I have no problem with the Boeing report but its conclusion is for tether lengths that are much longer than the ones that are being discussed in this article  This is where your lack of knowledge about engineering is a problem The mass of a space tether goes up with length  Assuming it could take the thermal environment you can build a space tether out of kite string  But there is a limit on how long this space tether could be made based on the strength to weight ratio of the string  This is where designers start making tapered lines that have more cross sectional area in the middle than at the ends  Even with this there are still limits on the length based on cost and total mass  You can make an Earth surface to geostationary orbit space elevator using kite string but it will be larger than the Earth hence not practical  That doesnt mean that you still cant use that kite string to fly a kite obviously you can  The difference is in the length  The space elevator is  km long  Your kite string is only a few hundred feet at most  The same applies to skyhooks  You could build a  km long space elevator out of TGB carbon fibers but it would have near planetary mass and as a result isnt practical  But like the much shorter kite string for flying a kite a skyhook made of carbon fibers in the  km to  km range is possible As to the references not all being open source on the internet there is not much I can do about that  You will need to either pay for them or go to a university library that pays for access to them and have them downloaded  References   and  are open source  Reference  is only for the part of that paper that covers nonrotating skyhooks and does not include the entire paper  If you want to see the entire paper do a search using the title on google it is open source   Quite simply the information is out there but you will have to do a little digging or pay for it  You will also need a basic understanding of engineering and orbital mechanics in regards to space tethers  For that I recommend the Tether in Space Handbook it is also open source on the internet see reference  You could also just read the abstracts for the nonopen source papers and you will get an idea that this is a workable concept  Or you could just notice who is writing these reports NASA reference  Lockheed Martin references    and  and Smithsonian Astrophysical Observatory reference   Do you really think these organizations would be wasting their time and money on a lie  To conclude with the Boeing report  The Boeing report says   His analysis showed that because a hanging tether must be tapered to support its lower end in the gravitational field of the Earth achieving a HyperSkyhook tether tip rendezvous with a  kms  kfts or Mach  airplane would require a HyperSkyhook tether mass of  times the payload mass   kms is  of low Earth orbit velocity  A tether mass of  times payload mass can be built  I have no argument with this   Trying to lower the tether tip speed to  kms  kfts or Mach  would require a HyperSkyhook tether mass greater than  times the payload mass   kms is  of low Earth orbit velocity  A tether mass of  times payload mass sounds about right and it is highly unlikely that such a tether length would be economic  Again no disagreement  The tether tip speeds for the nonrotating skyhook examples in this article and in all the references I have listed start at  of low Earth orbit velocity and go to approximately  of low Earth orbit velocity  There is no reason to go any lower As a result the final line of the Boeing quote In general the nonspinning tether HyperSkyhook concept does not look competitive with the spinning tether concepts  does not apply for two reasons   It doesnt apply to the skyhook lengths in the article and  it is an unfounded over generalization that falls under the category of sales BS that is promoting rotating skyhooks  Do you now understand how the Boeing quote that you are so fond of does not apply to the nonrotating skyhooks in this article  PS  The reference numbers are for the article as I have written it  Since you keep deleting references with your changes the reference numbers keep changing hence you will need to use the article as I have written it if you want the reference numbers quoted here to mean anything  So please read this until you understand it and do your research to confirm what I and many others are saying If you run into any problems that you cannot resolve easily write me here and I will do what I can to assist you