Nov29
Eating Our Seed Corn
on November 29, 2008 at 10:01 amJon Goff has some thoughts on the need for NASA to get back into the R&T business. And they remind me of my piece from last summer about the need for an orbital infrastructure, much of which will require that kind of technology investment. I hope, based on some conversations with transition people, that this issue will be addressed in the new administration.
So how much propellant do you want NASA to put into orbit, and by when? Presumably launching one or two 50-gallon drums in the year 2020 is not what you have in mind.
I don’t want NASA to put any propellant into orbit. I want NASA to purchase it on orbit from other providers.
NASA proposes itself to put a few thousand tons into orbit by then, if it wants to do lunar expeditions, with an Ares V. I would propose increasing it by an order of magnitude, at least.
So you want NASA to secure purchase of tens of thousands of tons of propellant in LEO in the next ten years? (When I said “put”, I meant that to include “secure purchase of”.)
I won’t say that I’m for or against this idea since space policy is not really my main concern. But if NASA did secure purchase of say, 10 thousand tons or 20 million pounds of orbital propellant in the next 10 years, how many launches to LEO would that entail? You were saying that you’re against heavy lift. For instance, the shuttle’s payload capacity is about 25 short tons and would thus mean 400 launches to make 10,000 tons. Would you put that on the side of too-heavy lift, or the practical range of lift?
Jim, it does not matter how big the booster is that gets those tens of thousands of tons to the orbit. What matters is the end price. Launch price, as we all know, is affected by things like per launch cost, development cost, capital cost, insurance cost and so on. It does not really matter if you launch a ton or ten tons at a time, as long as you end up with lower price per kg.
The key to all of this is driving launch costs down, and heavy lift with chemical rockets is a bad way to do that. The key to driving launch costs down with chemical rockets is doing lots of launches. The key to doing lots of launches is…doing lots of launches! E.g., getting way down on the vehicle processing learning curve as quickly as possible in terms of real time, having true reusability of core components, using non-cryo propellants when feasible for the first stage (especially avoiding LH2, as you have to keep it really really cold and its density is really really light which means really really big cryo tankage, extra wetted area for the booster which means more skin friction drag, more structural weight, etc.), etc, etc.
Let’s take the SpaceX Falcon 9; the published cargo capability is 13.75 tons to LEO, at a cost of $36.75 million. (That’s a decent cargo capacity, but I wouldn’t class it as “heavy lift”.) Delivering 10,000 tons to LEO would take just under 730 launches at a cost of $26.3 billion. This works out to $2.6 billion per year over 10 years, and 73 launches per year – i.e., the cost of a couple of shuttle missions per year, and a launch rate of 1.5 per week. That’s eminently doable with a decent launch system architecture, and is not particularly expensive even if the gov’t picked up the whole cost!
When you look at raw numbers, it’s easy to get overwhelmed – e.g., think about how many meals you have to eat in the next 10 years. But if you eat them a bite at a time, a meal at a time, it works out.
Let’s take the SpaceX Falcon 9; the published cargo capability is 13.75 tons to LEO, at a cost of $36.75 million. (That’s a decent cargo capacity, but I wouldn’t class it as “heavy lift”.) Delivering 10,000 tons to LEO would take just under 730 launches at a cost of $26.3 billion. This works out to $2.6 billion per year over 10 years, and 73 launches per year – i.e., the cost of a couple of shuttle missions per year, and a launch rate of 1.5 per week.
I strongly suspect that if we decided to contract for over 700 launches, you’d get a substancially lower cost per launch. First of all, with numbers that large, SpaceX would be able to invest in automated equipment to lower manufacturing costs. That equipment might not be cost effective at lower launch rates. Second, SpaceX holds the potential for partial reusability with their vehicles. If they can achieve that, you wouldn’t need to build as many boosters in the first place. Since all you’re carrying is propellant, you likely wouldn’t bother with expensive insurance. And, like the Russians did with the Soyuz booster, of one of them fails, you roll out another one and try again instead of grounding the vehicle for months/years like we tend to do with more expensive vehicles.
Once the propellant is in space, you need a use for it. Sure, there may be the occassional trip to the moon or elsewhere, but perhaps the initial market would be refueling a space tug. The tug would be designed to ferry satellites from LEO to MEO (e.g. GPS) or more likely to GEO. Once there, they could release the satellite and do a perigee lowering burn so aerobraking could lower the apogee back down to LEO for the next trip. This has the potential for greatly lowering the cost to get a payload out to GEO because each mission wouldn’t require the upper stage needed to get out there. Potentially, a Delta II or Falcon 9 class booster could carry the largest GEO payloads to LEO and let the tug take them the rest of the way to the intended orbit.
Propellant to space is still picking a winner and narrowing the focus to all chemical systems.
If you really want to incentivize things set up a contract for x tons of cargo to the lunar surface or lunar orbit or to Mars.
As I have argued here before, if we were to do things right, with an emphasis on extraterrestrial industrial development, the market will push vehicle in the directly of small to moderately sized RLV’s, which presumably will result in the lowest launch costs.
By your metric of propellant, a Sea Dragon design with 1 million lbs to LEO would be the best implementation but would to little to actually develop infrastructure for the economic development of the solar system. Beware of the unintended consequences of your chosen solutions.
By your metric of propellant, a Sea Dragon design with 1 million lbs to LEO would be the best implementation
Not when you factor in development costs.
Dennis, you wrote:
Propellant to space is still picking a winner and narrowing the focus to all chemical systems.
I notice all the vehicles you mention are chemical systems.
By your metric of propellant, a Sea Dragon design with 1 million lbs to LEO would be the best implementation but would to little to actually develop infrastructure for the economic development of the solar system. Beware of the unintended consequences of your chosen solutions.
At 500 tons to orbit, it’d only account for something like 20 launches. If you can make a profit with $20-30 billion revenue and 20 launches, then by all means do so. I see no unintended consequences here.
But let’s look at what you’d need to get a viable Sea Dragon. Development costs of the vehicle may be more than the expected revenue from the vehicle. Second, the size of the vehicle and the sound it generates means you’ll need new, more isolated launch infrastructure and probably need to develope new sound supression systems for the launch pad. I don’t see the economics working out here.
Propellant has the virtue of being near-infinitely divisible into small chunks.
What about laser-launch or something like the late Gerald Bull’s space cannon for such g-tolerant low value consumables?
Karl,
I don’t think the launch pad or noise suppression would be a factor at all with a Sea Dragon.
Unless you believe the Pacific Ocean to be too small.
Speaking of Sea Dragon
Every study that was done on the Sea Dragon concept in the early 60′s showed that it had a lower development cost as well as lower operational costs than “traditional” systems. I got to spend a lot of time with Truax back in the early 80′s when he was really pushing this and what he said was that when he went to the Aerospace companies, they basically said that the SD would be impossible to build.
Then he went to the shipbuilding companies, gave them the specs, and their response was, ok we can do this, where’s the check? This was Truax’s whole point regarding lowering the cost of development and construction. A single pressure fed first stage, coupled to a single pressure fed upper stage reduced costs dramatically, along with the launching of the bird in the ocean.
While I am not particularly an advocate of Sea Dragon as I think that Heavy lift is pretty much obsolete from a needs perspective, it was a heck of a way to actually look at lowering development, manufacturing, and the operation of a huge heavy lift booster.
Can someone explain why Sea Dragon’s development costs would be so much higher than, say, the Falcon 9′s? I’m not an engineer, but I looked at the Wikipedia pages and it looks like a fairly basic big rocket to me.
Of course, I think the downside to the Sea Dragon is excess capacity per launch. How often would you really need to put 500 tonnes into orbit in one go? Cheaper access to space could grow the market (just as super tankers allowed the industrial export economies of Japan and China), but the current market would be pretty saturated by a Sea Dragon’s cargo capacity, don’t you think?
p.s. – Rand, is that Amazon thingy supposed to be on the top like that, or is it just a teething issue? I think it should be on the left.
Propellant to space is still picking a winner and narrowing the focus to all chemical systems.
Most non-chemical systems still require propellant. (Technically, it may be reaction mass, but “propellant” is a convenient catch-all term.)
If you really want to incentivize things set up a contract for x tons of cargo to the lunar surface or lunar orbit or to Mars.
That’s a great idea in principle, but “you,” in this case, means the US government. The government won’t contract for delivery of cargo to a specific destination until it has decided on that destination. It will take a while for the Obama Administration to make any such decision. (The “Bush Vision” is no longer relevant.)
Even when the government’s made the decision, anyone developing a cargo vehicle will have to trust that the destination won’t change between the time they start development and the time they actually start flying cargo missions. Otherwise, they risk being stuck with a lunar cargo white elephant when Bob Zubrin becomes NASA Administrator.
The usefulness of a propellant depot would not be tied to any one destination. So, it’s something we could advocate now, rather than waiting months or years for the new Administration to complete the next big space policy review.
Also, don’t automatically assume that NASA’s primary goal will always be “sending NASA employees on cool trips to destination X.” That is admittedly a likely outcome since it’s been the goal ever since the 1960′s, substituting only different values of X. However, there are indications that the Obama Administration might be willing to consider different goals. The transition team is already asking questions about asteroid defense and space based solar power.
If the Obama administration decided that NASA should focus planetary defense or the development of space solar power, or even an expanded “Mission to Planet Earth,” an orbital propellant depot would still be relevant while cargo delivered to Destination X might not be.
You know, if you could get some really stretchy elastomer from which to make their skin, balloons full of hydrogen would loft themselves right out of the atmosphere.
Then you just need your tug to come down low enough to snag ‘em, and some clever solar-powered compressor.
I suppose every now and then one of the rising balloons would be struck by lightning. A side benefit of the program would therefore be the occasional really awesome fireball in the sky.
The usefulness of a propellant depot would not be tied to any one destination. So, it’s something we could advocate now, rather than waiting months or years for the new Administration to complete the next big space policy review.
Ed
You still have the same problem that you stated, the government changes its mind and poof there goes the business. ATK is about to find this out relative to the 5 segment SRB.
I don’t think that this is going to be like 1993 and the end of all exploration. We have a space station now, and since it is nearing completion the European, Japanese and American government is going to seek to do something with this huge investment. Supporting exploration (or microgravity) via ISS has the best chance of providing on ramps to commercial suppliers no matter the level of support beyond the basics.
As I have said now for years, now that the infrastructure at ISS is in place, we have amazing potential for this to become the golden age of human spaceflight.
You still have the same problem that you stated, the government changes its mind and poof there goes the business.
Yes and no. Even if the government changes directions, the propellant already placed in orbit will still have value. If NASA doesn’t need it, DoD might, or in the worst case, it could be sold as surplus to commercial users.
It’s not at all like the 5-segment SRB, which has no use to anyone but NASA. More like the strategic petroleum reserves.
Supporting exploration (or microgravity) via ISS has the best chance of providing on ramps to commercial suppliers no matter the level of support beyond the basics.
Perhaps, but until someone comes forward with a cost estimate and credible plan for refurbishing/maintaining ISS past its End of Design Life (2016), no private investor is going to take that seriously. Right now, that’s the black hole of space policy. NASA doesn’t have money in their budget plans to maintain it *or* deorbit it. No one even wants to talk about it, apparently hoping it will go away while they aren’t looking.
no private investor is going to take that seriously. Right now,
Bullshit, Elon is already banking on that. Don’t talk about Bigelow until he is actually up there, he is far more speculative than ISS.
I have seen the charts already for ISS support through 2020 and that was Mike Griffin’s NASA.
You are also assuming that the government would commit to supporting the propellant depot through completion when no investor out there would rely on a government promise of that order. It is far more likely that the government would support something already in place (like Gerst has supported ISS even in the face of Mike Griffin as well as the international partners) than something speculative.
Bullshit, Elon is already banking on that.
No, Elon doesn’t give a damn about ISS. He’s building Falcon and Dragon because he wants to go to Mars. He’s only pursuing COTS because it’s a convenient way of picking up a little bit of money while he’s doing what he wants to do anyway.
I have seen the charts already for ISS support through 2020 and that was Mike Griffin’s NASA.
Really? How much money did Mike have budgeted for replacement parts, Dennis?
Don’t believe everything Mike tells you. It’s one thing to put something on a chart. It’s another to fund it.
You are also assuming that the government would commit to supporting the propellant depot through completion
I’m not assuming the government will do anything.
What’s so special about 2020, Dennis? What do you think ISS will be doing between 2016 and 2020 that couldn’t be finished between now and 2016? (Right now, ISS’s only mission is to finish building itself — and that will soon be accomplished.)
Please don’t tell me it’s going to be a “national laboratory.” That’s a marketing label, not a mission.
No, Elon doesn’t give a damn about ISS. He’s building Falcon and Dragon because he wants to go to Mars.
Do you have anything concrete to support this assertion? I’ve been following him through his eMail updates and his website since the beginning and have not seen anything that supports this.
Do you have anything concrete to support this assertion? I’ve been following him through his eMail updates and his website since the beginning and have not seen anything that supports this.
You mean other than many years of public statements? He first came to the attention of the space community when he was a member of the Mars Society willing to fund experiments, but he later had a fall out with Bob Zubrin (shocking, I know). He has told me (and others) that his goal is to help colonize the cosmos with humanity, and Mars is key in his thinking. One doesn’t necessarily put things like this in a business plan, though.
So you agree he “doesn’t give a damn about ISS”? (Other than keeping his business plan sane that is). You’ve spoken with him, what do you think his opinion would be on ISS 2015+?
Carl Pham wrote:
“A side benefit of the program would therefore be the occasional really awesome fireball in the sky.”
_______________
I’d advocate for moving this from a side benefit to its primary purpose!
I don’t know if he doesn’t give a damn about ISS per se, but he certainly cares about anything that represents a potential market for his products.
> No, Elon doesn’t give a damn about ISS. He’s building Falcon and Dragon because he wants to go to Mars.
Do you have anything concrete to support this assertion?
Yes. First, I know that Elon toyed with the idea of investing in one of the reusable launch companies but dropped those plans because their vehicles didn’t seem to be on a direct path to Mars. Second, I was at meetings at FAA headquarters where SpaceX discussed the Dragon capsule long before anyone at NASA entertained the notion of allowing private vehicles to visit ISS. Third, their Washington representative at that time told me he didn’t believe NASA’s then-current plan (building a capsule to go back and forth to ISS) made much sense. He also intimated that the plan would soon change. He was referring, undoubtedly, to the famous meeting he and Elon had with Sean O’Keefe where they pitched the idea of using capsules to go to the Moon, Mars, and Beyond. That was the genesis of what came to be known as the Vision of Space Exploration.
COTS was not part of the original Vision but was added later, in part to meet ISS requirements since Bush said NASA must “finish what it started” and in part, perhaps, as a consolation prize for SpaceX since they were not allowed to bid on the contract to build the CEV and its launch system.
More recently, Elon has talked about his desire to get government funding to build a heavy-lift vehicle called the “BFR” that would launch 100 tons to LEO. By his own statements, such a rocket has no commercial applications but would be essential (in his view) for manned Mars missions.
If he can get the american taxpayer to foot the bill for yet another bfr more power to him, but I suspect his interest in ISS is somewhat greater than “doesn’t give a damn” (per se). A direct customer for dragon if nothing else.