GAO: The DSN is actually falling apart Options

[Guest_BruceMoomaw_*]

http://www.gao.gov/docsearch/abstract.php?rptno=GAO-06-445

[elakdawalla]

There was a lengthy presentation by Bob Preston from the DSN at OPAG on what the DSN wants and needs to do to improve over the coming decades, and it basically involves replacing all the gigantic, one-of-a-kind antennas with arrays of 6-, 12-, or 18-meter dishes (they are still experimenting to figure out which one will be the optimal size). Unlike the big dishes, each of which needs its own operator, whole arrays can be operated by a single person; also they can plan to have some percentage of all the dishes down at any given time for routine maintenance. Also they can just devote as many dishes as they need to a single spacecraft, splitting the array to support several spacecraft at once or using the whole array for high bandwidth. They've got to be replaced because the big dishes cannot be upgraded to support Ka-band communications.

--Emily

[Guest_Richard Trigaux_*]

They've got to be replaced because the big dishes cannot be upgraded to support Ka-band communications.

--Emily

Yes if the price of a large dish is proportional to more than the square of the diametre, it is better to use a collection of smaller dishes, which cost is only proportional to the square of the (simulated) diametre.


Upgrading the larger dishes to higher frequencies would require to resurface them with a greater accuracy, a thing impossible as the dish somewhat flexes with its movement or with wind, it would need to be rigidified, that means completely rebuilt. So the price of a large dish sharply increases with frequency, while not with small dishes.

Maybe the solution would come from many small dishes spread by clusters or isolated all over the world, in more or less politically stable places, by any state which would want to contribute, or even by private owners. To cut the cost, we would use mass production for the dishes, and ship them by sea.

[Bob Shaw]

Maybe the solution would come from many small dishes spread by clusters or isolated all over the world, in more or less politically stable places, by any state which would want to contribute, or even by private owners. To cut the cost, we would use mass production for the dishes, and ship them by sea.

Richard:

I'm for the democratisation of data, so far as possible, and the notion of many dish arrays is very attractive.

We need to look not only to the current costs of spacecraft data reception, but also the 'distant' costs - Voyager being a prime example. Imagine if Alexander Carnegie funded the Voyager Interstellar Mission, and the new institutions which would be required (anybody want to mention SETI?). We see another analogue in AMSAT, or even SLOOH. The bottom line is that a paradigm shift has to come, whether it be commercial or non-commercial - the rate of change in the volume of data transmission across the Solar System may not follow Moore's Law exactly, but it's certainly in the same league!

Bob Shaw