Space Radar History

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Radar love: t he tort ured history ofAmerican space radar programs

by Dwayne A. DayMonday, January 22, 2007

On January 11 Reuters published an article indicating

that an experimental National Reconnaissance Office

satellite had suffered a catastrophic failure and was

essentially unusable. Communications with the satellitewere lost, and ground controllers were struggling to

regain them, but the problems with the satellite were

apparently substantial. The most likely candidate is a

satellite launched in December from Vandenberg Air

Force Base that amateur satellite observers suspect is a

radar satellite.

High resolut ion airborne synthet ic apert ure radar image of the Pentagon.

(credit : Sandia National Laboratory)

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Page 1 of 12The Space Review: Radar love: the tortured history of American space radar programs

2/28/2011http://www.thespacereview.com/article/790/1


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For over four decades the United States has undertaken

numerous efforts to develop satellite radar to serve a

variety of purposes, from ocean surveillance to aircraft

detection and tracking to mapping and intelligence

collection. Despite starting almost a dozen separate

programs over this period, the actual number of radarsatellites flown by the United States is relatively lowless

than a dozen. Radar advocates have long made claims

about satellite radar capabilities that were not born out

by experience. What follows is a brief history of that

effort.

From Quil l t o Clipper Bow

Satellite radar imaging is among the most classified

activities conducted by the US intelligence community.The NRO will not even acknowledge the fact of the

existence of such a capability. However, it is no secret

that space radar is possible. Canada, Russia, ESA, and

recently Germany have all launched radar satellites. The

United States flew several civilian Space Shuttle missions

equipped with a radar imager and some of this

equipment currently hangs in the Smithsonian. The

mission these various spacecraft have performed is

producing imagery of the ground using a technique

known as synthetic aperture radar, or SAR, wherebymultiple images of the ground are taken as the satellite

moves overhead and are then stitched together by

computer, producing a high-fidelity three-dimensional

image. But while the space radar efforts of other

countries are relatively well known, in the United States

information on the operational systems is shrouded in

secrecy, and most of what we know concerns canceled

programs.

One of the hazards of writing about intelligence space

programs is the uncertainties inherent to the subject. It is

vital to remember that probabilities dont always add,

increasing certainty, but instead sometimes multiply,

decreasing it. So two conclusions with a fifty percent

confidence level may not produce truth, but a conclusion

that is far less accurate. Nevertheless, there is data to




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support the information in this article.

The possibility of using radar

from space was first discussed in

the US Air Force during the

Eisenhower administration.

However, President Eisenhower

placed very strict controls on

satellite intelligence collection

and at first insisted on personally

approving every photographic

satellite intelligence mission that

the United States conducted. In

this environment, the Air Force space leadership

determined that radar transmissions from a satellite

might be too provocative for a president alreadyconcerned about passively taking pictures and collecting

electronic transmissions, and so they did not start the

program at that time.

Although details remain sketchy, it appears as if an

experimental radar satellite program was started during

the Kennedy administration. This program, known as

Quill, produced three satellites: two flight models and a

test model. One satellite was launched in 1964. It used a

radar that was probably built by Raytheon to take imagesof the ground which were stored on magnetic tape. Quill

used the same recovery system as the Corona

reconnaissance satellite, returning the magnetic tape to

Earth in a recoverable capsule that was caught in mid-air

by an aircraft.

According to someone who talked to Quills program

manager, as well as another researcher who talked to a

former senior intelligence official, the flight and the

mission were successful, but the program was not

continued. It is easy to speculate why. The satellites

relatively low power and early technology undoubtedly

limited its capabilities, particularly the size of objects it

could spot. Quill could probably not spot anything

smaller than a naval vessel. In addition, the data retrieval

technique meant that information was not processed

Satel li te radarimaging is amongthe most classif iedactivitiesconducted by the

US intelligencecommunity. TheNRO will not evenacknowledge the fact of theexistence of such acapability.However, it is nosecret that spaceradar is possible.




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until long after it had been collected. The intelligence

value was therefore probably too limited to justify further

efforts.

By the early 1970s, the US Navy was considering a

program known as Clipper Bow (i.e. the bow of a clipper

ship). Clipper Bow was intended to detect ships at sea so

the information could be transmitted to naval vessels, a

technique employed by the Soviet Union with their Radar

Ocean Reconnaissance Satellite (RORSAT). But Clipper

Bow was soon canceled, apparently for cost and utility

reasons.

From sea to ground to air

By the mid-1970s a new proposal emerged for a radar

imaging satellite. Although details are scarce, this was

apparently a controversial battle within the intelligence

community. At the time, CIA officials wanted to add a

radar capability to their new KH-11 real-time

reconnaissance satellite. Department of Defense officials,

though, wanted a dedicated radar satellite. Eventually the

Air Force component of the NRO obtained approval to

start a new program to develop a radar imaging satellite

called Indigo. The name of this program was later

changed to Lacrosse (apparently spelled Lacros inofficial documents) and then to Onyx.

In 1988 the Space Shuttle launched the first Onyx radar

satellite (although a press leak referred to the satellite by

its earlier name, Lacrosse and the program might still

have had this name at the time.) More satellites were

launched in 1991, 1997, 2000, and 2005. In 1998 the

NRO even released images of one of these satellites

under construction. The satellite is a large rectangular

frame to which are attached numerous electronics boxes

covered in gold-colored kapton insulating foil. According

to amateur astronomers who have observed the actual

spacecraft in orbit, the satellite has a large dish and two

large solar panels sticking off the main body.

The satellites average radar resolution was reported to

be about one meter, probably in the standard




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pushbroom mode where the radar essentially looks

straight down and takes a continuous image, like a push

broom being pushed across a floor. However, synthetic

aperture radars have a mode called spotlighting

whereby they spend several seconds taking repeated

images of the same small area to improve resolution. Bytaking images for up to 17 seconds, Onyx reportedly

could obtain a resolution of about 0.3 meters for a small

area. Onyx remains the only operational American radar

satellite system.

Articles by independent analysts contained some

inaccurate speculation about radar satellites during this

period. In 1977, NASA launched a radar satellite known

as Seasat and used to observe the oceans. Seasat failed

early in its mission, and there has long been speculationthat the satellite had successfully detected American

submarines at sea and this was so alarming that it

prompted the Navy and/or the intelligence community to

demand that the satellite be shut off. However, this story

seems highly unlikely. If the satellite had been so

successful, it seems more likely that the military and

intelligence communities would have wanted it to

continue in order to gather more data. At the very least,

they would have wanted to try and track Soviet

submarines. They could have easily classified the data

while keeping the satellite in operation. There has been

enough information released on Seasats failure to make

it clear that a simple malfunction, and not a government

conspiracy, was the real problem.

Another claim, originally made by

the late British writer Anthony

Kenden, was that in January 1982

the US tested an experimentalradar satellite named Indigo.

However, it is now clear that this

launch was actually a modified

photoreconnaissance satellite,

part of a program called Higher

Boy, and not a radar satellite. Indigo was in fact the name

for the initial program to develop a radar satellite, but no

By t aking imagesfor up to 17seconds, Onyxreportedly couldobtain a resolut ionof about 0.3 metersfor a small area. Itremains the onlyoperationalAmerican radarsatellite system.




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actual spacecraft flew under the Indigo name. However,

it seems unlikely that the NRO would have committed to

a major new program without at least conducting some

experimental tests first. Whether these were space-based,

airborne, or simply conducted in a laboratory is

unknown.

By the early 1980s, the Air Force was interested in a new

project then designated Space Based Radar, or SBR. This

was a project championed by Air Force Space Command,

not the Air Force office that was part of the NRO. The

purpose of Space Based Radar was to detect aircraft in

flight. The justification was that such a satellite could act

as a kind of space-based airborne warning and control, or

AWACS, system, detecting Soviet bombers and tactical

aircraft in flight long before they could be spotted byground-based radars in Europe and elsewhere.

Throughout the 1980s, various Air Force generals

declared that Space Based Radar was their highest

priority new program. Despite this constant

endorsement, the proposal was never adopted by the Air

Force leadership or the Secretary of Defense for actual

development. When the Cold War ended, the

fundamental justification for the program evaporated

and Space Based Radar was dead.

Discoverer II, Space Based Radar (again), and FIA

By 1998 a new satellite radar project emerged. The

Defense Advanced Research Projects Agency (DARPA)

proposed a project known as Starlite. This proposal

actually broke a gentlemens agreement that DARPA

would not intrude on the National Reconnaissance

Offices satellite intelligence turf by building

experimental intelligence collection spacecraft.

Eventually both the National Reconnaissance Office and

the Air Force were included in what became a joint

program soon designated as Space Based Radar.

Although the program shared the same name as the late

1980s radar program, it had a different focus. Instead of

detecting aircraft, the target of this new satellite system




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was ground vehicles. During the Persian Gulf War in 1991

the Air Force had pressed into service a prototype aircraft

system known as the Joint Surveillance Target Attack

Radar System, or JSTARS. JSTARS was a large synthetic

aperture radar mounted on a modified C-135 aircraft.

JSTARS was a refined version of traditional syntheticaperture radar. JSTARS looked for the strong radar

returns from metallic objects on the battlefield, which

were most likely vehicles. JSTARS also had a capability

known as moving target indicator, which tracked moving

vehicles. But because it was a large aircraft, JSTARS was

limited in where it could go. Even if the United States

controlled the airspace, Air Force commanders were

reluctant to take JSTARS too far behind enemy lines

because of its vulnerability to missiles and aircraft. In

addition, JSTARS was limited by the curvature of theEarth and any terrain such as mountains that could block

its signal from reaching farther distances.

The new Space Based Radar would take JSTARS into

orbit. The initial joint plan was for two experimental

satellites as part of a program known as Discoverer II.

But the Discoverer II program languished for years for

reasons that are complex and also somewhat murky. At

least part of the problem was high cost and poor

management. But the NRO had also never been fond of

the project and there have been rumors that the

intelligence organizations leadership fought Discoverer

II at every opportunity. By early this decade the NRO

withdrew from Discoverer II and the joint project was

canceled.

Around the same time that Starlite had started, the NRO

had also signed a contract with Boeing to develop the

Future Imagery Architecture, or FIA. FIA was to involvea constellation of both photographic imaging and radar

satellites. These would replace both the current fleet of

photographic satellites and Onyx. When FIA was first

unveiledalbeit with little detail due to classification

concernsoutside observers questioned whether FIA

rendered the Discoverer II program moot. After all, if the

NRO was already starting to build a new class of radar




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imaging satellites, did it really need to support

Discoverer II? The FIA radar satellites and Discoverer II

were intended to perform similar but distinct missions.

Independent observers, as well as members of Congress

and some military officials, questioned if these two

missions could be merged. There was no inherenttechnical reason that they could not be merged, although

the requirements for the two systems are different.

Although Discoverer II was dead,

the Air Force continued its

advocacy of Space Based Radar.

For the next several years, the

United States appeared to have

had two separate radar satellite

programs: the radar componentof FIA and Space Based Radar.

Congress officially ordered the NRO and the Air Force to

merge their efforts into a single platform, and in January

2005 the NRO and the Air Force signed an agreement to

make Space Based Radar the radar component of FIA.

However, with SBR not scheduled to become operational

until 2015, one unanswered question was how the NRO

would meet its radar intelligence needs during the next

decade without building new satellites.

Another question was just how much the NRO was

actually cooperating. One possibility is that the NRO

converted its existing FIA radar program into a

demonstration project with the intention of developing

a satellite that could later be declared operational once

the Air Forces Space Based Radar program failedas

many people both within and outside of NRO expected

that it surely would.

As if this story was not convoluted enough, by 2005 the

photographic part of FIA was in major trouble. Ever since

the late 1950s Lockheed had built Americas

photographic reconnaissance satellites. The Onyx was

built by Martin Marietta. When the two companies

merged, the expertise for building both of these kinds of

satellites resided within a single company, and Lockheed

The Discoverer IIprogram languishedfor years forreasons that arecomplex and alsosomewhat murky.At least part of theproblem was highcost and poormanagement.




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Martin lost the FIA contract in a stunning upset. Boeing

later lost the photographic imagery portion of the FIA

contract, but reportedly maintained the radar imaging

portion.

Space Radar redux

By 2006 the Air Force had renamed its program as

simply Space Radar with an estimated operational date

of 2015. Space Radar would consist of a constellation of

satellites, but just how many and how powerful has not

been determined. The goal is to obtain near-continuous

coverage of important areas of the Earth without gaps in

coverage that could allow important events to go

unobserved. The more satellites, the fewer gaps in

coverage and the quicker the response time. However,both the intelligence community and the military may

have different requirements for how much coverage is

necessary.

Intelligence community requirements and military

requirements apparently primarily diverge over the issue

of moving target indicator capability, and it is this issue

that also has a major impact on the size and cost of the

satellites. A synthetic aperture radar capability for the

intelligence mission can utilize a relatively small antennaof approximately 40 square meters. However, such an

antenna would be hard pressed to detect relatively slow

moving targets on the ground. According to a recent

estimate, successfully detecting ground vehicles traveling

under about 30 kilometers per hour might require an

antenna as big as 100 square meters, thus driving up cost

and size, for a mission that the intelligence community

does not need.

The Space Radar program has been in funding limbo for

yearsfor fiscal 2006 the administration requested $228

million for Space Radar. Congress only gave the Air Force

$103 million. In 2007 the Air Forces request was

similarly chopped back.

There are several reasons for this.

One is the lack of a clearTo call Space Radarexpensive i s li ke




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justification. The Air Force has

not been able to make the case

that Space Radar is necessary for

its most important missions. Its

utility in the war on terror is

highly questionable. Osama bin Laden isnt made ofmetal and therefore wont show up on radar, even if he

does travel faster than 30 kilometers per hour. Closely

related to this is the Air Forces inability to demonstrate

how such a system would be used and whether it would

be better than a mixed fleet of radars mounted on various

aircraft, including large platforms like JSTARS and small

drones.

However, above all, is the overriding issue of cost.

To call Space Radar expensive is like calling the Pacific

Ocean a body of waterit doesnt exactly convey the

enormity of the issue. The Air Force repeatedly refused to

put a cost estimate on the program, saying that it would

be premature. However, the Air Force did want Congress

to commit to building it. One early estimate for Space

Radar put the cost at $34 billion for a nine-satellite

constellation. But the Air Force disavowed this estimate

at the same time it refused to provide another one. The

cost is driven by several factors, not only the number ofsatellites required for the constellation, but also the

amount of processing power required for the satellites

and their ground stations, and of course the size of the

radar antenna. Space Radar would also dwarf current

transmission bandwidth and signal processing

requirements for the military.

Considering the fact that the Air Force had long refused

to provide a clear cost estimate of the program, it was

inevitable that Congress would seek an independent

estimate. In early January the Congressional Budget

Office released a report on alternatives for space radar,

and the information it contained was rather startling. For

a 20-year lifetime, the CBO determined that such a

system could cost between $25 and $90 billion

depending upon the size of the system. CBO determined

calling the PacificOcean a body ofwaterit doesn texactly convey theenormit y of t heissue.




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that for its reference architecture of nine satellites with

40-square meter radar arraysessentially the system

that the Air Force has advocatedtotal costs would range

from $3550 billion.

To put this in context, consider that the largest current

space program that the Air Force has underway has a

cost estimate of around $12 billion. Other large projects

have cost estimates of around $10 billion. Simply put,

even the simplest version of Space Radar would cost

twice as much as any other military space program on the

drawing board, and the baseline version the Air Force is

seeking will cost three to four times as much as the most

expensive current space project.

However, what makes the situation more severe is thefact that many of the most expensive military space

programs now in development were originally estimated

to cost far less than their current estimates. The NPOESS

weather satellite, for instance, was supposed to cost $6

billion and will now cost $12 billionwith a significant

reduction in its capabilities. The SBIRS missile warning

satellite was supposed to cost $4 billion and will now cost

over $11 billion. Even though the Space Radar cost

estimates were done by the CBO, Congress has little

reason to believe that costs will not spiral out of control.Does Congress really want to fund a program that would

start costing three times as much as the most expensive

current space program, and could end up costing many

times greater?

Beams in the sky

Whether or not the December launch from Vandenberg

was an experimental radar satellite (and there are still

substantial questions about that), its failure can only

exacerbate the overall recent woes of military space

programs, contributing to the bad reputation that the

military space program has acquired. That is

unfortunate, because the American military space

program is vital to American defense, and its recent

troubles have been extremely disconcerting.




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Dw ayne A. Day frequently w rites on the history of

civilian and m ilitary space program s. His article on

NASAs future planning for hum an spaceflight appears

in the February issue ofSpaceflight m agazine. He can be

reached atzircon [email protected].

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