Paper by NAL on Lighter than Air development in India

1. High Altitude Airships - Aero India International Seminar 2011
Roadmap for Technology and Product Development of
High Altitude Airship in India
Dr A.R. Upadhya1, Mr. ML Sidana2 and Jitendra Singh3
Council of Scientific & Industrial Research
National Aerospace Laboratories, Bangalore-560017
Ph: + 91 80 2527 0584 Fax: +91 - 080 - 2526 0862
ABSTRACT
The main objective of the paper is to explore the scope for Development and Application of High
Altitudes Airship (HAA) in India. Therefore, this paper aims to look critically at the benefits derived
from such a system, and the challenges involved in upgrading the Technology Readiness level and
Operationalization of High Altitude Airship in India.
Eventually, it should be able to answer few important questions in this respect such as:
• Does India need an HAA?
• Is it available to India?
• Does India need to/and can develop an HAA system with or without international collaboration?
• What is the current technology status to develop such a system?
• What are the most critical technologies that need to be developed for this programme?
• What is required for System-level program development in terms of: Technologies, Organization
structure, Time & Cost?
Fundamentally HAA is a culmination of Lighter-than-Air (LTA) technologies which essentially means
that it uses aerostatic lift to remain airborne instead of aerodynamic lift. They are usually filled with an
inert gas such as Helium which expands as it rises through the air. Hence the principle of buoyancy comes
into play. That is the key difference between Heavier-than-Air systems that uses aerodynamic lift
generated by pressure difference created by the lifting surface.
History records that the LTA technologies has originated about 200 years ago and was the first way to fly
people. Over time Airship attempts provided with an opportunity to pioneer new applications and
ushering new technologies. This technology is also referred to as near-space technology due to its vicinity
and potential applications. This system is targeted to operate in stratosphere to provide platforms for
persistent surveillance, weather measurement, both civil and military communication. Besides, it can be
used for Military and Homeland security applications. For each role, multiple candidate missions can be
accomplished. Depending upon the payloads, an HAA can be used as a multi-mission platform i.e. it can
be used for remote sensing, surveillance communication and missile defence as the same time.
1
The Director, National Aerospace Laboratories, director@nal.res.in
2
Former Director, ADRDE, Agra, CSIR Technical Consultant, manosidana@nal.res.in
3
Scientist Fellow & Program Manager, National Civil Aircraft Development, jitendra@nal.res.in
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2. High Altitude Airships - Aero India International Seminar 2011
APPLICATIONS
The airship can have several applications and based on that multiple candidate missions can be planned
under each category of Civil, Military, and Homeland Security. Some of the most promising missions
could be envisaged as given below under Military / Paramilitary and Civil roles are briefly shown in
block diagram below.
Military / Paramilitary
Roles
Military Roles Para -Military Roles
Communications and Border
Ballistic/Cruise Surveillance
Tactical Networks and
Missile Defense
Electronic Intelligence
Fishery
Protection
Surveillance and 3
C I Missions
Tracking of Land / Counter
Naval Forces Insurrection
Long Range
Sovereignty
Anti Submarine Airlift
Enforcement
Warfare
AEW Roles
Civil Roles
Weather Measurement Communication
and Forecasting (Mobile and
Broadband)
Transportation Resource
Mapping
Customs and Search and Rescue
Immigration
Disaster Management and Scientific and
Tsunami Monitoring
Experimental
Research
Police customs and
Immigration
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3. High Altitude Airships - Aero India International Seminar 2011
AIRSHIP vs. SATELLITES
Now the question arises what key differences it has vis a vis satellite. In other words what advantages can
be expected over the satellites. HAA will essentially work like a low altitude geostationary satellite
offering following merits:
persistent 24/7 capability
low cost, rapid reconstitution of capabilities
low inherent detectability, observability
Satellites are quite expensive (over 10 times) due to cost involved with Rocket Launch,
Special Equipments (expensive Radios / High-Tech Cameras for same resolution image)
multi-mission, exchangeable/repairable/upgradeable payloads
Limited environmental impacts
With the foregoing discussions, several organizations in our country have expressed interest in promoting
this technology eventually leading to a fully fledged platform. Key stakeholders are Integrated Defence
Services, NTRO, National Remote Sensing, NTRO, IMD, Geological Survey of India, Homeland
Security, Communication, Survey of India etc.
Having a stratospheric grid between Air grid (below stratosphere) and Space grid (comprising satellites)
can enhance the effectiveness of Multilayer network relay in Military communication scenario.
In our country, there have been DST initiatives and other organizations too are actively involved in the
R&D activities of LTA systems. Some of the prominent ones are ADRDE, NAL, ISRO, PADD - IIT
Bombay, and TIFR - National Balloon Facility.
Following is a pictorial representation of how HAA could find its application in variety of areas which
with a particular mention of Sovereignty enforcement, fleet protection, Surveillance of Border and High
value assets.
A constellation of 20 Airships positioned at about 21 kms altitude can cover the entire country and offer
great advantage both in terms of cost & benefits.
HAA GLOBAL STATUS
There are several nations involved in development of High Altitude/Stratospheric Airships. A brief
summary is given below to provide a global status on overall scenario. In recent years, several R&D
projects of solar powered stratospheric platform have been aggressively promoted in different countries of
the world, for example:
• European Space Agency, Europe
• Japan Aerospace Exploration Agency (JAXA), Japan
• National Institute of Advanced Industrial Science and Technology (NI-AIST), Japan
• Korean Aerospace Research Institute, Korea (KARI)
• Advanced Technology Group, United Kingdom
• Sky Station International, United States of America
• Lockheed Martin, USA
• CAPNINA, University of York, UK
• NASA’s High Altitude Long Endurance (HALE)
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4. High Altitude Airships - Aero India International Seminar 2011
Apart from these agencies, there are other countries which have attempted or have been active in the
development of HAA or its part thereof. Such as, China, Germany, Canada, Israel, Russia & Switzerland.
The range of activities included from Technology familiarization to the development of scaled prototype
platforms. Several of these programs have also been halted due to lack of funding and/or inadequately
matured technologies. This has even led to some of the companies having been closed. The only active
development is reported to be happening in the USA (DARPA) and some other lesser known DOD
Sponsored as well as some Private Company Funded Projects. DARPA (Defence Advanced Research
Projects Agency) funded project on Integrated Sensors Is Structure (ISIS) is being jointly developed
between Lockheed Martin, Akron and Raytheon, taking responsibility for Platform and Payloads
respectively. Boeing Company also seems to have initiated a company funded project on this technology.
The Technology Demonstrator under the DARPA Programme is planned to be flown in 2014 and an
Operational System is likely to be planned for flying in 2018, if the Technology Demonstrator is
successful. Fig 1 below is a succinct explanation of all-pervasive potential usage of an HAA, and its
comparison with other platforms in terms of their ceiling and Range.
The Government to Government Collaborations
needs to be explored with the Governments of
Japan, Korea, USA, Germany, UK, Switzerland and
Russia to reduce uncertainties and the development
life cycle time & cost.
Fig 1. DARPA HAA concept (Source: DARPA - used by permission)
HAA/Lighter then Air (LTA) STATUS IN INDIA
In India, we have not yet developed any stratospheric airship so far; however there are other platforms
which have demonstrated LTA technology such as tethered aerostats by ADRDE, blimps by NAL,
Scientific Balloons at NBF TIFR and similar developments at ISRO & IIT Bombay. The experience with
Lighter-than Air System have so far been limited to the operation of two imported Aerostat Systems and
development of 250 cubic meters and 2000 cubic meters Aerostats at ADRDE Agra, which are yet to be
operationalized. Also, development of a prototype Blimp of 300 cubic meters is under progress jointly
between NAL Bangalore and ADRDE Agra. Small prototypes of unmanned airships have also been flown
by IIT Mumbai and ISRO as experimental vehicles. The NBF at Hyderabad has been playing a pioneering
role in Scientific Ballooning for over 50 yrs. The Center has flown more than 400 missions and is
recognized as an International Centre for fabrication and launching of balloons and for carrying out
Scientific Experiments up to altitudes of 50 km.
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5. High Altitude Airships - Aero India International Seminar 2011
POTENTIAL STAKEHOLDERS
Department of Science & Technology (DST) have been taking initiatives for exploring the scope for
development and application of this technology. Other potential stakeholders (as Users or development
partners) who have been encouraging the development of HAA are listed below:
A. Users
1. Defence Research and Development Organization (DRDO)
2. Defence Services and Para-military Forces
3. National Technical Research Organization (NTRO)
4. Indian Meteorological Department (MOES)
5. Geological Survey Of India (GSI)
6. National Disaster Management Authority (NDMA)
7. Department of Atomic Energy (DAE)
8. Airport Authority Of India (AAI)
9. Advanced Research Centre (ARC)
10. Communication Industry
11. Scientific Research Community
12. Oil Extraction and Process Industry
B. Development partners
1. Department Of Science And Technology (DST)
2. Ministry Of Defence (DRDO)
3. Council Of Scientific And Industrial Research (CSIR)
4. Department Of Space (ISRO)
5. Department Of Atomic Energy (TIFR), NBF
6. Indian Meteorological Department (MOES)
7. Academic Institutions like IITs / IISc / Universities
8. International partners
9. Public-Private Partnership
The workshop held at NAL in February 2010
established the need of having an HAA for various
applications for both Civil and Military / Paramilitary
applications. On the other hand it was recognized that
Technology Readiness Level (TRLs) needs to be
upgraded significantly to make this platform available
for use. Fig 2 is just a rough illustration that about of 20
airship positioned at 21 kms altitude can address the
surveillance needs of entire nation.
Fig2.An illustration of 20 Airships providing coverage on
entire Indian subcontinent
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6. High Altitude Airships - Aero India International Seminar 2011
In terms of sizing, for an operating altitude of 20km, some estimates based on the payload are given
below:
Organization Length Max Dia Payload Volume
Lockheed Martin HAA 150 m 46m 1800 kg 162000 m3
Lockheed Martin 73 m 21 m 20 kg 14150 m3
HALE
StratSat HAA 200 m 48 m 1000 kg 269000 m3
Berkut ET (0-30 la) 150 m 50 m 1200 kg 192000 m3
Berkut ML (30-45 lat) 200 m 50 m 1200 kg 256000 m3
Berkut HL (45-60 lat) 250 m 50 m 1200 kg 320000 m3
JAXA, Japan 245 m 61 m 1000 kg 480000 m3
KARI, Korea 50 m 12.5 m 100 kg 4091 m3
Target HAA (India) 250 60 2000 kg 470000 m3
Table 1: Airship size vs. Payload data on some major global programs
Target HAA for Technology Development is expected to carry the payload of about 50 kg.
HAA TECHNOLOGY & DEVELOPMENT ROADMAP
For the development, there are a few critical technologies that need to be matured to realize an Indian
HAA. The key technologies are:
• Envelope materials and fabrication processes
• Solar based Power System
• Regenerative Fuel Cells
• Aerodynamic configuration and optimization studies for technology demonstrator and full scale
development
• Control law, Control system algorithm, and System Architecture for geo- stationary positioning
of HAA.
• Launch and Recovery experimentation to demonstrate the technologies for an HAA configuration
• Payloads
In terms of specific design targets, there is a strong need of developing technologies for Envelope
Material, Power Management (Solar Cells and RFC), and Aerodynamic Configuration along with
establishing the Ground infrastructure for Launch and Recovery. Table 2 below provides a rough
overview of the design targets and the corresponding gaps that needs to be bridged to bring to a sufficient
Technology Readiness Level for Operationalization of airship.
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7. High Altitude Airships - Aero India International Seminar 2011
Envelope Material
Key Parameters Target Specifications Current Jump
(for Full Scale status Required
Operationalization) (in India)
Fabric Mass <100 gm / > 3 times
m2
Fabric Strength >1000 N/cm 500 N/cm > 2 times
Hydrogen Permeability 0.003L/m2/24 hr 2L/m2/24 hr > 660 times
Strength retention after >85%@ 5yrs ~50 % @ 1 TBD
exposure to UV light yr
and atomic oxygen
(max 1.4 kW/m2
and AO flux 10**17
atoms/(cm2.s))
Solar Cells
Cell efficiency at end-of- 15% 12-14 % ~20 %
life (%)
Power density of 2 kW/kg 0.5 kW/kg > 4 times
complete array
(kW/kg)
Power / surface area 2 kW/m2 ~ 0.5 kW/m2 > 4 times
(W/m2)
Table 2: Specific Design targets and technology jump required for a full scale HAA
The foregoing discussions provide a good indication of what kind of technology roadmap would be
necessary to achieve HAA mission. Specific details on each of these technologies are still being worked
out and expected to be completed toward later part of this year.
Envelope Material & Fabrication process: Material development suitable for high altitude airship
application, presents many a challenges to the material designer. The strength-to-weight ratio significantly
affects HAA system size and altitude. The challenge is to develop a very lightweight as well as strong
material that is capable of containing lifting gas and is resistant to the environment. The stratosphere
extends from approximately 17 km to 50 km above the Earth’s surface. The stratosphere is also called the
“ozone layer” because 90% of the earth's ozone is concentrated in this region. At this altitude, the nominal
temperature is -70ºF which can cause the material to become brittle with a resultant loss of flexibility. The
high ozone concentration and intense UV radiation can also deteriorate LTA material, resulting in a loss
of strength and permeability. The high strength-to-weight ratio, low creep, low moisture regain, and
improved hydrolysis resistance makes polyester fiber a good choice for lighter than air (LTA)
applications.
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8. High Altitude Airships - Aero India International Seminar 2011
Power Management: Development of a-Si based thin film solar cells on ultra thin metal and plastic
substrates. Further R&D efforts on Efficiency improvement and to develop the CIGS and CdTe based
thin film solar cells on ultra thin metal and plastic substrates. Significant R&D efforts on Regenerative
Fuel Cells (RFCs) to be undertaken.
Aerodynamic Configuration and Sizing: Development of the CFD tools needed for the analysis of
external flow past the HAA at stratospheric conditions (High fidelity viscous flow solvers). Development
of simulation and modeling capability for the thermal management of the internal flow. Leverage existing
capabilities of IIT Bombay to further improve their capability of aerodynamic shape optimization and
sizing including controllability of the HAA. Wind Tunnel Testing of stratospheric flow past the HAA for
CFD code validation. Exploring research collaboration with Labs like LEC in ETH Zurich, which has
developed rich expertise on Aerodynamics and Thermal Management specific to Airship technologies.
Ground Handling and Launch Preparation: A hangar large enough to hold the complete, inflated
envelope during vehicle assembly, and large enough to attach all the essential hardware. From the
perspective of launch and recovery procedures, all operations can be housed at a single facility and the
necessary infrastructure should be built. Siting-survey should begin immediately, and setting up should
begin at the completion of Project Definition Phase. Few experiments on Launch and Recovery can be
planned at National Balloon Facility of TIFR.
Other Technologies (CLAW, Payloads, Propulsion etc): The development of other supporting
technologies would heavily depend upon the sizing and shape optimization, fabric material, power
management system and availability of Ground Handling / Launch capabilities. That will be the point
when we should able to define target specifications for other systems such as propulsion, controls,
navigation etc. However, conceptual studies on these technologies can/shall continue on parallel path.
Based on the technology gaps and current level of technologies available in India and worldwide, the
authors recommends following roadmap to achieve a full scale operational HAA. Of course, collaboration
with international agencies, which have already been involved in the development efforts of HA, would
be key to success.
The overall development is recommended to come about in 2 major phases:
a. Phase 1 = Technology Demonstrator (7 years). Brief breakdown of the major
deliverables in Phase 1 are given below:
i. Critical Technologies Development. Concurrently Project Definition phase needs
to initiated.
ii. Infrastructure development
iii. Technology Demonstrator
At the end of 6 years (i.e. a year before we embark on Phase 2), a detailed critical review
shall be done to evaluate the progress and the corresponding gaps to achieve planned
objectives.
b. Phase 2 = Productionization and Operationalization of Full Scale Airship
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9. High Altitude Airships - Aero India International Seminar 2011
At the end of 7 years, a
detailed critical review
should be carried out
regarding overall cost,
schedule and deployment
benefits for
Productionization and
Operationalization of Full
Scale HAA.
Fig 3: Proposed HAA Development Roadmap
CONCLUSIONS
High Altitude Airship (HAA) HAA is of highly Strategic and Societal relevance to India. It can find
variety of applications such as Communication (broadband), Surveillance, Disaster Management,
Resource Mapping, Weather forecasting, Research in Atmospheric Sciences, & Astrophysics. Therefore,
it is strongly recommended to be pursued. The critical technologies required to be developed in India are
envelope materials and fabrication, solar based power system, fuel cells, aerodynamic configuration and
optimization, control system, launch and recovery including HAA configuration and payloads. Research
Proposals from National and International agencies can be immediately initiated in these areas
• Material Development
• Solar Power Management & RFCs
• Aerodynamic Configuration & Optimization
• Flight Controls
• Launch and Recovery Experimentation
• Reference Weather
International collaboration is equally important for the success of the Programme. Cross-Fertilization of
Technologies could result to benefits in other areas such as UAVs, Aviation and Societal Mission. The
Programme should be pursued in phased manner. Phase-I of the project should be taken up in mission
mode to focus on the technology development & demonstration and attending the civil society
applications like weather forecasting, resource mapping on large scale and disaster management etc. As
an immediate step, the authors are in the process of identifying, research agencies/partners for developing
various components of the technology, their financial requirement, galvanizing specific deliverables and
the corresponding schedules
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10. High Altitude Airships - Aero India International Seminar 2011
KEY REFERENCES
1. Dr. Rajkumar S. Pant, Mr. Kaviresh M. Bhandari, “Sizing and Optimization of High Altitude
Platforms”, IIT-Bombay, August 2009.Submitted to NAL Bangalore
2. Dr. Mangala Joshi, Mr. Raj Kamal Prasad, “Sizing and Optimization of High Altitude Airship –
Materials and Processes” , IIT-Delhi, April 2010”. Submitted to NAL Bangalore
3. Prof. R. K. Manchanda, Mr.S. S. Srinivasan,Mr. J. V. Subbarao and Mr. B Suneel Kumar Ground
handling, Launch and recovery operations of High Altitude Airships. Submitted to NAL
Bangalore
4. Prof P Guhathakurtha “Conditions of Indian atmosphere around 20km above mean sea level”,
India Meteorological Department, Pune. Submitted to NAL Bangalore
5. Dr. J.S. Mathur, “Aerodynamics of High Altitude Airships” NAL Bangalore
6. Lewis Jamison, Geoffrey S. Sommer, Issac R. Porche “High-Altitude Airships for the future force
army” (RAND Report)
7. Naval Research Advisory Committee Report. NRAC 06-01“Lighter-Than-Air Systems for Future
Naval Missions”
8. Anthony Colozza and James L. Dolce “High-Altitude, Long-Endurance Airships for Coastal
Surveillance”; NASA/TM—2005-213427
9. Anthony Colozza “Initial Feasibility Assessment of a High Altitude Long Endurance Airship”
NASA/CR—2003-212724
10. C. Barbiera, B. Delauréb, A. Laviec “Strategic research agenda for high-altitude aircraft and
airship remote sensing applications”
11. Persistent High Altitude Aerial Platforms & Payloads Private Industry & Defense Applications
Forecast 2009, Homeland Security Research Corporation (HSRC).
12. Dr. A.R Upadhya, ML Sidana, Jitendra Singh “Lighter than Air Systems: High Altitude Airship
and its Potential applications” National Convention of Aerospace Engineers, Institutions of
Engineer(India), Jaipur, November 2010
ACKNOWLEDGEMENT
• Department of Science & Technology (DST) for having funded the project “Detailed Project
Report: High Altitude Airship”.
• Participating Institutions for their valuable inputs: Integrated Defence Services (IDS), NTRO,
NAL, DRDO, ADRDE, NRSC, IMD, ISRO, TIFR, IIT Delhi, IIT Bombay, IISc, NMRL, Survey
of India, and Geological Survey of India.
• Organizations from abroad: Sky spectrum, Geo Eye, ITT, Lockheed Martin
• Apart from NAL Scientists, special mention of following Scientists for their interactions in
respective areas of expertise.
• Prof. Rajkumar Pant, IIT Bombay
• Prof. R.K.Manchanda, TIFR - National Balloon Facility
• Dr. Mangala Joshi, IIT Delhi
• Dr. P.S. Nair, ISRO
• Dr. P.S. Goel, RAC
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