US satellites that intercept communications have so far avoided the full weight of the media scrutiny that the Edward Snowden revelations have brought on other parts of the intelligence world. PAT NORRIS FRAeS* considers the ultra-secret world of spy satellites able to hoover up your mobile phone conversation.

On 22nd June 1960, less than three years after Sputnik-1 kicked-off the space age, the tiny GRAB spacecraft was launched by the US Department of Defense and became the first satellite designed to ‘observe’ the Earth on an operational basis. GRAB didn’t observe the Earth in the conventional sense (by taking pictures), instead it detected radio signals from below and relayed them to ground terminals thousands of miles away. GRAB provided the US with unprecedented information about the signals emitted by Soviet radars at a time when those two super-powers were Cold War adversaries and when information about activities inside the Soviet Union was almost impossible to obtain. The information collected by GRAB was sufficiently useful to justify the launch of more such satellites.

The ELectronic INTelligence (ELINT) satellites that followed the 80kg GRAB became more and more sophisticated and the types of radio signals they detected became more and more varied. Today satellites are one of the tools used by military and security services in several countries to eavesdrop on the information being transmitted through the air. Military information is still one of the targets of these satellites such as radar transmissions and radio links between military units and between them and their smart weapons (such as missiles). But this article focuses on the role of satellites in intercepting non-military information — the sort of intercepts highlighted in the documents leaked by Edward Snowden.

Satellites are involved in intercepting civilian communications in two different ways. The first technique is to eavesdrop from the ground on conversations, messages and data that are routed through commercial satellites. Since the 1980s, most long-distance communications are carried by cable — on land or under the sea. However, certain types of communication tend to go by satellite, for example where one of the parties is on a ship or an aircraft, and eavesdropping of these calls is viable.


Seven billion mobile devices 

GRAB  This US satellite, launched in 1962 was the first electronic intelligence satellite.(National Security Agency)

The second way satellites are involved in intercepting civilian communications is to have special satellites that listen to ground-based radio communications. Since the late 1990s the explosion in the use of cell phones has meant that more and more conversations and messages are being sent by radio. There are about seven billion cell phones and other mobile devices in use around the world (yes, the same as the world’s population!) and the number keeps growing — by 13% last year. All of the chatter, text messages, email, downlinks, etc from the handsets go by radio to the relay masts that have sprung up by the million across the globe. US satellites are, in principle, able to listen in to the billions of conversations and messages coming from or going to cell phones but the scale of doing so is daunting because of the huge numbers of phones in use. Before the eavesdroppers can decide if a conversation is worth listening to they have to decrypt it. To avoid having to decrypt every one of the billions of communications every day, the agencies try to narrow down the deluge of calls to those they reckon are worth devoting time and effort to. The number of the caller and the number of the receiver are not encrypted, so one tactic is for an eavesdropper to wait until a telephone number of interest is involved in a call before bothering to decrypt. Another tactic might be to focus on calls from or to a particular area. The encryption can usually be 'cracked' by the intelligence agencies, although the agencies claim that it requires special super-fast computers (and thus is costly) when they don’t know the encryption keys.

Several examples of the use of intercepted conversations by anti-terrorist agencies have been reported. In November 2002, the US National Security Agency (NSA) detected a phone call coming from Qaed Salim Sinan al-Harethi, considered to be the al-Qaeda operative who planned the attack on the USS Cole in a Yemeni harbour in 2000 that killed 17 US sailors. The satnav chip in Al-Harethi’s phone gave his exact location in rural Yemen. A Central Intelligence Agency Predator unmanned aircraft was dispatched from across the Red Sea in Djibouti and was directed by its operators to fire a Hellfire missile at al-Harethi’s car, destroying the vehicle and killing all of its occupants.

The US is not alone in targeting enemies by listening to their satellite phone calls. Russia killed Chechen rebel leader Dzhokar Dudayev in 1996 by using such a call to pinpoint his position.


Mobile phones in the military — a two-edged sword

Mission patch from the National Reconnaissance Office (NRO) NRO-39 spy satellite launch, December 2013.

The vulnerability of commercial cell phones to unfriendly interception has rebounded against the US military from time to time. For example, North Atlantic Treaty Organisation (NATO) forces in the Balkans in the 1990s did not have enough of the latest military radio sets to give to all of their troops, so many of the troops starting using their personal cell phones over the public networks available in the region.  The military agencies that NATO was fighting had access to those public networks and could gain information of military significance from this unauthorised use of cell phones by the NATO troops. There are reports that the use of smart phones and 3G phones by NATO troops in Afghanistan in the 2010s is causing similar problems — the troops are reacting to the lack of smart phone features in the standard military handsets.


Giant antennae in orbit 

The tiny GRAB evolved into massive satellites with enormous antennas. Many of these satellites were placed in geostationary orbit, 36,000km above the Earth, hence the need for the high gain antennas. One civilian commentator lists 12 satellites in this series launched since 1970 (see Table 1) but the accuracy of his analysis is unconfirmed. Some official information has been released about the two most recent launches in the Table (November 2010 and June 2012), complemented by information in the material leaked to The Washington Post by former NSA contractor Edward Snowden.

The satellite launched on 21 November 2010, NROL-32, was “the largest satellite in the world” according to public remarks by the then Director of the National Reconnaissance Office, General Bruce Carlson. This remark is taken by most analysts to refer to the large size of the antenna unfurled by the satellite once in orbit.

The next satellite in the series launched in June 2012, NROL-15, required an especially enhanced version of the RS-68 engine in the Delta 4H rocket, so it presumably is heavier than NROL-32. Whether it is also ‘larger’ has not been announced.

The budgets of the various US intelligence organisations obtained by The Washington Post from Edward Snowden included that of the National Reconnaissance Office (NRO)1. The detailed breakdown included a heading labelled ‘signals intelligence (high)’ in which the ORION 8 project received $182m in 2011, $130m in 2012 and $38m (requested) in 2013. It seems likely therefore that NROL-15 launched in June 2012 and ORION 8 are one and the same. The budget line ORION 7 received $9m in 2011 and nothing in 2012 and 2013, which fits with the time-frame of NROL-32 launched in 2010.

The most lavishly funded of the ‘signals intelligence (high)’ projects in the Snowden-supplied documents is the ‘SIGINT High Altitude Replenishment Program (SHARP)’, receiving more than $2·5bn in the 2011-2013 period. We can expect to see satellites emerging from this programme in the next few years, but in what sense they will be ‘sharp’ has not been revealed. General Carlson’s successor, Ms Betty Sapp, touched on this in public evidence to a Congressional Committee last year when she said that “Over the coming years, the National Reconnaissance Office will incorporate revolutionary new technologies into our architecture that will provide enhanced support to the warfighter while also improving the resiliency of our systems.”

Hoovering up information

The US military communications satellite Mobile User Objective System has the largest antenna publicly known. (Lockheed Martin)

The high cost of these monster satellites means that they are designed to last for 15 or more years — it would be too expensive to replace them more frequently. But communications is an area which changes dramatically every few years so there is a risk of these satellites becoming obsolete before they reach the end of their intended life.

The technology of the US eavesdropping satellites is impressive. Located 36,000km above the equator, the satellites need enormous antennas to pick up radio signals. The antenna on the US military communications satellite MUOS is 28·6m diameter when unfurled in orbit — the largest known publicly. But the secret eavesdropping satellites are reported in the media to have already had 50m wide antennas by 1994 and 90m ones by 2006.

The information hoovered up by these satellites is radioed to ground stations around the world and then sent across secure networks to the US. The satellites are developed and launched by the NRO but once in orbit they are used by the NSA to intercept radio traffic. The information collected is used by both military and civilian agencies — the Central Intelligence Agency being the largest of the civilian ones. The US-UK special relationship plays its part in this — according to the Federation of American Scientists website, “Menwith Hill [near Harrogate, Yorkshire] in the UK is the principal NATO theatre ground segment node for high altitude signals intelligence satellites.” The public website of RAF Menwith Hill says it “functions primarily as a field station of the NSA .… and is an integral part of the US [Department of Defense] worldwide defence communications network”.

Other nations

Launch of NROL-15 from Cape Canaveral on a Delta 4H rocket, 29 June 2012. (NRO)

The US is the only country that deploys technology in space on this scale. Russia has had electronic intelligence satellites in low orbits (about 1,000km altitude) since the 1960s and, in recent years, China has too. France has been experimenting with the low orbit type of surveillance from space for about a decade but has not yet made a commitment to full operation. The main targets of such satellites are probably military signals and communications, and the same is true of US low orbit signals intelligence satellites — the budget papers leaked by Snowden show a 2011-2013 spend on 'low' signals intelligence satellites of $2bn: about half the $3·8bn for the 'high' category.

NSA and its British counterpart, Government Communications HQ (GCHQ), have been much in the news since the Snowden leaks first emerged in the summer of 2013. In contrast, the NRO has largely escaped the limelight despite its budget being revealed to be about the same as that of the NSA – each funded at slightly more than $32bn for the 2011-2013 period, if media interpretation of the Snowden documents is correct.

The NRO’s roughly $10bn per annum buys more than just eavesdropping satellites. Director Betty Sapp says that its mission is “to provide Innovative Overhead Intelligence Systems for National Security” and that it “remains the premier space reconnaissance organisation in the world”. Much of that is in the form of low orbiting electronic intelligence satellites and spy satellites of the more conventional kind as described in the December 2010 issue of Aerospace International (‘Spies in the sky’ by Pat Norris, pp 26-29).

About $1bn of the NRO budget goes each year on launchers to place its various satellites in orbit. This figure reflects the need to buy large rockets to launch large satellites. But it also reflects a decision some years ago to buy all military launchers from a single supplier — United Launch Alliance. The recent successful launch of two commercial satellites into geostationary orbit by Space-X's Falcon-9 rocket is likely to lower future launch costs as Space-X becomes accepted as a viable supplier to the military community (see 'Reaching for the Stars' by Dr Adam Baker, AEROSPACE, September 2013, pp 36-40).


Spook central? RAF Menwith Hill in Yorkshire is a signals intelligence downlink station. (Wikipedia)

Future revelations by Edward Snowden might focus the media spotlight on the National Reconnaissance Office but, for the moment, the role of satellites in the communications intercept activities of the US Government has escaped detailed media scrutiny.


1. published 29 August 2013


*Note: This article is based on research for the chapter on 'Military Radio Surveillance from Space' in the author’s book Watching Earth from Space (Springer-Praxis, 2010) and the two chapters he has contributed to the Handbook of Space Security (Springer Verlag, in press): ‘Eavesdropping’ and ‘US Military Satellite Programs’.




Tim Robinson
13 March 2014