SSTO's would have made possible Arthur C. Clarke's vision of 2001.

On 10/22/2013 4:09 PM, Rick Jones wrote:
In sci.space.history Robert Clark wrote:
Elon Musk lecture at the Royal Aeronautical Society - YouTube.
http://www.youtube.com/watch?v=wB3R5Xk2gTY

About 30 minutes in, he gave the propellant fraction of the new Falcon 9
v1.1 as around 96%, or perhaps 95.5%. The 96% propellant fraction number
gives a 25 to 1 mass ratio. But at an Isp of 311 s for the Merlin 1D, the
rocket equation gives a delta-v of 311*9.81ln(25) = 9,800 m/s. Since the
delta-v to orbit is only about 9,100 m/s, this would allow a significant
amount of payload.
Then using the 9 engines and the full propellant load on the F9 first stage
would allow in fact not just a VTVL test vehicle, but in fact a fully
reusable and fully orbital vehicle.

Modulo the small matter of a re-entry shield no?

rick jones


Well there is that, but also note that not all that propellant can be
used for uplift. Some has be kept in reserve for the landing. Doesn't
that affect the mass ratio? Using Bob's figures there is a ~700 m/s
leeway in delta-v, but each unit drop of the mass ratio is a 125 m/s
loss in delta-v. Go down ~5 1/2 units and you're not at SSTO any longer.

If 30% of the propellant is kept in reserve how would that effect the
mass ratio?*

Dave

*Aerospace is not my specialty. I could probably spend an hour+
researching the answer for myself, or just ask the group and wait for
the answer. I'm lazy. I'll take option #2. ;-)

On 10/22/2013 6:03 PM, David Spain wrote:
If 30% of the propellant is kept in reserve how would that effect the
mass ratio?*

Admittedly that reserve figure may be too high.

Dave

On Tuesday, October 22, 2013 10:58:46 AM UTC-4, David Spain wrote:
...

This article says this "Grasshopper 2", as it were, would have all 9

engines of the regular F9 first stage. However, discussions on other forums

have said it would only have 3 engines. That would make sense since on stage

return, you are using at most 3 engines, and moreover this way, you would

not be risking an expensive loss of 9 copies of the Merlins during these

Grasshopper test flights.

Still, in point of fact there would be an advantage of using all 9 engines

on this first stage Grasshopper, and with a full propellant load. In

November, 2012 Elon Musk gave a lecture in London at the Royal Aeronautical

Society.




Bob do you know if they are replacing the other 6 engines with mass

equivalent dummy mass? From the other forums which 3 are staying? The 3

across the center bisection? Would it not might make sense to preserve

the nozzles in the octaweb configuration to keep the aerodynamics as

close to actual as possible?


Dave

Here is a discussion on the space forum TheSpacePort.us where it is discussed that the number of engines on "Grasshopper 2" will be three engines:

http://thespaceport.us/forum/topic/3...ates/?p=482632

I don't know if this has been officially confirmed though.


Bob Clark

Robert Clark wrote:
Here is a discussion on the space forum TheSpacePort.us where it is
discussed that the number of engines on "Grasshopper 2" will be
three engines:

http://thespaceport.us/forum/topic/3...ates/?p=482632

I don't know if this has been officially confirmed though.

Any ideas as to access to the "inside" there for when they are
installing the center engine? I would have guessed center engine
first then the others.

rick jones
--
I don't interest myself in "why." I think more often in terms of
"when," sometimes "where;" always "how much." - Joubert
these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...

When I was a graduate student at the Ohio State University back in the day I had the great opportunity to work with John Kraus, the famous radio engineer. He built 'Big Ear' OSU's famous radio observatory. We worked on SETI.. This garnered the interest of a lot of science fiction writers at the time, among them Arthur Clarke all the way from Sri Lanka.

On occasion when Clarke would call Kraus, he would talk to me and we had some interesting conversations. Bottom line is we got 40,000 possible detections along the lines of the 'WOW!' signal - but none met all the criterion for a real detection - basically none repeated in a structured way. So, none really made it through peer review into publication. To the chagrin of many a graduate student.

http://trashotron.com/agony/columns/05-24-02.htm

http://www.bigear.org/JDKpassage-art...spatch20040723

Anyway, according to Clarke himself 2001: A Space Odyssey presumed a gas core nuclear rocket with 1,800 sec Isp. The Orion III was launched with a tracked launcher and chemical booster to take it to an altitude and speed where low thrust gas core nuclear rocket would take it to low earth orbit. The Aires moonship used the same technology to boost from low earth orbit to a landing on the moon, where it was refuelled. The Discovery used a similar propulsive system.

https://archive.org/details/nasa_techdoc_19710024153

The maglev track for the Orion III spacecraft boosted it to near sound speed. It then used a rocket/ramjet operating at an effective specific impulse of 1,800 sec to take it to 1.4 km/sec (5,000 km/hr, 3,100 mph) where it soared into space along a sub-orbital trajectory. This requires a propellant fraction of 0.074 - very low. Once the Orion III got into space, on a sub-orbital trajectory, it would then use the gas core nuclear rocket to increase speed to orbital speed. This requires 0.356 propellant fraction.

The cool part, in Clarke's mind, is that this used hydrogen propellant throughout.

Structure fraction due to the shielding requirements was high - around 0.220 - leaving 0.350 payload fraction.

You can see in the movie that the Orion III had an interior similar to a DC-3. Clarke often spoke about how the DC-3 of space would change space travel the way the DC-3 changed travel across the Atlantic.

So, a 3 tonne payload means 8,572 kg take off weight, 1,885 kg structure weight, 3,686 kg of hydrogen propellant. A cylinder with spherical end caps 9.97 m long and 2.72 m in diameter holds this propellant.

The Aries moonship also carried 3 tonnes payload. It has the same 0.22 structure fraction and had to boost through a delta vee of 7.8 km/sec - the same delta vee as the Orion III, except it starts at the Moon. It has the same specific impulse, 1800 seconds. It boosts from the moon, travels to Earth in 9 hours. It executes an aerobraking maneuver and slows to orbital speed, arriving at the Station in low earth orbit. This is why it requires retractable gear.

Payload and passengers are transferred to the vehicle at Earth orbit.

After loading it boosts to a trans-lunar flight and arrives at the moon after 9 hours of travel. It then lands on the lunar surface. There it refuels to carry out the trip again. The weights and fractions are similar - the configuration is widely different.

Three flights a day for five major bases require a fleet of twenty ships. Fifteen tons per day is shipped to the moon. A person requires about a quarter ton a year from Earth to sustain a reasonable life on the moon, with only modest recycling. So, 21,915 people could be supported on the moon in this way. With a 20% turnover per year only 12 people per day would be transferred from the moon and back.

The Discovery One masses 5,440 tonnes is 140.1 m long and 17 m in diameter. She was originally intended to fly to Jupiter, but (in the book) she was re-tasked to Saturn's moon Iapetus, where the signal originated.

She carried 3,440 tonnes of propellant which was ejected with an efficiency of 1800 sec Isp.

Saturn and Iapetus was dropped from the movie by Kubrick. Yet Clarke wondered what folks would make of the movie today if that were the case since Iapetus has proven to look a lot like the Death Star from Star Wars! lol.

http://en.wikipedia.org/wiki/File:Ia...706_1419_1.jpg

http://pbr2010.files.wordpress.com/2...th-star-12.jpg

According to Clarke we didn't have close up pictures of Iapetus in 1968. We did however have some unusual observations of the moon - where one side is vastly brighter than the other - and things like that.

What actually transpired in our understanding proves that the cosmos is not only stranger than we imagine, it is stranger than we *can* imagine.

lol.

On Friday, August 5, 2011 8:02:05 PM UTC+12, Robert Clark wrote:
In regards to getting the most economical delivery of payload to
orbit. Quite key here is that if you use the principle of using *both*
the most lightweight stages *and* the most efficient engines *at the
same time* then you can loft even more payload to orbit with your mult-
stage launchers. Plus, the individual stages can now be used as SSTO's
to loft smaller payloads at a lower cost than using the full multi-
stage launchers.
I have discussed before that SpaceX is using weight optimized design
for their Falcon 9 launcher. They are getting a 20 to 1 mass ratio for
the Falcon 9 first stage. And they expect to achieve a 30 to 1 mass
ratio for the side boosters on their Falcon Heavy. If they had used
high efficiency engines such as the NK-33 or the RD-180 instead of the
Merlins on their Falcons they could loft even more payload to orbit as
well as using the first stages or boosters alone as SSTO's to launch
smaller payloads.
It is notable that Elon Musk this week announced that SpaceX will be
working on a "super efficient" engine which he says will allow
reusable launchers that can bring the price to orbit down to $50 to
$100 per pound, in the range of what I was saying. The key point is
this is doable now with the high efficiency engines already existing
and the lightweight stages already existing.

August 03, 2011
Looking at Spacex plans for Making Falcon Rockets Reusable to get to
$50 per pound launch costs.
http://nextbigfuture.com/2011/08/loo...or-making.html

August 02, 2011
Elon Musk of Spacex talks about a Reusable Falcon Heavy to get to $50
a pound to space.

Two technology areas Musk didn’t like were lifting bodies/wings
and nuclear rockets.
On the former, he said he was a “vertical takeoff, vertical
landing” type guy and eschewed wings since they had to be tailored for
each planet’s atmosphere and were useless on airless bodies such as
the Moon.
Drawbacks to nuclear power included the need for shielding
(heavy), water (heavy), and public objections against launching
nuclear fuel on a rocket. “IT’S A TRICKY THING GETTING A REACTOR UP
THERE WITH A TON OF URANIUM,” MUSK SAID AND WENT ON TO SAY WHILE
NUCLEAR POWER WOULD BE USEFUL FOR MARS OR LUNAR OPERATIONS, HE IMPLIED
THAT SOME ASSEMBLY (I.E., MINING AND PROCESSING FUEL OFF PLANET) WOULD
BE REQUIRED.

- {emphasis added - B.C.}
http://nextbigfuture.com/2011/08/elo...lks-about.html


Bob Clark


On Jul 4, 12:28*pm, Robert Clark wrote:
Space Travel: The Path to Human Immortality?
Space exploration might just be the key to human beings surviving mass
genocide, ecocide or omnicide.
July 24, 2009
"On December 31st, 1999, National Public Radio interviewed the
futurist and science fiction genius Arthur C. Clarke. Since the author
had forecast so many of the 20th Century's most fundamental
developments, the NPR correspondent asked Clarke if anything had
happened in the preceding 100 years that he never could have
anticipated. 'Yes, absolutely,' Clarke replied, without a moment's
hesitation. 'The one thing I never would have expected is that, after
centuries of wonder and imagination and aspiration, we would have gone
to the moon ... and then stopped.'"http://www.alternet.org/news/141518/space_travel:_the_path_to_human_i...

I remember thinking when I first saw 2001 as a teenager and could
appreciate it more, I thought it was way too optimistic. We could
never have huge rotating space stations and passenger flights to orbit
and Moon bases and nuclear-powered interplanetary ships by then.
That's what I thought and probably most people familiar with the space
program thought that. And I think I recall Clarke saying once that the
year 2001 was selected as more a rhetorical, artistic flourish rather
than being a prediction, 2001 being the year of the turn of the
millennium (no, it was NOT in the year 2000.)
However, I've now come to the conclusion those could indeed have been
possible by 2001. I don't mean the alien monolith or the intelligent
computer, but the spaceflights shown in the film.
It all comes down to SSTO's. As I argued previously [1] these could
have led and WILL lead to the price to orbit coming down to the $100
per kilo range. The required lightweight stages existed since the 60's
and 70's for kerosene with the Atlas and Delta stages, and for
hydrogen with the Saturn V upper stages. And the high efficiency
engines from sea level to vacuum have existed since the 70's with the
NK-33 for kerosene, and with the SSME for hydrogen.
The kerosene SSTO's could be smaller and cheaper and would make
possible small orbital craft in the price range of business jets, at a
few tens of millions of dollars. These would be able to carry a few
number of passengers/crew, say of the size of the Dragon capsule. But
in analogy with history of aircraft these would soon be followed by
large passenger craft.
However, the NK-33 was of Russian design, while the required
lightweight stages were of American design. But the 70's was the time
of detente, with the Apollo-Soyuz mission. With both sides realizing
that collaboration would lead to routine passenger spaceflight, it is
conceivable that they could have come together to make possible
commercial spaceflight.
There is also the fact that for the hydrogen fueled SSTO's, the
Americans had both the required lightweight stages and high efficiency
engines, though these SSTO's would have been larger and more
expensive. So it would have been advantageous for the Russians to
share their engine if the American's shared their lightweight stages.
For the space station, many have soured on the idea because of the ISS
with the huge cost overruns. But Bigelow is planning on "space hotels"
derived from NASA's Transhab[2] concept. These provide large living
space at lightweight. At $100 per kilo launch costs we could form
large space stations from the Transhabs linked together in modular
fashion, financed purely from the tourism interests. Remember the low
price to orbit allows many average citizens to pay for the cost to
LEO.
The Transhab was developed in the late 90's so it might be
questionable that the space station could be built from them by 2001.
But remember in the film the space station was in the process of being
built. Also, with large numbers of passengers traveling to space it
seems likely that inflatable modules would have been thought of
earlier to house the large number of tourists who might want a longer
stay.
For the extensive Moon base, judging from the Apollo missions it might
be thought any flight to the Moon would be hugely expensive. However,
Robert Heinlein once said: once you get to LEO you're half way to
anywhere in the Solar System. This is due to the delta-V requirements
for getting out of the Earth's gravitational compared to reaching
escape velocity.
It is important to note then SSTO's have the capability once refueled
in orbit to travel to the Moon, land, and return to Earth on that one
fuel load. Because of this there would be a large market for passenger
service to the Moon as well. So there would be a commercial
justification for Bigelow's Transhab motels to also be transported to
the Moon [3].
Initially the propellant for the fuel depots would have to be lofted
from Earth. But we recently found there was water in the permanently
shadowed craters on the Moon [4]. Use of this for propellant would
reduce the cost to make the flights from LEO to the Moon since the
delta-V needed to bring the propellant to LEO from the lunar surface
is so much less than that needed to bring it from the Earth's surface
to LEO.
This lunar derived propellant could also be placed in depots in lunar
orbit and at the Lagrange points. This would make easier flights to
the asteroids and the planets. The flights to the asteroids would be
especially important for commercial purposes because it is estimated
even a small sized asteroid could have trillions of dollars worth of
valuable minerals [5]. The availability of such resources would make
it financially profitable to develop large bases on the Moon for the
sake of the propellant.
Another possible resource was recently discovered on the Moon: uranium
[6]. Though further analysis showed the surface abundance to be much
less than in Earth mines, it may be that there are localized
concentrations just as there are on Earth. Indeed this appears to be
the case with some heavy metals such as silver and possibly gold that
appear to be concentrated in some polar craters on the Moon [7].
So even if the uranium is not as abundant as in Earth mines, it may be
sufficient to be used for nuclear-powered spacecraft. Then we wouldn't
have the problem of large amounts of nuclear material being lofted on
rockets on Earth. The physics and engineering of *nuclear powered
rockets have been understood since the 60's [8]. The main impediment
has been the opposition to launching large amounts of radioactive
material from Earth into orbit above Earth. Then we very well could
have had nuclear-powered spacecraft launching from the Moon for
interplanetary missions, especially when you consider the financial
incentive provided by minerals in the asteroids of the asteroid belt.

* * Bob Clark

1.)Newsgroups: sci.space.policy, sci.astro, sci.physics,
sci.space.history
From: Robert Clark
Date: Sat, 25 Jun 2011 21:36:07 -0700 (PDT)
Subject: A kerosene-fueled X-33 as a single stage to orbit
vehicle.http://groups.google.com/group/sci.s...b9bcc5ca2dc05?...

2.)TransHab.http://en.wikipedia.org/wiki/TransHab

3.)Private Moon Bases a Hot Idea for Space Pioneer.
by Leonard David, SPACE.com's Space Insider Columnist
Date: 14 April 2010 Time: 02:23 PM EThttp://www.space.com/8217-private-moon-bases-hot-idea-space-pioneer.html

4.)Mining the Moon's Water: Q & A with Shackleton Energy's Bill Stone.
by Mike Wall, SPACE.com Senior WriterDate: 13 January 2011 Time: 03:57
PM EThttp://www.space.com/10619-mining-moon-water-bill-stone-110114.html

5.)Riches in the Sky: The Promise of Asteroid Mining.
Mark Whittington, Nov 15, 2005http://www.associatedcontent.com/article/11560/riches_in_the_sky_the_...

6.)Uranium could be mined on the Moon.
Uranium could one day be mined on the Moon after a Japanese spacecraft
discovered the element on its surface.
By Julian Ryall in Tokyo 4:58PM BST 01 Jul 2009http://www.telegraph.co.uk/science/space/5711129/Uranium-could-be-min...

7.)Silver, Gold, Mercury and Water Found in Moon Crater Soil by LCROSS
Project.
Catherine Dagger, Oct 22, 2010http://www.associatedcontent.com/article/5922906/silver_gold_mercury_...

8.)NERVA.http://en.wikipedia.org/wiki/NERVA

I like VTOVL. I proposed a two-stage chemical booster 20 years ago. I'm glad to see Musk do it.

Nuclear pulse, especially fission free nuclear pulse, doesn't have the drawbacks Musk outlines for nuclear. So, its something that should be pursued and pursued aggressively.

http://www.e-ipi.net/isri/_media/pub...s:ag-09-01.pdf

Le 10/30/2014 12:53 PM, hanson a écrit:
Bob, the cause for the disastrous failure of the Space X
launch 28-Oct-2014 is given, by the operative word
=== "Environmental" === in the 2nd line of your tripe.

This disaster was precipitated by non other then being
a direct consequence of the idiotic demands by Greenies.

Any &all rocket launches combined have/are not causing
as much "pollution" as one part per billion that is naturally
emitted by one single small volcanic eruption.

One Shuttle solid rocket booster contained approximately 500 tonnes of
ammonium perchlorate. There were 135 missions, that's 2*135*500 tonnes
of ammonium perchlorate. A billion times that would be about 1.3x10^14
tonnes. If you estimate the density of what is emitted by a volcano at
about 10 tonnes per cubic meter, you would need a volcano emitting about
1.3x10^13 cubic meters of ejecta to have the same mass. That is about
13,500 km^3. I wouldn't call that a small volcano.

Of course most of the mass ejected by a volcano is just molten rock, so
it is a little difficult to claim that it is more of a pollutant than
ammonium perchlorate. Also, there were much more rocket launch pollution
than just that of the Space Shuttle. So, to put it kindly, let's say
that your assertion is an exaggeration.


Alain Fournier

In article ,
says...

Bob, the cause for the disastrous failure of the Space X
launch 28-Oct-2014

What "disastrous failure" would that be? SpaceX did not have a launch
scheduled for that date.

Green Fanatic and self-indicting Enviro Turd
"Alain Fournier" wrote:

hanson a écrit:
Bob, the operative word is = "Environmental" = in the
2nd line of your

This disaster was precipitated by non other then being
a direct consequence of the idiotic demands by Greenies.

Any & all rocket launches combined have/are not causing
as much "pollution" as one part per billion that is naturally
emitted by one single small volcanic eruption.

This sorry event is yet another example of the problems
produced by the Green Turds' irrational megalomania
to save the planet, ... which in reality is just a ruse they
use to conduct their enviro machinations to fatten their
own wallets.

Their Green Greed have suppressed progress, & instead
instituted measures that have produced disease and
poverty, which enabled & furthered only their own greed
for $$.

Enviros are to Earth Science what Relativists are to physics.
Both are committing crimes against humanity!

Send All Green *******s to Ebola infested Areas
and leave'em there for environmental reasons!

Culpable Green "Alain Fournicateur" lied & whined:

One Shuttle solid rocket booster contained
approximately 500 tonnes of ammonium perchlorate.
There were 135 missions, that's 2*135*500 tonnes of
ammonium perchlorate. A billion times that would
be about 1.3x10^14 tonnes. If you estimate the density
of what is emitted by a volcano at about 10 tonnes per
cubic meter, you would need a volcano emitting about
1.3x10^13 cubic meters of ejecta to have the same mass.
That is about 13,500 km^3. I wouldn't call that a small volcano.

Of course most of the mass ejected by a volcano is just
molten rock, so it is a little difficult to claim that it is more
of a pollutant than ammonium perchlorate. Also, there were
much more rocket launch pollution than just that of the Space
Shuttle. So, to put it kindly, let's say that
your assertion is an exaggeration.

hanson wrote:
"exaggeration?".. pas vrais, mon cher verte ami.

Volcanoes do not emit "just molten rock"... Never
mind your nitpicking over " big or small volcanoes"
to get you out of your Green fantasy, but consider

also the global numbers of the emissions from
the millions of 24/7/365 ongoing fumaroles and
other terrainian fissures,
(emissions which you Green Misanthropes do not
consider as pollution, even though they consist
of the same chemicals, but are not "man-made")

So, educate yourself at the edge of one & measure
its emission output quantities of CHx, CO, CO2,
HCl, N2, NOx, H2S, H2SO4 etc for a few says, then
estimate how much pollution came/comes out of
the earth **globally** since the dawn of rocket
launches and then make your Green case against
the puny amount of manmade booster pollution.

Furthermore, you lying or stupid enviro-moron,
Solid propellant booster material **consists**
of Ammonium Perchlorate but neither the NH4+
nor Perchlorate ClO4- gets into the atmosphere.

NH4ClO4 is the oxidizer of the organics (poly-
urethanes) and the Al dust, which reduce the
NH4ClO4 to Nitrogen and Chloride products
together with the generation of Aluminum oxides,..

... all of which are items that are present in the
atmosphere at all times from natural sources
and events.

You are guilty as charged, Enviro Fournicateur.
Now do the right thing, repent, exculpate and
redeem yourself by going to the Ebola infested
Areas & stay there for environmental reasons!