Doughnut balloon-chute spaceships to reach Mars, Neptune

How?

How do you deploy an inflatable ballute from a craft entering an atmosphere at 20km/s? How do you keep the ballute attached to the craft? How do you Stop the ballute deflating if it's hit by a micro-meterorite? Hmmmmmmm. Nice try fellas.

how quaint

another supersonic shockwave rider, how 1960s.

XB70 did it. Now thats what I call variable geometry

@Robinson

Such easy questions.

The answers are, in order:

1) Press the "deploy" button and, when that fails, poke it out with a straightened wire coat hanger.

2) Duct tape.

3) Duct tape.

@Robinson

I suspect one of their plans is to deploy this device while in the very uppermost parts of the atmosphere (where the 'air', and hence drag, is very low indeed), and do so whilst at a relatively low angle of descent (you know, more like 'almost' following the shape of the planet, a decreasing orbit, rather than attempt a 90 degree free fall towards mars firma.. although I suspect the later stages of descent will feature this kind of angle).

I presume they will keep it attached with an (to me) unknown number of cords of (to me) unknown composition.

micro meteorites? tough call, I have no idea. Mind you, once they encounter the mars planetary defence system that will be the last of their worries.

Ballute is rubbish

Paraloon is much catchier

any fule kno the old ballute braking ploy...

Hmm, quoting from the Odyssey File (the book of the making of 2010 by Arthur C Clarke and Peter Hyams)...

"We have arrived at the Rectal First Big Ballute Plasma Shower Gas Saving Low Energy Fart Aerobraking Manoeuvre As Conceived By Arthur C Clarke (It can also be referred to as the old R.F.B.B.P.S.G.S.L.E.F.A.M. ploy)

Mmm...

mmmmm mars.... doughnuts...... mmmmmmmm interesting article..... doughnuts......

@Robinson, @Mark_T,

@Robinson

"How do you deploy an inflatable ballute from a craft entering an atmosphere at 20km/s? "

You deploy it outside the atomosphere. The clue is from *outside* the atmosphere. Inital atmospheric pressure is a millionth of ground level. Its *differential* pressure that keeps it solid.1KPa (c0.147psi) is enough to keep it rigid at this altitude. The vehicle is enteriing at a shallow (<10 deg max) angle to the horizontal.

How do you keep the ballute attached to the craft?

I'll presume your looking at the cords. Both Alumina and Zirconia based fibres are available (Melting point to 1800c/3300F) but its not clear if this is available in long form. Carbon fibre would need protection. FeCrAlY is in wire form and usable to 1400c. The ami is to keep the deceleration low and the lift high.

" How do you Stop the ballute deflating if it's hit by a micro-meterorite?"

Initial work on this in the 1960s has the high temperature mesh/fibres on the outside with the pressure membrane. Its an inside out tyre.

@Mark_T,

"Yet another business designed on the model of consuming R&D money for profit."

Ex NASA guys get their old buds to cough up some cash to pursue their pet project.

Sure sounds that way. But this idea has knocked round since the 1960s and it should be pushed further. SBIR is a good idea in theory but I wonder just how many of those SBIR start-ups actually blossom into self-financing companies with *real* incomes and products someone can buy. Otherwise its basically corporate welfare.

Mine is the one with the basic re-entry book written in the 1960s in the pocket.

LOL

"any fule kno the old ballute braking ploy"

Mine's the one with the copy of Down with Skool in the inside pocket.

not only on Mars

It would seem that the space shuttle could use a safer means of returning to earth.

Of course the shuttle only uses fuel to slow its orbit so that it enters the atomosphere. But, relying only upon a heat shield has proven deadly.

Maybe a donut is not the best shape. And materials are key. But, the idea of using a large lightweight object of some kind to slow reentry/entry might make a lot of sense (economics/engineering). And maybe a propeller shape of some kind might even serve to recapture some energy. Maybe a big corkscrew? Adjustable of course. And perhaps one that breaks down into an autorotational set of blades.