Air Force Signs on to Darpa's All-Seeing Blimp
By Nathan Hodge March 12, 2009 
 For years, the idea of super-sized blimp that could see a whole city at once 
seemed like something only Darpa, the military's far-out research arm, could 
love. Now, unexpectedly, the Air Force has signed on to the concept, as well. 

Built around a giant, flexible antenna, the all-seeing airship -- dubbed ISIS, 
short for Integrated Sensor Is Structure -- would provide a God's-eye view of 
the battlefield in real time. In theory, it could spot a cruise missile 
hundreds of miles away, or track a group of insurgents on the ground.

Darpa spokeswoman Jan Walker confirmed to Danger Room that the Air Force 
recently signed a memorandum of agreement with the agency on ISIS. It's a 
fairly big deal: Most ideas that originate within Darpa do not have a long life 
unless a service picks up on it.

It's significant for another reason: Tony Tether, who recently stepped down as 
chief of Darpa after almost eight years on the job, was a big fan of ISIS. This 
ensures that development of the concept will continue in some form after 
Tether's departure. 

Noah has tracked ISIS since its inception; click here to read his dispatch from 
the 2004 DarpaTech conference describing the initial feasibility study for the 
super-blimp. 

[IMAGE: Raytheon via MSNBC]

http://blog.wired.com/defense/2009/03/air-force-signs.html

http://www.noonehastodietomorrow.com:80//index.php?option=com_content&task=view&id=922&Itemid=33

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Pentagon’s airship plans are up in the air

Near-space initiatives encounter some congressional resistance

 

Raytheon
The "Integrated Sensor Is Structure" initiative calls for developing prototype 
airships like the one shown in this artist's conception. The craft could hover 
at an altitude near the edge of space and track ground and aerial targets for 
up to a year at a time.

By Jeremy Singer
Space News staff writer
Several companies have begun design work on a prototype airship that could 
hover at an altitude near space where it would be able to track ground and 
aerial targets for up to a year at a time. Whether the program, known as 
Integrated Sensor Is Structure, or ISIS, moves beyond the design stage anytime 
soon, however, will depend on the final version of the 2007 defense budget.

The U.S. House of Representatives funded the full $16.3 million request for the 
effort in its version of the 2007 Defense Appropriations Act, which passed the 
House in June. The Senate Appropriations Committee, however, has recommended 
denying the Defense Advanced Research Projects Agency’s entire $16.3 million 
budget request for the program in 2007. The bill is currently awaiting a vote 
on the Senate floor.

The House and Senate will address the issue when they meet to resolve 
differences between their bills later this year.

Jenny Manley, a spokeswoman for the Senate Appropriations Committee, did not 
respond to a request for comment on the committee’s proposed cut to the ISIS 
program.

Jan Walker, a spokeswoman for the Defense Advanced Research Projects Agency, 
said that program officials declined to comment on the ISIS effort at this time.

Contracts awarded

The Air Force Research Laboratory of Rome, N.Y., has awarded several contracts 
to industry to begin work on various aspects of the ISIS program. The lab 
awarded a two-year, $10.3 million contract to Lockheed Martin Maritime Systems 
and Sensors of Akron, Ohio, in June to begin work on the airship platform.

The lab awarded two contracts earlier this year to Northrop Grumman Corp. for 
the ISIS effort. Northrop Grumman Space Technology of Redondo Beach, Calif., 
will develop a transmit-and-receive module for the radar sensor that is 
expected to be lightweight and extremely power-efficient under a $6.8 million 
contract awarded in April. Northrop Grumman’s Electronic Systems sector, which 
is based in Linthicum, Md., is developing an antenna that can handle radar as 
well as transmit data simultaneously under an $8 million contract. Raytheon 
Space and Airborne Systems of El Segundo, Calif., also is working on a design 
for the antenna under an $8 million contract.

If the program does go forward, the airship will feature a radar sensor of 
“unprecedented proportions,” according to a Pentagon document. 

Tracking sensor

DARPA’s 2007 budget justification materials, which are posted on the agency’s 
Web site, describe ISIS as a sensor capable of conducting surveillance and 
tracking hundreds of time-critical targets in both urban and rural 
environments. 

The sensor is being designed to track airborne targets at a range of 375 miles 
(600 kilometers), and ground targets at a range of 188 miles (300 kilometers) 
while distributing that information to U.S. forces through hundreds of covert 
wideband communications links, according to the budget justification materials.

The agency wants the sensor to detect and track targets including aircraft, 
cruise missiles, tanks and troops, according to briefing charts posted on the 
agency’s Web page. The agency also wants the sensor to detect mortar and 
artillery fire.

Challenges involved with building the system include finding ways to keep the 
weight, power requirements and logistics requirements minimal, according to the 
budget justification materials. 

Largest radar sensor

The ISIS sensor would be the largest radar sensor built to date, and is much 
larger than the Sea Based X-Band Radar sensor built for the U.S. Missile 
Defense Agency, according to Michael Wechsberg, director of radio frequency 
programs and ISIS program director at Raytheon Space and Airborne Systems.

Much of the size of the Sea Based X-band Radar, which features a Raytheon-built 
sensor, is material needed to keep the radar sensor stiff, Wechsberg said in a 
July 19 interview. The company is able to avoid this issue on ISIS by using the 
structure of the airship itself to stiffen the sensor, which will be placed 
either inside or outside the craft, he said.

One way of handling the need for the antenna to transmit and receive data 
simultaneously is a technique called time multiplexing, which involves changing 
the function from sensing to transmitting data in less than a second, Wechsberg 
said.

Another airship program

The Missile Defense Agency is developing another large airship, known as the 
High Altitude Airship, or HAA, that would operate at the near-space altitude, 
which is generally defined as the area around 12.5 miles (20 kilometers). 
Lockheed Martin is under contract to build and demonstrate the HAA.

However, the HAA project is primarily focused on demonstrating the airship 
platform in the near term, while ISIS is more focused on the payload, Wechsberg 
said. The payload aboard the HAA represents about 1.7 percent of the platform’s 
weight, while the payload aboard ISIS accounts for roughly 30 to 40 percent, 
according to the Defense Advanced Research Projects Agency’s briefing charts.

Ron Browning, HAA business development director for Lockheed Martin, said 
during an Aug. 1 briefing for reporters that the Missile Defense Agency has not 
yet chosen the type of payload that will fly aboard the HAA in its first 
prototype flight, but said that the available room could host a communications 
or optical sensing system based on mature technology that would not add risk to 
the HAA development effort.

The small amount of dedicated payload space aboard the HAA means that that 
sensor will be far less capable than that envisioned for ISIS, Wechsberg said.

Building on experience

Dave Filicky, Lockheed Martin’s ISIS program manager, said that the company 
will be able to build on its experience with the HAA as it designs the ISIS 
platform. 

However, ISIS poses its own challenges with the platform, due to the size of 
the sensor as well as the longer duration that it is expected to hover over 
particular areas.

ISIS will require a lighter platform to deal with the larger radar sensor, and 
systems that can operate for long periods at relatively low power, Filicky said 
in a July 19 interview.

“If it wasn’t brand new, never been done before, [the Defense Advanced Research 
Projects Agency] wouldn’t have funded it,” Filicky said.

The HAA is currently expected to be demonstrated in flight for the first time 
around 2008; ISIS is scheduled for a reduced scale prototype flight in 2009, 
with plans for a full-scale demonstration to be determined afterwards, 
Wechsberg said.

Like ISIS, the HAA also is encountering some resistance in Congress, where 
members of the House and Senate have both moved to trim the $40.1 million 
request for the program in 2007 in order to steer funding towards other missile 
defense efforts. The House version of the 2007 Defense Appropriations Act cuts 
the request for the High Altitude Airship by $20 million, while the Senate 
version of the bill reduces it by $25 million.

Click for related stories
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http://www.msnbc.msn.com/id/14275624/

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