Comparison of 1 ton class launchers

[Robotbeat]

ABL  -  $12M  -  1,350 kg to LEO
Firefly  -  $15M  -  1,000 kg to LEO
Relativity  -  $12M  -  1,250 kg to LEO

Also, I just saw this and grabbed a third screenshot. If this is to be believed, these engines can run on Jet-A!

It is surprising what performance ABL squeezes out of this vehicle. It is the smallest in class with least engine thrust and lifts highest payload. With the last redesign (when they went from 3 to 9 first stage engines) they even managed to increase LEO payload by 12.5 % while decreasing 1st stage thrust by 13.5 %. How that?

Disadvantage of RS1 is the smallest payload fairing in class. Btw, it runs on RP-1 according to the payload user's guide, not Jet-A.

Well, it helps not to try to 3D print your rocket tanks. 3D printing thinwalled anything is a questionable idea. 3D printing has a super hard time 3D printing small features as there’s a fairly hard trade off of feature size and speed plus if you DO manage to print thin-walled stuff, there’s poor surface quality and higher porosity (than on thicker parts) and sometimes you even have to worry about pinhole leaks. So you need a BUNCH of post-processing (or even harder, complicated in-situ processing) and you STILL need to oversize your wall a bit more than you otherwise would have to.

So it’s not THAT surprising.

[trimeta]

ABL  -  $12M  -  1,350 kg to LEO
Firefly  -  $15M  -  1,000 kg to LEO
Relativity  -  $12M  -  1,250 kg to LEO

Also, I just saw this and grabbed a third screenshot. If this is to be believed, these engines can run on Jet-A!

It is surprising what performance ABL squeezes out of this vehicle. It is the smallest in class with least engine thrust and lifts highest payload. With the last redesign (when they went from 3 to 9 first stage engines) they even managed to increase LEO payload by 12.5 % while decreasing 1st stage thrust by 13.5 %. How that?

Disadvantage of RS1 is the smallest payload fairing in class. Btw, it runs on RP-1 according to the payload user's guide, not Jet-A.

Well, it helps not to try to 3D print your rocket tanks. 3D printing thinwalled anything is a questionable idea. 3D printing has a super hard time 3D printing small features as there’s a fairly hard trade off of feature size and speed plus if you DO manage to print thin-walled stuff, there’s poor surface quality and higher porosity (than on thicker parts) and sometimes you even have to worry about pinhole leaks. So you need a BUNCH of post-processing (or even harder, complicated in-situ processing) and you STILL need to oversize your wall a bit more than you otherwise would have to.

So it’s not THAT surprising.

That doesn't explain the comparison with the Firefly Alpha, though. Unless their carbon-composite tanks are heavier/thicker than ABL's aluminum tanks...but that would kind of defeat the purpose of using carbon-composite tanks, wouldn't it? It is generally believed that Firefly are using some sort of double-layer carbon-composite tanks with insulation, so they might actually be thicker, but if they're ending up strictly worse than aluminum, it seems kind of a waste.

[PM3]

Removed my post from the ABL thread and re-posted here, to avoid the ABL thread going offtopic. Have compiled some data of different rockets and hope I got them all right.

ABL  -  $12M  -  1,350 kg to LEO
Firefly  -  $15M  -  1,000 kg to LEO
Relativity  -  $12M  -  1,250 kg to LEO
...

It is surprising what performance ABL squeezes out of this vehicle. It is the smallest in class with least engine thrust and lifts highest payload. With the last redesign (when they went from 3 to 9 first stage engines) they even managed to increase LEO payload by 12.5 % while decreasing 1st stage thrust by 13.5 %. How that?

Disadvantage of RS1 is the smallest payload fairing in class.

[Davidthefat]

Firefly's performance might be from the performance of their engines. I am wondering how efficient that "crossfire injector" is. As far as I can tell, it's like a deconstructed pintle injector where the fuel annulus is moved out much further radially on the head end of the injector. ABL seems to be using a face shut off pintle injector for their engines, and they may be taking some performance figures from the Merlin/Falcon assuming they can hit those performances.

Also, I wouldn't take unlaunched vehicles' performance measures to heart. From what I've seen, at least for the first few iterations, the performance of launch vehicles are overestimated. Some of those figures may be overpromising, planning to get to that performance once in operation, some may be failing to account for the unknown, and others may be more on the mark of actual performance. I reckon since Firefly has actually tested both stages and know actual dry mass figures that their performance numbers are more on the mark. Not sure about Relativity as I don't believe they even had full up engine hot fires yet (I think the last press release only showed them running the LOX pump only)

edit: I think also how their performance numbers are derived. Are they coming out of a simple rocket equation or are they generated using flight simulations that walk through the flight profile using real performance figures?

[Robotbeat]

ABL  -  $12M  -  1,350 kg to LEO
Firefly  -  $15M  -  1,000 kg to LEO
Relativity  -  $12M  -  1,250 kg to LEO

Also, I just saw this and grabbed a third screenshot. If this is to be believed, these engines can run on Jet-A!

It is surprising what performance ABL squeezes out of this vehicle. It is the smallest in class with least engine thrust and lifts highest payload. With the last redesign (when they went from 3 to 9 first stage engines) they even managed to increase LEO payload by 12.5 % while decreasing 1st stage thrust by 13.5 %. How that?

Disadvantage of RS1 is the smallest payload fairing in class. Btw, it runs on RP-1 according to the payload user's guide, not Jet-A.

Well, it helps not to try to 3D print your rocket tanks. 3D printing thinwalled anything is a questionable idea. 3D printing has a super hard time 3D printing small features as there’s a fairly hard trade off of feature size and speed plus if you DO manage to print thin-walled stuff, there’s poor surface quality and higher porosity (than on thicker parts) and sometimes you even have to worry about pinhole leaks. So you need a BUNCH of post-processing (or even harder, complicated in-situ processing) and you STILL need to oversize your wall a bit more than you otherwise would have to.

So it’s not THAT surprising.

That doesn't explain the comparison with the Firefly Alpha, though. Unless their carbon-composite tanks are heavier/thicker than ABL's aluminum tanks...but that would kind of defeat the purpose of using carbon-composite tanks, wouldn't it? It is generally believed that Firefly are using some sort of double-layer carbon-composite tanks with insulation, so they might actually be thicker, but if they're ending up strictly worse than aluminum, it seems kind of a waste.

It is possible that composites provide worse mass fraction. As we know with SpaceX, sometimes carbon fiber requires more factor of safety than you’d like. Also, ABL may be using lower ullage pressures which could reduce the required tank pressure.

And the difference between ABL and Firefly isn’t as great as with Relativity.

[trimeta]

Not sure about Relativity as I don't believe they even had full up engine hot fires yet (I think the last press release only showed them running the LOX pump only)

Relativity Space posted a video back in November which they described as a "fully integrated Aeon 1 engine hotfired running at full power for 187 seconds," so not just the LOX pump.

[Kryten]

 Are these definitely apples-to-apples comparisons? These differences could reflect their chosen definition of 'LEO' more than the capabilities of the vehicles.

[Nomadd]

It is possible that composites provide worse mass fraction. As we know with SpaceX, sometimes carbon fiber requires more factor of safety than you’d like. Also, ABL may be using lower ullage pressures which could reduce the required tank pressure.

I don't know about rockets, but with airliners, there are reasons composites don't scale down well. Boeing said there would be little weight advantage in a 737 size fuselage using CFRP.

[trimeta]

Are these definitely apples-to-apples comparisons? These differences could reflect their chosen definition of 'LEO' more than the capabilities of the vehicles.

The 500 km SSO comparisons should be pretty apples-to-apples, that's the same apogee/perigee (since these are circular orbits) and altitude.

[trimeta]

Oh, and if we're making comparisons, we may want to add in Rocket Factory Augsburg (the launch arm of OHB). They're a little vague, only saying they'll put 1100 kg to a 700 km SSO (so not a direct apples-to-apples comparison), but at "slightly more payload than ABL," they probably should still be part of this conversation.

[edzieba]

ABL  -  $12M  -  1,350 kg to LEO
Firefly  -  $15M  -  1,000 kg to LEO
Relativity  -  $12M  -  1,250 kg to LEO

Also, I just saw this and grabbed a third screenshot. If this is to be believed, these engines can run on Jet-A!

It is surprising what performance ABL squeezes out of this vehicle. It is the smallest in class with least engine thrust and lifts highest payload. With the last redesign (when they went from 3 to 9 first stage engines) they even managed to increase LEO payload by 12.5 % while decreasing 1st stage thrust by 13.5 %. How that?

Disadvantage of RS1 is the smallest payload fairing in class. Btw, it runs on RP-1 according to the payload user's guide, not Jet-A.

Well, it helps not to try to 3D print your rocket tanks. 3D printing thinwalled anything is a questionable idea. 3D printing has a super hard time 3D printing small features as there’s a fairly hard trade off of feature size and speed plus if you DO manage to print thin-walled stuff, there’s poor surface quality and higher porosity (than on thicker parts) and sometimes you even have to worry about pinhole leaks. So you need a BUNCH of post-processing (or even harder, complicated in-situ processing) and you STILL need to oversize your wall a bit more than you otherwise would have to.

So it’s not THAT surprising.

What kind of 3D printing? Addtivie manufacture encompasses a wide range of deposition technques: Powder-bed? Melting or sintering? Continuous melt deposition? Laser or EBM or inductive heating? Powder deposition? Vapour or plasma deposition? etc, etc. Big differences in materials capabilities, materials properties and part geometry capabilities with different processes.
Remember also that it's not just tanks being printed. One of the things that scuppered VentureStar - even after tank leakage was solved - was that while the thin walled composite tanks themselves were lighter than Al-Li tanks in isolation, once you added all the extra mass for mounting those tanks and distributing the load, they massed more than the Al-Li tanks to which you could more easily weld mount points. Additive manufacture can build in all the 'external' supports, piping, valves etc into a monolithic part rather than needing assembly and attachment. Then there are the fun things you can do with internal macrostructure control, like making your tanks vacuum-insulated double-walled in place of externally applied foam, routing plumbing through structural braces, etc. Additive manufacture may not be able to beat a traditionally manufactured tank in isolation when it comes to part mass, but a tank alone does not a rocket make.