# SoftBank Corp. and TOPPAN Holdings Develop Lightweight, Durable Skin for Solar HAPS Aircraft Wings

- Link: https://www.thailand-business-news.com/pr-news/softbank-corp-and-toppan-holdings-develop-lightweight-durable-skin-for-solar-haps-aircraft-wings
- Published: 2026-04-27T11:52:00+07:00
- Author: PR Newswire

Skin’s compatibility with stratospheric conditions such as extreme UV rays and ultra-
low temperatures makes longer HAPS operations possible

TOKYO, April 27, 2026 /PRNewswire/ — SoftBank Corp. (TYO: 9434) (President & CEO:
Junichi Miyakawa, "SoftBank") and TOPPAN Holdings Inc. (TYO: 7911) (President & 
COO: Satoshi Oya, "TOPPAN Holdings") jointly developed a lightweight, durable skin
for use on solar High-Altitude Platform Station (HAPS) aircraft wings and devised
a testing method that replicates the stratosphere’s environment. Test production
will go forward, and the aircraft wing skin is planned for use with HTA-type^([)
^(1]) HAPS, which SoftBank plans to deploy for commercial services from 2029 onwards.

This jointly developed HAPS aircraft wing skin and test method that reproduces stratospheric
conditions were made possible by combining SoftBank’s HAPS expertise and TOPPAN 
Holdings’ know-how accrued over years of creating advanced multi-layered film technology
designed for packaging and construction materials. TOPPAN Holdings also leveraged
its proprietary technology that evaluates weather resistance. This joint development
mitigates film damage (degradation) caused by strong ultraviolet (UV) rays and ultra-
low temperatures of almost -100°C. As a result, the aircraft can stay in the stratosphere
for longer periods. 

**Development BackgroundHAPS, also referred to as "base stations in the sky," provide
communication services from uncrewed aircraft that remain airborne in the stratosphere.
Being able to keep an aircraft with a communications payload airborne for extended
periods of time would make it possible to provide an alternative means of communications
in the aftermath of large-scale natural disasters, as well as provide communication
services to under-connected areas, such as mountainous regions and remote islands.
As these platforms operate from the stratosphere at an altitude of approximately
20 km above, they offer wider-area coverage than base stations on the ground, while
also providing high-quality, high-volume, low-latency communications superior to
satellite-based communications. However, at this altitude in the stratosphere, UV
ray and ozone exposure is far greater than at ground level, and with exposure to
extremely cold temperatures that sometimes drop to almost -100℃, impaired efficacy
due to these environmental factors had been a serious issue with conventional all-
purpose skins. Responding to this challenge, SoftBank and TOPPAN Holdings jointly
developed a new ultra-lightweight, high-durability skin for aircraft wings capable
of withstanding the harsh conditions of the stratosphere, along with a specialized
methodology for its evaluation.     

**Wing Skin & Evaluation Method Characteristics1. Use of impact-resistant advanced
resin and proprietary structure to achieve both lightweighting and safetyLeveraging
converting technology^([)^(2]) developed for packaging by TOPPAN Holdings, an optimized
skin structure was achieved by precisely layering original materials and impact-
resistant advanced resin suitable for use at extremely low temperature conditions.
The resulting skin weighs the same as or less than average conventional all-purpose
skin, and even if damage to the skin were to occur, the break-resistant design keeps
damage from spreading, allowing for both a safe and lighter HAPS airframe.    

**2. Advanced durability to address harsh stratospheric conditionsSoftBank has contributed
real-world data from its stratospheric HAPS flights, including actual temperature
measurements and deep ultraviolet (UV-C) ray exposure conditions, and has also defined
requirements such as weight reduction and other performance criteria. This has enabled
TOPPAN Holdings to design a skin that addresses exposure to the harsh environmental
conditions of the stratosphere by applying technology developed for construction
materials. These conditions particular to the stratosphere include everything from
extremely low temperatures (approximately -50℃ to -95℃) to extreme heat (approximately
100℃) from direct sunlight. The skin is also resistant to short wave UV-C and high-
concentration ozone (10-20 ppm, parts per million) exposure that are far stronger
than at ground level. This durability will allow for extended HAPS operation periods.

**3. Establishing a testing method that simulates stratospheric conditions to ensure
reliabilityTOPPAN Holdings leveraged its knowledge of packaging film testing and
accelerated durability testing of construction materials, to construct a new test
environment that assesses the skin under a simulation of the ultralow temperatures
of the stratosphere, while also facilitating the testing of simultaneous exposure
from short wave UV rays and the ozone. By using this test environment, it is possible
to understand the detailed mechanisms of deterioration particular to the stratosphere
and to use that knowledge for improved product design. This understanding and design
adjustment makes it possible to carry out a more precise and more reliable evaluation
compared to former testing methods.     

**Roles of Both CompaniesSoftBank
Provide expertise required to evaluate the suitability
of the skin as well as expertise on HAPS operationsSupervision of advancing use 
with HAPS aircraft and transferring advances to practical application

TOPPAN Holdings
Develop and provide skin material suitable for HAPS aircraftProposal
for evaluation method in stratospheric environment

**Future DevelopmentsSoftBank and TOPPAN Holdings will proceed with research to 
make the skin material developed within the scope of this project even lighter and
stronger by fiscal 2027 (the year ending March 31, 2028). Additionally, while evaluating
durability in the stratosphere, both companies will also attempt to establish mass
production technology capable of ensuring sufficient supply and reliable quality
by fiscal 2028. Also, based on testing outcomes, additional functions will be added,
and the skin is expected to be used by SoftBank on HTA-type HAPS aircraft that provide
commercial services, planned for launch from 2029 onwards. Both companies also plan
to apply this skin to other fields that require a high level of durability.

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^([1]) HTA (Heavier-Than-Air) refers to HAPS that remain airborne by generating aerodynamic lift, similar to conventional aircraft.

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^([2]) Converting technology is the process of transforming materials like film into high-function final products through specialized processing such as printing and lamination. 

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**For more information:[https://www.holdings.toppan.com/en/news/04/newsrelease260427_1.html](https://www.holdings.toppan.com/en/news/04/newsrelease260427_1.html)

**About SoftBank Corp.Guided by the SoftBank Group’s corporate philosophy, "Information
Revolution – Happiness for everyone," SoftBank Corp. (TOKYO: 9434) operates telecommunications
and IT businesses in Japan and globally. Building on its strong business foundation,
SoftBank Corp. is expanding into non-telecom fields in line with its "Beyond Carrier"
growth strategy while further growing its telecom business by harnessing the power
of 5G/6G, IoT, Digital Twin and Non-Terrestrial Network (NTN) solutions, including
High Altitude Platform Station (HAPS)-based stratospheric telecommunications. While
constructing AI data centers and developing homegrown LLMs specialized for the Japanese
language, SoftBank is integrating AI with radio access networks (AI-RAN), with the
aim of becoming a provider of next-generation social infrastructure.
[https://www.softbank.jp/en/corp/](https://www.softbank.jp/en/corp/)

**About the TOPPAN GroupEstablished in Tokyo in 1900, the TOPPAN Group is a leading
and diversified global provider committed to delivering sustainable, integrated 
solutions in fields including printing, communications, security, packaging, décor
materials, electronics, and digital transformation. The TOPPAN Group’s global team
of more than 50,000 employees offers optimal solutions enabled by industry-leading
expertise and technologies to address the diverse challenges of every business sector
and society and contribute to the achievement of shared sustainability goals.
[https://www.holdings.toppan.com/en/](https://www.holdings.toppan.com/en/)
[https://www.linkedin.com/company/toppan/](https://www.linkedin.com/company/toppan/)

 

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**Read the original article :** [SoftBank Corp. and TOPPAN Holdings Develop Lightweight, Durable Skin for Solar HAPS Aircraft Wings ](http://www.prnasia.com/story/archive/4942898_CN42898_0?rand=184833)
