[AR] Re: 500,000 tons

  • From: Ben Brockert <wikkit@xxxxxxxxx>
  • To: "arocket@xxxxxxxxxxxxx" <arocket@xxxxxxxxxxxxx>
  • Date: Tue, 6 May 2014 17:18:33 -0600

That's interesting, can you do 150kft at the MTA, or is this a Black
Rock project? How high do you expect it to go with the dummy stage?
Any cameras or other payloads?

I've gotten a lot more into microcontrollers over the last year, some
relevant (rocket avionics) and some less so (brains of a 3'x6'
"Operation" game). I've also been putting some effort into 3D printed
liquid engines, which I'm fascinated by; I wish the southern
California student group that has test fired one at FAR and helped by
list members would post some details on it.

I visited two new-to-amateurs possible space launch sites in day
driving distance of Denver, and had extended discussions with the FAA
on the first one. The second one has more difficult airspace but quite
appealing launch altitude and population density. I've also been out
to the possible Spaceport Colorado a few times, and they said they
expect to have a new director soon. I may have managed to convince
them that having a rocket static testing area would be more likely to
get used than the ability to do suborbital point to point.

I also blew up my shop's shared CNC mill last week. The brake came
loose internally during a run and took out one of the conical plates
of the variable speed drive. In the smallest of victories, I was in
the process of machining part 6 out of 4, so at least I could finish
the project with one spare.

At the Denver Mini Maker Faire over the weekend, the Denver Science
Museum had a fantastic rocketry outreach project for kids. They'd make
a construction paper rocket with a film canister in the base, then
mount it on the launcher which was some plumbing pumped to 60psi with
a bicycle pump (by the kid if they were large enough).

A solenoid valve powered by a cordless drill battery (and activated by
a big red red arcade button) would launch the rocket. Launching at a
45 degree angle they were getting distances of a hundred feet on the
good ones. All the rocketry lessons of stability and aerodynamics were
there.

We did a similar thing at Iowa State, using alka seltzer and water in
the film canisters to make carbon dioxide and launch the rockets
upward. But the air system was so much cleaner and more powerful. I'm
going to post some pics of it, and probably try to convince some SEDS
chapters to build some for outreach.

Ben

On Tue, May 6, 2014 at 4:41 PM, Bill Claybaugh <wclaybaugh2@xxxxxxxxxx> wrote:
> Ben:
>
> I've not personally ever had much success at convincing a fool to stop being
> foolish. I have found that foolish talk thrives in the absence of serious
> conversation.
>
> So upon what are you working?
>
> I've got three six inch motors under construction; one for static test,
> another for flight and the third as a dummy second stage on the flight
> motor. Backup is the "flight" motor becomes a static test article.  In
> theory a two stage six inch should be good for around 180,000 feet;
> accordingly, I'm say'n 150,000.  Might could actually have time for this
> over the nest year....
>
> You?
>
> Bill
>
>
>
>
> On 5/6/14 5:15 PM, "Ben Brockert" <wikkit@xxxxxxxxx> wrote:
>
>> For the love of FSM, please, go, build a successful and highly
>> profitable SBSB company and prove us all wrong. Just stop wanking
>> about it on a rocketry mailing list.
>>
>> On Tue, May 6, 2014 at 1:53 PM, Rüdiger Klaehn <rklaehn@xxxxxxxxx> wrote:
>>> On Tue, May 6, 2014 at 12:03 PM, Uwe Klein <uwe@xxxxxxxxxxxxxxxxxxx> wrote:
>>>>
>>>> Am 06.05.2014 02:32, schrieb James Bowery:
>>>>>
>>>>> About 5 years ago I did a blog post titled "Arrival of the Solar Power
>>>>> Satellite
>>>>>
>>>>> <http://jimbowery.blogspot.com/2009/07/ive-been-following-space-solar-power
>>>>> .html>"
>>>>>
>>>>> and did a rough calculation that, based on the Powersat patents, it
>>>>> would take 20,000 Falcon9 launches to loft 250GW capacity and the total
>>>>> installed capacity would be under $3/W.  If you do that over the course
>>>>
>>>> Medium scale Photovoltaics are now @ ~1€/Wp here ( Germany )
>>>>
>>>>
>>>
>>> 3 USD per watt of _continuous_ power from a solar power satellite is much
>>> more economical than 1 EUR per watt for seasonal, intermittent power with a
>>> capacity factor of less than 0.1 (in Germany). You would need 10W of
>>> terrestrial solar for the same _average_ power production. But producing
>>> power when power is cheap is not economical without subsidies. So you would
>>> need 13W of terrestrial solar power (because of storage inefficiencies) and
>>> maybe a month of storage to have roughly the same capability for base load
>>> production. I guess space solar power will have a hard time being
>>> competitive with ground solar power in places like California and the
>>> American south west where there is plenty of sun and cheap property. But in
>>> places like Germany where there is very little sun and property is very
>>> expensive, it will be much easier to be competitive.
>>>
>>> Good luck finding a place for the huge pumped storage plants that would be
>>> necessary for storing energy on a large scale. Every time somebody proposes
>>> to build pumped storage in Germany, the environmentalists are up in arms
>>> about it. See the proposed Schluchseewerk or Jochberg pumped storage
>>> facilities.
>>>
>>>
>>> In fact I think providing peak power could be a niche for space solar power
>>> to grow in until it is cheap enough for base power. You are already
>>> transmitting energy over 36000km. You can easily redirect the power to the
>>> other side of the world in seconds by just moving the beam. So you might as
>>> well take advantage of this to provide power to wherever in the world it is
>>> most valuable at the moment.
>>>
>>> If you imagine a world mostly powered by intermittent power sources like
>>> solar and wind, there will always be places where there demand exceeds
>>> supply and energy costs are therefore very high (*). For solar power, there
>>> is a mismatch between demand and supply in the morning and especially the
>>> evening. And of course there are large fluctuations due to cloud cover and
>>> seasons. For wind there are also large fluctuations that can last several
>>> weeks to months.
>>>
>>> If you had receivers near most large consumers around the world, you could
>>> follow the seasonal, daily and even hourly demand/supply mismatch. The
>>> economical advantage is huge: while bulk base/off-peak energy costs less
>>> than 5 cents per kWh in most countries, peak energy costs up to 10 times
>>> more. Of course, to take advantage of this you would need a design where the
>>> receiver is relatively cheap (maybe infrared laser power transmission to
>>> tethered stratospheric platforms). But that is exactly what is required for
>>> a small prototype power plant anyway.
>>>
>>> (*) Providing full backup using gas power plants is becoming uneconomical
>>> for the few days per year that backup is needed. In Germany, extremely
>>> efficient gas power plants are being shut down because they are
>>> uneconomical, while lignite coal power plants thrive.
>>>
>>>>
>>>>> of 5 years that's an average of about of one Falcon9 launch every 2
>>>>> hours.
>>>>>
>>>>> The calculations I went through are pretty simple so any bad assumptions
>>>>> or calculation errors should stand out.
>>>>>
>>>> Ever looked at the carbon footprint for those PowerSats ;-?
>>>>
>>> If it is cheap enough to be economical without subsidies, it will
>>> automatically have an EROI (energy return on investment) of much more than
>>> 1. It is just in heavily subsidized markets like corn ethanol that something
>>> can be economical without having a positive EROI.
>>>
>>>>
>>>> Uwe
>>>>
>>>>
>>>
>>
>
>
>

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