A new alliance. This is long overdue.
I’m not sure about the prize idea, though. I’d rather the government actually purchase bulk items (e.g., water) on orbit. The goal should be a low cost per pound, not reusability per se. I’m pretty sure that reusability would naturally fall out of that. And reusable vehicles will have to be reliable to hit the cost goal.
I wouldn’t mind the prize idea, if, and only if, it was based on price per pound. As is, it invites a useless form of reusability; one that isn’t cost effective.
As an example of the flaw in their reasoning, what if the prize causes SpaceX to revisit second stage reusability on the F9? They’ve abandoned it due to the payload hit and R&D cost, but… it wouldn’t be hard to build a one-off second stage that’s recoverable, when they can devote several tons to the recovery, and thus snag a billion-dollar prize. It’d also be a truly useless development, because it wouldn’t be practical reusability.
The most important number in spaceflight isn’t ISP, and it’s certainly not thrust. It’s $ per payload pound. Reusability is only useful if it lowers cost per pound. Otherwise, it’s at best useless.
I totally agree with Rand; a government offer to buy bulk items in orbit at a fixed price per pound would be far better.
Who judges what the price is, then?
How about $X allocated for purchasing commodity delivered on orbit at best offered price, not to exceed $Y/kg?
I agree. The government should just rent space, transportation flights (e.g. seats), and purchase consumables.
One thing that might also be a problem is interoperability. Ideally there should be common interfaces to connect the space modules and perform resupplies. But it might be a bit early to start defining the interfaces at this point.
I believe you’re saying, Arizona CJ, that a reusable vehicle with a one metric ton payload isn’t economically viable. If not, please correct me. But making Falcon 9 V1.1 fully reusable could easily result in a net of far more than a metric ton of payload. And if the entire vehicle could be reused twice with no refurbishment, it would reduce the LEO cost per pound of payload to about $1,000. That’s a little less than half the current F9 cost, but 1/5th the cost of the Delta II, the prior low-cost leader. And it is far from not economically viable, if one takes steps to put the final assembly and test of spacecraft where it belongs: in space. Though you might need to establish and sustain an orbital infrastructure of technicians to do that assembly, test, and final “launch” of spacecraft, the money saved by not having to test each satellite to see if it (as an integrated system) will survive the environments imposed by launch into orbit, and subsequently function in an expensive ground simulation of space is such that the whole thing comes out cheaper in the end.
@ MFK;
What I meant was that if SpaceX (or anyone else – but SpaceX is closer to having the capability) decided to make a one-off upper stage just to get the prize, and it wasn’t something economically viable (in this case, because they’d never use it again), it’d be a waste.
However, I agree with you; a fully reusable vehicle that’s economically viable would be a very good thing. My guess is SpaceX could do second stage recovery for a lot less recovery mass than in my above hypothetical.
My guess as to what they had in mind for second stage recovery was put a PicaX heat shield on the top, and have it protrude slightly to help shield the sides. Two big challenges they faced were keeping it stable during reentry, and landing it. Landing was problematic due to the enormous (and very costly) vac bell on the Merlin. Also, that Merlin has vastly too much thrust to be of any use for landing. So, for the actual touchdown, use a single superdraco in the heat shield (so it’d land upside down). Dragon-2 style legs (very short) would be all they’d need.
The stability during reentry and landing is said to be problematic, and would take a rather heavy active thruster system and lots of prop. I disagree. The easy way, IMHO, would be to have a pair of regular Draco thrusters positioned to spin the stage, so it’d use spin-stabilization for reentry. It’d also need a pair of small grid fins to deploy from the skirt (for both de-spin and guidance, plus stability).
I don’t know how much of a braking burn they’d need to make this viable. If none, it’d be low mass, around one ton. I suspect, though, that a braking burn would be impossible; the second stage is extremely light (about 11000 lbs dry mass plus residual fuel), so nearly empty and sans payload, the Merlin Vac, even at 60% thrust (108000 LBF) would be applying about 10G, which I suspect is a more than the stage and engine structure could handle.
I am curious as to what you mean by “This is long overdue”, more specifically what the this is that is long overdue. Is it the purpose? The goals? The objectives? All of the above?
I’m just curious, because as with the Pioneering Space Declaration I’m just not seeing much new here. Now, seeing astronaut Ron Garan talking about cislunar infrastructure over at HuffPost Live, that just warmed the cockles of my Moon Society heart.
The goals. They’ve finally stopped using the worse-than-useless phrase “space exploration.”
Yes. I noticed that too. Development generally means sustainability. Exploration is more along the line of flags and footprints. That’s how the terms are generally used.
In my LunarCOTS.com concept, I envision an equivalent to the CRS namely a Commercial Cis-lunar Supply Service (C2S2) in which NASA pays a first and second place prize to winners bringing water for propellant to designated locations in space and that two prizes would be reserved for lunar sources and two from asteroid sources. In this way, there would be competition within a source and between the sources thereby ensuring redundant companies from two different sources.
CATS needs to be carefully thought through. Reusability costs more than just the propellant. There is the whole operations costs and then the cost and losses of a propellant depot confined to a single inclination. Compare that to a partially reusable (I.e. the first stages) Falcon Heavy. Dock two and you have nearly the equivalent of a Saturn V. Dock three and you have as much as any proposed government HLV. Are we certain that two or three partially reusable Falcon Heavies are going to cost more than say maybe 13-20 fully reusable F9-sized rockets and the depot?