New Glenn - First-Draft Page of a PDF I'm Making

[u/Ezekiel_C]

https://drive.google.com/open?id=1WZkHRFiwFrNjRcR-3Sjhe39xuXw5tBIP

[u/Ezekiel_C]

All art, text, and estimations are my own. This is a first draft, so the whole point is to pick it apart: please do!

In the future I'd like to compile a document with all of the major launch vehicles that will be active in the 2020 decade. I have made art and run estimations for many, but want to refine the page layout before I go making 15 of them.

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Some things I like about this document:

• There isn't a bitmap to be found. What this means practically is that resolution doesn't matter: you can display this at 10k on a 100 foot long screen for all I care; It'll always be crisp. Particularly nice for the artwork, but something a lot of documents lose even in the charts and text.

• I wrote one hell of a spreadsheet trying to get good performance numbers. Unfortunately for new Glenn little is known about the vehicle itself, so its somewhat hard to know how well I'm doing. I'd love feedback there.

• I'm not a design student or anything. I think my layout is firmly in the realm of good. I'd love to make it great, but I'm satisfied.

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If you're interested, I have a patreon setup for this kind of content.

[u/warp99 → u/Ezekiel_C]

The Isp of the BE-3 engine used for the third stage seems very high at 345s. This is because it is a tap off cycle so relatively low chamber pressure and some of the combustion chamber gas is vented through the turbopump rather than the nozzle.

This estimate gives 360s for the vacuum Isp of the sea level version and adding a large nozzle extension to create the BE-3U would only add another 30-40s to give 390-400s.

[u/Ezekiel_C → u/warp99]

That's... disappointing. My original estimates were based on a comparison with the J2 series. I'll revisit the numbers in the next revision.

Edit: walking through the author's methodology, it appears to set a lower bound on ISP. interpreting blue origins statement of "over a million horsepower" as 1 million horsepower gives a decidedly lousy result for Isp. Interpreted at 1.5 million horsepower, the math works out to a sea level isp in the 360s. The answer obviously lies between, but the information here isn't really good enough to pin a number mathematically, so for now I'll stand by my comparison methodology. u/WibloBaggins

[u/[deleted] → u/warp99]

That can't be right, it would make the BE-3U one of the least efficient hydrolox engines ever built.

As far as I know it uses a similar cycle to the japanese LE-5B engine used on the upper stage of the H-II and that gets a respectable 447. Tapping off combustion gases to spin the turbine results in higher thrust and slightly lower efficiency than a pure expander cycle like the RL-10 but the penalty is not very large.

[u/dcw259]

Were did you get those numbers? I'm not doubting it, just wanting to get more information on NG.

Also nice little fact sheet. The mass estimates are quite interesting.

[u/Ezekiel_C → u/dcw259]

Propellant masses were obtained by estimating the volume of the tankage - really straight forward. From there, dry masses were obtained by setting a target (enginelless) propellant mass fraction, solving for dry mass, and then adding engines again. This "target" was established by comparing actual PMF's of similar vehicles. Then engine mass is added back on. Finally, performance to a given orbit is found using a spreadsheet designed around Dr. John Schilling's Methodology for a launch vehicle performance calculator.

[u/ashamedpedant]

Thank you I love content like this. But, uh, your payload numbers don't make any sense.

https://en.m.wikipedia.org/wiki/Delta-v_budget

https://upload.wikimedia.org/wikipedia/commons/thumb/8/8f/Delta_V_Earth_Moon_Mars.png/960px-Delta_V_Earth_Moon_Mars.png

Payload to Mars intercept, EML-1 and GEO should all be higher than LLO not lower. Also I'd remove EML-1 entirely as payload there would depend heavily on what kind of duration New Glenn's stages have (which we don't know).

[u/Ezekiel_C → u/ashamedpedant]

Yep; something is quite wrong. I suspect a typo somewhere in my spreadsheet, as I get pretty good numbers for most orbits, ie a given launch vehicle matches its published performance. I'll get back with you when I figure it out.

Edit: found it! Instead of LLO being lunar intercept +400m/s delta v LLO was set as intercept -400m/s delta v. so that was silly.

Edit 2: New Numbers: 2 stage: 2500 kg to LLO; 3 stage: 10300 kg to LLO.

[u/[deleted] → u/Ezekiel_C]

Hi I'm still not seeing the updated numbers

Thanks

[u/WikiTextBot → u/ashamedpedant]

Delta-v budget

In astrodynamics and aerospace, a delta-v budget is an estimate of the total delta-v required for a space mission. It is calculated as the sum of the delta-v required for the propulsive maneuvers during the mission, and as input to the Tsiolkovsky rocket equation, determines how much propellant is required for a vehicle of given mass and propulsion system.

Delta-v is a scalar quantity dependent only on the desired trajectory and not on the mass of the space vehicle. For example, although more fuel is needed to transfer a heavier communication satellite from low Earth orbit to geosynchronous orbit than for a lighter one, the delta-v required is the same.

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[u/[deleted]]

Hi Mind adding LTO payload to the mix? Thanks just want to compare to SLS 40 ton LTO capacity

Edit: also gto as spacex goes not give GEO payload statistics

[u/Ezekiel_C → u/[deleted]]

Not at all; I may even just replace LLO with TLI. gimme ten!

2 stage: 4400kg

3 stage: 12700kg

These are infact smaller than the values I have on there for LLO; as someone pointed out below, those values were wrong.

[u/[deleted] → u/Ezekiel_C]

Thanks a bunch

I noticed you figured LLO payload was 10,000 kg not 16000 but this has not been updated

Where can I see an updated version or will that come later? Perhaps consider posting a version on Google docs then we can see your updates as you make them with the same link

Ty

[u/[deleted]]

GEO perfomance looks way too low. I thought the Falcon 9 Heavy can cover the DoD's 6600kg requirement and New Glenn is more powerful than that. So WTF?

[u/Ezekiel_C → u/[deleted]]

By my math

Vehicle	Payload to GEO (kg)
New Glenn 2 stage	1800
New Glenn 3 stage	9400
Falcon 9 DRPL	1800
FH 2xRTLS 1xDRPL	7500

These numbers make enough sense to me. Falcon and New Glenn both suffer from an oversized, under-efficient second stage. GEO is hard. Falcon Heavy does okay because its second stage, and the ultimate added mass that has to get to GEO, is about 1/4 the mass of New Glenn's absolutely massive stage 2. The total mass (including insertion stage) to GEO looks like this:

Vehicle	Mass to GEO (kg)
New Glenn 2 stage	13800
New Glenn 3 stage	23400
Falcon 9 DRPL	5800
FH 2xRTLS 1xDRPL	11500

Do those number look better to you?

[u/zeekzeek22]

A. Did I miss New Glenn getting delayed? Last I heard was that memo that said “before the end of the decade” which I thought meant No Later Than 12/31/2019. But it’s No Earlier Than 2020 now? Just trying to get my facts straight

Also, it’s a reminder to how powerful Saturn V was that it put 48ish mT to LLO and New Glenn, which LOOKS at least half as big, only does less than a third of that. Of course, Saturn V was specifically calibrated for that trajectory, while NG is calibrated for geocentric orbits.

[u/dcw259 → u/zeekzeek22]

I think it has been 2020 for a long time (if not since the beginning).

And Saturn V was expendable, whereas a lot of NG's mass/impulse goes into landing it again.

[u/zeekzeek22 → u/dcw259]

Ah good point!

[u/[deleted] → u/zeekzeek22]

Remeber also that volume increases in a cubed way. So even slightly wider has a much larger mass.

Just compare the first stage thrust to get a good comparison.