At least publicly, NBN Co's satellite policy has been explained extensively and in detail whereas the Coalition's response has been reduced to sniping soundbites.

When a heated Twitter exchange saw Malcolm Turnbull challenging the legitimacy of NBN Co's numbers around satellite capacity this week, he may have bitten off more than he was planning to chew.

Asked whether he had seen a rather extensive analysis at Delimiter that ultimately savaged the Coalition's response to NBN Co's $2Bn satellite program and $620m satellite purchase, Turnbull suggested the telecommunications industry is not in agreement with NBN Co's network design engineers.

Those engineers argued they had spent two years doing capacity planning, and said the company could probably have "kludged together" up to 10GHz of total leased satellite capacity to deliver the NBN to rural areas; that's apparently around one-quarter the total capacity available in Australia, and around 10 per cent of the 90GHz in additional capacity the two planned NBN Co satellites will contribute.

Capacity is only one issue with leasing capacity: risk is another. Companies like NewSat, an Australian company that has been a vocal critic of the NBN Co move, gets much of its capacity from third parties. However, cobbling together a decent slab of Ka bandwidth from a large number of providers - even if it were available - would introduce significant logistical and management complexity for NBN Co. Convoluted chains of command and variable service levels, not to mention widely variable disaster recovery, would all dramatically change the risk profile of a leased NBN Co solution compared with owning and operating its own satellites.

Risk aside, it took just hours before Turnbull's challenge - presumably linked to NewSat's angry lobbying campaign - was answered by none less than the CEO of Optus, which operates the country's largest array of satellites and runs NBN Co's temporary 6Mbps Interim Satellite Service (ISS).

Yes: Optus CEO Paul O'Sullivan says the company's birds are already well accounted for and that there isn't enough capacity on its network to even begin to meet NBN Co's requirements. Furthermore, their use of the Ku microwave band (which operates in roughly the 12 to 18GHz frequency range) limited the speed of the services they can deliver.

In other words, not even the country's largest private satellite operator could hope to deliver services comparable to those set to be delivered by NBN Co.

Turnbull, who fell into a familiar tempo by deriding NBN Co's plan as a 'Rolls-Royce' solution in his response to the announcement, readily concedes that Ku-band satellites are an inadequate solution for providing satellite broadband, instead conceding that the Ka-band birds NBN Co is buying are necessary to provide reliable 12Mbps services to large numbers of customers (Ka-band systems operate in the 26.5 to 40GHz range and offer higher throughput but are more susceptible to interference from ground weather conditions).

While Ka-band transmission is better for broadband, Turnbull argued, "it doesn't follow that NBN had to buy its own".

Just where this capacity will come from, however, he has not said. NewSat might offer a bit of capacity with its Australia-focused Jabiru-2 satellite offers Ku-band connectivity, while its Jabiru-4 will offer 6GHz of Ka and Ku-band coverage across the Pacific Ocean region (including Australia). However, its Jabiru-1 will deliver 7.6GHz of direct Ka-band capacity primarily in a swathe from eastern Africa to India; Jabiru-3 focuses Ka-band coverage on Europe and Africa; and Jabiru-5 covers North America, South America, and western Africa.

A look at other satellite operators around the world reveals that none currently have operational Ka-band satellites in the sky anywhere near Australia: North American operator ViaSat is first to offer Ka-band commercial services via its ViaSat-1, but is targeting the impending JUPITER and other satellites at high-density markets like Brazil, India and China.

Other well-known satellite networks are still many years away from flying Ka band satellites. Inmarsat's Broadband Global Area Network still boasts of data speeds of up to 256Kbps; Globalstar, which will finish a 24-satellite network upgrade later this year, will still only support a whopping 9.6Kbps through its Voice/Duplex data services. Optus has the abovementioned Ku capacity but Ka is still some time in the indeterminate future. Iridium is selling its Iridium Global Network on the basis of its reliability and not its speed, which is best suited for making voice calls from anywhere on earth but woefully specified for broadband.

Projects such as Eutelsat Communications' W5A satellite will deliver more Ku-band capacity, for example, as will nearly every satellite to be launched in the first half of this decade. Indeed, a search of the work plans for other major satellite providers reveals scarce Ka-band capacity in the works for Australia and surrounds.

Satellite launch-tracking site SatLaunch.net shows that of 53 satellites due to be launched this year, just two - Al Yah Satellite's YAHSAT 1B (centred on the Middle East) and Avanti Communications' HYLAS 2 (Africa and the Middle East) - will have large numbers of Ka beams suitable for broadband services.

Of around 48 satellites due for launch next year, just two - INMARSAT 5 F1 and INMARSAT 5 F2, part of that company's mobility-targeted Global Xpress broadband network - have substantial Ka capacity. How much of this will be centred on Australia is not clear - but history, and the guidance of industry leaders like Hughes, suggest that our region is hardly a priority given the size of other markets.

In 2014, 42 scheduled launches include Ka capacity only on INMARSAT 5 F3, ViaSat 2 (which may well be delayed), and the TV-focused DirecTV 14. And in 2015, the year NBN Co plans to fly its twin satellites, there are 21 planned launches as of now - and just two predominantly Ka-band satellites.

Their names? NBN Co 1A and NBN Co 1B.

There's a theme here, and it's a simple one: Ka-band satellite broadband is currently still largely a fantasy within the Australian market, and none of the launches currently scheduled for the next four years is going to substantially change that.

Even if capacity were available on putative satellites with the right coverage area, securing the kind of bandwidth that NBN Co requires would demand almost complete assumption of the capacity of the third-party satellites. Given that those satellite launches have already been greenlit based on lessor precommitment, there is no indication of whether NBN Co could even have secured adequate capacity even if it had tried to.

All this suggests that Turnbull should have done his homework before badmouthing the NBN Co solution. Faced with the reality of Ka-band satellite's future, Turnbull's preference for leasing capacity from the private sector simply falls apart.