I’ve got an update to yesterday’s post, in which I discuss the flawed oil rig analogy. I should add that the submarine analogy is equivalently flawed. If we needed a giant and expensive machine to get an assembled submarine underwater, we might very well be tempted to do underwater assembly. But we don’t.
Category Archives: Space
The Heavy-Lift Fetish
I’ve discussed this many times before, but Al Fansome has a useful comment over at Space Politics (scroll way down–it’s in the forties):
Other than Bob Zubrin (e.g., the Mars Society), I don’t know of any space advocacy organizations who have made super-heavy-lift a priority. The only reason that super-heavy-lift is a priority now is because Mike Griffin came in and made a command decision. He already knew the answer — ESAS was a facade to justify the decision he had already made.
Let me try to give you a serious response to your question.
Have you thought about how all the truly GREAT engineering projects on this planet have been built?
Let me list a few obvious ones.
– The Pyramids
– The Great Wall
– The Empire State Building
– The Hoover Dam (or pick your favorite dam)
– The Eiffel Tower
– The Kremlin
– The U.S. Capitol Building
– The Statue of Liberty
– The Golden Gate BridgeThey all have at least ONE thing in common. The pieces of each & every one of these great engineering projects were transported to the final site in pieces, and then assembled on site.
Great engineering in enabled by low-cost transportation and the ability to assemble the technology on site.
We are KILLING ourselves by not taking the same approach to space.
Next — think about standard home construction.
1) There are estimated to be more than 100 million homes in America.
http://www.census.gov/prod/1/pop/p25-1129.pdf+Number+of+houses+in+United+States&hl=en&ct=clnk&cd=2&gl=us
Of that number, the estimated number of mobile homes is ~9 million
http://www.census.gov/Press-Release/www/releases/archives/census_2000/001543.htmlIn other words, well over 90%, or over 90 million, of American “homes” (whether in single family dwelling, apartments, condos, etc.) are assembled by the same method that is used to assemble the great engineering projects. This choice is obviously driven by economics (nobody mandated this result.)
SUMMARY: The large majority of Western and Eastern civilization has been built using the approach of cheaply transporting the pieces of the construction project to the site, and then final assembly at that site.
So, why are we ignoring the dominant traditional approach that is used over the entire planet?
Why are we not assuming that the right way to build our space economy, and to develop the space frontier, is to develop & use reusable launch vehicles to transport things to space at very low costs, and then assemble the pieces on-site.
Mike Griffin gave a speech a couple years ago talking about constructing the great cathedrals in Europe. Well, those cathedrals were transported to the final site in millions of pieces, and then assembled.
We continue to treat space differently than earthly endeavors for contingent reasons of history, not rationality or technology. Thus we get the cargo-cult approach of ESAS, in which NASA attempts to replicate Apollo, except without either the associated urgency, or the budget.
[Update on Sunday afternoon]
Since some people seem to imagine that the oil rig is a useful analogy, let me expand on it. It actually is one, but not in a way advantageous to the heavy-lift fetishists.
Yes, it is assembled in port and then towed to its operational location. But this is in no way analogous to assembling on the ground and launching to orbit. This is because of the huge energy barrier between the two. It’s no big deal to tow something from one place in the ocean to another–that’s a very old technology, and an extensive transportation infrastructure exists with which to do so. Thus, it makes sense to assemble it essentially in the ocean, but near land, to take advantage of the local work force.
But note that what we don’t do with oil rigs is assemble them in Colorado, and then build a humungous custom truck (and associated reinforced roads, with clearances) to move it to the shore and put it in the water. But that’s essentially what people are proposing in saying that things should be fully assembled on earth, and then launched into space, on a giant rocket that flies just once in a while, at a very high cost (particularly after amortizing the development cost).
In space the oil rig scenario would be analogous to having an existing assembly facility in LEO (that had presumably been bootstrapped up), with a robust low-cost transportation infrastructure to get things to and from earth, and from point to point in space. The “oil rig” (or large telescope facility, or prop depot for use at L1) would be assembled there, and then a space tug would move it to its final destination.
This was in fact part of the original vision for the SSF in the eighties. The “dual truss” configuration was intended to act as an orbital assembly hangar. Unfortunately, we didn’t have the transportation infrastructure to support it. But the fact remains that what we need is not heavy lift, but affordable, reliable and frequent lift. Once we get the latter, it will become clear how to best utilize it to accomplish our goals.
Will Reynolds Get The Contract?
A woman Down Under has a novel approach to asteroid management: wrapping it in foil.
More Thoughts On The Tether Permits
Paul Breed notes in comments that the decision to require permits or waivers for tethered testing didn’t originate with AST (though I never claimed it did), but with the FAA chief counsel’s office. To me, this is just one more argument for making the office independent of the FAA and report directly to the SecDot, as it did from its inception until the Clinton administration “streamlined” it into the FAA.
They Never Learn
NASA just lost two hypersonic test vehicles on an untested sounding rocket, built by ATK, the same company that is slated to build the paint shaker first stage for the Ares I. It’s not clear whether it was destroyed by the range, or it if just blew up on its own.
Sigh…expendables, and particularly solid expendables. Gotta love the continuing notion of putting things into space on modified munitions.
PITA
Alan’s a great science and tech reporter, but I wish that he’d asked George Nield about this:
We have poured a pad for tethered hover testing at our new location, but there was a recent FAA re-interpretation of the law that absurdly states that testing under a tether, as we have been doing for over eight years, is now considered a suborbital launch, and requires a permit or waiver just as a free flight would. This is retarded and counterproductive in so many ways, and the entire industry is lashing back over it, but it is an issue we have to deal with in the next couple months.
Maybe I will.
Happy Birthday, FAA
I hadn’t realized that it’s about the same age as NASA. I’d thought it went back further than that. For the occasions, Alan Boyle interviews the current head of the space side of the agency, George Nield.
Oopsie
Some folks have been criticizing the recent Orion parachute test failure as just one more screwup at NASA that they’ve been covering up, and made a bigger deal of it than it is, but Henry Spencer has a more nuanced, and correct view:
Foul-ups in testing are not uncommon, especially when the test setup is being tried for the first time. One of the headaches of high-tech test programmes is having to debug the test arrangements before you can start debugging the things you’re trying to test.
Sometimes a malfunctioning test setup actually gives the tested system a chance to show what it can do in an unrehearsed emergency. During a test of an Apollo escape-system in the 1960s, the escape system successfully got the capsule clear of a malfunctioning test rocket.
But sometimes the test conditions are so unrealistically severe that there’s no hope of correct functioning. Unpleasant though the result often looks, this isn’t properly considered a failure of the tested system. That seems to have been what happened here.
As I’ve noted before, requirements verification is where the real cost of a development program comes from, particularly when the only useful verification method is test.
More On Oscillation Mitigation
NASASpaceFlight has technical details of yesterday’s briefing. It still looks nuts to me.
A Milestone For New Space
XCOR has attracted the funding of an institutional investor. It’s not just angels any more.