Howdy All, Ken here. I just decided to weigh in a bit on an interesting article today. (and provide a bit more grist for Jon’s mill)
Over at the The Space Review, Mr. Grant Bonin visits the question “are heavy-lift launch vehicles the best technology for opening space to humankind?”. While I personally feel the question should have been something more along the lines of ‘Are HLLVs the right technology right now for opening space to all of humankind?’, I’m not going to pick nits. 😉
M. Bonin then sets out two goals:
1) to dispel the belief that HLLV is an economic necessity for human spaceflight; and
2) to demonstrate the feasibility (both technically and economically) of undertaking human space exploration beyond low Earth orbit using existing, more modest launch systems.
This is quite a chore, and he gives himself two parts to answer it, so we’ll see what unfolds next week.
In this week’s part, he jumps right in to the the ideas of Payload Fraction (payload as total % of mass of vehicle) and mass-to-orbit (where it’s generally assumed in spite of decades of miniaturization and industrial advances that it will nevertheless require hundreds of tonnes to do anything [ which is true to some extent, but…]).
In both cases the larger lifts seem to carry the day. But that’s only on a very superficial and first blush basis. Luckily, this is why we have folks like trained investment bankers, who look at things from an entirely different perspective from aerospace engineers. M. Bonin cites Ed Wright’s [not an investment banker] Ad Astra article and one of its contentions, that optimizing mass-fraction alone does not necessarily lead to a more cost effective system, as most of the lift-off weight is propellant, and fixed infrastructure and labor-hours are what really chew up the budget. It would require far more than two launches per year to even come close to making an argument that an HLLV is cost-effective. He (Mr. Bonin) also notes that the complexity of the big honkin’ rockets makes them harder to get off the ground in the first place. I’m not so sure about the analogy with the model rockets. I seem to remember an earlier post about how many Falcons, Atlases and Deltas could be flown before the first HLLV gets off the ground, and the huge amount of mass that would already be in orbit before the first Longfellow flew..
I’ve long been an advocate of high volume to orbit, but in conjunction with high frequency. Getting 100 tonnes to orbit at one time hasn’t been conclusively proven to me to be the most strategically effective way of doing it. What if the materials scientists and private consortiums need access to orbit more than twice a year? How is this thing going to serve access to the ISS?
(Answer: It’s not supposed to. It’s supposed to be a disposable means of conveying a few NASAnauts to the Moon to do a couple of practice runs for Mars. When I say a couple I do not mean a lot. Maybe 3)
M. Bonin also makes note of the learning effect. When someone does something a lot they tend to get very good at it, and figure out the thumbnail rules and shortcuts (oops, I mean procedural efficiencies…yeah, that’s it). This helps to bring overall costs down, and makes for a better overall launch experience.
While citing some economic arguments, M. Bonin fails, as so often do aerospace engineer economists, to take the economic and financial considerations deeper and start applying them to what companies actually face out in the real world. Other things than your standard cost-of-capital and value-to-shareholder buzzwords.
Look at the insurance. There’s no way to gather the risk pool sufficient to cover all of the small payloads of small companies that would be aggregated into such a behemoth. Even on larger payloads, like Bigelow’s Nautilus balloons, there’s no way anyone would launch four at the same time. This means you still need freight aggregation services to get full use out of the payload capability. Again, you run into the problem of gathering a sufficient risk pool to cover the potential losses in event of a failure.
And there will be failure. Just because a rocket is as big and complex as the Saturn V does not mean it will have the flight record of the Saturn V. It is, however, doable to get a risk pool together for a single EELV launch or some kind of RLV.
The whole point is mass production. Whether that mass number of flights is done by a boatload of cheap disposable rockets (and they will be cheap once we start using them in number) or by a whole bunch of RLV flights is something to which I’m indifferent. If the RLV guys can come up with something I’ll get behind them (and I’m more optimistic than I used to be), but I know we’ve got a bunch of 20 mt to ISS lift capability that is desperate to be used.
If NASA uses the same launch systems as everyone else, then each successive launch will be cheaper for everyone. If NASA continues to be supplied with its own private launch system, then the taxpayers will continue to have to foot the bill for inefficient and ultimately ineffective access to orbit. Besides, if NASA uses the same rockets as everyone else then when a rocket goes boom (which it will) who do you think is going to get blamed? NASA? No way, it’ll be the launch vehicle manufacturer. There’s a benefit if I ever saw one.
There’s also the question of launch risk. Is it really risk effective to put all of one’s eggs in a single basket? Business teaches us no, it’s not. It is better to spread the risk amongst a number of launches so that any individual failure does not compromise the entire investment. Business is more likely to go with the 11th launch with a 9 out of 10 success record (and only lofting 20mt of assets), than the 3rd launch of a 2 for 2 vehicle hauling 100mt of assets.
Also, I don’t understand why there seems to be an assumption that any launches to the Moon require a free-space rendezvous and direct return from Lunar orbit. This seems to have a built-in implicit assumption that the proposed ESAS HLLV will really have nothing to do with the ISS, nor the ISS anything to do with a return to our Moon. To me this is silly as we have a space platform with at least one robotic arm (I’m not sure what ever happened with the German one). With a facility in orbit you have less of a sense of urgency of getting everything together to go quick, and one can re-think the launch sequence as well as double and triple check all systems post-launch (THE single most traumatic period of any payload’s life).
We need to get lots of skilled people into space to do skilled-people things like make better products (materials science) or increase the efficiency (combustion science) of stuff here on Earth.
Hypothetical question: What if every single rotary machine on Earth used perfectly spherical, space produced ball bearings? What would be the decrease in energy required to operate each machine? What would be the aggregate of that? And the corresponding intangible benefit of less pollution from energy production?
This is of course complete fantasy, but the point is that there is so much unknown business opportunity in space it’s mind-boggling, and this is the kind of opportunity that used to excite the American spirit. Tumlinson’s “Return to the Moon” attempts to be a manifesto in this regard, but falls a bit short, I feel. It is in the right spirit, though, and this is important for our country.
Nevertheless, the idea of commerce and industry in space, fields in which the U.S. has a competitive advantage, needs wider acceptance. Investing our nation’s capital and resources in a private launch vehicle for NASA, which serves no other interests, is in my view a dead end for NASA and a dead end for the American space industry. We can’t afford this kind of investment right now, but we can afford to do it in small bite-size pieces. If we’ve got three launch vehicles and each can launch 4x per year, then we have a launch per month, and 240 mt in orbit per year. (Wait, but that’s what the HLLV is going to do 8 years from now…)
That’s not half-bad, and we know we can scale up from there. The Boeing facility is supposed to be capable of something like 40 cores per year or 14 launches just of the D-IV. The Falcon’s supposed to be cheap and easy so we should be able to launch water or expendable cargo at least once a month on that one. Give Atlas half a dozen per year and you’re talking about 30 launches per year, or 600mt to orbit per year at full speed. 2 or 3 launches per month is not a burdensome task for a smaller rocket, especially if different facilities are used.
Isakowitz doesn’t really give us any insight into the launch costs of the vehicles (prices negotiable), but I’ll assume $250Mn for the D4, $200Mn for the A5, and $25Mn for the F9. That’s (14×250)+(6×200)+(12×25)=3,500+1,200+300 = $5.0Bn for 600mt. There’s no way HLLV is going to be cheaper than that. Even at $100Mn per Falcon 9 that’s still less than $6.0Bn.
And the thing is, once you ramp up to that level of production, per-unit costs start coming down, which means that after a couple of years the D4s are down to $150Mn, A5s are $75-100Mn, and F9s are the Bic lighters of space. Okay, maybe a bit optimistic, but don’t be bamboozled by the NASA finesse. They could be applying their skills towards 20mt Moon machines, or international interface standards (now that’s useful!) for space vehicles instead of fussing over launch systems. NASA asked itself the question of whether it should be in the business of flying airplanes around. In most cases the answer was no. Should NASA be in the launch vehicle business? (Or provide engineering insight like they do with aircraft…)
Some folks seem to be fixating on the ‘Proximity Ops’ issue as a killer for the deal, as if each and every thing that has to meet up with something else in space has to have a complete set of maneuvering devices and complicated and heavy equipment and you’re sacrificing payload on an already tight 20mt limit and…
They seem to forget that this issue has already been looked at and the answer is tugboats and robot arms. You launch something near the ISS. A tugboat runs out and fetches it. The arm attaches it to the station or something else. The tugboat can also be used for releasing/retrieving free-flyers, ferrying s/c over to the fuel depot, and so forth.
This doesn’t need to be a complicated machine. It doesn’t even need to be pretty or aerodynamic. Just capable of moving stuff around in orbit. It’s been variously called an OTV or OMV over the years. It’s also a craft that would be functional at an L-1 station as well, so it’s not just a mono-purpose or mono-location vehicle.
It’s also the kind of design challenge that would likely excite more kids than updating their grand-dad’s Apollo.
It’s been said that NASA needs a serious infusion of young talent and fresh ideas. Perhaps this project is the catharsis that will have this infusion inflicted upon them…