By Duncan Steel 09/01/2019 1


With regard to tracking military satellites newly-launched from eastern Asia and potentially of concern to our allies, New Zealand’s geographical position is of huge (yet overlooked) significance.

 

Surely no-one could imagine that space-wise there is not a lot going on at present, with another probe just landed on Mars, three other spacecraft missions having encounters with asteroids, and many other announcements showing how our exploration of the solar system is proceeding apace. Exciting times. In future posts I will turn my attention to several of these giant leaps, but immediately there is something more important to discuss and closer to home.

In the latter half of 2018 the announcement by the present President of the United States that the nation would be establishing a new service within the US military, a ‘Space Force’, attracted much derision in the world’s media. The reality, however, is that this is not a new concept, and the idea has been around for some time. A good (and brief) discussion of the historical context appeared a few days ago; on the other hand a recent report has cast doubt on the viability of such a Space Force.

Two recent space-related events that have prompted me to write about this now are seemingly unconnected: the Chinese landing of a rover vehicle on the far side of the Moon, and the re-entry of a Russian military Earth-orbiting satellite that occurred over New Zealand a few days ago (and lit up the sky during a Black Caps/Sri Lanka cricket match).

The first of those made many members of the public aware of something that space professionals have known for years: that China has an advanced space program and therefore technical capabilities that many in the West might find worrying. (Then again, how many people know that India has had a probe in orbit around Mars for more than four years? And that the United Arab Emirates also plans to send a satellite to Mars very soon?)

The second event – the unexpected re-entry of Kosmos-2430 seen as a bright meteor or fireball over the North Island – tells you that NZ has no domestic capability to track objects crossing above our territory, and the reality is that thousands of satellites pass overhead every day.

The fact that the exploitation of space is essential for the world’s militaries is undeniable. The US agency that receives the most space funding from the government there is not NASA; the Department of Defense and the various intelligence agencies (such as the National Reconnaissance Office) spend more on space than NASA. Many of their space exploits are publicly-known, some are top secret, whilst information about others which were classified until recently is now being made available.

It may make you feel uncomfortable, but every time you use Google Maps on your cellphone to work out where the nearest café might be, or the GNSS (Global Navigation Satellite System) display in your car to find your way around, you are accessing signals from a US military satellite constellation (i.e. GPS Navstar). One of the unanticipated hiccups that will occur due to Brexit (if it goes ahead) is that the UK will not have access to the full-precision military encrypted system being provided by the European Union’s Galileo GNSS constellation, despite the fact that the satellites were largely manufactured in Britain.

It would seem that the further militarisation of space is inevitable, despite what various international treaties might say. There are four domains of warfare which have developed over the millennia: land, then sea, then air, and most recently cyber. To those, a fifth will surely be added: space.

Is NZ too far from any of the action to be affected? The answer, unfortunately, is a resounding NO. As I mentioned above, NZ is crossed many times by orbiting satellites every day, and many of those are operated by the militaries or spy agencies of developed nations. When it comes to looking down from space, nowhere on Earth is remote and inaccessible. It is also true that nowhere is safe from the potential of being attacked from space although, again, an international treaty prohibits the positioning of weapons of mass destruction in orbit; but do you really think that will stop certain states from doing just as they please?

In 2016 NZ published a Defence White Paper (DWP), outlining the capabilities that are considered to be necessary forward to various future time horizons. Public input was solicited in the preceding year. I made a submission in which I argued that there are special reasons for NZ to look to develop a space surveillance capability. In the jargon this is termed Space Situational Awareness (SSA). (More recently, in July last year, the Government published a Strategic Defence Policy Statement in which space featured prominently, both in terms of the benefits it delivers to the NZ military, but also the potential for disruption by adversaries.)

In that DWP submission I outlined various arguments for NZ becoming involved in SSA, but the one on which I want to focus here is our (geographical) position. Few recognise it, but NZ is in a vitally-important location in terms of keeping tabs on what is orbiting high above us.

If we consider not just ‘New Zealand’ as it is generally understood, but rather the full Realm of New Zealand (RNZ), then just as NZ has a huge Exclusive Economic Zone (EEZ) and also search-and-rescue responsibilities for almost half of the South Pacific, so the volume of space above the RNZ represents a vast region through which most satellites must pass at some stage in their orbits.

The RNZ includes the Ross Dependency down south, and northwards the associated states of the Cook Islands, and Niue, and a dependent territory, Tokelau. (Of course there are other Pacific island nations with which NZ has close relationships, such as Tonga, Samoa, and Fiji, but let’s leave those aside.) In essence the RNZ can be thought of as representing a chain that stretches from the South Pole through the various sub-Antarctic islands, NZ itself, the Kermadec Islands, and then the Cook Islands, Niue and Tokelau, so reaching almost to the equator.

 

For present purposes I just want to assume that it might be feasible to locate in Tokelau, Niue or the Cook Islands a suitable radar system for space monitoring. This would perhaps be a phased-array system working in the radio C-, S- or L-band, requiring a block of land perhaps a hundred metres on a side (i.e. a hectare). Similar radars could be located in the far north and south of NZ, say near Auckland, and close to Invercargill. In the diagram below I have depicted their potential coverage as rather-flat inverted cones of opening angle 150 degrees (i.e. starting 15 degrees above the local horizon), with apices at Invercargill, Auckland and Avarua in the Cook Islands, and extending up to an altitude of 800 km. I could make these extend further – say to 1,500 km, covering all low-Earth orbits – but it would look a bit confusing. This diagram should be enough to get the general idea.

 

 

In the preceding diagram you will also have noted that I labelled Kwajalein in the Marshall Islands, which is where a space surveillance radar array is being installed by the US Department of Defense. This is part of the new Space Fence intended to detect space vehicles coming across the Pacific. With sensors in Hawaii and also Alaska, the northern half of the Pacific could therefore be covered in terms of a capability to patrol what is crossing the ocean in low-Earth orbit. (Note that in previous employments I have been privy to certain information that I may not disclose, and that is why in some cases here I am somewhat nebulous in my descriptions and give open-source links such as Wikipedia pages.)

The USA already has agreements in place with Australia for the operation of various space surveillance sensors – both optical and radar – that have been/are being installed there. The problem is that for certain purposes Australia is too far west, as I will indicate later.

The space coverage of my three mooted radars in Invercargill, Auckland and the Cook Islands might be better understood by considering the diagram below at left. Therein I have added two further locations: Jiuquan, a rocket launch site in the People’s Republic of China (PRC), and Sohae, similarly one of the launch sites used in North Korea (DPRK).

For the sake of argument I will assume here that in a situation of enhanced international tension there is the potential for an offensive satellite launch from one of those sites. The fact of a launch can be determined from various surveillance mechanisms (here is an example) such as thermal infra-red emission from rocket plumes, but this does not render accurate information on the trajectory of the launch and the orbit achieved.

 

 

 

Here at right are the paths and positions of four satellites at ten minutes post-launch; one each from Jiuquan and Sohai launched due east, and also one each launched south-east. An altitude of 500 km (above the equatorial radius) has been used for their orbits; that’s about the distance between Auckland and Wellington.

As background I note this: many satellites are directed due east from their launch sites because this gives them the minimum orbital inclination (the angle their orbit makes to the equatorial plane), and that inclination is equal to the latitude of the launch site; later rocket burns in orbit can alter the inclination, but these are costly in terms of fuel requirements. The inclinations of the hypothetical satellites labelled as PRC_due_E  and DPRK_due_E  are therefore just below 41 and 40 degrees respectively.

Any other launch azimuth results in a higher inclination. An alternative launch direction might be south-east, hence PRC_SE  and DPRK_SE. These both have inclinations of 60 degrees, and so reach latitude extremes of 60 degrees north and south.

We now step forward to 28 minutes post-launch. As seen in the panels below, three of the four satellites are now within the radar cones for the putative set of RNZ sensors. One (DPRK_due_E) is too far north for detection from the three RNZ radars but passes over Hawaii from where it is potentially trackable; PRC_due_E  could be picked up by the Kwajalein radar earlier than the Cook Islands sensor; but in terms of early warning it is obvious that such a chain of radars spread across the RNZ would be invaluable. What would be hugely important, should these satellite launches indeed be hostile in intent, is their detection and then orbit determination at the earliest possible opportunity.

 

 

The coverage of the three strawman radars in terms of ground footprints, and their overlap, is perhaps clearer in the 2D map below.

 

The opportunity to pick up these satellites is transient: they are travelling at just above 7.6 kilometres per second. By 35 minutes post-launch they have all left the sensor coverage and are heading for South America, as shown at right.

I would imagine that some readers have read this post so far in the presumed context of NZ being a cog in the US surveillance of space and so service of the US military, but perhaps the diagram at right will have given them pause, seeing the satellite paths going nowhere near North America (although I could of course have chosen launch directions of greater immediate concern to the US). So now let us follow the satellites onward.

At 75 minutes post-launch the two satellites that US ground-based sensors in Hawaii and Kwajalein could have detected (i.e. those launched due east from Jiuquan and Sohai) are passing over Africa, as shown in the diagram at left.

The 2D map that follows is pertinent here, in that it shows how those two satellites only reach latitude 40-41 degrees south, and are similarly constrained in the north.

The two other satellites, both launched south-eastwards, attained latitude 60 degrees south over the Pacific/Southern Ocean and are now, 75 minutes after launch, approaching that same latitude north, it taking 94-95 minutes to complete an orbit at this 500-km altitude. One (DPRK_SE) has just passed over the Iberian Peninsula and France, and is now above Germany. The other (PRC_SE) is over the Atlantic and heading for the British Isles.

 

 

Note that these two are the satellites that could only have been detected by the hypothetical Auckland and Invercargill radars, not by the US space surveillance network (although the C-band SSA radar now located in Western Australia might have been able to pick up PRC_SE  when it was above the Arafura Sea/Gulf of Carpentaria/north-western Queensland).

In view of the above it seems clear that New Zealand is in a pivotal location with regard to the future of SSA, and therefore global security. We are well aware of the size of our EEZ in the Pacific, and the responsibilities that come with that, and also the vast area for which NZ carries the burden for maritime search and rescue. The time has come, though, to think about an upward projection of that area, and whether we should at least be able to detect the myriad objects flying overhead.

It’s not just functioning satellites we need to monitor: it is now well-recognised that space debris (uncontrolled pieces of broken up satellites and rocket boosters) pose a hazard that might limit our future utilisation of low-Earth orbit (LEO). A US company (LeoLabs) has recently announced its plan to build and operate a space junk radar in Central Otago. But NZ surely should also have a domestic capability to track overpassing space objects. This is what I argued in my DWP submission.

In the above I have talked mainly about US efforts to track objects in space, and what NZ might do to contribute in this regard in terms of international collaborations. Australia’s role has also been mentioned. However, just as I wrote about two hypothetical hostile satellites approaching Europe, so one should be aware that Europe (through both the European Union and also the European Space Agency) has burgeoning activity in terms of SSA, and the militaries of various individual European nations are also enhancing their SSA capabilities.

Many will look askance at the idea of the militarisation of space, but certain things seem to be unavoidable. Even if nothing else, we need to be able to monitor what is going on in our skies. Earlier I wrote of the US Space Fence, and that may have reminded you of the old adage which says that good fences make good neighbours. When it comes to Earth-orbiting satellites, all of us are effectively neighbours, no matter what our geographical distances may be, with objects in the lowest orbits circuiting our planet in barely an hour-and-a-half. Having our own space fence, and contributing to SSA efforts in collaboration with our allies, tells any potentially-hostile neighbours (no matter how distant they may seem) that we are able to see what they are doing in space, and will not be taken by surprise; this in itself would impart discouragement to any who might wish New Zealand harm.