On Friday, June 6, 2014 11:37:45 PM UTC+12, Jeff Findley wrote:
In article ,
says...
On Thursday, June 5, 2014 11:32:53 PM UTC+12, Jeff Findley wrote:
Bigger and bigger launch vehicles aren't the answer to everything.
Agreed. Space travel is a complex business. You have to do many
things well. Even so, we can look at the highlights needed today.
Highly reusable vehicles, ones that have 20 year working lives,
cost less than 0.1% or less their purchase price in maintenance
to reuse, and are usable 2,000x or more without compromising
safety or reliability - is a critical technical achievement.
This is going to take several iterations of designs to get there.
A continuous improvement process gets there, and moves beyond - the time it takes is a measure of the effort expended and the efficiency of the expenditure.
The
space shuttle was iteration 1.0, and it sucked.
Nixon wanted something different than the Apollo era hardware because they were associated strongly with JFK, whom he did not like. I think it poetic that the Shuttle is remembered the way you mention, and its associated with him.
Anyone who remembers the 1952 Collier's cover "Man Will Conquer Space Soon" knows that vonBraun had promoted fly-back boosters for a long time,
http://www.centauri-dreams.org/?p=24888
http://i.imgur.com/D67k1.jpg
and it would have been a natural extension of the Saturn booster to make it so;
http://www.aerospaceprojectsreview.c...es/v1n2ad8.gif
http://up-ship.com/blog/wp-content/u.../05/image3.gif
http://sites.google.com/site/spaceod...9/stsbl70a.jpg
If you look at NASA's budget, and subtract out;
(1) the SRB,
(2) the SSME (sticking with J2/F1/RL10 combination),
(3) the ultra-light heat shield,
(4) the advanced delta wing,
And modify the Saturn V first two stages to produce a hydrogen/oxygen upper stage, powered by J2 engines, with an F1 powered first stage, along the lines of Maxime Faget's design, you end up with a $2 billion - not $200 billion system.
The problem was that
NASA sold it as "operational" after five flights and proceeded to treat
it as "finished". It wasn't.
If you read the internal documents and endless white papers of the committees that reviewed the project you will see how much spending was politically motivated. Those who wanted to get their piece of the pie were actually fearful of efficient low-cost designs since it would break their rice bowl.
This is the nature of real leadership, the willingness and capacity to break rice bowls in the service of efficient achievement of goals. Standing up to the Army for example and telling them you weren't going to use SRBs on the system, no matter what that did to the price of gunpowder.
Continuous spiral development could have
improved it quite a bit.
Continuous improvement is a good idea, as long as it doesn't morph into and excuse for continuous waste. This goes back to the motivations and rewards of individuals.
Instead, we got a few piecemeal upgrades, some
driven more by replacing obsolete, hard to maintain, hardware rather
than staying "ahead of the curve". In other words, they reacted to
problem rather than being proactive.
That's the nature of long-standing government bureaucracies. They actually repel innovative thinkers. Which is why vonBraun and Faget were sidelined early in the process.
https://archive.org/details/MiltonFr...ndCollectivism
It's unclear how much it could have truly evolved though, because the ET
being throw-away with the SSME's on the orbiter was a design decision
that meant that the system could never have been made fully reusable
Yes, the ET-redesigned as a modular booster would have been a natural evolution of the Shuttle technology, once it got flying. The ET was actually built at the same facility Michoud, as the Saturn V first and second stages were built, so, this was the real heart of the infrastructure that gave the US leadership in space. At least as far as airframes go.
without a major change to the overall system design. In other words, it
was a dead end in terms of reusability.
An inflatable thermal protection system, to protect it and maintain it at the right altitude during re-entry, so that the heat and gee loads were survivable, with an inflatable lift system after its speed falls to subsonic speeds, would have been an interesting experiment to try, especially after the lift capacity of the shuttle was derated.
Falcon 9R is another approach to resuability, but it's not quite there
yet. The hardest part will be trying to reuse the second stage. I'd
say we have at least 5 to 10 years before we'll know if the second stage
can become reusable.
Timing is a function of effort level, and the efficiency of that effort. We've been building re-entry vehicles from suborbit since the 1950s. There's no real reason we cannot build a TSTO-RLV highly reusable vehicle.
Then, and only then, will we truly find out if
this approach is viable.
We know how to build TSTO-RLV and we know how to build highly reusable modular rockets. Its just a matter of giving the right team the right money to do it.
Reusable systems with 20 year working times are far, far into the
future.
Not necessarily. If we spent as much developing boosters as we spent on developing ICs we could have something flying in 2 years, with the right people and financial controls in place.
Because of this, I'd rather focus on the present and what can
be done with relatively inexpensive vehicles like Falcon 9R.
The SpaceX developments benefit from TRW's work on the Pintle Fed engine throughout the 1960s 70s 80s and 90s, when he bought those assets from TRW in 2003. He has since invested several billions of dollars - with appropriate fiscal controls and management oversight - to move steadily forward.
Had he $70 billion a year instead of $0.7 billion a year, he would already be flying his Mars Colonial Transporter, which is basically a large modular freighter rocket capable of putting up over 1,250 tonnes into LEO.
Musk is struggling against forces within the military and government that fear that he will break their rice bowls. He is benefiting from the fact that lack of funds are creating other issues for the same folks he threatens, and so there is a distraction there. Still, its the politics, not the technology that is challenging.
However, in concise conversation, bigger and hotter launch vehicles
lower the cost of space access more rapidly than anything else, if
choices must be made about what to talk about in a 4 minute elevator
conversation.
I quite disagree. Going big early (for launch vehicles) locks you into
super high fixed costs and very low flight rates, preventing rapid
spiral development of launch technology.
Well, it depends on what the mission is. If your goal is to increase the mass flow rate between worlds for each dollar invested, you need bigger hotter rockets to achieve that. Its pretty straight forward.
Experimental rockets to prove a concept before committing to larger systems, is part and parcel of the larger rocket programme. Fortunately, there are many opportunities for many types of missions. So, for a commercial operation, you can use profits from one scale to fund the development of another scale, as you explore design details.
For example, you can build a small one stage suborbital transport for space tourism, use it later as an upper stage for a small two stage to orbit RLV to put up communications satellites, then use the first stage as the upper stage on an even larger RLV, to put tourists into orbit, while a three stage version is used for GTO, and deep space applications.
Of course, if you're not cash strapped, and you have a larger vision, you can start larger as in the Apollo programme.
Saturn V had this problem,
The problem of Apollo was that the plug was pulled in a meeting on November 24, 1963 between McNamara and LBJ - this was actually the first meeting of the new President following the assassination and leaders like vonBraun were sidelined.
Cutting back the 1964 NASA budget, and actually reducing funding dramatically thereafter, while increasing the budget for Vietnam turned the Saturn V from a workhorse into a white elephant.
Had the $200 billion spent on Vietnam in the 1960s would have been added to the $20 billion spent on Apollo, at the same time, we would have seen broad commercial ventures in space bear fruit by the 1970s. Had ROVER/NERVA funding been maintained and continued support from the US military been sustained throughout the 1960s, we would have seen safe reliable, low cost, compact high temperature reactors roll out by the 1970s that made synthetic oil from sea water and coal at about $0.10 per barrel, which would have ended the age of conventional oil, and sustained continued economic growth in the 8% to 12% range from 1960 through 2000.
the
shuttle had this problem,
The shuttle's original design and flight rate was perfect for expanded low cost presence in space. Continual redesign to meet political goals combined with a reduction in actual flight rate because there was no budget for the payloads, made this potential workhorse into a white elephant also.
and SLS will have this problem.
Yes, given who is doing it and why, and how it is being done, combined with a lack of clear mission.
Going big early would only work with a massive infusion of cash
amounting to at least 10s of billions of dollars of *additional* NASA
funding per year.
NASA shouldn't be designing and building spacecraft. NASA should be controlling transfer and access to classified information for qualified vendors, and funding fundamental research into improved technology with the help of the US military. In this role they would operate like NACA did during the heyday of airline development in the 1920s, and the result would be the same, the commercial development of space.
THIS ISN'T GOING TO HAPPEN, EVER!!!!
No, the USA has collapsed economically. So, US government agencies, not allied with the drug and criminal cartels, don't have the money to carry out any mission.
Not accepting
this reality is what keeps NASA going down this same FAILED path
repeatedly.
NASA, like George Washington, should step back from the power offered them. Washington was offered Kingship over the American colonies following the Revolutionary War. He stepped back and urged the people to support a Republic.
NASA should step back from the roles they have played in the past, sell off the assets they no longer need, to qualified commercial entities, and focus on those tasks that secure the national interest, public safety and progress, carried out by commercial operators.
This is a lesson that NASA and you should learn.
Building small test vehicles to gain an understanding that can then be used by commercial ventures is a good model for NASA to follow. NACA played a similar role with the introduction of streamlining, monocoque construction, jet engines, and cantilevered wings in airliners.
In
particular, developing technologies like inflatable reentry shields is
one of many enabling technologies that helps to eliminate the "need" for
very large launch vehicles for a manned Mars mission.
Inflatable technologies are near and dear to me. I've been a
proponent of inflatable technologies for low-cost re-entry and entry
into Mars' atmosphere for many years.
Saying we have to ignore one good idea to do another good idea is
the fallacy of 'false choice' - there is nothing in inflatable
thermal protection gear that makes us not choose to build
adequately sized vehicles with high exhaust velocities. (bigger &
hotter)
It would be far better to invest in the following *before* investing in
big launch vehicles:
Inflatable habitat modules.
Inflatable heat shields for Mars atmospheric entry and braking.
Cryogenic storage of propellants.
Transfer of cryogenic propellants (i.e. fuel depots).
In-situ fuel production (lunar as well as Mars).
There are 471 civilian nuclear plants in the world produce 2,756 TWh of electricity. along with over 5,500 coal fired power plants in the world that produce 8,700 TWh of electricity. The average cost of electricity in the world today is $0.14 per kWh. The nuclear plants earn $385 billion per year.. The coal fired plants earn $1,218 billion per year.
A programme that arranged for off-take contracts for nuclear plant operators as well as coal plant operators to buy electricity from space at $0.06 per kWh has the potential to reduce the cost of energy for these operators as well as generate $165 billion per year for nuclear plant operators and $522 billion per year for coal plant operators.
If the governments of the world gave nuclear and coal plant operators ten years unregulated operations if they signed up for a solar receiver for each of their plants, and committed to clean laser energy from space, these operators would sign up for 20 year contracts and make a modest deposit against their first year's plants. The value of a 20 year contract, discounted at 6.25% per year, is worth $1,854 billion for the nuclear side and $5,867 billion for the coal side. A total value of $7,721 billion.
Of course, these off-take commitments, and the deposit, cannot be spent today. But they can be used to arrange a bond, or some other debt instrument, that bears substantially higher rates of return for energy speculators. Let's say we have a 5 year programme that follows a typical development schedule;
$0.08 - the first year
$0.17 - the second year
$0.33 - the third year
$0.25 - the fourth year
$0.17 - the fifth year/startup
$1.00 - total
If we pay 40% annual rate of return, compounded, for all money at risk over the term of the programme, we have the following return schedule;
RISK RETURN
$0.08 $0.45 - Year one
$0.17 $0.64 - Year two
$0.33 $0.91 - Year three
$0.25 $0.49 - Year four
$0.17 $0.23 - Year five
$1.00 $2.73 - Total
Dividing the amount risked, into the total percentage of the return allocated to support that risk, gives market value of the programme going forward;
PCT $/pct
16.44% $0.51 - year one
23.48% $0.71 - year two
33.55% $0.99 - year three
17.97% $1.39 - year four
8.56% $1.95 - year five
100.00% TOTAL
So, basically, for each dollar invested, there is $2.43 allocated. If the cost of delivering all the power contracted for in the 20 year deliver schedule (starting in five years) is less than
$7,721 billion / 2.43 = $3,177 billion
then we can offer 40% compounded annual rates of return. We can also profit share, splitting any savings with investors, contractors, and managers to reward efficiency. This will cut costs to a minimum since it will result in profit without any cost and is beneficial to all as long as profit margins are below 30% to 40% range.
So, this gives the scope of a programme that can be used to displace nuclear and coal fired power plants with beamed energy from space.
Within this context, we cut out a budget to build an adequately sized highly reusable launcher to support these operations.
We require to orbit 1.3 trillion watts of solar power satellites. The Mars Colonial Transporter proposed by SpaceX has a capacity of 1,250 tonnes into LEO. An inflatable concentrator that masses an average of 4 grams per square meter, forms a disk 20 km in diameter and intercepts 425.3 billion watts. With a 30% conversion and transfer efficiency, this generates a laser beam 127.6 billion watts. A total of 11 satellites are required to meet the demands of the contracts called for. A fleet of five launchers consisting of 36 modules, along with a supply of 12 satellites, with sufficient budget for small scale trials, would have a high probability of delivering the power on time and on budget. Allocating $1 trillion for the satellites, and $1 trillion for the launcher, and reserving $1.177 trillion for over-runs, and incentives, we have $200 billion per launcher and $82 billion per satellite as our budget.
Since the Market Cap of Boeing is $101 billion and the Market Cap of Lockheed is $53 billion, and the market Cap of United Technologies is $109 billion - we can see that the ability to raise $3,177 billion in financing leans heavily toward the MAKE in our MAKE BUY decision matrix.
That is, we would be buying so much hardware, that it makes more sense to buy the company, once financing is secured, than to buy rockets.
So, we buy the largest commercial space operations around today, merge them all together, then break the companies along divisional lines, into independent operations, and sell those divisions we don't need for our programme, then use the money received to fund the development of the launcher and satellite supply chain.
That's how you do it.
You don't go hat in hand to the American people or the US government or NASA and beg to spend this or that few hundred million this or that way.
If all of the above prove successful, the need for large launch vehicles
is reduced or perhaps even eliminated.
It depends on what your goals are.
Most of what you need for a Mars
mission is fuel. That does *not* have to go up on a large launch
vehicle since it's infinitely divisible into smaller pieces.
The logistical cost is a factor, as well as reliability. There is no demand to go to Mars. There IS a demand for clean, low-cost, abundant energy.
On a smaller scale, there is a demand for global wireless broadband. One can build a system around that. However, the total amount of money, and lift capacity, needed, is such that, you cannot support the acquisition of assets. The MAKE BUY decision leans toward BUY in that case. This puts you in the headlights of oncoming interest groups that will flatten you and derail the programme.
Better to think big, go after the dirtiest energy producers, acquire what you need, and then use your profits to
a) expand into the global communications market
b) expand off world into;
i) Mars colonization;
ii) asteroid mining;
c) develop laser propelled spacecraft to replace chemical boosters
Putting the launch vehicle first, before you really know how big the
payloads *need* to be is stupid, plain and simple.
Correct.
Jeff
--
"the perennial claim that hypersonic airbreathing propulsion would
magically make space launch cheaper is nonsense -- LOX is much cheaper
than advanced airbreathing engines, and so are the tanks to put it in
and the extra thrust to carry it." - Henry Spencer