Fwd: [luf-team] More Open Source Space
Bryan Bishop
From: Eric Hunting <erich...@gmail.com>
Date: Wed, Feb 3, 2010 at 8:43 PM
Subject: [luf-team] More Open Source Space
To: luf-...@yahoogroups.com
Looks like the concept of Open Source space programs is starting to snowball.
Eric Hunting
erich...@gmail.com
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Thomas Fledrich
> Looks like the concept of Open Source space programs is starting to
> snowball.
>
> http://cstart.org/
>
The unmanned suborbital hybrid rocket seems doable, but that's a long way from
an orbital spacecraft and even more from one capable of going to the Moon.
At this time I think it's more important to focus on setting up an automated
open source manufacturing base than directly aiming at the Moon.
The costs of spaceflight is not just $$, but mainly work hours of the people
working on it. So automising the design and production process, developing
OpenSource blueprints for components (turbopumps, valves, etc.) is a
prerequisite for any small effort orbital travel.
Kevin Carson
>
> > Looks like the concept of Open Source space programs is starting to
> > snowball.
> >
> > http://cstart.org/
> The unmanned suborbital hybrid rocket seems doable, but that's a long way from
> an orbital spacecraft and even more from one capable of going to the Moon.
BTW, has everyone here seen that Analog short story "Openshot," about
an OS moon shot project?
--
Kevin Carson
Center for a Stateless Society http://c4ss.org
Mutualist Blog: Free Market Anti-Capitalism
http://mutualist.blogspot.com
Studies in Mutualist Political Economy
http://www.mutualist.org/id47.html
Organization Theory: A Libertarian Perspective
http://mutualist.blogspot.com/2005/12/studies-in-anarchist-theory-of.html
Luke Maurits
I'm one of the founding members of CSTART. One of our other members
stumbled across this discussion and pointed it out to the team.
I just wanted to let the interested people here know that a lot of us
at CSTART are very interested in talking/working with the Open
Manufacturing Network (and other similar communities!) about what we
should/can and shouldn't/can't do to best facilitate the low-cost,
distributed construction of potentially large physical hardware. We
have certainly given this *some* thought, but there has also been a
little bit of "magical thinking" along the lines of "if we just make
sufficiently detailed plans available under permissive licenses,
eventually *someone* will build it!". It looks like your community
and others have a lot to teach us about how to improve our chances of
success beyond this.
As for the issue of open source blueprints, we are absolutely onboard
with this - our Social Contract (see http://cstart.org/wiki/CSTART_Social_Contract)
obliges us to (amongst other things) release all blueprints etc. under
a CC license.
If anyone wants to talk more about ideas to facilitate the success of
an open source space agency, myself and others from CSTART will be
very happy to carry on detailed conversations here, on our forums
(http://cstart.org/forum/) or via personal email.
Thanks for taking an interest in what we do!
Cheers,
Luke Maurits (on behalf of CSTART)
Thomas Fledrich
> If anyone wants to talk more about ideas to facilitate the success of
> an open source space agency, myself and others from CSTART will be
> very happy to carry on detailed conversations here, on our forums
> (http://cstart.org/forum/) or via personal email.
Since NASA's Moon program has been cancelled now Japans, Europe's and the US's
manned government space programs are all behind those of Russia, China and
India.
I believe this charade that has been going on for several decades now, with
each new administration cancelling the programs of the previous one has made
it difficult to make any progress with long term stuff and is now even
failing to maintain already achieved capabilities.
So it's pretty much up to private industry and open source manufacturing if we
ever will be able to establish a permanent off world presence. While I wish
the national programs of the countries that still seem to be determined to
make manned space happen good luck it would still be better if we could pull
it off ourselves, optimally without any government involvement.
But it's all a long way off, lot's of work to do. My idea is to begin really
small, do what we need to do anyway for everything else in the open source
project.
- We need to set up the online blueprint producing and sharing infrastructure.
This means upgrading/developing open source CAD programs and an easily
accessible database for the blueprints along the lines of wikipedia.
- We need something like Cubespawn as a basic unit,coupled with some kind of
robot arm that can automatically assemble the parts produced by it and also
exchange worn out pieces.
- Then we can go on to design and build other tools with this assembly and
then build more advanced products with these tools.
It is important that everything we do is able to be traced back to that basic
unit and that the production process be ideally fully automated.
When designing anything new it should be standard practice to build it
yourself first and only add the new blueprints into the online database when
it has been proven to work in reality.
I don't know how long this will take and if we can get enough people
interested in it but if we manage to get a contributor base of the size
wikipedia is today it would completely change the world from the ground up.
So it's definitely worth a try.
Luke Maurits (CSTART)
> manned government space programs are all behind those of Russia, China and
> India.
Very true. My money is on China being the next nation to do anything
in the field of manned lunar work, most probably a circumlunar flyby
in a Shenzhou spcecraft, and on India becoming the 4th nation in space
in the near future with their Orbital Vehicle. Russian progress seems
a little bit slow at the moment, tied down by uncertain plans to
cooperate with Europe. As far as I know Japan have no active manned
spaceflight projects at the moment (although they have planned some
very interesting stuff in the past, like the Fuji capsule).
> - We need to set up the online blueprint producing and sharing infrastructure.
> This means upgrading/developing open source CAD programs and an easily
> accessible database for the blueprints along the lines of wikipedia.
There definitely needs to be more open source CAD work done. Earlier
drafts of CSTART's Social Contract bound us to only use open source
software for design work, but we quickly realised that this would more
or less cripple us, as the open source software of the kinds we would
need are lagging quite badly behind the proprietary software. The
Open Luna Foundation posted about this same problem on Slashdot
recently, I think I saw a post about it in this group somewhere. For
what it is worth, BRL cad is the most capable seeming open source CAD
software that we have found.
> - We need something like Cubespawn as a basic unit,coupled with some kind of
> robot arm that can automatically assemble the parts produced by it and also
> exchange worn out pieces.
I hadn't heard of Cubespawn before, it looks very interesting, thanks
for bringing it up.
One thought on spaceflight which lends itself rather well to this
automated assembly line approach is the construction of large launch
vehicles by clustering small, simple rockets together. This approach
was tried in the 70s by a German company called OTRAG, but it fell
through largely for political reasons (the idea seems technically
sound). Armadillo Aerospace are looking in this direction for the
future orbital vehicle plans, and to the extent that CSTART is
interested in building launch vehicles (which varies with our changing
assesments of how much of a legal pain it will be (ITAR, etc) and how
cheap new generation LVs such as those made by SpaceX are likely to
become), we are also very interested in this clustered approach, since
it works well for distributed manufacturing (build the individual
small rockets all over the world, ship them to one location and then
cluster them together).
> I don't know how long this will take and if we can get enough people
> interested in it but if we manage to get a contributor base of the size
> wikipedia is today it would completely change the world from the ground up.
> So it's definitely worth a try.
I would wager we could do incredible things with a much smaller
contributor base than that. The team at Copenhagen Suborbitals
(http://www.copenhagensuborbitals.com) seem to be doing very well with
their one man suborbital microspacecraft project (first unmanned
launch scheduled for June or July this year), and their team is just
17 people large (with the vast majority of the work being done by a
core team of 2).
Herbert Snorrason
Hash: SHA1
On 9.2.2010 03:41, Luke Maurits (CSTART) wrote:
> Russian progress seems a little bit slow at the moment, tied down by
> uncertain plans to cooperate with Europe.
The main problem the Russians have is similar to the one faced by NASA:
Space exploration doesn't provide military superiority, and hence they
don't get any money. Of course, even direct military research is getting
shafted in the Great Motherland these days, but that's another issue.
> There definitely needs to be more open source CAD work done.
[snip]
> Armadillo Aerospace are looking in this direction for the future
> orbital vehicle plans, and to the extent that CSTART is interested in
> building launch vehicles (which varies with our changing assesments
> of how much of a legal pain it will be (ITAR, etc) and how cheap new
> generation LVs such as those made by SpaceX are likely to become), we
> are also very interested in this clustered approach
Not to be a killjoy, but there are some elementary points here. You are
talking about designing an orbital launch vehicle, and making the full
design, schematics, control electronics and all available to all comers.
The applications such a design could - and _would_ - have are rather
magnificent. Specifically, any such vehicle could be used to move
payloads from one continent to another. There is, incidentally, a
special name for a vehicle used for that purpose.
Now, I don't know about you, but I think there are some very powerful
folks out there who don't want to have to think about all the
implications of that. The way they won't have to think about it is by
stopping the project, and once they realise how dangerous the
environment it sprang out of genuinely is ... I don't think this group
and other like-minded thinkers will be able to go unsupervised much longer.
Basically, what I'm saying is that just maybe it might be wise to leave
the ICBMs to the big (proprietary) boys for now. That way, we might not
grab their attention until it's too late for them.
With greetings,
Herbert Snorrason
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Luke Maurits (CSTART)
> talking about designing an orbital launch vehicle, and making the full
> design, schematics, control electronics and all available to all comers.
> The applications such a design could - and _would_ - have are rather
> magnificent. Specifically, any such vehicle could be used to move
> payloads from one continent to another. There is, incidentally, a
> special name for a vehicle used for that purpose.
Yes, we're quite aware of this unfortunate complication. ITAR seems
to completely rule out hosting open source launch vehicle information
in the US or Canada. Building orbital LVs is rather unpopular at
CSTART at the moment for this very reason. Even if that project goes
ahead, it is almost certain that we will still use commercial launch
vehicles for our earliest projects simply because none of our own
stuff will be ready in time.
It seems like our first orbital projects will almost certainly be
light weight, simple satellites, launched by the cheapest proprietary
option and designed primarily to test proposed communications and
other hardware for use on the manned capsule (which is by far the
project we have planned in the most detail).
Cheers,
Luke
Thomas Fledrich
> automated assembly line approach is the construction of large launch
> vehicles by clustering small, simple rockets together. This approach
> was tried in the 70s by a German company called OTRAG, but it fell
> through largely for political reasons (the idea seems technically
> sound).
Actually one of the key members of OTRAG, Dr. Hau-Po Mok, was teaching at the
university I went to. He tought us about fluid dynamics. Sadly he passed away
two years ago in a heart attack.
On an occacion he presented that project. The whole idea was born out of
necessity. After ww2 Germany was forbidden from building any rockets with a
diameter exceeding 270mm. So they figured they'll just stack together a lot
of these and see what that assembly is cabable of doing.
Their calculations showed a rocket with a launch mass of about the Saturn V
would be able to put about 10 tons into LEO. The modules were quite simple
metal pipes with a pressure fed propellant. I can't remember the propellant
type now, only that it was liquid, but can look it up if you like. It was
pressure fed using nitrogen, not helium like is usual. It was chosen to
reduce cost and complexity.
They made a successful test launch somewhere in Africa (I think it was Zaire)
before the project was shut down for several reasons. One was that the French
were not all to happy with Germany developing long range rockets (quite
understandable given the time and situation). But the other reason was that
ESA was starting to form seriously and they were developing more conventional
rockets in a European cooperation. So it was decided to scrap this project
and invest into the likes of Ariane instead.
Ok so what do I think about this approach? It might be good for simple access
to space, but if we are really looking to set up a continous stream of
vehicles to orbit better performance design with more reusability, like I
hope Falcon will prove to be look like a better choice.
Also the rocket itself is just a part of the cost of a launch. There is also
the cost of the launch infrastructure (OK for OTRAG this was quite small,
they built a launch tower from wood they got from the local forest). But an
air launched vehicle like SpaceShipTwo is much more flexible. You can
assemble it anywhere in the world, then fly to an other airport with the
carrier plane, refuel and it's ready for take-off. Of course the size is
limited if you want to be able to use most airports but should still be good
enough for small satellites.
For bigger vehicles I like the sea launch, that could be made more or less
independent from a single country. I'm quite surprised that the Sea Launch
company went bancrupt. Launching GEO payloads from the equator should be a
big advantage to all other sites except Corou.
But I've seen concepts for floating launch vehicles that don't need a swimming
launch platform at all (Sea Dragon, proposed by Boeing if I remember
correctly)
In the end it would be nice to build something like the Loftstrom Launch Loop,
but there are a few small problems to overcome before that will happen...
http://launchloop.com/
For politics, I know about the delusional ways of certain governments to try
to bring the whole world under their control, but in the end this looks to me
very much like the Ming in the 15th century who scrapped their own fleet
because of fears. It didn't do them any good in the long run and it won't do
any good for these governments today either. You don't need ICBMs to cause
trouble if you really want to in this world, the notion that some space
exploration group would waste all their work in this way is laughable.
But as Herbert said, this is still a long way in the future. You can't do a
true open source based spacecraft today because we haven't even closely
developed the open source manufacturing infrastructure to that point.
Of course you can still try a semi-open source project like CSTART seems to
look to me, but the question is what you want to achieve.
Do you want to put a wo-/man on the moon for 50 million $ with an architecture
that would require a similar amount of money for each new flight?
Or do you (like I) want to contribute to make spaceflight so cheap that anyone
will be able to go out and survive there permanently?
Then this is a slower approach with more work before any great results but I
hope with very big long term gains.
> I would wager we could do incredible things with a much smaller
> contributor base than that. The team at Copenhagen Suborbitals
> (http://www.copenhagensuborbitals.com) seem to be doing very well with
> their one man suborbital microspacecraft project (first unmanned
> launch scheduled for June or July this year), and their team is just
> 17 people large (with the vast majority of the work being done by a
> core team of 2).
Thanks for the link, I'll have a look at their project.
Thomas
Luke Maurits (CSTART)
> university I went to. He tought us about fluid dynamics. Sadly he passed away
> two years ago in a heart attack.
It's really cool that you got to learn from someone with such
excellent experience. It's a shame to hear he's died. As far as I
know, the founder of the company, Lutz Kayser, is still doing well.
He visited Armadillo Aerospace's facility somewhat recently, I recall
reading.
> Their calculations showed a rocket with a launch mass of about the Saturn V
> would be able to put about 10 tons into LEO. The modules were quite simple
> metal pipes with a pressure fed propellant. I can't remember the propellant
> type now, only that it was liquid, but can look it up if you like. It was
> pressure fed using nitrogen, not helium like is usual. It was chosen to
> reduce cost and complexity.
> They made a successful test launch somewhere in Africa (I think it was Zaire)
> before the project was shut down for several reasons. One was that the French
> were not all to happy with Germany developing long range rockets (quite
> understandable given the time and situation). But the other reason was that
> ESA was starting to form seriously and they were developing more conventional
> rockets in a European cooperation. So it was decided to scrap this project
> and invest into the likes of Ariane instead.
It's been a while since I read up on OTRAG in too much detail, but if
I recall correctly, the pressurant was actually just compressed air,
the propellants were LOX and kerosene, and the African launches were
done in Libya. I could be wrong about any of these, though.
> But an
> air launched vehicle like SpaceShipTwo is much more flexible. You can
> assemble it anywhere in the world, then fly to an other airport with the
> carrier plane, refuel and it's ready for take-off. Of course the size is
> limited if you want to be able to use most airports but should still be good
> enough for small satellites.
It is true that a vehicle like the SpaceShipN vehicles can be
assembled at point A and then flown to point B for launch, but there
still has to be a point A - somewhere with a workshop large enough to
create the entire vehicle. The big appeal of the OTRAG approach for
CSTART was that the booster could be built at points A, B, C,..., Y
and then shipped to point Z for launch. Constructing the individual
modules would require only a fairly small and simple workshop, well
within the means of a dedicated hobbyist. With this approach, access
to space can be constructed in a *massively parallel fashion* at low
cost. This approach takes maximum advantage of the open source
approach. I will admit though that it has downsides, for example
there is little scope for reusability.
> For bigger vehicles I like the sea launch, that could be made more or less
> independent from a single country. I'm quite surprised that the Sea Launch
> company went bancrupt. Launching GEO payloads from the equator should be a
> big advantage to all other sites except Corou.
> But I've seen concepts for floating launch vehicles that don't need a swimming
> launch platform at all (Sea Dragon, proposed by Boeing if I remember
> correctly)
If you are interested in sea launches, you should definitely talk to
the guys from Copenhagen Suborbitals. They plan to launch their
manned suborbital craft from a float launch pad outside of Danish
territorial waters to get around various regulatory hassles. One of
their team previously participated in the design and construction of
the world's largest amateur submarine (the UC3 Nautilus, see
http://www.uc3nautilus.dk/), so I believe they have what it takes to
pull this off.
> In the end it would be nice to build something like the Loftstrom Launch Loop,
> but there are a few small problems to overcome before that will happen...
> http://launchloop.com/
I hadn't heard of launchloop before, thanks for the link, I will check it out.
> But as Herbert said, this is still a long way in the future. You can't do a
> true open source based spacecraft today because we haven't even closely
> developed the open source manufacturing infrastructure to that point.
> Of course you can still try a semi-open source project like CSTART seems to
> look to me, but the question is what you want to achieve.
> Do you want to put a wo-/man on the moon for 50 million $ with an architecture
> that would require a similar amount of money for each new flight?
> Or do you (like I) want to contribute to make spaceflight so cheap that anyone
> will be able to go out and survive there permanently?
> Then this is a slower approach with more work before any great results but I
> hope with very big long term gains.
This is perhaps a legitimate criticism of our current plans re: manned
spaceflight. It betrays our origins as a very informal, almost
whimsical group interested in getting a human on the moon as simply
and cheaply as possible, without much thought about the bigger
picture. Now that we have become a little more organised and directed
we are trying to remold our ideas and projects into something of a
more coherrent direction. It might be that our second manned
spaceflight project, should we get that far, will be more geared
around minimal cost, highly reusable, quickly relaunchable ideas.
Cheers,
Luke
Thomas Fledrich
> It's been a while since I read up on OTRAG in too much detail, but if
> I recall correctly, the pressurant was actually just compressed air,
> the propellants were LOX and kerosene, and the African launches were
> done in Libya. I could be wrong about any of these, though.
I can't remember it very well either, only heard that one presentation about
the project. And Mok was talking a lot about the different design choices
they had to make along the way, so I could me mixing it up. But the one thing
I clearly remember is the low payload mass to LEO for a very big rocket. That
and the lack of reusability seem to make the apprach not very well suited as
a long term solution.
Thomas Fledrich
> the guys from Copenhagen Suborbitals. They plan to launch their
> manned suborbital craft from a float launch pad outside of Danish
> territorial waters to get around various regulatory hassles. One of
> their team previously participated in the design and construction of
> the world's largest amateur submarine (the UC3 Nautilus, see
> http://www.uc3nautilus.dk/), so I believe they have what it takes to
> pull this off.
Yes I've looked at the link you provided before, they seem to be quite far
with their project already, definitely looks interesting. I will gladly help
once I will have brought my current projects on the way.
> This is perhaps a legitimate criticism of our current plans re: manned
> spaceflight. It betrays our origins as a very informal, almost
> whimsical group interested in getting a human on the moon as simply
> and cheaply as possible, without much thought about the bigger
> picture. Now that we have become a little more organised and directed
> we are trying to remold our ideas and projects into something of a
> more coherrent direction. It might be that our second manned
> spaceflight project, should we get that far, will be more geared
> around minimal cost, highly reusable, quickly relaunchable ideas.
The suborbital rocket project seems doable, it's only the Moon landing one
that I have doubts about. 50 millions is no small pricetag, you can take a
Soyuz to the ISS for that.
Basically I believe human spaceflight is unlikely to become viable before the
cost to orbit per mass can be cut by at least a magnitude. All the NewSpace
companies are trying to accomplish this and it should be happening in the
coming years now if developments continue in the pace they had been going on
in the past decade.
As for the truly OpenSource part I would go with component development first,
there is really a lot to do from gyros to engine nozzles. But we need to set
up the basic production infrastructure in the first place. That will be a lot
of work in itself.
Luke Maurits (CSTART)
> that I have doubts about. 50 millions is no small pricetag, you can take a
> Soyuz to the ISS for that.
Sure, 50 million is enough to put a Soyuz into LEO. The Soyuz TMA has
a mass of 7220 kg. So a one person conical capsule (basically a
modernised Mercury) with a mass of 1000 kg (this isn't a made up
figure, it's been extrapolated from mass breakdowns of Mercury and
Gemini and I think it is possible) can be put into LEO with 6000 kg of
propellant behind it for this price. Okay, this is actually an
exaggeration, you have to account for the mass of the propellant tank,
engines, etc. Let's say 5000 kg of propellant for the sake of
argument. If the propellants have a vacuum specific impulse of 250 s
(which is achievable using hydrogen and oxygen), then the rocket
equation gives a total impartable delta-v of 4390 m/s, which is more
than enough for a TLI burn (these are around 3100 m/s). It's not
enough for a TLI plus lunar insertion and lunar escape burns, so it
couldn't do a full lunar landing, but it could do a circumlunar flyby.
Now, with the Falcon 9, 50 million will buy you 10,400 kg into LEO,
more than the Soyuz mass used above, which by our calculations is
*just* enough to get a 1000 kg capsule, a 300 kg open-cab lander and
all required propellant for a return lunar landing.
Of course, the spacecraft aren't free so the actual price is 50
million plus spacecraft costs. The 50 million total figure you've
seen in our material is due to us accidentally using an outdated
Falcon 9 cost of 35 million (this was the estimated price in 2006) and
figuring 15 million would certainly be enough for the spacecraft.
We'll have to revise the total cost estimate in light of this,
obviously, but it's still definitely under 100 million.
Thomas Fledrich
> a mass of 7220 kg. So a one person conical capsule (basically a
> modernised Mercury) with a mass of 1000 kg (this isn't a made up
> figure, it's been extrapolated from mass breakdowns of Mercury and
> Gemini and I think it is possible) can be put into LEO with 6000 kg of
> propellant behind it for this price. Okay, this is actually an
> exaggeration, you have to account for the mass of the propellant tank,
> engines, etc.
I know this is theoratically doable.
> Let's say 5000 kg of propellant for the sake of
> argument. If the propellants have a vacuum specific impulse of 250 s
> (which is achievable using hydrogen and oxygen),
Have you made any specific engine designs? LOX/LH2 should be capable of more
that that, more like 400-450. The Ariane's HM7 has 444s at 35 bar combustion
chamber pressure
http://en.wikipedia.org/wiki/HM7B
But it's turbopump fed. You would get less chamber pressure without the
turbopump, but should still be quite high exhaust velocity. I heard with this
propellant it is tricky to restart the engine. But that might be a turbopump
related problem, so it probably is no concern for a pressure fed solution.
I guess you already made more detailed calculations concerning ISP. But you
should build a small engine and test reignition if you want to be sure about
that part.
> then the rocket
> equation gives a total impartable delta-v of 4390 m/s, which is more
> than enough for a TLI burn (these are around 3100 m/s). It's not
> enough for a TLI plus lunar insertion and lunar escape burns, so it
> couldn't do a full lunar landing, but it could do a circumlunar flyby.
> Now, with the Falcon 9, 50 million will buy you 10,400 kg into LEO,
> more than the Soyuz mass used above, which by our calculations is
> *just* enough to get a 1000 kg capsule, a 300 kg open-cab lander and
> all required propellant for a return lunar landing.
>
> Of course, the spacecraft aren't free so the actual price is 50
> million plus spacecraft costs. The 50 million total figure you've
> seen in our material is due to us accidentally using an outdated
> Falcon 9 cost of 35 million (this was the estimated price in 2006) and
> figuring 15 million would certainly be enough for the spacecraft.
> We'll have to revise the total cost estimate in light of this,
> obviously, but it's still definitely under 100 million.
It all sounds very exciting, question is just how you get people to fund it. I
guess if you can prove it successful for several times you even might get
some of those ISS tourists interested. But it's still very much out of reach
of us simple non-billionaires.
Luke Maurits (CSTART)
> that that, more like 400-450.
Oh, do pardon me, I absolutely meant to say 450s, which is the very
upper range of what LOX/LH2 can do. In fact, you *need* 450s to get
this to fit on a Falcon 9 (or you need to be able to get the hardware
masses quite a bit lower than our estimates of what is reasonable -
which may in fact be possible), so it's very close to the line. 250 s
would not be anywhere near enough, I had that figure on my mind from
work I was doing recently on our suborbital project.
> The Ariane's HM7 has 444s at 35 bar combustion
> chamber pressure
> http://en.wikipedia.org/wiki/HM7B
> But it's turbopump fed. You would get less chamber pressure without the
> turbopump, but should still be quite high exhaust velocity. I heard with this
> propellant it is tricky to restart the engine. But that might be a turbopump
> related problem, so it probably is no concern for a pressure fed solution.
We will certainly be using a pressure fed solution for simplicity. I
don't specifically know what impact this has on reignitability, it is
something we will have to look into. We could certainly use the help
of people who have real experience with this stuff.
> It all sounds very exciting, question is just how you get people to fund it. I
> guess if you can prove it successful for several times you even might get
> some of those ISS tourists interested. But it's still very much out of reach
> of us simple non-billionaires.
$100 million is a lot of money in the sense that the number of people
who could afford to buy themselves a ticket to the moon at that price
is very small. It's not so bad from the point of view of "we need to
get this much money to send our first person up". Figures in the $10
million range are routinely raised through sponsorship and donations
to finance teams entering things like high profile yacht races.
Surely a manned lunar landing could attract a lot more than these
sorts of endeavours? It's the kind of thing that wealthy IT
executives, for instance, might be willing to throw rather a lot of
money at. Also, if it looks like we're actually going to pull this
off, there's always the chance that SpaceX will give us a discount on
the launch simply in order to secure themselves the prestige of being
the company that build the rocket that returned man to the moon.
Of course, this approach works well for the first time "proving that
we can do it, despite the doubts of the world!" mission. It's not
going to work for a sustainable industry of lunar landings. In a
sense this isn't a problem for us because CSTART isn't a space tourism
company or anything like that. We're heading to the moon to explore
and to do science.
Thomas Fledrich
> upper range of what LOX/LH2 can do. In fact, you *need* 450s to get
> this to fit on a Falcon 9 (or you need to be able to get the hardware
> masses quite a bit lower than our estimates of what is reasonable -
> which may in fact be possible),
You will also have a problem with the chamber walls. I don't want to say
anything totally wrong here and you're almost making me get out the
calculator :-) , but the max temperatures for that ISP and propellant should
be about 3000K. So you would need some very good cooling and/or expensive
materials. Tungsten is not taken because it is eroded fast by the propellants
at this temperature if I remember correctly. I've had a radiation cooled
nozzle made of pure platinum once in my hand, but that's not really cheap to
experiment with I would say.
> We will certainly be using a pressure fed solution for simplicity. I
> don't specifically know what impact this has on reignitability, it is
> something we will have to look into. We could certainly use the help
> of people who have real experience with this stuff.
I don't have any real experience with chemical rockets either. Could build you
a nice high quality vacuum chamber though, but I guess that wouldn't help you
much either :-)
It would be great to get some experience, the only problem is if you work on
too many projects at the same time you won't make much progress in any of
them.
> Surely a manned lunar landing could attract a lot more than these
> sorts of endeavours? It's the kind of thing that wealthy IT
> executives, for instance, might be willing to throw rather a lot of
> money at.
Maybe. But given how difficult it was for bigger groups like the Planetary
Society to get their solar sail project funded, I wouldn't be too optimistic.
http://www.planetary.org/programs/projects/innovative_technologies/solar_sailing/whatis.html
> In a sense this isn't a problem for us because CSTART isn't a space tourism
> company or anything like that. We're heading to the moon to explore
> and to do science.
But if you're just out to explore, then why take humans? A solar powered rover
on the Moon would be much smaller mass and work for years. There is a reason
why the likes of Elon Musk say they're out to make mankind a multiplanetary
species. Statements like this would get you a laugh at best or in trouble if
you were working as an employee for one of our glorious well funded
government space programs.
Luke Maurits (CSTART)
> anything totally wrong here and you're almost making me get out the
> calculator :-) , but the max temperatures for that ISP and propellant should
> be about 3000K. So you would need some very good cooling and/or expensive
> materials. Tungsten is not taken because it is eroded fast by the propellants
> at this temperature if I remember correctly. I've had a radiation cooled
> nozzle made of pure platinum once in my hand, but that's not really cheap to
> experiment with I would say.
Since LH2 and LOX are both cryogenic liquids, regenerative cooling is
a definite possibility. I fully admit I don't know if regenerative
cooling will work in this situation. I'm not a rocket scientist and
nobody currently at CSTART is. Most of us aren't much at all in the
way of experts on anything, we just have good broad knowledge (degrees
in things like mechanical engineering and applied mathematics). What
we've done is crunch the basic numbers are described an overall
mission architecture built on existing technology / test ideas and
shown that a minimalist manned lunar return trip can be done for maybe
$60 or $70 million dollars. What we desperately need now are lots of
people with all sorts of experience to help us fill in details like
these, help us figure out how to go about actually building this
stuff, help us figure out how to finance the efforts, etc. We're
headed to SpaceUp later this month to try to find some of these
people. I am hoping that the Open Manufacturing Network can help us
find some people to handle that middle problem.
> I don't have any real experience with chemical rockets either. Could build you
> a nice high quality vacuum chamber though, but I guess that wouldn't help you
> much either :-)
It won't help with propulsion, but it could certainly be helpful when
it comes to testing that our capsule is pressure-tight, and especially
testing EVA procedures (our capsule features an EVA hatch much like
Gemini - EVA requires venting and repressurising the capsule). We're
far away from having hardware ready to put in a chamber right now, of
course, but the need will definitely be there one day!
> Maybe. But given how difficult it was for bigger groups like the Planetary
> Society to get their solar sail project funded, I wouldn't be too optimistic.
> http://www.planetary.org/programs/projects/innovative_technologies/solar_sailing/whatis.html
Perhaps I'm being optimistic, but I think that the general public
would be a lot more interested in / excited by a manned lunar landing
than a solar sail test. Hopefully, anyway.
> But if you're just out to explore, then why take humans? A solar powered rover
> on the Moon would be much smaller mass and work for years. There is a reason
> why the likes of Elon Musk say they're out to make mankind a multiplanetary
> species. Statements like this would get you a laugh at best or in trouble if
> you were working as an employee for one of our glorious well funded
> government space programs.
Okay, I need to clarify a few things.
First and foremost, in retrospect I never, ever should have said that
CSTART was doing anything to explore and do science. I retract this
statement. CSTART is an open, collaborative effort and we do anything
that we do for all of the myriad reasons that our individual
contributors want to see us do them. Not I nor anybody else speaks
with any kind of authority about "why" we do things, we just do things
because our community wants us to. When I said "exploration and
science", I was speaking only for myself.
I can say that as far as I know, nobody involved in CSTART yet is
viewing CLLARE as a leadup to any kind of high-volume tourist
application. Thus, it hasn't really been designed toward this end.
Now, when *I* said "exploration", I suppose I implicitly meant "human
exploration". Going there for the sake of being there. I personally
would love to see mankind become a multiplanetary species. I agree
with the idea that this is essential to our long term survival. That
said, I don't really see CLLARE as much of a lead up to this either,
although components of it could be used to drop supplies to a colony.
Other open source groups, like the Open Luna Foundation, obviously are
working on things which are a lead up to this. CLLARE is designed to
get someone there quickly and cheaply to prove that simple, low cost
spaceflight by large, collaborative teams is possible. It is possible
that in the future CSTART will have other projects which are more
geared toward long term human presence on the moon. Personally, I
would like to see this. But we're going to pace ourselves and try to
achieve simple things before aiming for huge things.
Thomas Fledrich
> Since LH2 and LOX are both cryogenic liquids, regenerative cooling is
> a definite possibility. I fully admit I don't know if regenerative
> cooling will work in this situation.
What know about that is you will get thermal erosion at the cooling channels
if you re-ignite often. On one side there is the extremely hot gas on the
other cryogenic liquid. That leads to uneven expansion of the walls due to
heat. Each time the engine is turned off the channels bend back into the
neutral position, then bend again after re-ignition. It's called
the "doghouse effect" because the side closest to the chamber will bend into
the shape of a roof after several ignitions.
Shouldn't be much of a problem unless you are planning to do a lot of burns.
Will be bigger trouble to set up the cooling channels in a way that they
survive the first burn in the first place.
> I'm not a rocket scientist and
> nobody currently at CSTART is. Most of us aren't much at all in the
> way of experts on anything, we just have good broad knowledge (degrees
> in things like mechanical engineering and applied mathematics). What
> we've done is crunch the basic numbers are described an overall
> mission architecture built on existing technology / test ideas and
> shown that a minimalist manned lunar return trip can be done for maybe
> $60 or $70 million dollars.
The people who originally "invented" rocket science were not rocket scientists
either. They were enthusiastic visionaries of a similar kind as the group of
people you describe. Unfortunately they had the very same problem with
funding until politics got interested in what they were doing when it occured
to the government hierarchy what great weapons those rockets would make.
Maybe we will be able to pull this off without governments this time, but I
believe the best way to do this is to get the effort needed into a range that
we can handle ourselves. And for this we need DIY component development. For
this we need to make open source manufacturing cabable of producing those
components. Which is a huge load of work in itself.
> What we desperately need now are lots of
> people with all sorts of experience to help us fill in details like
> these, help us figure out how to go about actually building this
> stuff, help us figure out how to finance the efforts, etc. We're
> headed to SpaceUp later this month to try to find some of these
> people. I am hoping that the Open Manufacturing Network can help us
> find some people to handle that middle problem.
Definitely for a project of this size we need a lot of people to cooperate. We
should also make sure different projects will be able to use each other's
work for their own developments.
I can help you with advice for now, but not much else until I got my own stuff
together.
> It won't help with propulsion, but it could certainly be helpful when
> it comes to testing that our capsule is pressure-tight, and especially
> testing EVA procedures (our capsule features an EVA hatch much like
> Gemini - EVA requires venting and repressurising the capsule).
For simple testing of pressure tightnest the easiest way to go is to increase
the pressure in the capsule by the difference you will have between vacuum
and cabin atmosphere.
This can be done before any more accurate vacuum chamber testing.
Luke Maurits (CSTART)
> if you re-ignite often. On one side there is the extremely hot gas on the
> other cryogenic liquid. That leads to uneven expansion of the walls due to
> heat. Each time the engine is turned off the channels bend back into the
> neutral position, then bend again after re-ignition. It's called
> the "doghouse effect" because the side closest to the chamber will bend into
> the shape of a roof after several ignitions.
> Shouldn't be much of a problem unless you are planning to do a lot of burns.
> Will be bigger trouble to set up the cooling channels in a way that they
> survive the first burn in the first place.
This is a good thing to know, thank you very much. The bare minimum
number of burns that would be involved is 3: trans lunar injection,
lunar orbit insertion and trans Earth injection. Of course, it would
be sensible to ensure that the engine can survive more than this bare
minimum so that we have a safety margin to do minor corrections on
course.
>> I'm not a rocket scientist and
>> nobody currently at CSTART is. Most of us aren't much at all in the
>> way of experts on anything, we just have good broad knowledge (degrees
>> in things like mechanical engineering and applied mathematics). What
>> we've done is crunch the basic numbers are described an overall
>> mission architecture built on existing technology / test ideas and
>> shown that a minimalist manned lunar return trip can be done for maybe
>> $60 or $70 million dollars.
>
> The people who originally "invented" rocket science were not rocket scientists
> either. They were enthusiastic visionaries of a similar kind as the group of
> people you describe. Unfortunately they had the very same problem with
> funding until politics got interested in what they were doing when it occured
> to the government hierarchy what great weapons those rockets would make.
This is true, and quite an inspirational thing to keep in mind, thanks. :)
> Maybe we will be able to pull this off without governments this time, but I
> believe the best way to do this is to get the effort needed into a range that
> we can handle ourselves. And for this we need DIY component development. For
> this we need to make open source manufacturing cabable of producing those
> components. Which is a huge load of work in itself.
I agree that DIY component development would be a fantastic boon to
CSTART and other projects like it. I am very interested to see what
can be achieved in this field.
> For simple testing of pressure tightnest the easiest way to go is to increase
> the pressure in the capsule by the difference you will have between vacuum
> and cabin atmosphere.
> This can be done before any more accurate vacuum chamber testing.
Of course, this is certainly something that we should try first.
Cheers,
Luke
Thomas Fledrich
> CSTART and other projects like it. I am very interested to see what
> can be achieved in this field.
It might take quite some time to get it to the level where we will be able to
DIY spaceship parts, but one has to begin somewhere...
And open manufacturing will solve a lot of other problems along the way, too.