Elon Musk: ticket to Mars for $500,000.

[Robert Clark]

Elon Musk was interviewed on the U.S. news program "60 minutes" on
Sunday:

SpaceX: Entrepreneur's race to space.
March 18, 2012 4:44 PM
From PayPal to electric cars to rockets, billionaire entrepreneur Elon
Musk wants his company, SpaceX, to build America's next manned
spacecraft. Scott Pelley reports.
http://www.cbsnews.com/video/watch/?id=50121782n

He was also interviewed on a BBC radio program where he states that
eventually, after perhaps a decade of regular flights, the price for a
round trip ticket to Mars might be down to $500,000 per person:

20 March 2012 Last updated at 19:25 ET
Jonathan Amos, Science correspondent.
Mars for the 'average person'.
http://www.bbc.co.uk/news/health-17439490


Bob Clark

[hanson]

hanson wrote:
Yes, that was a very interesting interview.
Elon Musk is an example of why it is important to
have an environment that allows folks to become rich.
>
Such successful people then invest in endeavors
that CREATE something & will push the envelope
for the advance of Sci & Tech & ultimate benefit
humankind....
UNLIKE...
the current Obama admin, that merely tries to take
the loot from successful folks and dole it out to
community organizers, union bosses and phony
crony kickback enviro capitalists... for causes that
have yet to demonstrate any social benefit.
>
Back to the SL: "ticket to Mars for $500,000."... ahahaha..
Well, it remains to be seen whether that opportunity will
have an impact onto the greater social good, besides
the open question:
"Why would anyone pay $500'000 to visit a place that is
1000 times worse then the Gobi, Mojave or the Sahara"?
>
But then the same same situation and question occured
when Pizzarro, Cortez & DeSoto got in line....some 500
years ago...

[jacob navia]

Le 24/03/12 13:14, Robert Clark a écrit :

A trip to Mars needs a human rated interplanetary spacecraft,
i.e one with:

1) Artificial gravity
2) Radiation shielding
3) Food/water/air recycling
4) Big energy supplies.

for long trips of several years.

As of 2012 mankind doesn't dispose of ANY of those technologies. A
spacecraft carrying people to mars must be completely HUGE by today
standards, i.e. at least 50 times the ISS.

Of course you can babble anything on TV. Another thing is to discover
that people start losing weight and vision without gravity for periods
longer than 3-4 months. I posted the relevant scientific findings to
this group several weeks ago.

Another things is to discover that radiation in deep space is VERY high,
and if you are not suicidal you better get some shielding...
Water supplies could do double duty as shield and drink water, but first
you need to figure out what happens with the radioactive water when high
energy gamma rays hit it...

Yes, you can send supplies along the way before your ship starts, but
that is not scalable and you will need anyway recycling to reduce the
huge costs... That technology is being developed at the ISS now, but it
is far from being usable for years.

But anyway, on TB anything runs, even Mars trips for rich people...

jacob

[bob haller]

On Mar 24, 8:31 pm, jacob navia <ja...@spamsink.net> wrote:
> Le 24/03/12 13:14, Robert Clark a crit :

besides low cost to orbit which must come first.

to do mars travel time must be cut dramatically. which probably means
a nuke engine of some type.

cutting travel time dramatically will also cut the amount of supplies
and consumables needed

[Brad Guth]

Nukes and fusion in space is perhaps almost as good as a tether dipole
powered ion thruster that could have been accomplished as of a decade
ago.

Why bother with funding a round trip (at more than ten fold increasing
the price), when returning body-bags of either dead or soon to be dead
passengers is all that remains?

http://groups.google.com/groups/search
http://translate.google.com/#
Brad Guth, Brad_Guth, Brad.Guth, BradGuth, BG / “Guth Usenet”

[Alan Erskine]

Why will it take years?

>
> As of 2012 mankind doesn't dispose of ANY of those technologies. A
> spacecraft carrying people to mars must be completely HUGE by today
> standards, i.e. at least 50 times the ISS.

What? Why does it have to be 50 times larger?

People need 1.4kg of oxygen per day; that can be recycled.

People need about 1.5kg of food each day; that can be done quite easily.
The idea is that the return supplies would be flown into Martian orbit
ahead of the crew's arrival, similar to Lunar Surface Rendezvous. For a
crew of six, 365 days of food, at 1.5kg per day, would weigh 3287.25kg

>
> Of course you can babble anything on TV. Another thing is to discover
> that people start losing weight and vision without gravity for periods
> longer than 3-4 months. I posted the relevant scientific findings to
> this group several weeks ago.

People might start losing weight after a short time, but the trip's
going to a planet with 38% of Earth's gravity - the return will be the
tough part, but that can be handled.

>
> Another things is to discover that radiation in deep space is VERY high,
> and if you are not suicidal you better get some shielding...
> Water supplies could do double duty as shield and drink water, but first
> you need to figure out what happens with the radioactive water when high
> energy gamma rays hit it...

Radiation is no higher in 'deep space' as you put it than it is after
the Van Allen belts are left behind on a trip to the Moon.

>
> Yes, you can send supplies along the way before your ship starts, but
> that is not scalable and you will need anyway recycling to reduce the
> huge costs... That technology is being developed at the ISS now, but it
> is far from being usable for years.

Why isn't it scalable?

[Jonathan]

"Robert Clark" <rgrego...@yahoo.com> wrote in message
news:831f1ce4-9216-4437...@h5g2000vbx.googlegroups.com...

> Elon Musk was interviewed on the U.S. news program "60 minutes" on
> Sunday:
>
> SpaceX: Entrepreneur's race to space.
> March 18, 2012 4:44 PM
> From PayPal to electric cars to rockets, billionaire entrepreneur Elon
> Musk wants his company, SpaceX, to build America's next manned
> spacecraft. Scott Pelley reports.
> http://www.cbsnews.com/video/watch/?id=50121782n
>
> He was also interviewed on a BBC radio program where he states that
> eventually, after perhaps a decade of regular flights, the price for a
> round trip ticket to Mars might be down to $500,000 per person:

OK, and which World Fair was it that predicted we'd all be
riding around in jet cars by 1960?

He must be trying to sucker in...ah I mean, make a sales pitch
to potential investors. Thirty years from now you couldn't burn up
someone's ashes in the atmosphere of Mars for half a million.

I mean...I feel that I've spent the last 7 years walking around
the surface of Mars with the rovers. And anyone that really
wants to know what Mars is like would be looking at them
too.

I've seen so many close up pictures that I can almost hear
the sound of my footsteps pushing through the delicately
crusted soil. Almost slipping at times over sheets of iron spheres
or slippery clay. I can almost smell the sulfur and taste the
salt rich soil, and feel the brief shoves from the stray dust-devil
causing the ever present talcum powder-like dust to
force it's way into every crease.

Even almost see the smaller sun, and how at noon, it's effects
never get close to as strong or bright as on Earth.
Almost sense how obvious it is that just a few feet or meters
below the surface, there must be a layer where water can
flow, the only question being just how deep.
Feet or meters?


Opportunity Rover Gallery (165,000 pics)
http://marsrover.nasa.gov/gallery/all/opportunity.html

True Color Images Spirit and Opportunity Rovers
http://areo.info/mer/


And in ten or twenty years from now, with the pace of
computers, will going there really be the better choice?
Look at some of what we already have!


iMove

"...is a new form of digital interactive video that uses multiple cameras
to capture and seamlessly display video from panoramic views up to
complete 360° x 360° spherical views, placing the user in the scene
with the ability to look in every direction and move through space."

Infinite Z

"Its multisensory platform provides a highly realistic way to view,
manipulate, and communicate complex ideas through direct
interaction with zSpaceT virtual-holographic simulations.
zSpace simulations appear 100% in open space, with full color
and high resolution. They appear realistically "solid" and can be directly
manipulated using a stylus, as if they were real physical objects.
They move our physical world into a sensory-rich virtual world"

http://www.iqt.org/technology-portfolio/index-information-communications-technology.htmlhttp://www.iqt.org/





s

[JRStern]

On Sat, 24 Mar 2012 05:14:34 -0700 (PDT), Robert Clark
<rgrego...@yahoo.com> wrote:

>He was also interviewed on a BBC radio program where he states that
>eventually, after perhaps a decade of regular flights, the price for a
>round trip ticket to Mars might be down to $500,000 per person:

I expect the energy costs alone would be several times that.

J.

[JRStern]

On Sun, 25 Mar 2012 08:27:49 -0700, JRStern <JRS...@foobar.invalid>
wrote:

Some scribble on the napkin calcs.

http://en.wikipedia.org/wiki/SpaceX#Background

Projected dollar cost per pound to orbit could drop from $4,000 to
$1,300 ($8,800/kg to $2,900/kg) between Falcon 1 and the five-engine
concept vehicle, Falcon 5. CEO Elon Musk said: "I believe $500 per
pound ($1,100/kg) or less is very achievable.

So, if a human weighs 200 pounds, how much has to be moved to orbit to
get him to Mars and back?

First, current cost to *orbit* @ $4,000/pound is $800,000, and that's
if he's stark naked. Fortunately return to Earth is cheap, let's
assume free as an orbit decays.

But you'd better boost a few pounds of oxygen, water, and food if he's
going to stay there for a while. Let's say a ridiculuous minimum of
overhead is another 200 pounds, I'm guessing realistically it might be
ten times that. But for now, 400 pounds to orbit at today's price is
on the order of $3m.

Now, that cost per pound is not just energy (fuel), that is total
ticket price.

Let's call that one SpaceX unit.

Very roughly, let's say it takes one more unit to get to Mars (2), one
more unit to slow down to orbit Mars (3), one more unit to land on
Mars and return to orbit (4), and one more unit to return to Earth
orbit (5), and we'll then land for free. And, you have to boost those
units of fuel and consumables to orbit, so let's add say one more unit
of overhead for that (6).

So at today's price, a rough estimate of a trip to marks might be
$18m. Musk thinks he can reduce the price to orbit by 90%? That
would still leave it around $1.8m. So the $500k estimate is just way
low. And I'm guessing my estimates here are too low by a factor of at
least 3x, maybe more depending on how fast you want to go fourth and
back, and whether you'd like some radiation shielding on the way. Not
to mention the stewardesses, the band, the chef, and the floor show.

So basically, the most wildly optimistic number I could possibly
accept, would be on the order of $10m. But unless there's a serious
breakthrough in fusion technology, basically I don't expect to see
passenger tickets to Mars for less than a billion bucks anytime in the
next century. Only provisioning the orbit-to-Mars-and-back loop from
the moon or asteroids could possibly affect the system price and drop
it below, oh, $100m.

And as someone already said, how many tourists would want to spend
like that, to go stand on a desert? You can go to Flagstaff, AZ a lot
more easily.

OK, those are my napkin notes on the issue.

J.

[jacob navia]

Le 25/03/12 07:12, Alan Erskine a écrit :

Because, for instance the curiosity rover launched Nov 27th will arrive
to Mars in august, 9 months trip one way. Assuming that you stay in Mars
at least for a year (earth years), then you come back (another 9 months)
you need a life support system for 2 years at least.

Depending on the mass of the spaceship, the time could be even longer
since Mars and Earth come closer every 2 years. If the next window in
two years is too short, you have to wait till the next one, making for a
4 years round trip.

>>
>> As of 2012 mankind doesn't dispose of ANY of those technologies. A
>> spacecraft carrying people to mars must be completely HUGE by today
>> standards, i.e. at least 50 times the ISS.
>
> What? Why does it have to be 50 times larger?
>

Because you need the artificial gravity, what means a minimum size to
avoid bad side effects of spinning a too small spaceship. Then you need
all the shielding, food/water/air supplies, for 2 years at least or for
a very long time anyway even with recycling...

> People need 1.4kg of oxygen per day; that can be recycled.
>

I do not say it is impossible. I say that we do not have that
technology now. Yes, we can recycle oxygen, water, etc. But
the first water recycled used in the ISS failed after only a few months
service. A failure like that would be DEADLY in a spaceship bound for
Mars.

> People need about 1.5kg of food each day; that can be done quite easily.
> The idea is that the return supplies would be flown into Martian orbit
> ahead of the crew's arrival, similar to Lunar Surface Rendezvous. For a
> crew of six, 365 days of food, at 1.5kg per day, would weigh 3287.25kg
>

3 TONS to Mars is around 3 times the maximum payload we have sent
there, the curiosity rover...

>>
>> Of course you can babble anything on TV. Another thing is to discover
>> that people start losing weight and vision without gravity for periods
>> longer than 3-4 months. I posted the relevant scientific findings to
>> this group several weeks ago.
>
> People might start losing weight after a short time, but the trip's
> going to a planet with 38% of Earth's gravity - the return will be the
> tough part, but that can be handled.
>
>
>>
>> Another things is to discover that radiation in deep space is VERY high,
>> and if you are not suicidal you better get some shielding...
>> Water supplies could do double duty as shield and drink water, but first
>> you need to figure out what happens with the radioactive water when high
>> energy gamma rays hit it...
>
> Radiation is no higher in 'deep space' as you put it than it is after
> the Van Allen belts are left behind on a trip to the Moon.
>

Yes, but a Moon trip is a few days only, not the 700 days of a Mars trip...

It is a factor of 100 MORE. That's surely not trivial. You can
support space radiation for a week. But if you take 2 years you are
DEAD.

>>
>> Yes, you can send supplies along the way before your ship starts, but
>> that is not scalable and you will need anyway recycling to reduce the
>> huge costs... That technology is being developed at the ISS now, but it
>> is far from being usable for years.
>
> Why isn't it scalable?
>

The expense is completely enormous. And the usefulness is not much more
than what an automatic system can accomplish for a small fraction of
that cost.

Not until we have invested in space technology for a century we will be
able to go there.

Maybe in 2060, but not before.

[bob haller]

need a nuke booster to cut travel time to a minimum.......

power to 1/2 point, then declerate the other 1/2 with a heavy heat
shield for fast entry, perhaps a transhab like landing ballon


no doubt it would be better to invest in robotiic exploration with
artificial intelligence......

this technology can be useful back here on earth.

eventually most jobs will be done by robots

[Brad Guth]

On Mar 25, 8:27 am, JRStern <JRSt...@foobar.invalid> wrote:
> On Sat, 24 Mar 2012 05:14:34 -0700 (PDT), Robert Clark
>

> <rgregorycl...@yahoo.com> wrote:
> >He was also interviewed on a BBC radio program where he states that
> >eventually, after perhaps a decade of regular flights, the price for a
> >round trip ticket to Mars might be down to $500,000 per person:
>
> I expect the energy costs alone would be several times that.
>
> J.

Not to mention that 99.9% of everything else necessary has to come
from Earth, plus a few robotic care packages (such as one every month
or so).

A one-way ticket with no travel insurance might conceivably be
accomplished at $500,000

For many of the Zubrin Mars club, that's more than a fair enough deal,
because coming back alive without excessive radiation or multiple
other complications doesn't seem likely, no matters how much you'd
care to spend.

$500M each way seems doable, plus another $50M/month on Mars and still
w/o travel or vacation insurance.

[Brad Guth]

On Mar 25, 9:09 am, JRStern <JRSt...@foobar.invalid> wrote:
> On Sun, 25 Mar 2012 08:27:49 -0700, JRStern <JRSt...@foobar.invalid>

Your napkins are being way conservative, and by no means all-inclusive
of what the birth-to-grave cost per 100 kg person truly involves,
including all the R&D oops and do-overs.

At $500M each way plus another $50M/month spent on Mars could be
doable with reasonable assurances of returning alive, and not on any
brink of death from exposures.

Roughly, the high profile cost of life-term imprisonment for a nasty
20 year old inmate that'll live past 100 can easily run us $100,000/
year, and 80 years worth of that is only $8M. However, death row
inmates of California have been costing us as much as $300M each.

So, Mars isn't even viable for sending our worse life-term prisoners,
unless that one-way ticket to ride gets below $5M, or unless we're
talking about sending death row inmates as of day one. Obviously
keeping anyone alive with health complications plus the logistics of
Mars is simply not an option without some extremely new and improved
transportation that isn't conventional fly-by-rocket limited, and its
fuel has to be really cheap.

[Suzanne Blom]

On 3/24/2012 11:51 AM, hanson wrote:
>
> Yes, that was a very interesting interview. Elon Musk is an example of
> why it is important to
> have an environment that allows folks to become rich.
>>
> Such successful people then invest in endeavors that CREATE something &
> will push the envelope for the advance of Sci & Tech & ultimate benefit
> humankind....
>>

> Back to the SL: "ticket to Mars for $500,000."... ahahaha..
> Well, it remains to be seen whether that opportunity will have an impact
> onto the greater social good, besides the open question: "Why would
> anyone pay $500'000 to visit a place that is 1000 times worse then the
> Gobi, Mojave or the Sahara"?
>>
> But then the same same situation and question occured
> when Pizzarro, Cortez & DeSoto got in line....some 500
> years ago...
>

Um, no. They went to places with real live people who'd already mined
gold; people who grew crops and cooked food; people who had snug houses
where needed. Of course, a lot of them died soon after P C & D got there...

[hanson]

"Suzanne Blom" <bo...@sueblom.net> wrote:
in message news:jkqu9c$3u6$1...@dont-email.me...

> On 3/24/2012 11:51 AM, hanson wrote:
>>
>> Yes, that was a very interesting interview.
>> Elon Musk is an example of why it is important to
>> have an environment that allows folks to become rich.
>>>
>> Such successful people then invest in endeavors
>> that CREATE something & will push the envelope
>> for the advance of Sci & Tech & ultimate benefit
>> humankind....
>>>
>> Back to the SL: "ticket to Mars for $500,000."...
>> ahahaha..
>> Well, it remains to be seen whether that opportunity
>> will have an impact onto the greater social good,
>> besides the open question: "Why would anyone pay
>> $500'000 to visit a place that is 1000 times worse
>> then the Gobi, Mojave or the Sahara"?
>>>
>> But then the same same situation and question occured
>> when Pizzarro, Cortez & DeSoto got in line....some 500
>> years ago...
>>

Blom in drag wrote:
> Um, no. They went to places with real live people
> who'd already mined gold; people who grew crops
> and cooked food; people who had snug houses
> where needed. Of course, a lot of them died soon
> after P C & D got there...
>

hanson wrote:
So, you had to swallow the hook I put into the tripe
at the end of my post... ahahahaha... Factually you
simply tow the pc line. If you can see the analog
between the 2 events, terrestrial expansion and
space traveling, you will get kudos. If not then just
dwell on it and consider that dawn rises slowly over
Blom's marble head... Thanks for the laughs though,
you splendid yenta... ahahaha.. ahahanson

[Alan Erskine]

On 26/03/2012 3:58 AM, jacob navia wrote:
> Le 25/03/12 07:12, Alan Erskine a écrit :

> The expense is completely enormous. And the usefulness is not much more
> than what an automatic system can accomplish for a small fraction of
> that cost.

You can say the same thing for all spaceflight. The real cost is _not_
going there. Yes, it will be expensive, but have a look at what the
newstarts/upstarts are achieving with space access; give them a simple
order: "Get six people to Mars and return them safely to Earth in the
shortest time and with the least amount of equipment" and they will do
absolute miracles compared to the 'old-timers' like NASA.

>
> Not until we have invested in space technology for a century we will be
> able to go there.
>
> Maybe in 2060, but not before.

As for supplies, it's quite easy to take a cargo module to Mars with the
crew. Once there, the waste matterials (faeces, cans, bottles, paper
etc) can be left behind. Propellant for the return voyage can be made
on Mars - see Zubrin's plan (Mars Direct) for that. On the way to Mars,
the CM could be used to provide some radiation shielding by having it
face towards the Sun for most of the time. And if they're going to be
there for a year (or more), then they can grow fresh food for the return
journey; something similar is done at the Australian Antarctic bases -
based in modified 40ft freight containers. Some supplies would be
needed for emergencies (maybe a leak in the greenhouse or something),
but these supplies are small and only needed until the leak can be fixed
and food production can resume. Human waste can be used, via a
composting system or TDP (Thermal Depolymerisation Process) to provide
whatever nutrients are not present in Martian soil. Nutrients could
also be taken with the crew and would mainly consist of what are called
'micronutrients' that are used in _very_ small amounts. The main
nutrient for plants is carbon dioxide; what a wonderful process plants
use to get rid of their waste - they enable us to breath; that's just a
small bonus of such a system.

Yes, the water recycling system on ISS failed after a couple of months,
but that is where ISS can be really useful for human occupation of
space; we now know which parts of that system are most likely to fail.
Afterall, the actual structure of the U.S. modules has never been used
for people before and they are working quite well.

As for the amount of propellant needed, don't just go by escape velocity
comparisons between Earth and Mars - remember that to get from Earth
Orbit to the Moon, the Saturn V used just 5% of its total propellant
supply at launch. The propellant needed to get from Mars orbit back to
Earth is considerably less than that needed for the entire trip from the
Martian surface. If necessary, that can also be made on Mars, but it
could be sent into Martian orbit ahead of the crew, say using UDMH and
N2O4 which are storable for many months/years. That means the crew
vehicle can be scaled back somewhat.

As for artificial gravity, I agree that it may be needed for such a
voyage, but people don't need 1G for comfort or good health; one-sixth G
is easier to achieve and 'live' with. A system of ion thrusters could
be used to slowly increase spin to 0.38G before arrival at Mars and then
the same thrusters could be used to slowly increase G levels for the
return to Earth.

I remember seeing video of Skylab crew members 'jogging' around the
inside of the OWS; the same exercise could be used to reduce the effects
of zero-G. This would eliminate the need for artificial gravity for
most of the journey altogether. That brings Bigalow's space station
modules into use (large internal diameter with minimal weight/mass).
And you don't need a long module, just a wide one.

As for radiation on Mars, why not use a system similar to that proposed
for the Moon - bury habitation modules under a layer of Martian soil?.
Easy enough to do considering the lack of rocks in some areas. A small
mini-loader could be used. This also provides a more permanent location
for people when the second crew arrive.

Going to Mars and returning safely isn't all that difficult and it isn't
all that expensive; even when compared to Apollo. My own Moon return
idea could be expanded to get people to Mars as well as people to the
Moon. Getting to Mars is more difficult than getting to the Moon, but
no that much more.

It takes about 10% more energy to escape Earth gravity compared to
getting to the Moon. Once on the way, more supplies are needed, but
only a small amount more air/atmospheric gases. As for escape
propellant, it depends on the outward journey time and also
decelleration at the end of the trip (arrival at Mars).

After all this typing, my fingers are sore; I need a break for a while. ;-)

[Jeff Findley]

In article <0beum718kahvpp2eq...@4ax.com>,
JRS...@foobar.invalid says...

The fact is that fuel costs are a tiny fraction of today's launch costs.

Remember, for a Mars transportation system, you're not limited to what
you can carry from Earth. If you add in technologies like in-situ fuel
production at Mars, those fuel costs that you're talking about can drop
quite a bit.

If you think that costs can't drop to $500,000 because energy costs
would be more than that, then show us the math please. Given Musk's
history, I'm sure he, or his employees, has already done the math,
otherwise he'd be spouting baseless assertions, like so many here do.

Jeff
--
" Ares 1 is a prime example of the fact that NASA just can't get it
up anymore... and when they can, it doesn't stay up long. ;) "
- tinker

[Jeff Findley]

In article <95711578-680c-42dd-b229-
b96540...@k6g2000vbz.googlegroups.com>, hal...@aol.com says...

>
> need a nuke booster to cut travel time to a minimum.......

Nice to have, but not necessary.

> power to 1/2 point, then declerate the other 1/2 with a heavy heat
> shield for fast entry, perhaps a transhab like landing ballon

Not necessary, unless you're using high efficiency (in terms of ISP) but
very low thrust engines.

> no doubt it would be better to invest in robotiic exploration with
> artificial intelligence......

You've been told repeatedly that "artificial intelligence" like you
believe in isn't ready for "prime time". Toasters are still very dumb
and require constant human supervision and intervention to keep them
going. Add in the (radio signal) time delay to Mars and this is a real
p.i.t.a. to deal with. We put up with this problem because we have a
lack of human presence near or at Mars.

> this technology can be useful back here on earth.

Teleoperated machinery is quite useful in industries like mining.
Conditions can change in an instant, and having a human "in the loop" is
not only desirable, but necessary to prevent expensive machinery from
being lost to accidents. It would be useful to have people very close
to the teleoperated machinery on Mars in order to reduce the time delay
to an acceptable level.

Completely automated machinery is useful *only* in *very* controlled
environments, like factories and package sorting facilities.

> eventually most jobs will be done by robots

Hardly. This assertion might be true in a "perfect world", but here in
the real world, people are needed to deal with the unexpected. Toasters
can't deal with anything they're not programmed to expect. And guess
who does the programming... people like me who are paid to write
computer software for a living.

[Jochem Huhmann]

Jeff Findley <jeff.f...@nospam.ugs.com> writes:

> If you think that costs can't drop to $500,000 because energy costs
> would be more than that, then show us the math please. Given Musk's
> history, I'm sure he, or his employees, has already done the math,
> otherwise he'd be spouting baseless assertions, like so many here do.

I think $500,000 *is* a stretch. To get that low you'd need access to
water on Mars, produce your fuel there *and* have fairly routine
reusable launches here on Earth. Even then it would be tight. It would
require launches to be routine as aircraft or nearly so.

Still, as a beacon towards what's possible and what's actually not
really the problem that number surely is useful. Especially when you
look at NASA where $5B per person would be more like it and talking of
"ten years after flights started" would be just a laugh, since everyone
knows that the NASA approach would mean flag-and-footprints and then
nothing. How cheap got landing on the Moon ten years after Apollo 11?

Even if it will be $5M instead of $500,000 this would still be just a
tenth of what NASA pays to deliver an astronaut to the ISS (on a Soyuz,
and this is still cheaper than it was with STS) -- at this rate we might
not get a Mars colony, but surely a sustained Mars base.


Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery

[bob haller]

On Mar 28, 3:39 am, Fred J. McCall <fjmcc...@gmail.com> wrote:

> bob haller <hall...@aol.com> wrote:
>
> >need a nuke booster to cut travel time to a minimum.......
>
> >power to 1/2 point, then  declerate the other 1/2 with a heavy heat
> >shield for fast entry, perhaps a transhab like landing ballon
>

> Utter stupidity.

>
>
>
> >no doubt it would be better to invest in robotiic exploration with
> >artificial intelligence......
>
> >this technology can be useful back here on earth.
>
> >eventually most jobs will be done by robots
>

> Too bad we can't replace you with artificial intelligence.  It would
> be refreshing for you to exhibit SOME kind of intelligence....
>
> --
> "Some people get lost in thought because it's such unfamiliar
>  territory."
>                                       --G. Behn

cutting travel time dramatically cuts the need for consumables and
spare parts too, which decreases the costs and risks.

multi year missions culd be lost for just the lack of spare
parts............

besides we cant afford much of anything in space let alone a multi
year trip

[Brad Guth]

Given that WW3 is just around the next ZNR oligarch false-flagged
opportunity of another perpetrated round of global inflation via
hoarding and their insider price speculated hydrocarbons, we'll be
lucky to get tele-robotics of even the most basic remote science
stations functioning on our moon or Venus.

[Rob]

On 27/03/2012 16:08, Jeff Findley wrote:
> In article<0beum718kahvpp2eq...@4ax.com>,
> JRS...@foobar.invalid says...
>>
>> On Sat, 24 Mar 2012 05:14:34 -0700 (PDT), Robert Clark
>> <rgrego...@yahoo.com> wrote:
>>
>>> He was also interviewed on a BBC radio program where he states that
>>> eventually, after perhaps a decade of regular flights, the price for a
>>> round trip ticket to Mars might be down to $500,000 per person:
>>
>> I expect the energy costs alone would be several times that.
>
> The fact is that fuel costs are a tiny fraction of today's launch costs.
>
> Remember, for a Mars transportation system, you're not limited to what
> you can carry from Earth. If you add in technologies like in-situ fuel
> production at Mars, those fuel costs that you're talking about can drop
> quite a bit.
>
> If you think that costs can't drop to $500,000 because energy costs
> would be more than that, then show us the math please. Given Musk's
> history, I'm sure he, or his employees, has already done the math,
> otherwise he'd be spouting baseless assertions, like so many here do.
>
> Jeff

He did - $10M min. Rather conservative, too.
Musk selling snake oil?

[JRStern]

On Thu, 29 Mar 2012 13:35:27 +0100, Rob <no...@nowhere.noway.con>
wrote:

>He did - $10M min. Rather conservative, too.
>Musk selling snake oil?

Just talking out of his ass, I can't see he was actually benefiting
from the bad math.

J.

[Jeff Findley]

In article <dd072365-421b-497f-a6bf-
2c7e9f...@i2g2000vbv.googlegroups.com>, hal...@aol.com says...

>
> On Mar 28, 3:39 am, Fred J. McCall <fjmcc...@gmail.com> wrote:
> > bob haller <hall...@aol.com> wrote:
> >
> > >need a nuke booster to cut travel time to a minimum.......
> >
> > >power to 1/2 point, then  declerate the other 1/2 with a heavy heat
> > >shield for fast entry, perhaps a transhab like landing ballon
> >
> > Utter stupidity.
> >
> >
> >
> > >no doubt it would be better to invest in robotiic exploration with
> > >artificial intelligence......
> >
> > >this technology can be useful back here on earth.
> >
> > >eventually most jobs will be done by robots
> >
> > Too bad we can't replace you with artificial intelligence.  It would
> > be refreshing for you to exhibit SOME kind of intelligence....
> >
> > --
> > "Some people get lost in thought because it's such unfamiliar
> >  territory."
> >                                       --G. Behn
>
> cutting travel time dramatically cuts the need for consumables and
> spare parts too, which decreases the costs and risks.

Baseless assertion, especially when the faster trajectory requires more
fuel and possibly exotic engines.

> multi year missions culd be lost for just the lack of spare
> parts............

More of your gloom and doom based on bad sci-fi movies no doubt.

> besides we cant afford much of anything in space let alone a multi
> year trip

And yet you're advocating mission architectures which would be more
expensive just to "get there faster" when there is no *real* requirement
to do so.

[bob haller]

On Apr 3, 8:50 am, Jeff Findley <jeff.find...@nospam.ugs.com> wrote:
> In article <dd072365-421b-497f-a6bf-
> 2c7e9fd9c...@i2g2000vbv.googlegroups.com>, hall...@aol.com says...

getting there faster reduces rdiation exposure in dep space and
dramatically cuts the quantity of spare parts and consumables needed.

just like low cost to orbit is necessary, so is fast transit....

a 6 month each way for a couple weeks on mars, or a 6 month each way
for a multi year mission is far less workable than a 3 month each way
and a few months on mars mission.

cuts risks consumables etc.

although with the coming necessary cuts in entitlements nasa will be
lucky for a few low cost unmanned missions....

Imagine cutting SS while spending trillions or more to go to mars..
NEVER HAPPEN

[Jeff Findley]

In article <6e3576cf-fdb1-4bbb-a4c3-ff3209d56281
@z31g2000vbt.googlegroups.com>, hal...@aol.com says...

>
> On Apr 3, 8:50 am, Jeff Findley <jeff.find...@nospam.ugs.com> wrote:
> > In article <dd072365-421b-497f-a6bf-
> > 2c7e9fd9c...@i2g2000vbv.googlegroups.com>, hall...@aol.com says...
> >

> > > cutting travel time dramatically cuts the need for consumables and
> > > spare parts too, which decreases the costs and risks.
> >
> > Baseless assertion, especially when the faster trajectory requires more
> > fuel and possibly exotic engines.
> >
> > > multi year missions culd be lost for just the lack of spare
> > > parts............
> >
> > More of your gloom and doom based on bad sci-fi movies no doubt.
> >
> > > besides we cant afford much of anything in space let alone a multi
> > > year trip
> >
> > And yet you're advocating mission architectures which would be more
> > expensive just to "get there faster" when there is no *real* requirement
> > to do so.
>

> getting there faster reduces rdiation exposure in dep space and
> dramatically cuts the quantity of spare parts and consumables needed.

Radiation exposure can be mitigated with adequate shielding.

Consumables will be a small part of the overall mission mass budget,
even if you assume zero recycling.

In fact, those consumables you're trying to minimize actually make for
quite good radiation shielding. Why minimize consumables if your mass
budget for radiation shielding is going to go up by about the same
amount? It makes no sense to me at all.

And finally, your assertion that reducing transit time "dramatically
cuts the quantity of spare parts" is putting the cart before the horse.
Where is your analysis which shows just how many spare parts you would
need for the short mission versus the long? Such an analysis would need
to be done in order to turn your baseless assertion into a proper
argument.

> just like low cost to orbit is necessary, so is fast transit....

This fast transit "requirement" has no basis in reality. It's a figment
of your imagination. Perhaps it's just a bit of undigested meat stuck
in your gut...

> a 6 month each way for a couple weeks on mars, or a 6 month each way
> for a multi year mission is far less workable than a 3 month each way
> and a few months on mars mission.

Except your "few months on mars mission" is extremely stupid when
orbital mechanics is taken into account. There have been numerous
studies done on Mars mission transit times and surface stay times.
Perhaps you should read a few of them. You might learn something.

[Robert Clark]

On Jul 30, 4:37 pm, Robert Clark <rgregorycl...@yahoo.com> wrote:

On Saturday, March 24, 2012 8:14:34 AM UTC-4, Robert Clark wrote:
> Elon Musk was interviewed on the U.S. news program "60 minutes" on
> Sunday:

> SpaceX: Entrepreneur's race to space.
> March 18, 2012 4:44 PM
> From PayPal to electric cars to rockets, billionaire entrepreneur
Elon
> Musk wants his company, SpaceX, to build America's next manned
> spacecraft. Scott Pelley reports.
>http://www.cbsnews.com/video/watch/?id=50121782n

> He was also interviewed on a BBC radio program where he states that
> eventually, after perhaps a decade of regular flights, the price
for a
> round trip ticket to Mars might be down to $500,000 per person:

> 20 March 2012 Last updated at 19:25 ET
> Jonathan Amos, Science correspondent.
> Mars for the 'average person'.
> http://www.bbc.co.uk/news/health-17439490

Elon Musk to Address Mars Society Convention in Pasadena.
posted Jul 20, 2012 10:05 AM by Mars Society - PR [ updated Jul 21,
2012 1:13 PM ]
[Quote]
The Mars Society is very pleased to announce that SpaceX Founder and
CEO Elon Musk will address the 15th Annual International Mars Society
Convention in Pasadena, California, on Saturday, August 4th during the
organization's evening banquet.[/quote]
http://www.marssociety.org/home/press/announcements/elonmusktoaddressmarssocietyconventioninpasadena

   Bob Clark

[Robert Clark]

On Jul 31, 1:08 am, Hg <H...@Hg.Hg> wrote:
> Smart timing of Mars speech - two days later MSL will hopefully
> touchdown safely on the Red Planet.
>
> --
>                                                                         T

Curiosity’s Grand Entrance with Star Trek’s William Shatner and Wil
Wheaton – Video Duet
by KEN KREMER on JULY 30, 2012
http://www.universetoday.com/96529/curiositys-grand-entrance-with-star-treks-william-shatner-and-wil-wheaton-video-duet/

Bob Clark

[Robert Clark]

On Aug 8, 7:35 pm, Hop <hop4...@gmail.com> wrote:

> Nope. He did nothing of the sort. Reread, this time for comprehension.
>
> JRStern has said energy costs alone would exceed Musks' goal.
>
> Findley correctly points out energy costs are a minute portion of costs. Until you or Stern show some math on *energy costs* you will be among those spouting baseless assertions.


This web page illustrates this in regards to flights to LEO:

Cost to Orbit.
"A Kilowatt-Hour of electricity usually costs less than a dime, so ten
Kilowatt-Hours costs less than a dollar. So the energy cost of
putting a kilogram (slightly more than two pounds) into orbit is less
than a dollar.
"Now if I'd done this calculation exactly, I'd taken account of the
fact that gravity decreases with altitude. This would decrease the
energy slightly. I'd also have calculated the exact orbit velocity,
which is slightly less than eight km/sec. Either way, the energy
would be slightly less than 36 million Joules.
"Suppose I get even more picky. Suppose I say "I can't put a payload
directly into orbit. I have to put a rocket, with a payload on top
of it, into orbit. So I have to put the rocket mass, including fuel,
into the equation as well." Even if I do this, and assume I need ten
to twenty kilograms of rocket mass (including fuel) for each kilogram
that goes into orbit, I can still put one kilogram into orbit for an
energy cost of ten to twenty dollars."
http://home.earthlink.net/~kstengel226/astro/cost2orbit.html

Peter Diamandis makes this point as well in this TED lecture at about
the 6 minute mark:

Peter Diamandis: Taking the next giant leap in space.
http://www.youtube.com/watch?v=sUOBLX55h4s

Jerry Pournelle also argues this here:

THE SSX CONCEPT.
Jerry E. Pournelle, Ph.D.
http://www.jerrypournelle.com/slowchange/SSX.html

He notes it takes about the same amount of fuel to get to orbit as to
take an airline flight from the U.S. to Australia.


Bob Clark

[Robert Clark]

> organization's evening banquet.[/quote]http://www.marssociety.org/home/press/announcements/elonmusktoaddress...
>

Elon Musk "Mars Pioneer Award" Acceptance Speech - 15th Annual
International Mars Society Convention.
http://www.youtube.com/watch?v=PK0kTcJFnVk


Bob Clark

[Robert Clark]

On Aug 15, 10:26 am, Robert Clark <rgregorycl...@yahoo.com> wrote:
> ...
>
> Elon Musk "Mars Pioneer Award" Acceptance Speech - 15th Annual
> International Mars Society Convention.http://www.youtube.com/watch?v=PK0kTcJFnVk
>
>    Bob Clark

An advantage of SSTO's is that with orbital fueling they can be used
both for flights to the Moon and for flights to Mars:

The Coming SSTO's: Applications to interplanetary flight.
http://exoscientist.blogspot.com/2012/08/the-coming-sstos-applications-to.html

Bob Clark

[Greg Goss]

Robert Clark <rgrego...@yahoo.com> wrote:

>On Aug 15, 10:26�am, Robert Clark <rgregorycl...@yahoo.com> wrote:
>> ...
>>
>> Elon Musk "Mars Pioneer Award" Acceptance Speech - 15th Annual
>> International Mars Society Convention.http://www.youtube.com/watch?v=PK0kTcJFnVk
>>
>> � �Bob Clark
>
> An advantage of SSTO's is that with orbital fueling they can be used
>both for flights to the Moon and for flights to Mars:

Not really. The most important part of a single stage FROM orbit
vessel is a design to shed orbital velocity via an atmosphere. None
of that design work and weight will be any use for the Moon or Mars.

>The Coming SSTO's: Applications to interplanetary flight.
>http://exoscientist.blogspot.com/2012/08/the-coming-sstos-applications-to.html

--
I used to own a mind like a steel trap.
Perhaps if I'd specified a brass one, it
wouldn't have rusted like this.

[Robert Clark]

On Aug 27, 2:23 am, Fred J. McCall <fjmcc...@gmail.com> wrote:

> Robert Clark <rgregorycl...@yahoo.com> wrote:
>
> > An advantage of SSTO's is that with orbital fueling they can be used
> >both for flights to the Moon and for flights to Mars:
>

> Just how is that "an advantage of SSTO's"?  Seems like just about ANY
> vehicle could do that.  In fact, like most things, it seems something
> that a non-SSTO would do better.
>
> --


Actually no. If you look at two stage to orbit vehicles most of the
delta-V to orbit is provided by the second stage. So the first stage
might provide ca. 3,000 m/s of delta-V while the second stage ca.
6,000 m/s.
Then even if this second stage were to be fully refueled in orbit it
still would not have enough delta-V to make the *roundtrip* flight to
the Moon and back, which requires ca. 8,650 m/s total delta-V with
aerobraking on the return trip.
That second stage might be able to just barely make the flight from
LEO to low Mars orbit since that requires a delta-V of ca. 6.1 km/s.
But the SSTO, designed to deliver a larger delta-V from the start,
would be able to do it with a larger payload.
Also, the SSTO could make all these missions, Earth launch to LEO,
round trip to the Moon, flight to Mars, on its own without requiring
additional vehicles, assuming you do have these propellant depots
available. Then if one had his own private SSTO he would also have his
own lunar and Mars transport vehicle, allowing these refueling pit
stops.


Bob Clark

[Orval Fairbairn]

In article
<9e341a7b-f26a-44ba...@r4g2000vbn.googlegroups.com>,

Don't confuse the SSTO advocates with facts!

[Robert Clark]

On Aug 27, 2:22 pm, Orval Fairbairn <orfairba...@earthlink.net> wrote:
> In article
> <9e341a7b-f26a-44ba-b711-2b2bc4ff5...@r4g2000vbn.googlegroups.com>,

The fact is a two stage to orbit vehicle would not be able to make
*roundtrip* flight to the Moon and back even with LEO refueling, while
a SSTO could.


Bob Clark

[Robert Clark]

On Aug 28, 12:49 am, Fred J. McCall <fjmcc...@gmail.com> wrote:
> Robert Clark <rgregorycl...@yahoo.com> wrote:
> >On Aug 27, 2:23 am, Fred J. McCall <fjmcc...@gmail.com> wrote:
> >> Robert Clark <rgregorycl...@yahoo.com> wrote:
>
> >> > An advantage of SSTO's is that with orbital fueling they can be used
> >> >both for flights to the Moon and for flights to Mars:
>
> >> Just how is that "an advantage of SSTO's"? Seems like just about ANY
> >> vehicle could do that. In fact, like most things, it seems something
> >> that a non-SSTO would do better.
>
> >> --
>
> > Actually no.
>

> Actually, yes.  Just because you can make up numbers doesn't prove
> anything.

>
>
> >If you look at two stage to orbit vehicles most of the
> >delta-V to orbit is provided by the second stage.
>

> If you look at single stage to orbit vehicles, THERE AREN'T ANY.  That
> would seem to settle the 'use historical numbers' issue.
>

It's a question of delta-V. Take a look at this table of the delta-V
requirements for flights to the Moon:

Delta-v budget.
Earth–Moon space — high thrust.
http://en.wikipedia.org/wiki/Delta-v_budget#Earth.E2.80.93Moon_space_.E2.80.94_high_thrust

Many people have argued in favor of reusable two-stage to orbit
vehicles to cut the costs to space, notably SpaceX with the
development of a reusable version of the Falcon 9. Elon Musk has
argued you can cut the costs to space by two orders of magnitude in
that fashion.
Then the costs of just getting the large amount of propellant to
orbit needed to carry out manned missions beyond low Earth orbit (BEO)
to the Moon, Mars, etc. could dramatically be cut. NASA reports have
shown such propellant depots would greatly reduce the cost of manned
flights beyond low Earth orbit. So let's hypothesize propellant
depots in orbit.
I agree with the SpaceX plan to produce a reusable TSTO since I agree
that it would indeed reduce the costs of space access. However in the
debate about the question about whether to produce a reusable TSTO or
a reusable SSTO the argument is made even if you could produce a
reusable SSTO the reusable TSTO could carry more payload, so why
bother? But when you have a TSTO, a big chunk of the needed delta-V to
orbit is provided by the first stage. This necessarily means the upper
stage, which does reach orbit along with the payload, is far short of
the delta-V needed to reach orbit on its own.
But the delta-V required for the *roundtrip* mission to the Moon and
back is nearly that required to reach LEO from the Earth's surface. So
the upper stage of the TSTO being well short of the delta-V of this
amount could not perform the *roundtrip* mission even if it were
refueled in LEO.
So let's make the reusable TSTO vehicles and even greater reusable
multi-stage vehicles such as a reusable version of the Falcon Heavy to
carry large payloads and large amounts of propellant to orbit at low
cost. However, a reusable SSTO would have a use in that it would allow
private ownership of a smaller vehicle that not only could make
flights to orbit but even flights all the way to the Moon and back,
with the use of orbiting propellant depots. This extra capability
would be a significant advantage in providing a market for such
vehicles.

Note: SpaceX has said the side boosters on the Falcon Heavy will be
taken from the first stage of the new version of the Falcon 9, version
v1.1, and will have a mass ratio of 30 to 1. This is a majorly
important fact if true since many in the industry don't believe a mass
ratio this high is possible, corresponding to a propellant fraction of
nearly 97%.
A big reason why it was argued that SSTO's were infeasible was
because it was said you would need such large mass ratios which, it
was argued, were beyond current technology. So SpaceX producing such a
vehicle stage is important for showing that argument is no longer
valid.


Bob Clark

[Robert Clark]

Elon Musk on SpaceX’s Reusable Rocket Plans.
SpaceX is hard at work trying to design rocket parts that can fly
themselves back to the launchpad for reuse. We talked to founder Elon
Musk about how far the company’s designs have come.
February 7, 2012 6:00 PM
By Rand Simberg
[Quote]
The key, at least for the first stage, is the difference in speed.
"It really comes down to what the staging Mach number would be," Musk
says, referencing the speed the rocket would be traveling at
separation. "For an expendable Falcon 9 rocket, that is around Mach
10. For a reusable Falcon 9, it is around Mach 6, depending on the
mission." For the reusable version, the rocket must be traveling at a
slower speed at separation because the burn must end early, preserving
enough propellant to let the rocket fly back and land vertically. This
also makes recovery easier because entry velocities are slower.
However, the slower speed also means that the upper stage of the
Falcon rocket must supply more of the velocity needed to get to orbit,
and that significantly reduces how much payload the rocket can lift
into orbit. "The payload penalty for full and fast reusability versus
an expendable version is roughly 40 percent," Musk says. "[But]
propellant cost is less than 0.4 percent of the total flight cost.
Even taking into account the payload reduction for reusability, the
improvement is therefore theoretically over a hundred times."[/quote
http://www.popularmechanics.com/science/space/rockets/elon-musk-on-spacexs-reusable-rocket-plans-6653023

For the current version of the Falcon 9 with a 10,000 kg capability
to LEO was made reusabe, this would mean its payload is reduced to
6,000 kg. According to SpaceX though the price per kilo would reduce
because it would be reused.
SpaceX though is moving to a larger version the Falcon 9 v1.1. On its
website SpaceX now gives the specifications for the new Falcon 9
version:

http://www.spacex.com/falcon9.php

The new version will have a payload capability of 13,150 kg to LEO.
Oddly though, it still gives on that page the price for the current
F9, $54 million. I don't know if they mean to keep the price the same
for the larger version or not.
The reusability would come into play when the new version is in use;
so assuming a 40% payload reduction, the payload to LEO for the
reusable F9 v1.1 would be 7,890 kg.
The key question is of reusability of the engines. Can SpaceX make
them reusable at low cost? While watching the retrospectives on Neil
Armstrong on NASA TV, they showed images of him as a X-15 pilot. This
reminded me we actually had reusable rocket engines from the very
earliest days of manned rocket-powered flight. The XLR-99 engine used
on the X-15 was reusable for 20 to 40 times before overhaul, after
which it could be reused again:

XLR-99.
http://www.astronautix.com/engines/xlr99.htm

The 3 copies of the X-15 aircraft flew for a total of 199 flights.
Can you imagine how expensive that program would have been if an
entire new X-15 aircraft had to be used for each flight?

Bob Clark

[Harri Tavaila]

28.8.2012 15:47, Robert Clark kirjoitti:
> On Aug 28, 12:49 am, Fred J. McCall<fjmcc...@gmail.com> wrote:
>> Robert Clark<rgregorycl...@yahoo.com> wrote:
>>> On Aug 27, 2:23 am, Fred J. McCall<fjmcc...@gmail.com> wrote:
>>>> Robert Clark<rgregorycl...@yahoo.com> wrote:
>>
>>>>> An advantage of SSTO's is that with orbital fueling they can be used
>>>>> both for flights to the Moon and for flights to Mars:
>>
>>>> Just how is that "an advantage of SSTO's"? Seems like just about ANY
>>>> vehicle could do that. In fact, like most things, it seems something
>>>> that a non-SSTO would do better.
>>

>>> Actually no.
>>
>> Actually, yes. Just because you can make up numbers doesn't prove
>> anything.
>

> It's a question of delta-V. Take a look at this table of the delta-V
> requirements for flights to the Moon:

It is certainly amusing to toy with an idea of dual purpose spacecraft,
capable of launching from the ground, refueling in the orbit and
continuing to further targets, but in the forseeable future the need for
such missions is very low and the disadvantages of committing to the
technical compromises required could be crippling.

Consider just following details:

- choice of oxidizer
- choice of fuel
- airframe
- heatshield
- maintenance
- thrust

Ability to throttle thrust sufficiently for lunar landing is almost
certainly a requirement that would not improve a SSTO (1/6 of a gee for
sustained hovering!). Just using nozzles designed for sea-level takeoff
would be a handicap. An airframe on a purely lunar vehicle would be
redundant. Maintenance requirements for a vehicle that would spend years
in vacuum and possibly never be serviced (Mars) would be quite different
from a launcher that could return for an overhaul in a nice
shirt-sleeves hangar after every few hour flight. Heatshield
requirements would be very different for any vehicle attempting
aerobraking from lunar or trans-lunar velocities and a mere orbital
launcher. And just how storable propellants could a SSTO use?

Now if one would be able to build a SSTO that would use space storable
oxidizer and fuel it would certainly be an incentive to re-use some
parts of the technology in exoatmospheric transport designs, but even
then it would be easier to optimize the design for the different
requirements. The delta-v needed for different missions could easily be
achieved with suitable mass rate adjustment, heatshield could be
optimized, nozzles extended for vacuum operation, number of engines
adjusted for the mass/thrust requirements etc. But that is just as true
with a TSTO design.

For the forseeable future any launcher design - TSTO or SSTO - is bound
to be determined by the requirements associated with its use as a
launcher. Attempts to prematurely introduce additional requirements for
exoatmospheric use are unlikely to help.

H Tavaila

H Tavaila

[Robert Clark]

On Aug 28, 3:12 pm, Harri Tavaila <Harri.Tava...@helsinki.fi> wrote:
> ...

>
> It is certainly amusing to toy with an idea of dual purpose spacecraft,
> capable of launching from the ground, refueling in the orbit and
> continuing to further targets, but in the forseeable future the need for
> such missions is very low and the disadvantages of committing to the
> technical compromises required could be crippling.
>
> Consider just following details:
>
> - choice of oxidizer
> - choice of fuel
> - airframe
> - heatshield
> - maintenance
> - thrust
>
> Ability to throttle thrust sufficiently for lunar landing is almost
> certainly a requirement that would not improve a SSTO (1/6 of a gee for

> sustained hovering!)...

Elon Musk prefers vertical, powered descent for his reusable rocket
stages, a la the DC-X.
Such a stage if SSTO capable could serve such multiple roles, as was
the case with the DC-X:

McDonnell Douglas DC-X.
[quote]Returning the DC-X design to NASA's active research portfolio
has been considered for some time now.[citation needed] Some NASA
engineers believe that the DC-X could provide a solution for a manned
Mars lander. Had a DC-type craft been developed that operated as an
SSTO in Earth's gravity well, even if with only a minimum 4-6 crew
capacity, variants of it might prove extremely capable for both Mars
and Moon missions. Such a variant's basic operation would have to be
"reversed"; from taking off and then landing, to landing first then
taking off. Yet, if this could be accomplished on Earth, the weaker
gravity found at both Mars and the Moon would make for dramatically
greater payload capabilities, particularly at the latter destination.[/
quote]
http://en.wikipedia.org/wiki/DC-X#The_future_of_the_DC-X


The question about whether there would be a market for flights to the
Moon is of course dependent on cost. Having propellant depots in orbit
along with orders of magnitude price reductions due to reusability
would have a big influence on the cost question.


Bob Clark

[Robert Clark]

The new Falcon 9 v1.1 will have its engines arranged in an octagonal
arrangement:

Untested Rocket Boosts SpaceX Revenue Nearly $1 Billion.
By Amy Svitak
Source: Aviation Week & Space Technology
September 17, 2012
[Quote]
...Another change, she says, involves the rocket's nine Merlin 1D
engines, which will be positioned in an octagonal configuration,
rather than the “tic-tac-toe” placement on the current Falcon 9.
“You actually want the engines around the perimeter at the tank,
otherwise you are carrying that load from those engines that are not
on the skin,” she says. “You've got to carry them out to the skin,
because that is the primary load path for the launch vehicle." [/
quote]
http://www.aviationweek.com/Article.aspx?id=/article-xml/AW_09_17_2012_p40-495349.xml&p=2

See this thread on NasaSpaceflight for how this engine arrangement
might look:

SpaceX Falcon 9 v1.1.
http://forum.nasaspaceflight.com/index.php?topic=28882.msg956757#msg956757

This could have another advantage in that the octagonal arrangement
of the engines makes possible the use of an aerospike in the center,
if the center engine is removed.
This would give the first stage engines Merlin Vacuum type
performance, raising the Isp from the ca. 311 s of the Merlin 1D to
the ca. 340 s of the Merlin Vacuum.
This would result in a marked improvement in payload.


Bob Clark

[Robert Clark]

On Sep 30, 11:27 am, David Spain <nos...@127.0.0.1> wrote:
> aka Skin Strength Of Liquid Fueled Rockets...
>
> Sorry I couldn't help myself, I thought the given subject title more catchy! :-D
>
>  From the thread entitled:
> Re: Elon Musk: ticket to Mars for $500,000.

>
> On 9/30/2012 3:00 AM, Robert Clark wrote:
>
>
>
>
>
>
>
>
>
> >   The new Falcon 9 v1.1 will have its engines arranged in an octagonal
> > arrangement:
>
> > Untested Rocket Boosts SpaceX Revenue Nearly $1 Billion.
> > By Amy Svitak
> > Source: Aviation Week & Space Technology
> > September 17, 2012
> > [Quote]
> > ...Another change, she says, involves the rocket's nine Merlin 1D
> > engines, which will be positioned in an octagonal configuration,
> > rather than the tic-tac-toe placement on the current Falcon 9.
> > You actually want the engines around the perimeter at the tank,
> > otherwise you are carrying that load from those engines that are not
> > on the skin, she says. You've got to carry them out to the skin,
> > because that is the primary load path for the launch vehicle." [/
> > quote]
>

> Isn't this generally the case for most (if not all) liquid fueled rockets? Doesn't a lot of the structural strength derived from the
> vertically stacked skin and whatever structural elements that are arrayed around the tanks? After all, the majority of mass in the
> center is literally quite fluid!
>
> Were there ever any rockets build that used multiple tanks arrayed around a skeletal core? Can't think of any. Can't think of a
> reason why that would be advantageous either! Hence the exo-skeletal model will always win over the skeletal model?! Opinions?
>
> Hence: Roaches Conquer Space!
>
> Dave

It is generally the case that the propellant tank skin supports the
thrust loads for orbital rockets, often with vertical stringers, or
longerons, arrayed internally in the tanks to help support the axial
loads. However, I found an image of a proposed design of the Altair
lunar lander that shows such a skeletal support struture:

http://www.parabolicarc.com/2009/03/01/boeing-submits-proposal-altair-lunar-lander-design-nasa/

Bob Clark

[Greg Goss]

Even static tanks need structure. I used to commute past a wooden
water tower. Eventually they did something else and no longer needed
to put water in that tower. However, by that time, they'd hung a
bunch of telephone cells onto the tower, so they couldn't take it
down. So they removed the wooden bits and left a very odd-looking
cell tower behind. http://goo.gl/maps/1kaWB


While looking up the above, I noticed that the streetview image
included a second streetview car. In all the "interesting
streetviews" I don't think I've ever seen recursion before.
http://goo.gl/maps/1JLds

[alie...@gmail.com]

On Oct 2, 10:48 am, Greg Goss <go...@gossg.org> wrote:

> >http://www.parabolicarc.com/2009/03/01/boeing-submits-proposal-altair...

>
> Even static tanks need structure.  I used to commute past a wooden
> water tower.  Eventually they did something else and no longer needed
> to put water in that tower.  However, by that time, they'd hung a
> bunch of telephone cells onto the tower, so they couldn't take it
> down.  So they removed the wooden bits and left a very odd-looking
> cell tower behind.  http://goo.gl/maps/1kaWB
>
> While looking up the above, I noticed that the streetview image
> included a second streetview car.  In all the "interesting
> streetviews" I don't think I've ever seen recursion before.http://goo.gl/maps/1JLds

That's not recursion, that's a paradox; the car photographed itself,
so obviously it was traveling FTL!


Marj L. "I wonder what the speeding fine is?" Fergerson

[Greg Goss]

>> streetviews" I don't think I've ever seen recursion before. http://goo.gl/maps/1JLds

>
> That's not recursion, that's a paradox; the car photographed itself,
>so obviously it was traveling FTL!
>
>
> Marj L. "I wonder what the speeding fine is?" Fergerson

Look, I've commuted across the Knight Street Bridge. You're lucky to
get into second gear. Nobody goes FTL on that road.

[Wayne Throop]

::: While looking up the above, I noticed that the streetview image

::: included a second streetview car. In all the "interesting
::: streetviews" I don't think I've ever seen recursion before.
::: http://goo.gl/maps/1JLds

:: That's not recursion, that's a paradox; the car photographed itself,
:: so obviously it was traveling FTL!

: Greg Goss <go...@gossg.org>
: Look, I've commuted across the Knight Street Bridge. You're lucky to

: get into second gear. Nobody goes FTL on that road.

I'm pretty sure I saw a google picture vehicle when looking at
street views. But I don't recall where, or whether maybe it was
a reflection in a window or something. But if there's a bottleneck
where two of them would have to use a bridge... well, that makes
it less improbable.

Hm... looking at the url, it seems like it's not at all like
the google vehicles I saw, which were white trucks. But the camera
pole sure looks bolted to that grey car. I wonder if it's a competitor.
Or if google really has competitors for street view compilations.


When I drive that slow you know it's hard to steer
I can't get my car out of second gear!
--- I Can't Drive 55

My Maserati does 185
I lost my license, now I don't drive
--- Life's Been Good

My dad said "Son, you're gonna drive me to drinkin'
If you don't stop drivin' that hot... rod... Lincoln."
--- Hot Rod Lincoln

[alie...@gmail.com]

"Hey buddy how do I get this car outa second gear?"

Little Nash Rambler


Mark L. Fergerson

[Will Janoschka]

On Tue, 2 Oct 2012 20:03:42, "nu...@bid.nes" <alie...@gmail.com>
wrote:

> > Even static tanks need structure. ĸI used to commute past a wooden
> > water tower. ĸEventually they did something else and no longer needed
> > to put water in that tower. ĸHowever, by that time, they'd hung a

> > bunch of telephone cells onto the tower, so they couldn't take it

> > down. ĸSo they removed the wooden bits and left a very odd-looking
> > cell tower behind. ĸhttp://goo.gl/maps/1kaWB

> >
> > While looking up the above, I noticed that the streetview image

> > included a second streetview car. ĸIn all the "interesting

> > streetviews" I don't think I've ever seen recursion before.http://goo.gl/maps/1JLds
>
> That's not recursion, that's a paradox; the car photographed itself,
> so obviously it was traveling FTL!
>
>
> Marj L. "I wonder what the speeding fine is?" Fergerson

That is only multiple photos with tranport delay. Like pointing
a tv camera at a display of the output of that tv camera.

[Robert Clark]

On Oct 2, 9:52 pm, wil...@nospam.pobox.com (Will Janoschka) wrote:
> ...

>
> > > While looking up the above, I noticed that the streetview image

> > > included a second streetview car. In all the "interesting

> > > streetviews" I don't think I've ever seen recursion before.http://goo.gl/maps/1JLds
>
> >   That's not recursion, that's a paradox; the car photographed itself,
> > so obviously it was traveling FTL!
>
> >   Marj L. "I wonder what the speeding fine is?" Fergerson
>
> That is only multiple photos with tranport delay.   Like pointing
> a tv camera at a display of the output of that tv camera.

???

Bob Clark

[Snidely]

Wayne Throop wrote on 10/2/2012 :
> Hm... looking at the url, it seems like it's not at all like
> the google vehicles I saw, which were white trucks. But the camera
> pole sure looks bolted to that grey car. I wonder if it's a competitor.
> Or if google really has competitors for street view compilations.

Google uses a variety of vehicles for street view; I've seen something
in the Focus/Yaris size range, with either a fancy paint job or vinyl
skins in garish green, hyping the Googleness Of It All. Some of the
"Google Street View Finds" in various web loggia have part of the
camera car in view (directly, like Curiosity filming its fender), the
shadow of the car, or a reflection of the car.

(Why sci.astro? Hubble doesn't use skeletal tank frames)

/dps

--
Who, me? And what lacuna?

[Paul Madarasz]

On Tue, 2 Oct 2012 16:27:02 -0700 (PDT), "nu...@bid.nes"
<alie...@gmail.com> wrote, perhaps among other things:

"Beep Beep"
>
>
> Mark L. Fergerson
--

"One thing happened after another, and before
we knew it, we were dead"
-- Michael O'Donoghue

[Will Janoschka]

On Wed, 3 Oct 2012 04:57:03, Robert Clark <rgrego...@yahoo.com>
wrote:

> On Oct 2, 9:52ÿpm, wil...@nospam.pobox.com (Will Janoschka) wrote:
> > ...
> >
> > > > While looking up the above, I noticed that the streetview image
> > > > included a second streetview car. In all the "interesting

> > > > streetviews" I don't think I've ever seen recursion before.http://goo..gl/maps/1JLds
> >
> > > ÿ That's not recursion, that's a paradox; the car photographed itself,

> > > so obviously it was traveling FTL!
> >

> > > ÿ Marj L. "I wonder what the speeding fine is?" Fergerson
> >
> > That is only multiple photos with tranport delay. ÿ Like pointing

> > a tv camera at a display of the output of that tv camera.
>
>
> ???
>
> Bob Clark

Get cheap USB camera for computer. Continuously display
output from that camera on computer display. Point camera
at the computer display, rotate camera slowly. The weird
display is a result of transport delay between camera and
the resulting displayed image.

[alie...@gmail.com]

On Oct 3, 8:11 am, wil...@nospam.pobox.com (Will Janoschka) wrote:
> On Wed, 3 Oct 2012 04:57:03, Robert Clark <rgregorycl...@yahoo.com>

> wrote:
>
>
>
>
>
>
>
>
>
> > On Oct 2, 9:52 pm, wil...@nospam.pobox.com (Will Janoschka) wrote:
> > > ...
>
> > > > > While looking up the above, I noticed that the streetview image
> > > > > included a second streetview car. In all the "interesting
> > > > > streetviews" I don't think I've ever seen recursion before.http://goo..gl/maps/1JLds
>

> > > > That's not recursion, that's a paradox; the car photographed itself,
> > > > so obviously it was traveling FTL!
>

> > > > Marj L. "I wonder what the speeding fine is?" Fergerson
>

> > > That is only multiple photos with tranport delay. Like pointing

> > > a tv camera at a display of the output of that tv camera.
>
> >   ???
>
> >   Bob Clark
>
> Get cheap USB camera for computer. Continuously display
> output from that camera on computer display.  Point camera
> at the computer display, rotate camera slowly. The weird
> display is a result of transport delay between camera and
> the resulting displayed image.

Yeah, that was a SPFX on the B&W Twilight Zone TV show IIRC.

But how does that apply to a Googlemobile?


Mark L. Fergerson