2/LOX runs out. Simply switching the plumbing means the GH2, instead of going through the central injector, would go through the vortex injector, nullifying this effect. That might be the reason they used LOX as coolant.

Bypassing this problem would have meant additional injectors for cold-gas thrusters, or a more complicated valving system. Why they skipped this idea and simply use LOX as coolant, I have no idea.

[Winter Man]

Is it even worth developing though? With the Falcon 9-R promising to cut costs down to a fraction whilst keeping a decent safety rate, what's the point?

[Nibb31]

It has yet to be seen whether SpaceX can actually keep that promise. Many in the industry have their doubts.

[sgt_flyer]

Well, SpaceX CRS-3 will attempt to show if it's feasible or not (march 2014 launch)

After all, space X have the will to try something new

[K^2]

Is it even worth developing though? With the Falcon 9-R promising to cut costs down to a fraction whilst keeping a decent safety rate, what's the point?

If they manage to get as much of it reusable as they promise, no, that will pretty much mark the beginning of the end of disposable launchers. No disposable system can compete with what they are promising for 9R. How that goes, though, is another question.

Keep also in mind that the project in question has been proposed at about the same time as F9, and 9-R wasn't even thought up yet.

[Nibb31]

Reusability doesn't necessarily reduce launch costs. There is a rule of thumb in the space industry called the rule of fifths: "One fifth of the budget for the satellite bus, a fifth for the rocket, a fifth for ground systems, a fifth for the payload, and the rest for various systems work (e.g. integration)."

Reusing the rocket only impacts the 20% of the budget that is allocated to the rocket. In that fifth, you still have the cost of refurbishing, testing, transport, refueling, etc... so end customers are potentially looking at a rough estimate of less than 20% savings on their project compared to an expendable launch vehicle.

Also remember that the reusable Falcon 9R will have a reduced payload. It will be competing with the medium-lift Soyuz market, not the heavy GEO comsat market. And remember, some of the fundamental systems haven't been proven yet. Nobody knows yet if a Merlin engine can actually restart facing a supersonic airflow, or if the lightweight tank structure can resist the stress of reentry and landing without damage. This is stuff that has hardly been researched, let alone tested, and yet the whole concept relies on it working. There is still a long road before anyone can assess the idea as feasible.

There are other ways of making stuff cheap. For example, mass production of disposable items. That is the route that Arianespace is following with the Ariane 6: 4 near-identical SRBs per rocket for 12 launches per year means that the factory has to churn out nearly 50 solid booster cores per year. In space terms, that's mass production, and has the potential to massively reduce costs.

SpaceX is also going this way, with a facility that is designed to build 400 Merlin engines per year, the equivalent of 40 falcon 9s. But that pretty much flies in the way of their reusability plans, because once SpaceX starts reusing all those Merlins, their production facility has to slow down and loses its competitive advantage.

Add to the fact that the commercial launch market isn't expanding at a huge rate. The comsat market is reaching saturation while land-based networks are becoming more pervasive. The institutional market is under a lot of pressure too. And new markets will need more than a 20% discount to become viable. In fact, there isn't really much demand for a higher launch rate right now.

So, you see, there's very fine balance to be found in the industry, and I applaud SpaceX for trying something new. But this is an industry where technical achievements, no matter how impressive they are from an engineering standpoint, don't always become an industrial success. The success of SpaceX relies on much more than just bringing their rocket back.

Edited January 28, 2014 by Nibb31