Book Review: Deep Space Propulsion

Recently finished reading Deep Space Propulsion - A Roadmap to Interstellar Flight by Kelvin F. Long, 2012. A book review has already been written here so won't duplicate however will comment on a few points made in this excellent introductory text.  A rundown of current known propulsion schemes is given outlining their pros and cons for interstellar flight ranging from electric and nuclear based propulsion, solar sails, beamed power, nuclear fusion and external nuclear pulse propulsion, antimatter etc. Projects Daedalus and Icarus are also mentioned.

 

 

Some interesting points I picked up while reading the book:

Seven key motivations for interstellar travel are given:

 

Continued survival ie the ability of humans to survive on another planet would greatly increase our prospects for long term survival and also makes the point that while some suggest we should be focusing inwards on our problems on Earth and remain home  the author's reply to this is "These attitudes will only lead to one result: stagnation and regression of the human race" which I agree with. If one looks back in history some of those nations that went to the trouble of building ships to explore new worlds are fairly well off financially and increased our knowledge base (scientifically and culturally).

Balance of resources given the rate of population growth there will be a breaking point as far as the need for resources to sustain the future population unless more resources outside earth are found. When a nation runs out of critical resources they either buy more, take it by force or perish.

Economic opportunities ie plenty of money to be made by mining asteroids etc. Very rare minerals/metals required for certain key technologies on Earth may be in abundance in other places in our solar system.

Quest for knowledge ie Are we alone for eg? How many Earth like planets are there within 50 ly from Earth for eg? Astronomy / AstroPhysics / Universe etc

Spreading of life

Freedom factor

Starstuff driver ie the atoms in our bodies were made in stars and the author hints that we have a longing to return to what created us.

 

Another interesting point made by the author: "Any material that is launched into Earth orbit will cost typically around $50000 / Kg." This needs to be reduced substantially for any large scale space exploration. The current alternatives to chemical rockets are:

 

 The space elevator: feasible however the technology to mass fabricate the Earth to Orbit cable using high strength carbon nano-tubes is not in place (steel wire cable won't do the job).

 

 Project Orion: (external nuclear pulse propulsion): the energy release from nuclear reactions is of the order a million times greater than that from a typical chemical reaction making this vehicle a feasible alternative to chemical rockets. However detonating nuclear bombs in earth's atmosphere to get the vehicle off the ground leaving a radioactive trail behind isn't a good idea.

 

 Skylon Project: although this proposed spaceplane still would use a liquid oxygen/hydrogen rocket to reach orbit it is worth a mention because this is a step in the right direction as far as reducing the cost of getting hardware into orbit is concerned however not the breakthrough solution I am after (ie an elegant non-chemical propulsion solution).

All in all a good introductory text worth a read, has nice colour pages of the various designs talked about in the book.

CI.

Dampier, WA with Red Dog.

 

Some thoughts for 2012

Haven't posted for a while so better put something up! Wishing everyone clear skies and smooth waters for the year. What is the difference between Mathematics and Physics? Picked up this interesting quote which is food for thought:

"We are able to demonstrate geometrical matters because we make them; if we could prove physical matters we would be able to make them".  

Giovanni Vico (1668-1744).

What's happening with Propulsion Physics and where are we going? Is Interstellar Travel going to happen sometime soon? Several interesting papers were published in 2011 and the 100 year Starship conference went ahead however don't see them leading to a breakthrough anytime soon. Several key technologies such as fusion reactors need to be in place before the propositions in the papers can be turned into a Starship so one might have to wait at least 50 years, Marc has his wonderings on a possible future timelime here. It appears that the Universe as we understand it with our current models is not human friendly as far as practical interstellar flight is concerned although the Physics doesn't deny us Interstellar Travel, it appears that one needs to be prepared for the extreme challenges of distances and time required to travel to possible nearby Earth-like planets in our Galaxy.

If Schiller's Strand model for eg turns out correct, then it looks like Physics is close to being complete which would make it even more difficult for Breakthrough Propulsion Physics. Between work, I am pursuing my studies for 2012 in Quantum Vacuum Physics & Engineering and see where it leads. The other big problem is getting large amounts of hardware into orbit without using chemical rockets. Is there a viable solution without using space elevators?

Some recents photos taken when I was recently in Exmouth, Western Australia. Most interesting sites are the US Navy VLF transmitter for submarines and the Learmonth Solar Observatory. Didn't see any turtles laying eggs on the beach, they turn up at night.     

CI.

Local Exmouth resident.

Vlamming Head Lighthouse.

Navy VLF station in the distance.

Closer view.

Checkout the Sydney outline diagram!

An interstellar position fixing method

Paper is now available for download at:

http://vixra.org/abs/1106.0053

CI.

Nuts and bolts

It has been an interesting start of the year for 2011 with some recent items worth mentioning:

Marc Millis of the Tau Zero Foundation posted two papers related to interstellar flight:

Progress in revolutionary Propulsion Physics: summarises the current state of where we stand towards a solution? for "timely interstellar flight - to reach other habitable worlds within a human lifespan". There are currently many options available to reach other stars using known physics. Most would take many decades just to reach our neighbour stars and none of them can get us to destinations beyond many light-years away in a timely, human lifespan timeframe. The paper uses many references from the first recent textbook devoted to this area of research and is worth every dollar: Frontiers of Propulsion Science. I like Figure 1 in the paper which graphically shows the many areas of Physics and concepts that need further research grouped by the key barriers to practical interstellar flight as stated in the paper: Non-propellant propulsion, faster than light travel and energy breakthroughs.

Second paper by Marc: Energy, incessant obsolescence, and the first interstellar missions: there's a review here. Regarding the "incessant obsolescence postulate: No matter when an interstellar probe is launched, a subsequent probe will reach the destination sooner and with more modern equipment": better launch as soon as one has the capabilities to do so because the opportunity may not present itself again due to unforseen circumstances in the future or "societal retardation" ie unforseen catastrophies or less energy production. The implicit motivations for interstellar flight, Table 6 in the paper is interesting, apart from the obvious scientific benefits from the mission and safeguarding humanity's long term survival, I liked another reason that Marc mentions in his talk to pursue interstellar flight: it gives nations something to conquer peacefully and together rather than concentrating on conquering each other on Earth.

Significant results released by the Kepler space telescope shows possible candidates for other Earth like planets. From the NASA press release:

"The fact that we’ve found so many planet candidates in such a tiny fraction of the sky suggests there are countless planets orbiting stars like our sun in our galaxy," said Borucki. "Kepler can find only a small fraction of the planets around the stars it looks at because the orbits aren’t aligned properly. If you account for those two factors, our results indicate there must be millions of planets orbiting the stars that surround our sun."

Also checkout APOD, Centauri Dreams, this and this.

Got in the mail a few days ago: Advanced Propulsion Systems and Technologies, Today to 2020. Another major problem to practical interstellar flight is getting the expected large amounts of hardware out of Earth's gravity well into orbit without using chemical rockets. Space elevators have been proposed (which seems only viable if ultra high strength carbon nanotube cables can be commercially fabricated in the required lengths). A more elegant solution? from Space Drive Physics is worth looking into (see Marc's first paper for an introduction, Chapter 3 Prerequisites for Space Drive Science and Chapter 12 Thrusting against the Quantum Vacuum in Frontiers of Propulsion Science). Anyway should be an interesting read.

CI.

Fremantle Harbour, Western Australia.

Dampier Harbour, Western Australia.

Book Review: And Yet It Moves

Today I finished reading And Yet It Moves: strange systems and subtle questions in Physics by Mark P. Silverman. I found this book particularly interesting as it introduced me to quantum phenomenon which previously weren't very familiar to me. The author being a research physicist has first hand experience with the topics he discusses. Several experiments are descibed including the wave like propagation of electrons in the two-slit experiment describing the familiar wave interference effect and the Aharonov-Bohm effect and other subtle behaviour of electrons. To me the nature of this particle is somewhat still not understood. Some texts for example will describe the electron as point-like as today's experiments give no measurable size of this particle (the classical electron radius is given as 10^-13 cm), however there is no such thing as a point-like entity (and no such as thing as a mathematical singularity in nature for that matter which rules out infinities as well, the Universe is not infinite) so suffice to say the electron must have a size albeit very small and unmeasurable with current technology.

The author goes on to describe some exotic atoms describing some which can be nearly the size of bacteria!, the physics of light reflections, light polarisation, the Mach-Zehnder interferometer, the amazing (check this out!)  Vortex Tube and other interesting subtle effects. The author asks on p204:

"Can the rotation of the Earth influence the structure of an atom?"

And goes on to discuss biomolecular chirality ie why living things make and use specific types of molecules such as right-handed sugar molecules or left-handed amino acids (this isn't understood, Earth evolutionary reasons?). The last chapter "Science and wonder" gives a personal account on various issues with science education, from the last page:

"To teach science well, one must have the philosophical attitudes of a scientist: to see science as culturally important, technically useful and aesthetically moving; to understand that the pursuit and acquisition of scientific knowledge helps free the mind from the bondage of ignorance, superstition and prejudice; to have a driving curiosity to comprehend the reason that manifests itself in nature and to enjoy sharing this curiosity with others.

  Einstein's eloquent words say it all:

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. He who knows it not and can no longer wonder, no longer feel amazement, is as good as dead, a snuffed-out candle."

Great book, definately recommend reading it, got me chasing up some of the references at the back as well.

Red Bull Flugtag 2010 photos

     

A few weeks ago we had the judges onboard for the Red Bull Flugtag event in Farm Cove near the Sydney Opera House. Those crazzy people with their flying machines were at it again! It was a nice sunny day and there was a good turnup with the crowds and boats.

One of the teams made quite a long flight (it was pretty much a standard flying kite though, no exotic design). Most just fell straight down off the ramp to see their flying machine broken into bits and pieces. The judges gave scores to each team for design, asthetics etc.

After the crew are rescued by Surf Rescue, what happens to these flying machines?

Although few teams have demonstrated their mastery of flight, it was a fun day out on the water.

CI.

A day out on a 100 tonnes mobile slewing crane

I recently finished a course at Botany Cranes to get a WorkCover 100 tonnes mobile slewing crane licence (for work reasons on boats). Because I was the only one in the class, they sent me with one of the crane drivers for a day for a dual lift job to see first hand the operations of the crane and get some dogging experience. I thoroughly enjoyed the course and more importantly passed the big test at the end. The crane I went on was a Liebherr 100 tonnes crane who make some of the best cranes in the world. The other crane that came with us was the 130t crane. A support truck and crew is also needed for the cranes to carry additional hook blocks, counterweights, packing for the outriggers etc.

Leaving the yard from Botany Bay our destination was the P&O container depot near Bankstown to put together an Omega Megastacker crane (brand new) which is used to lift and move shipping containers.



The Cranes



The job

After a toolbox meeting with the other crew, the cranes are parked into position and outriggers for the cranes extended to maintain stability of the crane during lift. Timber packings are used under the outrigger pads to spread the weight of the crane over a larger surface area onto the ground. All the wheels of the crane must be above ground and the crane dead horizontal. There is an electronic equivalent of a spirit level which makes this process fairly straightforward.



Setting up the outriggers



The crane operator will decide what hook blocks are required for the job, what hook radius he will be operating (and hence how much boom needs to be blown out) and more importantly how much the load mass with all lifting gear such as spreader beams need to be included. The crane operator reads the Load Chart for the crane which gives all this important information and will decide how much counterweight needs to be placed at the rear of the crane. All these factors will dictate what the maximum load the crane can lift for those parameters. With the boom fully extended, this crane would tip over if the operator forgets to place counterweights on the crane. The Liebherr cranes have an onboard computer which also makes all this process straightforward and safe (we don't want the crane to be tipping over or brake the $2.5 mil crane!). The more the boom is blown out or the more the boom is lowered for a given boom length, the less the crane can lift.

After unhooking the hook block at the front of the crane and setting up the counterweights, the crane operator blows out the necessary boom sections. Everything is hydraulically operated and one selects from the computer screen how much boom we want. Two heavy hauler trucks turned up with the Megastacker's boom and arms, nice $20000 paintwork!



The first truck looks like a Transformer in disguise? ;-)



After both cranes are setup and the truck with the first part of the Megastacker in position, the dogmen setup the chain slings required for the job. One person will direct the crane operators for the dual lift job. This is a delicate operation and both cranes need to work together so no extra stress is placed on the cranes and lifting gear. The first part of the job required the boom section of the Megastacker to be placed into position so the Omega technicians could pop in the holding pins for the boom. Once this was done hydraulic rams needed to be lifted and bolted on both sides. The position of the boom had to be in perfect alignment otherwise the pins wouldn't go in.



Putting the million dollar Megastacker together



After the boom section and rams were secured, the next part of the job was to lift and attach the grabber (which grabs and locks into the containers). This was also a delicate operation. Hydraulic rams needed also to be lifted and bolted into position.

The grabber section for the Megastacker

By late afternoon the job was finished and it was time to pack up the gear and stow the cranes for road travel. Because of the tare weight of these cranes, they aren't allowed to travel on some bridges (including Sydney Harbour bridge), tunnels etc so he needs to have a good read of a street directory to decide what is the best route to get to and from a job. We make it back to the Botany Cranes yard after heavy traffic on the main roads. With all the construction that goes around the city, the other cranes are also out doing jobs.

So there you go, great day out and learnt a lot. If you want to see how big these cranes get, checkout the Liebherr 1200 tonnes mobile slewing crane! (Other crane types get even bigger). Doing the Dogman course at the moment (at another school because of timetable reasons). A Dogman is the person who slings the loads, directs the crane operator etc, big test in a few days so better get back to studying! Till next time.

CI.

Caricature

Got a visit in the wheelhouse yesterday by Caricaturist Gavin Bell during a cruise in Sydney Harbour (Red Bull Flugtag event photos coming soon). Here it is!