Relativity Space: General Thread

[playadelmars]

https://arstechnica.com/science/2020/03/relativity-space-has-big-dreams-is-the-company-for-real/

Tons of new news. They have two new test facilities at NASA with the expansion to the E2 facility originally used for Raptor development. This is a pretty substantial footprint.

Larger fairing of 3m diameter was due to a new customer need back in fall, but now that means they need a slightly larger rocket too.

Aeon engine is now larger, 23k thrust vs 17k, and thus they switched to gas generator cycle and already been in testing. Launch still in 2021, but now fall.

Sounds like some big changes but also fast progress to react. I imagine this is one of the reasons 3D printing will be disruptive, next time it may be the market shifting out from everyone and being able to adapt is critical.

[ParabolicSnark]

Resizing the Aeon engine from 17k to 23k is a big effort. They've changed the cycle from dual expander to gas generator, presumably because the available heat in the regen channels isn't enough to support the turbines (engine power scales at the cube; available heat scales at the square). In the photos, you can see their DMLS-printed chamber has been swapped out with a slug of copper AKA a heat sink chamber. While the exhaust looks impressive, that's likely one of a few frames that they were able to get because these chambers can't run more than a few seconds before melting. Good enough to work on engine startup testing, but certainly a step back from a regen chamber.

The igniter turns on, initiating combustion of the methane fuel and liquid oxygen oxidizer. After two seconds, the thrust chamber shuts down. The purposefully short test was a complete success.

It was purposefully short because it would melt if it were any longer.

Then there's the turbopumps, made by Barber Nichols (at least the original baselines). Unless they've substantially changed the combustion pressure, you can then assume that the propellant flow rate has also increased by 35%. In the pump, this means pushing your operating point way off-nominal (35% increased flow will crash your developed pressure). You can offset this by increasing chamber pressure and keeping the pump operating point near constant, but the required power has increased and you need to increase the shaft speed to make up for it. Turbopump speed can usually only be increased 5-10% before you start running into stress limits in the rotor.

So that means a new cycle, an added combustor (gas generator), new turbopumps, and a new chamber. This isn't a new "version": this is a new engine. While they can leverage lessons learned from Aeon-1, this "Aeon-2" will likely add at least a year to their design cycle (and making a 3Q2021 launch date laughable).

[playadelmars]

It will be interesting to see what other customer announcements they have coming up. Since they said this redesign to a 3m fairing was for a customer, presumably there is enough demand and a large enough contract waiting that would justify the schedule impacts.

[novak]

Good enough to work on engine startup testing, but certainly a step back from a regen chamber.

The igniter turns on, initiating combustion of the methane fuel and liquid oxygen oxidizer. After two seconds, the thrust chamber shuts down. The purposefully short test was a complete success.

It was purposefully short because it would melt if it were any longer.

Usually, you see heatsink testing being done to refine an injector design.  Which probably means their previous thrust chambers looked impressive but weren't quite high enough performance.

So that means a new cycle, an added combustor (gas generator), new turbopumps, and a new chamber. This isn't a new "version": this is a new engine.

I haven't seen them start "an engine."  I've seen them start thrust chambers, pressure fed.  So I think they had to do all that anyway, and their schedule has never been that serious.  Going away from expander to GG is (in my opinion) still a good call because they've decoupled a lot of their system and made their engine much simpler to control.  At least they're thinking about development time.

[Markstark]

https://twitter.com/relativityspace/status/1236025888589754368

zubenelgenubi: fixed link

[FutureSpaceTourist]

Very cool tank construction video

Did you know our Stargate printer has no fixed tooling? This is part of how we are reimagining 60 years of aerospace manufacturing #DYK

https://twitter.com/relativityspace/status/1236025888589754368

[FutureSpaceTourist]

https://twitter.com/jeff_foust/status/1237067666227109896

Interesting detail from Relativity Space's #satshow keynote -- the company has completed more than 320 hot firings across 20 different engine iterations.

[JEF_300]

https://twitter.com/jeff_foust/status/1237067666227109896

Interesting detail from Relativity Space's #satshow keynote -- the company has completed more than 320 hot firings across 20 different engine iterations.

This sort of thing is what most excites me about Relativity; 3D printing allows them to be as or more interative than SpaceX, and without any of the... I'll call it "Elon Musk"-ness.

[FutureSpaceTourist]

Relativity Space’s focus on 3D printing and cloud-based software helps it weather the COVID-19 storm
Darrell Etherington
@etherington / 7:49 pm BST • April 7, 2020

Just like in almost every other industry, there’s been a rash of layoffs among newer space startups and companies amid the novel coronavirus crisis. But Relativity Space has managed to avoid layoffs — and is even hiring, despite the global pandemic. Relativity CEO and founder Tim Ellis cites the company’s focus on large-scale 3D printing and its adoption of cloud-based tools and technologies as big reasons why his startup hasn’t felt the pinch.

https://techcrunch.com/2020/04/07/relativity-spaces-focus-on-3d-printing-and-cloud-based-software-helps-it-weather-the-covid-19-storm/

[Blackjax]

A bit of an update on where they stand:

https://mainenginecutoff.com/podcast/154

[TrevorMonty]

A bit of an update on where they stand:

https://mainenginecutoff.com/podcast/154

Not lot new for people following them. Did touch RLVs at end of podcast, Tim didn't quite give a definitive yes, but was positive about it. Seems like it is on their todo list after they are launching ELVs regularly.

Terrain 1 is small enough to do mid air recovery, whether it needs a reentry burn or not is another question. That burn may not need to be as long as F9R as its lighter LV . Unlike the Electron they do have little more payload margin to work with.

[GWH]

The really interesting thing in that podcast was where he discussed changing internal stiffeners of the rocket structure to suit the payload and its particular vibration frequency requirements.

[GWH]

A fairly short TechCrunch interview with Relativity. Some footage might be new, a really cool close up and slow motion video of the "printing" process which looks just like MIG welding.

https://twitter.com/TechCrunch/status/1258739291980730369

[FutureSpaceTourist]

Space start-up Relativity verified its 3D printing process works to build a rocket
PUBLISHED TUE, MAY 12 2020 9:14 AM EDT
Michael Sheetz
@THESHEETZTWEETZ

KEY POINTS

Rocket builder Relativity Space, which is 3D-printing almost entire rockets, recently passed a key milestone as it moves closer to its first launch.

"It's a pretty big deal to show that the materials actually work and the manufacturing process actually works," Relativity CEO Tim Ellis told CNBC.

Additionally, the company's rocket development is still on track for its first launch in 2021, Ellis noted, despite the coronavirus pandemic that's begun causing delays within the space industry.

https://www.cnbc.com/amp/2020/05/12/relativity-space-verifies-3d-printing-works-to-build-its-rocket.html

Animated GIF attached

[FutureSpaceTourist]

twitter.com/sciguyspace/status/1262516614400020487

Some news: Relativity Space has hired Zach Dunn away from SpaceX. Dunn is an exceptionally hard worker who rose from an internship to lead production and launch at SpaceX. Story coming.

Edit to add:

https://twitter.com/elonmusk/status/1262524756831633409

Zach made a significant contribution to SpaceX & is a friend. I wish him well as he tries something new.

[FutureSpaceTourist]

Here’s Eric’s article:

A senior engineer has left SpaceX to work for Relativity Space
Dunn played an important role in the history of SpaceX.

ERIC BERGER - 5/19/2020, 12:21 AM

Relativity Space, a California-based company pushing hard toward the inaugural flight of its Terran 1 rocket by the end of 2021, has hired a senior launch official from SpaceX. Zach Dunn, formerly Senior Vice President of Production and Launch at SpaceX, will become Vice President of Factory Development at Relativity.

https://arstechnica.com/science/2020/05/relativity-hires-spacexs-senior-vice-president-of-launch-zach-dunn/

Photo caption:

Zach Dunn with the Merlin engine that powered the successful fourth flight of the Falcon 1 rocket.

[playadelmars]

Wow, this is a pretty insane hire, good for Relativity’s future prospects. Someone like Zach could have done just about anything he wanted to, and choosing to lead the 3D printing factory is a big sign of confidence the cost and engineering advantage could be real. It’s not just any leadership hire, from what I’ve heard he was the very top engineer and helped drive spacex through a ton of their hardest challenges from org to org.

[AnalogMan]

Came across plans for Relativity Launch Complex 16 which I thought might be of interest to followers of this thread.  Documents were submitted to the St Johns River Water Management District yesterday - they can be found here: https://permitting.sjrwmd.com/epermitting/jsp/Search.do?theAction=searchDetail&permitNumber=162674

I've attached a couple of plans showing the site location and layout.

[HMXHMX]

Came across plans for Relativity Launch Complex 16 which I thought might be of interest to followers of this thread.  Documents were submitted to the St Johns River Water Management District yesterday - they can be found here: https://permitting.sjrwmd.com/epermitting/jsp/Search.do?theAction=searchDetail&permitNumber=162674

I've attached a couple of plans showing the site location and layout.

So, are they building the launch complex with "zero human labor?"

[playadelmars]

I don’t think they’ve used that phrasing for a few years since this forum thread was started. Not the most politically correct phrasing for government to say you won’t hire people, their LinkedIn says over 150 people now.