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SpaceX's Challenge Against Blue Origins' Patent Fails To Take Off
speedplane writes As was previously discussed on Slashdot, back in September SpaceX challenged a patent owned by Blue Origin. The technology concerned landing rockets at sea. Yesterday, the judges in the case issued their opinion stating that they are unable to initiate review of the patent on the grounds brought by SpaceX. Although at first glance this would appear to be a Blue Origin win, looking closer, the judges explained that Blue Origin's patent lacks sufficient disclosure, effectively stating that the patent is invalid, but not on the specific grounds brought by SpaceX: "Because claim 14 lacks adequate structural support for some of the means-plus-function limitations, it is not amenable to construction. And without ascertaining the breadth of claim 14, we cannot undertake the necessary factual inquiry for evaluating obviousness with respect to differences between the claimed subject matter and the prior art." If SpaceX wants to move forward against Blue Origin, this opinion bodes well for them, but they will need to take their case in front of a different court.
Space launches tend to go east in order to pick up the Earth's spin to reduce the speed needed by that amount. Therefore, when launching from Canaveral (or that newfangled launch pad in Virginia Beach), a sea landing is the only logical choice.
APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?
Furthermore, that is why rockets launch from the east coast in the first place: if something goes wrong, the flaming debris comes down over the sea.
However, SpaceX are aiming to do a return to launch site for recovering their stage I boosters. (This surprised me - this must use more fuel than land-at-sea, and the mass of that fuel is directly subtracted from your available stage II payload.) The landing at sea is an interim measure while they prove the technology (because of the afore mentioned potential for flaming debris.)
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
The ultimate goal is for the rockets to get back to landing pads near their launch pad, including their launches from Florida. They're only landing at sea right now because they need to demonstrate a consistent track record before the interested parties will let them attempt a return-to-launch-site landing. They've got various approval processes going on to build landing sites at Kennedy Space Centre. Based on where the Falcon 9 staging happens, it doesn't take that much more fuel to return to the original launch site versus an offshore ship.
That's not to say that all their effort into the drone ships is wasted. Apart from the obvious need to demonstrate safe landings on hard surfaces before doing it on actual land, there are some circumstances in which they'll not be able to return to the launch site. Very heavy payloads that eat into their reusability fuel budget, for example. Another is the center core of the Falcon Heavy: it separates much later than the two side cores of the rocket, which means that by the time it separates it's going much faster and is much farther away. Those will always have to land at sea. There are rumours, however, that SpaceX has plans to refuel the rockets on the drone ship after they've landed and then fly them back to the launch site propulsively.
The first stage is suborbital, so that's not really an option. And when it comes to aerodynamics, on the way up it's pushing hypersonic speeds with a not-even-supersonic-friendly profile, not even the usual "nose-needle" to break the shockwave, presumably because it's having to fight gravity the whole way without lift surfaces, so can't face directly into the line of motion. Plus with the fact that it doesn't start really pouring on the speed until it's mostly clear of the atmosphere anyway.
Bottom line - it's a rocket: with minimal lift surfaces efficiency isn't really high on it's feature list to begin with. On the return trip it's free to travel at much lower speeds though - it's basically a tradeoff between air resistance and the fuel consumed to hold it in the air instead of falling like a rock. Still, fuel is currently only a couple percent of the total cost of a launch, so even if you had to double the amount used you'd still see negligible effect on the total launch cost. First they have to get rocket reuse working - once you can get a half-doze uses out of a rocket, then maybe it makes sense to start worrying about efficiency on the return trip.
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