Relativity Space
Relativity at Stennis
Relativity is leasing space to test its Aeon 1 engines at Stennis Space Center, an old stomping ground of the Apollo Program.
As an astronaut collects his thoughts and transmits back to base, the defining engineering achievement of a lifetime is complete, and a team of engineers sit back in their goose bumps, a sensation felt by millions on a summer’s night 50 years earlier.
Launcher Inc. celebrated its second anniversary in March by taking in Todd Douglas Miller’s Apollo 11 documentary, a 2019 feature film spotlighting the milestone that fuels the ambitions of Launcher, and just about every other business in its industry.
Harnessing inspiration from the 1969 Moon Landings, Launcher is committed to jumpstarting the progression of rocket design. Operating out of New York, it is among the latest in its market to capitalise on the advancements in technology to do so. Launcher became the first customer of EOS’ Customised Machines business, and earlier this year announced it had successfully printed its E-2 engine combustion chamber in a single piece on a modified EOS M 400 – re-named EOS M 4K, because of its new ability to print at 1000mm in the Z axis.
Tobias Hase
Launcher combustion chamber
Launcher combustion chamber.
At roughly a metre tall, Launcher’s combustion chamber is believed to be the largest liquid rocket engine to be 3D printed without needing welding or flanges to assemble even the smallest of pieces. Intricate channels integrated into the design enable optimised cooling, with excess powder from the printing process being removed from these channels with vibration tables, shakers, and chemical cleaning. The first combustion chambers have been printed in aluminium, but this summer, the company aims to complete another iteration, this time using copper chrome zirconium. It is taking Launcher around three days to produce each combustion chamber, where it might previously have taken up to 18 months.
The industry has seen an upsurge in activity in the last decade with a significant push from angel investors, financial support escalating as SpaceX’s vehicles began to be launched. In what has become known as the ‘entrepreneurial space age’, the billions of dollars being injected into these companies are shifting the rate of space vehicle innovation through the gears. This new generation of companies have absorbed what’s gone before them – the triumphs in breaking ground and the cumbersome evolution of rocket engineering since – and are pioneering the use of new manufacturing technologies to achieve ambitions decades in the making.
“The newer upstarts are taking hold of additive,” observes Andy Brooker, the Additive Manufacturing Development Manager at Frazer Nash Manufacturing (at the time of writing), an engineering partner of one such firm in Edinburgh.
Skyrora is working towards a British Government aim of capturing 10% of the global space market by 2030, and is soon to be carrying out launch tests at Cornwall Airport. In similar fashion to Launcher, the company is throwing metal additive manufacturing – from Renishaw rather than EOS – at the Leo engines inside its suborbital Skyrora 1 and orbital Skyrora XL launch vehicles, the latter of which boasts a payload mass of up to 315 kg.
To do this, Skyrora’s engineering team has collaborated with Frazer Nash, a machining company which counts as one of only three firms within the UK to have been certified in accordance with the AS9100 aerospace quality management standard, ensuring repeatability of the parts produced at its Hampshire base.
Skyrora motor
Skyrora's 3D printed motor.
Through working with Frazer Nash, the Leo engine is about 70% 3D printed, with the number of components being consolidated to make the welding assembly more time-efficient. Many of those parts have also been lightweighted to make the aircraft easier to lift, and thus reduce the fuel used. Parts like rings, mounting points, and the filter assembly are being machined for cost purposes. Machining is required on printed components too as a postprocessing step to make sure fit and alignment are accurate. Meanwhile, the internal bore of the combustion chamber undergoes polishing to remove any irregularities.
Robin Hague, the Lead Engineer at Skyrora, told TCT that using 3D printing brought about big advantages, enabling the team to “greatly simplify our design and constructing, allowing many features to be created as one - embedded cooling channels running around the combustion chambers, for example.”
As with Launcher, the role of this active cooling mechanism is to keep the engine at a steady temperature while the propellants (hydrogen peroxide and kerosene) are heated, ensuring the engine survives the internal combustion temperature.
The application of 3D printing technologies is becoming increasingly common, from lesser-known outfits like Skyrora and Launcher to the poster child of this new wave of space vehicle companies, SpaceX. Indeed, it was at SpaceX, working on its SuperDraco engine, where Jordan Noone, CTO and co-founder of Relativity Space, pondered how 3D printing could be applied to an entire vehicle. Noone teamed up with his University of Southern California rocket propulsion lab mentor, Tim Ellis, in 2015, and four years on has a workforce of 75 and will soon open a 500,000-square-foot factory.
Relativity is initially planning to print 95% (by weight) of its two-stage orbital Terran 1 rocket, which has a maximum payload of 1,250 kg up to 185 km in low-Earth orbit. Flight tests are pencilled in for the end of next year, 4 with engine testing being carried out at the Stennis Space Center, an old stomping ground of the Apollo Program.
On Terran 1, Relativity says it has taken 100,000 individual components down to 1,000, and its Aeon 1 engines have fewer than 100 assembled pieces each. It has its own Stargate arc-welding printing system in-house, which boasts a cylindrical build volume of 9 x 15 ft, and is utilised to produce propellant tanks, structural components, and feedlines, among other things. Inside Stargate there are three robot arms, one with a deposition head, and the other two with post-processing heads to remove material or polish printed parts. Smaller applications are typically outsourced, while the company has a fleet of DMLS machines in-house to generate and test applications.
Relativity Mu Space
James Yenbamroong from mu Space and Tim Ellis from Relativity mark their partnership.
This process all amounts to an approach that Relativity believes will get its ideas into orbit quicker than has previously been possible. Print, test, change design, print again, test again, and then get it out into the field in the space of weeks and months, rather than years. Noone references the Delta Program and the Atlas Program, successful projects from which there’s been much to garner, but also a lot to consider with each iteration. Too much for his liking, and too long to complete for the liking of OneWeb, Telesats, and mu Space, all Relativity customers who want their constellations in low-Earth orbit as soon as possible.
“Our thesis is if you simplify the company down to two processes, and reap the benefits of those two processes, like combining multiple parts into one, significantly fewer fasteners, manufacturing processes, [and] operations to happen to these parts, you dramatically decrease labour hours, or the amount of supply chain, or quality engineering you need to do, and lower the number of interfaces between parts. Then you have less design effort,” Noone emphasises. “A lot of the design work on a rocket is making sure these hundred thousand pieces all fit together correctly. If that’s all done within a printer and a CAD system, you really lower the number of people you need in order to make these things happen. That’s where the benefits come in.”
And that’s why the investment keeps coming. Space Angels, a financial services company, has recorded 18 billion USD being poured into the space sector between 2009-2018, with a sixth of that figure coming in the last year alone. It is driving these start-up companies to move quicker, iterate more efficiently, and fulfil their role of sending observational and communicational satellites into orbit, following that with supplies to maintain their function. It is projected more than 10,000 small satellites will be launched worldwide within the next five years.
For a long time, the space vehicle industry has moved slowly, hitting dizzy heights in the late sixties and early seventies, its progress then stalling somewhat with manned missions becoming fewer and farther between. Breakthroughs like that of July 1969 consigned to nostalgia. But the industry has remained a complementary field, collaboration between public and private organisations is still rife, the big and small firms supplementing one another’s existence, to where we are today. With a new age come new ideas.
Relativity Space
Relativity Space Aeon 1 test
Relativity's Aeon 1 engine undergoes testing.
“There’s a lot of unknowns with AM, and it’s the new upstart businesses that are exploring the technologies a little bit more openly, whereas the long-established [companies] are much slower to take up those [technologies] because they’ve got heritage with the current design,” Brooker notes. “A lot of the technology within space is probably 10 to 15 years old, even on the latest launches.”
“We feel the customer base is looking for much quicker response times and much quicker iteration times from us, to be able to iterate on these designs and rockets much quicker,” Noone offers. “Aerospace has been a very stagnant industry, there’s a new design of launch vehicles, historically, every 20 years, 30 years, and they’re generally variants of an older one.
“These vehicles are so complex, they have so many parts, and [if] you tackle it from that direction, you can actually change the design much quicker because there’s lower part count, or because you have a factory that has a smaller footprint, much more flexible tooling. That’s how we view printing, very flexible tooling, and the ability to change quickly within the design process.”
On July 20th, 1969, the world gathered around their TV screens, mouths ajar, hairs upright, to witness the Apollo 11 Moon Landings. Though more successful missions followed in the next three years, public interest in space exploration dwindled; such is the fickle nature of human intrigue, and the US Government that financed the projects placed its focus elsewhere. But in a new age, where innovation is being matched step for step by private investment, the space industry is set to speed up, and demand we all sit down and take notice once more.
This article was first published in the print editions of TCT Magazine Europe Vol 27 Iss 3 & Vol 5 Iss 3. Access the digital versions of the mag here and to have the print issue delivered to your home or office subscribe here.
