As we head into the end of 2018, we can’t help but recognize the many accomplishments revolving around space exploration that have kept us fascinated and pondering the question of “what next?” From NASA celebrating a legacy that spans 60 years in which they have kept true to their mission “to reach for new heights and reveal the unknown so that what we do and learn will benefit all humankind” to SpaceX’s combination of “cool Tesla car and cool Falcon Heavy rocket" that was sent into orbit to the Curiosity rover discovering organic molecules on Mars' surface, this year has indeed been one of distinction, discovery and breakthrough. There are many dedicated people who have believed in pushing our limits and going beyond the stars to learn more about distant planets and deep space. As astrophysist Neil deGrasse Tyson aptly said, “Ever since there have been people, there have been explorers, looking in places where others hadn't been before. Not everyone does it, but we are part of a species where some members of the species do—to the benefit of us all.”
The Sealing & Polymer Effect
Our space team of engineers hopes that they can be put into that category of advocate; it has been their goal in the last 60 years to help pioneers to explore the vast unknown with sealing and polymer solutions for launch vehicles, rovers, and satellites. If you took a time machine back to the late 1950s, you would see us on NASA’s Project Mercury where we worked to solve pressure and temperature limitations, which resulted in the creation of our Omniseal® RACO® spring-energized seal that is still being used in many critical applications today. Set the dial on our time machine to the next three decades and you will find us working on the Apollo, Viking, and Space Shuttle programs. As we go from one millennium to the next, we have the pleasure of supporting on the Mars Exploration Program, Mars Rover Curiosity and Space Launch System; and now going from public to private domain with other private launchers.
Exactly what and where has our seals and materials been used on these launch vehicles and other space equipment? Our high performance solutions are used in propulsion and payload systems, ground support equipment, and structures and tanks in such applications as:
- Valves controlling liquid oxygen and fuel in rockets
- Turbo pump applications
- Main fuel valves
- Main oxygen valves
- Preburner valves
- Center pushers
- Manhole covers
Because seals are critical in many of these areas, it would be very common to see hundreds of seals on one rocket. In fact, the Atlas V rocket engine, which launched the Curiosity rover into space in late 2011, used more than 60 Omniseal® spring-energized seals in the Atlas booster stage and Centaur second stage systems alone. Over these many years of closely working with space engineers and manufacturers, our sealing and polymer solutions have progressively improved whether to increase pressure of the fluids to seal or being more aggressive from a chemical standpoint. The speed of service has significantly increased in this demanding field as public and private sectors take their exploration aspirations to a higher level.
The Changing Landscape in Today’s Race to Space
After six decades of space exploration, the landscape has changed significantly to include emerging countries and the private sector in the race to space. Omniseal Solutions now works with a number of new space companies in the private sector, in addition to traditional space companies, with about 50 percent of its aerospace business today in each.
Who are the key players? Who sits at the private space table? SpaceX, founded by Elon Musk in 2002 to design, manufacture, and launch advanced rockets and spacecraft with the ultimate goal of enabling people to live on other planets, is one example of a modern and innovative company. It became the first private company to return a spacecraft from low Earth orbit in 2010, and its Dragon spacecraft became the first commercial spacecraft to deliver cargo to and from the International Space Station in 2012. In February 2018, its Falcon Heavy rocket carried a red Tesla Roadster into space, which has now traveled beyond Mar’s orbit, and which fans of “Starman” are still tracking to this day.
Jeff Bezos’ Blue Origin—with the vision of millions of people living and working in space via its New Shepard and New Glenn launch vehicles—as well as Richard Branson's Virgin Galactic, Relativity Space (backed by Mark Cuban), and Vector Space are also examples of modern companies competing to be first in space. NASA has set stringent timelines for these companies to have a capsule tested next year when the ability for private companies to launch from the U.S. will open up.
At Omniseal Solutions, we have taken some proactive steps to ensure that we are keeping up with the tight timelines, arranging our engineers to be on site at companies in order to enhance communication and speed response times, furthering the expedition of design.
In the public sector, we are also working with government agencies in Europe and Asia, in addition to continuing to supply parts being used by NASA. our team recently exhibited at the Bengaluru Space Expo (BSX), organized by the Confederation of Indian Industry (CII), in cooperation with the Indian Space Research Organization (ISRO), and the commercial arm of the Department of Space (Antrix) in September to show our support for this country’s quest for space travel.
ISRO built India's first satellite, Aryabhata (launched by the Soviet Union in 1975); launched lunar orbiter, Chandrayaan-1 in 2008 and its Mars orbiter in 2013. The Mars success made India first to succeed on its first attempt and ISRO the fourth space agency and first in Asia to reach Mars on September 24, 2014. In 2017, it launched 104 satellites in a single rocket, with PSLV-C37, tripling Russia’s record. It also launched its heaviest rocket: a three-stage, medium-lift expendable Geosynchronous Satellite Launch Vehicle, Mark III, that year.
ISRO continues its ambitious space program. It expects to launch its second lunar mission, Chandrayaan-2, in January 2019 and send three astronauts to the moon for 5 to 7 days on its Gaganyaan spacecraft by 2022. With its commitment to its space program and lower salary requirements, India could be a major player in space exploration in the future.
What do space companies need to keep competitive and maintain success? In working with countries with an ambitious space program and companies in the private sector, one trend we have noticed is the increased need for many organizations to keep costs low.
Another is increased reusability. Where in the past rockets might be used once, only to land in the water and be discarded, private companies are now seeking to reuse them. The benefits include recycling and saving costs.
Public and private companies are also both seeking to address growing pressure requirements. Increased pressure can enable greater efficiency to contain more fuel and oxygen in smaller containers. This enables smaller vehicles to perform at a higher capacity.
The Requirements for Seals in Space
Going the distance is quite an understatement when you talk about what makes a complex machine like a rocket operate in extreme conditions. From cryogenic temperatures to high pressure requirements, high-performance polymer seals from Omniseal Solutions address critical requirements to make space exploration successful, including:
- HPHT and increasing pressure
- Aggressive chemicals
- Cleanliness requirements, including IEST-STD-CC1246E
- Continuous and rapid innovation
- Proven designs/successful missions
Our Omniseal® RACO® spring-energized seals are frequently used by NASA. The seals, comprised of a polymer jacket energized by a corrosion resistant, heavy duty/high load RACO® spring, offer a high spring force along the sealing lip and excel at addressing extremely high-performance requirements at low/cryogenic temperatures. They are also lightweight, often can operate with little to no maintenance and can address temperatures from -250 to +150 °C and pressures of UHV to 100 MPa, as well as maximum speeds off 0.1 m/s. For this reason, they are frequently used in critical applications in space.
While Omniseal® RACO® spring-energized seals offer a U-shaped spring that can only be used in face seals, our Omniseal® 103A spring-energized radial seals offer a coil spring that can be used in radial seal configurations. While there continues to be strong demand for high-performance Omniseal® RACO® seals, we are seeing growing interest in Omniseal® 103A Spring Energized Radial Seals as more OEMs and developers design with radial seals in mind.
As a high force seal suitable for cold temperatures, Omniseal® 103A radial seals are comprised of a jacket, made of A20 or A01 polymer material, and a coil or round ribbon spring, typically made of Elgiloy®, 17-7PH stainless steel, or Inconel® 718. They offer static and moderate speed dynamic sealing, moderate to high spring load, and can address low temperature and gases in extreme conditions. They are used where ultra-low friction, chemical compatibility and extreme temperature (ranging from -250 to +250 °C) is required. They can address pressures of UHV to 100 MPa and maximum speeds of 1 m/s in anti-blowout seals, such as in the rocket engine check valve, and static/low speed applications, providing excellent leakage control at high pressure and low temperature.
While these seals do not offer as high a spring force as Omniseal® RACO® seals, they still meet the needs of many critical applications in space where leakage requirements may not be as stringent, and are also less expensive, to address this growing need in the industry.
Additionally, we are seeing more and more use of our Meldin® thermoset polyimides for high-demand applications—such as with Meldin® 7001 and 7021. Parts made of these polymer materials offer high thermal resistance and good mechanical properties at high temperatures. They withstand harsh chemicals, such as liquid oxygen (LOX); can address tremendous pressure, extreme speeds, friction, and wear, and are also lighter in weight. They also retain critical properties at continuous operation at temperature ranges from cryogenic through +600°F (+315°C), and can be used intermittently at even higher temperatures.
Load, friction, and sealing requirements are all important considerations in determining the best product and seal to use in a specific application.
At Omniseal Solutions, we work directly with OEMs and private companies to determine which seal designs and custom-developed materials are best for their applications. We draw on extensive experience in design to help engineering teams to reduce design time and leverage the latest testing and simulation techniques, such as finite element analysis to model, design, and validate complex designs to achieve higher quality parts for better, more reliable performance.
Want to join our space team on a future space adventure? Discover how we can help you to address needs for high-performing sealing and polymer critical parts by contacting us today!