The guy wires are in the lower atmosphere so they need to survive lightning strikes.  Unless you can find a version of CNT that is a very good conductor of electricity you need a metal lightning conductor.  Depending on the metal the lightning conductor will weigh 6 to 10 tons.  When you have that much metal you might as well use it as the chain.

With a 7.1 hour cycle time I suspect that the system will take several days to settle down.

The resonant frequency is defined by the length of the ribbon which will act as a strong filter.  Standing waves are used by the quartz crystals in computers and also the highly accurate frequency control system in mobile phones.

If too little power gets through more power can be added at GEO and the counter weight.  Being stationary we can use large solar arrays permitting these two to be solar powered.

If the bolo and the descending spacecraft are in the same orbit the approach could be something like 5 or 6 km/h.  Delta Vs of 0.00167 km/s are not normally considered fast

A straight forward way to get people up into space is the beanstalk type Space Elevator, which can send then to both GEO and LEO.  Return is possible from GEO but difficult from LEO, the spacecraft to SE velocity differences are too great.

Given the Space Elevator, what we now need is a cheap way of getting people back from LEO.  The Space Shuttles are being withdrawn on safety grounds and the Apollo type capsules needed the hiring of several very expensive aircraft carriers to perform the retrieval.  Even the US Government found it could not afford that.

Yuri Gagarin had to jump out of his craft and land with a personal parachute.  I do not know what the Russians use now.

The proposed CEV has a heat shield that can only be used once, making it the world's weirdest retrorocket.  A solid “fuel” that takes weeks to refuel is unlikely to be cheap.

Andrew Swallow

I suspect that you posted your reply in the wrong thread.

A straight forward way to get people up into space is the beanstalk type Space Elevator, which can send then to both GEO and LEO.  Return is possible from GEO but difficult from LEO, the velocity differences are too great.

What we now need is a cheap way of getting people back from LEO.  The Space Shuttles are being withdrawn on safety grounds and the Apollo type capsules need the hiring of a very expensive aircraft carrier to perform the retrieval.

Sounds like bolo's need their own paragraph on that Wiki page.

A bolo that can reduce the speed of high drop cargos and change their inclination would save a lot of fuel.

There is a big need for a safe method of returning people to the Earth.  The Space Elevator can do this from GEO but, due to to the delta V needed, is poor from LEO.  There may be someway of using a bolo/rotovator to lower and slow down the space craft.  I notice that the thin skinned Space Ship One was able to glide down at Mach 3.

As described in http://en.wikipedia.org/wiki/Rotovator a Rotovator should make a good Stage 3 of a cable based Launch System.  The tips of Rotovators spin at between 1 and 3 km per second.  This is a convenient fit for cargos high diving to LEO from the Space Elevator.  For a circular LEO orbit such cargos need to slow down by between 2.0 and 2.2 km/s.

The cargo would be raise to the drop height using a Space Elevator and then be released to dive to LEO.  During the drop a rocket would change the inclination of the orbit.  After arriving at LEO the spacecraft meets up with the Rotovator which slows it down to a near circular orbit.  A small engine is then used to taxi the spacecraft to the correct height and latitude.

NASA - corporate entities can be schizophrenic, they consist of different departments with different agendas.  A scientific department that wants to launch a satellite cheaply may like a new method into space, when they can be bother to read the sales leaflet.  The department that runs the launch pads will quickly decide LiftPort is a rival and want to get rid of it.

An exclusive contract might buy off the NASA top management but the launch pads department cannot be bought.  Launching SE1 for payment may be considered to be their duty by the appropriate parts of NASA, ESA or the Russians – so getting SE1 into space may possible, just do not try to find the limits of duty.

Exclusive contracts with NASA, ESA or the Russians are a danger to LiftPort.  Anything that sounds like a cartel or price fixing or a subsidy attracts the cartel busters.  LiftPort cannot afford to spend 10 years fighting assumed guilty until proven innocent charges, especially if it is innocent.

However LiftPort may be able to give NASA a fixed fee equal to say $500 per kg to GEO for the first year.  Check the legality with the lawyers.  After a year the accountants should be able to tell the directors exactly what the costs are.

Rolled lead has a speed of sound of 1960 m/s
http://en.wikipedia.org/wiki/Speeds_of_sound_of_the_elements_%28data_page%29
Cork is slower at 500 m/s
http://hypertextbook.com/physics/waves/sound

There may be something more appropriate.

The non-linearity of scale models is a problem that also effects the models used to test aircraft, ships and trains.  The compromise is that somethings do not get scaled.

The thickness of the ribbon will have to be one of ours.  Just pick a wire thickness that does not break.  A different model will have to test cable thickness, probably using incorrect length.

As for the mass of the mini-climber, calculate how much power the system produces and use that to set the size of the demonstration climber.

Until we have working models in the laboratory lets not rush to making outdoor models that are several miles long.

Spring (Device)
http://en.wikipedia.org/wiki/Spring_%28device%29

Suspension bridge
http://en.wikipedia.org/wiki/Suspension_bridge

Spring (Math)
http://en.wikipedia.org/wiki/Spring_%28math%29

Vehicle suspension
http://en.wikipedia.org/wiki/Suspension_%28vehicle%29



As a proof of concept build an oscillating elevator that is 2 metres tall.  Have a tiny climber go
up and down it.  People will not understand what is going on until they have actually seen it.  The material could either be CNT, cotton, copper or steel.

The up climber and the down climber may have to be different since we can do without the complexities of a gear box.

All the parameters will have to be scaled down to 2m
String length L = 2 metres
Wave length λ = 2L = 4 metres
Frequency  f = v/(2L)

v depends on what the ribbon is made of.

Steel v = 5960 m/s
Steel f = 5960 /(2 * 2) = 1490 Hz      (corrected)


1% amplitude is λ/100 = 4/100 = 0.04 metres (4 cm)

Ribbon speed = amplitude /  frequency = 0.04 / 1490 = 0.000,026,8 m/s = 26.8 e-6 m/s

It may be easier to reel in 4 cm but staying shrunk

I do not know what Q for steel is but using the same value 20
Reeling distance = 5% of amplitude = 5% of 0.04 m = 0.0002 m = 0.2 mm
Reeling speed = 5% of ribbon speed = 5% of 0.000,026,8 = 0.000,001,34 = 1.34e-6 m/s

I suspect that the loads are not symmetrical.  Gaps in the middle of satellites are not normal so customers will want the entire stage 2 rocket in front of the ribbons.

If it is moment of inertia that needs balancing rather than mass then the cabins can be balanced by having long booms out of the back.

My underline.

You have connected the top and the bottom, that turns your two ribbons into a single band.  The cross connections may be short but both ends are supplying large forces so they cannot be ignored.  Fortunately the band and the double ribbon have may resonant frequencies in common, including the one you are using to lift the cabins.  The cross connections synchronise the oscillation in both vertical sides.

Andrew Swallow

By the time I had draw the second diagram I had worked out what you were doing.  I have done a lot of radio work so I understand how resonant frequencies work.  This has also taught me the sort of things that go wrong.

One of the purest examples of a resonant frequency is an element's X-ray spectrum.  Below is the diagram for magnesium.

 You are designing the Oscillating SE around the equivalent of the yellow bit.  This is fine and will get your lift cabins into space.  Unfortunately the equivalent of the blue bits will then strike.  No frequency is pure.  The system will vibrate, it may be a slow vibration but it will vibrate.  Fortunately you only have to survive the effects of the impurity - strength and dampening.

Heavier climbers can be used when the wider cable inserted at GEO arrives at the powered pulley.  Since we know the cable's length this can be calculated in advance.  To maintain 10 levels of tapering will require careful planning.

To maintain a pull of 1 ton as the ribbon gets wider the inserted mat needs to get shorter.  The weight of each map being (1 ton – weight of climber)/2.  The ribbon containing two cables that presumably get updated together.

Can the GEO to counter weight part of the ribbon have more tapering levels?