Author Topic: Blue Moon Lunar Lander  (Read 12248 times)

Online Space Ghost 1962

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Re: Blue Moon Lunar Lander
« Reply #40 on: 04/06/2017 02:15 AM »
Please note that no one has demonstrated a hydrolox stage with ZBO necessary for such a mission.

Also, a methalox propulsion lander would need a similar means as well.

Online Robotbeat

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Re: Blue Moon Lunar Lander
« Reply #41 on: 04/06/2017 02:37 AM »
Why do we need zero boil-off, again? Oh right, we don't. Small amount of boil-off is fine.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Online Space Ghost 1962

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Re: Blue Moon Lunar Lander
« Reply #42 on: 04/06/2017 03:29 AM »
Why do we need zero boil-off, again? Oh right, we don't. Small amount of boil-off is fine.
Ok.

Please calculate the boil-off for a hydrolox stage that launches to parking orbit, does TLI, coasts 3-4 days, does LOI to LLO, two orbits - about 8-10 hours, does PDI,  and hour of life and perhaps a braking burn.

You'll find irrespective of the other requirement of continuous power to keep the stage alive (something like a kilowatt base, improvable with stage power downs / bring ups, which are a bit chancy beyond prelaunch conditioning) that you'll lose a minimum of 60-70% of your props over that time.

If you don't, I'd really love to see how you bring that off, and so would a lot of other talented folk. Oh, and that's not all - remember its an US and all that goes with it, including the mass budget to do so.

In short, it's all about weight budget and getting payload to the surface. With ZBF your trades for preserving mass look the best.

If we're to be doing Amazon Prime to the lunar surface, perhaps you don't want to end up just delivering a bag of Kona coffee with each mission?

Offline daveklingler

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Re: Blue Moon Lunar Lander
« Reply #43 on: 04/06/2017 06:05 AM »
Why do we need zero boil-off, again? Oh right, we don't. Small amount of boil-off is fine.
Ok.

Please calculate the boil-off for a hydrolox stage that launches to parking orbit, does TLI, coasts 3-4 days, does LOI to LLO, two orbits - about 8-10 hours, does PDI,  and hour of life and perhaps a braking burn.

With passive thermal management and 40 MLI layers, about 8% annually for an EELV-sized hydrogen tank, or about 2-3% per year for the same number of layers on a 200 mt tank.  I think the claim was pretty close to zero for ACES with IVF.  Unless I'm missing something? 

ACES with a XEUS kit?

http://www.ulalaunch.com/uploads/docs/Published_Papers/Upper_Stages/ACES-Stage_Concept-AIAASpace_2015.pdf

« Last Edit: 04/06/2017 06:06 AM by daveklingler »

Online yg1968

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Offline daveklingler

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Re: Blue Moon Lunar Lander
« Reply #45 on: 04/08/2017 01:20 AM »
Or one can just put 25 tons on the lunar surface and return to orbit with something a little more elaborate.  :)

http://www.ulalaunch.com/uploads/docs/Published_Papers/Upper_Stages/ACES-Stage_Concept-AIAASpace_2015.pdf

I have a sneaking suspicion that Blue and ULA will find more areas of cooperation over the next few years.  A NG would do a nice job tanking up an ACES depot in L2.

Online FutureSpaceTourist

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Re: Blue Moon Lunar Lander
« Reply #46 on: 04/26/2017 03:01 PM »
From today's senate hearing:

Quote
Jeff Foust‏ @jeff_foust

Meyerson: Blue willing to invest in “Blue Moon” lunar lander concept in partnership with NASA; return to Moon worthy national goal.
https://twitter.com/jeff_foust/status/857242844934877185

Quote
Eric Berger ‏Verified account @SciGuySpace

Eric Berger Retweeted Jeff Foust

Willing to invest "significantly." Which IMO is significant.
https://twitter.com/SciGuySpace/status/857242959653351424

Online oldAtlas_Eguy

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Re: Blue Moon Lunar Lander
« Reply #47 on: 04/26/2017 08:47 PM »
From today's senate hearing:

Quote
Jeff Foust‏ @jeff_foust

Meyerson: Blue willing to invest in “Blue Moon” lunar lander concept in partnership with NASA; return to Moon worthy national goal.
https://twitter.com/jeff_foust/status/857242844934877185

Quote
Eric Berger ‏Verified account @SciGuySpace

Eric Berger Retweeted Jeff Foust

Willing to invest "significantly." Which IMO is significant.
https://twitter.com/SciGuySpace/status/857242959653351424
Ok, so now it is only a question of When not If.

It will happen, but when will the first launch of the BML occur?
Did he mention a NET date for first landing?