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Strain Measurement



In space exploration, weight is paramount. Reducing weight sometimes shifts design to more-flexible, inflatable structures. Such structures are usually lower weight and have smaller packing footprints than solid structures. Woven materials have a tendency to stretch under load. Fabric-based materials, like Vectran and Kevlar, are applicable to inflatable habitats for crews in orbit, crews in transit to a destination or crews on the surface of another body. The creep test (time-lapse investigation of the deformation of a material under load) is a means of exploring and characterizing these flexible materials under tension and at relatively high temperatures. The NASA Strain Measurement Challenge was created to find a method that measures strain on Kevlar and Vectran straps with high differential fiber movement at temperatures from 25 to 125 degrees Celsius, performs as well as photogrammetry and eliminates the twisting and bulging of fibers that occurs in current techniques.

Hidden Signals Challenge Logo

The challenge provided NASA with a simple solution for an inflatable structure with the promise of providing large, habitable volumes within a small launch package. (Photo courtesy of NASA)

NASA hoped to attract participants that are difficult to reach through traditional mechanisms such as Small Business Innovation Research (SBIR), grants, Space Act Agreements (SAAs), contracts, Requests for Proposals (RFPs), etc. The challenge platform approach allowed NASA access to a globally dispersed and diverse solver network.

The challenge was posted on Oct. 25, 2012, and remained open until Jan. 2, 2013. There was a potential $20,000 award associated with this challenge. However, all solvers who submitted a solution received feedback from NASA subject matter experts.

NASA Langley Research Center (LaRC) pursued this challenge working with NASA's Center of Excellence for Collaborative Innovation (CoECI). CoECI facilitates the process for the challenge owners, monitors challenge progress, provides guidance where required and will add any specific lessons learned to its developing knowledge base. CoECI also is responsible for overall contract management. The prize was run as an InnoCentive Theoretical Challenge through NASA's contract with InnoCentive. InnoCentive conducted the challenge including facilitating completion of the challenge draft, posting of the challenge on the platform and the initial review and submittal of the solver solutions to NASA. InnoCentive also provided the due diligence and intellectual property (IP) transfer to NASA .


In just over two months, 347 potential solvers from more than 40 countries looked at the problem and generated 71 solutions from 19 different countries. Three winning solutions that were similar in approach were awarded. Two solutions were from the United States and one was from Serbia. The winning solutions suggested adding a strip of elastomeric material (a rubber strap) along with the woven strap in the test jig. The measurements are then taken off of the rubber strap and correlated back to the woven strap. The solution was extremely elegant, simple and repeatable.

Areas of Excellence

Area of Excellence #1: "Verify Winners"

Challenges launched by CoECI through its contracts with crowdsourcing companies are launched as procurements, and the execution of the challenge and all its steps are the responsibility of the contractor. In this particular instance, InnoCentive used its standard verification process to ensure the individuals who were selected as winners by the NASA evaluation team met the eligibility criteria required to pay them. Once challenge winners are selected, InnoCentive requires individuals, whether participating as an individual or as part of a team, to complete extensive paperwork that verifies their eligibility to receive awards and also addresses the IP licensing aspects of the competition. This is the contractor's responsibility, and as a result the government is provided with only the best solutions that meet the requirements as specified in the challenge. The government's time spent evaluating solutions is also greatly reduced. Additionally, the contractor has the responsibility of handling all IP negotiations. For this particular challenge, the government received an unlimited license to use the winning techniques.

Area of Excellence #2: "Document the Challenge"

As part of its standard process, InnoCentive conducts a close-out interview with challenge owners to evaluate the overall response to the challenge process as well as InnoCentive's performance so it can understand and respond to feedback as required. For the purposes of CoECI challenges, InnoCentive updated the close-out interview to include questions of specific interest to CoECI as it continued to mature the use of this process. The interview includes a general description of the challenge and highlights the winners and their specific solutions. The interview is comprised of questions in the following areas:

  • general questions associated with how long the problem had been worked on before becoming a challenge; specific questions about working with InnoCentive and with the NASA team; questions about the evaluation and selection process; questions about the level of time and people required to support
  • results questions associated with the outcome of the challenge
  • process questions specific to all aspects of the challenge execution process

These close-out interviews have been instrumental to CoECI's ability to better execute challenges and prepare new challenge owners for the experience. The CoECI team has learned something from every one it has conducted, primarily in the area of better understanding how to support a first-time challenge owner.

Challenge Type


Under the InnoCentive construct the Strain Measurement Challenge was a theoretical design challenge which requires a more detailed engineering design as part of the solution submission. This effort was perfect for this challenge type because the team had been working on the problem for over three years when they were given the opportunity to launch it as a public competition through the InnoCentive contract. The team was, like so many technical teams, resource constrained and had not had the opportunity to assign the level of resources required to find an internal solution to the problem. One of the lessons learned from this challenge, however, was that CoECI needed to improve the first time challenge owner's level of time commitment required to launch an external crowdsourced competition. It does require a resource investment, particularly in the evaluation phase. In the end, the team members were extremely pleased with the solutions they received and stated that the solutions provided were so simple and so elegant they were surprised they had not thought of them already.

Legal Authority

Procurement Authority

Challenge Website