Relativity Space: General Thread

[Norm38]

I saw this Twitter exchange today and thought it was relevant for this topic.

.@elonmusk agrees that Tesla is relying on too many robots to make the Model 3 & needs more workers

https://twitter.com/timkhiggins/status/984833456029843457

Yes, excessive automation at Tesla was a mistake. To be precise, my mistake. Humans are underrated.

https://twitter.com/elonmusk/status/984882630947753984

[AbuSimbel]

People see whatever they want to see in short statements like these.

[catdlr]

Entrepreneur seeks to boldly go where no one has gone before: 3-D printing nearly an entire rocket

Los Angeles Times article: http://www.latimes.com/business/la-fi-rocket-tim-ellis-relativity-20180427-story.html

The 20-person company has raised more than $45 million of venture funding, and recently signed a lease agreement with NASA's Stennis Space Center in Mississippi to use a large testing facility.

Relativity plans to test-fly its Terran 1 rocket in 2020.

[Patchouli]

Hmmmmm! Ideas?

Elegance of Aeon’s staged ignition system: multiple upper stage restarts possible. No TEA/TEB required.

It’s a nearly passive system [not spark], and methalox ignition especially is not super straightforward. So that’s the win there.

https://twitter.com/relativityspace/status/971078902054502401

Perhaps resonance ignition, though that requires a high pressure source, generally.  Maybe laser.  Could be catalytic.  Lots of options.  But ignition isn't the pacing issue for low-cost launch – labor is.

I'm thinking something much simpler like a glow plug since their approach is variation of BDB/MCB using a low cost disposable booster.
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090015380.pdf

[catdlr]

Entrepreneur seeks to boldly go where no one has gone before: 3-D printing nearly an entire rocket

Los Angeles Times article: http://www.latimes.com/business/la-fi-rocket-tim-ellis-relativity-20180427-story.html

The 20-person company has raised more than $45 million of venture funding, and recently signed a lease agreement with NASA's Stennis Space Center in Mississippi to use a large testing facility.

Relativity plans to test-fly its Terran 1 rocket in 2020.

Now updated with a video of Tim Ellis
http://www.latimes.com/business/la-fi-rocket-tim-ellis-relativity-20180427-story.html

[playadelmars]

Interview starts at 24:30 on TMRO.

[Davidthefat]

Interview starts at 24:30 on TMRO.

So they are printing with Haynes R41/Rene 41 for their engine components?

[playadelmars]

Not sure but he does say “not Inconel” and that it’s stronger at higher temperatures. And not a standard alloy.

[playadelmars]

They just hired Tim Buzza to help out. That’s a big hire, he is very well regarded both technically and in organization leadership from what I’ve heard.

https://arstechnica.com/science/2018/08/an-early-spacex-employee-will-now-help-relativity-reach-the-launch-pad/

Edit: also some pretty core SpaceX/Blue Origin engineers too.

https://qz.com/1363591/relativity-space-just-hired-a-legendary-spacex-executive/

[ChrisWilson68]

I applaud a company trying to come up with a business plan to fit into Musk's Mars colonization plans.

However, I think this idea of building a rocket on Mars is the wrong way to do it.

SpaceX is only taking care of transportation with BFR/BFS.  There are lots of holes on Mars that need to be filled by other companies, such as habitats, life support, farming, vehicles, entertainment, manufacturing, etc.

What isn't needed, in any way, is a rocket built on Mars.

The only way Mars colonization is successful is if BFR/BFS or something like it is successful -- i.e. fully-reusable transport between the Earth's surface and Mars.  But if you have that, building additional rockets on Mars is pointless.  BFS will already be regularly going to and from the surface.  If you really need more than what is already there from colonization trips, just build another BFS and leave it on Mars to go between the surface and Mars orbit.  It would be far cheaper to do that than to try to build a rocket factory on Mars.

So the long-term plan doesn't make sense.

And in the short term, there are lots of competitors, both small expendable rockets and large reusable rockets.  There's nothing new relativity brings to the table for that.  I think all the expendables, small and big, are doomed pretty soon anyway because a small expendable is still more expensive per flight than a large reusable rocket, and even with expendable large rocket, ride sharing makes the large rockets less expensive per payload when the volume is high enough.  And if the volume isn't high enough for rideshares on the large rockets, it's not enough to keep the small launchers in business.

So, unless they pivot hard, I'm not seeing a future for Relativity Space, even if they are able to execute and build a nice expendable small rocket that is mostly printed with little touch labor.

[ChrisWilson68]

Have you ever heard about the drunk guy looking for his lost keys under a street light?  A passerby notices that he keeps looking and looking and can't find them.  Finally, he asks the drunk guy if he dropped his keys under the street light.  The drunk guy answers, no, he dropped them over in the bushes, but there's no light there, so he's looking where there's light.

I think the drunk guy is everyone starting a rocket company, the area under the street light is small, expendable launch vehicles, and the bushes are large, fully-reusable launch vehicles.  The light is what it's possible for a start-up company to do.

It sucks that what you're looking for is where you won't be able to get it, but that doesn't make it any better to look in the wrong place.

[Cinder]

Possibly stupid layman Q:

Why couldn't Relativity print a reusable rocket?

Mostly unrelated, I keep picturing an RS printer setup inside a large enough hab like the bigger Bigelow habs, in a bolo for standard gravity, somewhere in Earth neighbourhood to prove out NEO ISRU.

[edzieba]

Possibly stupid layman Q:

Why couldn't Relativity print a reusable rocket?

In theory: no reason why they couldn't.
In practice: practical re-usable rockets are physically larger than expendable rockets. Current 3D printing hardware (be it FDM, SLS, SLM, EMD, etc) is volume limited, and price tends to scale with working volume (as does print time). Smaller expendable rockets can thus be built with less startup capital for building the printer (plus design of your rocket is somewhat cheaper).

[ChrisWilson68]

Possibly stupid layman Q:

Why couldn't Relativity print a reusable rocket?

In theory: no reason why they couldn't.
In practice: practical re-usable rockets are physically larger than expendable rockets. Current 3D printing hardware (be it FDM, SLS, SLM, EMD, etc) is volume limited, and price tends to scale with working volume (as does print time). Smaller expendable rockets can thus be built with less startup capital for building the printer (plus design of your rocket is somewhat cheaper).

Yeah, and also reusable rockets (at least if you do them similarly to how SpaceX has proven they can be done) require thermal protection, legs, and grid fins, all of which might be difficult or impossible to simply print along with the rest of your rocket.

[playadelmars]

More updates, this time showing ability to exceed the most stringent fracture and mission-critical specification.

https://qz.com/1366576/how-relativity-space-ensures-3d-printed-parts-are-strong-enough-for-space/

I feel like this is notable for the ability to perhaps one day print a reusable rocket, as the fatigue life of such low-flaw parts should be pretty good. Also, with no fixed tooling they should be able to iterate much more quickly toward an optimal reusable design. They may not need it at first due to lower part counts and reduced labor of an expendable rocket. Their arguments for the 3D printing approach seem quite smart to me because no one else will be able to catch them if they can develop this method quickly enough. It will be very disruptive, even in a world where BFR and New Glenn are flying with moderate reuse there’s a lot of synergy possible using both methods farther in the future.

[Tulse]

Their arguments for the 3D printing approach seem quite smart to me because no one else will be able to catch them if they can develop this method quickly enough.

I don't think that's true.  Surely mastering 3D printing would be easier than mastering all the processes involved in standard manufacturing, would involve far less capital risk, and there are a lot of commercial 3D printing companies out there that would be eager to partner with some other rocket maker.

[TrevorMonty]

Most small LV competitors are using 3D printed engines and additive manufacturing for tanks. Build cost of LV is only one part launch costs, still have to build and maintain launch infrastructure, repay investors money plus direct launch costs like payload intergration and fuel.

Their arguments for the 3D printing approach seem quite smart to me because no one else will be able to catch them if they can develop this method quickly enough.

I don't think that's true.  Surely mastering 3D printing would be easier than mastering all the processes involved in standard manufacturing, would involve far less capital risk, and there are a lot of commercial 3D printing companies out there that would be eager to partner with some other rocket maker.

[imprezive]

Have you ever heard about the drunk guy looking for his lost keys under a street light?  A passerby notices that he keeps looking and looking and can't find them.  Finally, he asks the drunk guy if he dropped his keys under the street light.  The drunk guy answers, no, he dropped them over in the bushes, but there's no light there, so he's looking where there's light.

I think the drunk guy is everyone starting a rocket company, the area under the street light is small, expendable launch vehicles, and the bushes are large, fully-reusable launch vehicles.  The light is what it's possible for a start-up company to do.

It sucks that what you're looking for is where you won't be able to get it, but that doesn't make it any better to look in the wrong place.

There is more than one place to go in space. Almost all of those big rockets go to a handful of orbits. If you want a different orbit you either need to add a bunch of fuel to your spacecraft or buy a 3rd stage and wait the transfer time. On top of that there are design restrictions you are imposed with as a rideshare. Those costs can be more than the savings on the launch price. You’re argument is basically saying since trains are so cheap we should stop building cars but the world isn’t that simple.

[TrevorMonty]

Bryce Salmi (@KB1LQC) tweeted at 10:45 AM on Thu, Nov 29, 2018:
Yeah, @relativityspace is printing HUGE metal structures. I've stood next to our prints and it's crazy to think that chunk of rocket didn't exist not to long before... all tooling necessary to print domes/tanks/structure it is literally in this picture... maybe like ~400sqft! https://t.co/MIIN75L4jE
(https://twitter.com/KB1LQC/status/1067897377862742017?s=03)

Now if they can make it work in space,  large habitats should be possible. Not only could it print shell but all the interior.

[Steven Pietrobon]

Here's the image to go with that tweet.