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Other US Launchers / Re: US Launch Schedule
« Last post by Salo on Today at 06:34 am »
https://twitter.com/jeff_foust/status/1769855034609615227
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Jeff Foust @jeff_foust
The FAA's Kelvin Coleman says at the #payloadspacecapitol event this evening that he didn't see any major issues with last week's Starship launch, but SpaceX still needs to carry out a mishap investigation. SpaceX, he says, is aiming for 6-9 more Starship launches this year.
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Rocket Lab / Re: Rocket Lab launch schedule
« Last post by Salo on Today at 06:18 am »
https://twitter.com/NatReconOfc/status/1769816107198599657
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NRO @NatReconOfc
LAUNCH UPDATE: WELCOME TO LAUNCH WEEK!

We’re targeting no earlier than 2:40 a.m. EDT, March 21 to launch #NROL123 on a @RocketLab
 #Electron rocket from @NASAWallops
 at @Virginia_Space
 Mid-Atlantic Regional Spaceport.

Follow along this week to get ready for the launch!
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Other US Launchers / Re: US Launch Schedule
« Last post by Salo on Today at 06:18 am »
https://twitter.com/NatReconOfc/status/1769816107198599657
Quote
NRO @NatReconOfc
LAUNCH UPDATE: WELCOME TO LAUNCH WEEK!

We’re targeting no earlier than 2:40 a.m. EDT, March 21 to launch #NROL123 on a @RocketLab
 #Electron rocket from @NASAWallops
 at @Virginia_Space
 Mid-Atlantic Regional Spaceport.

Follow along this week to get ready for the launch!
4
Other US Launchers / Re: US Launch Schedule
« Last post by Salo on Today at 06:00 am »
https://twitter.com/planet4589/status/1769913752298918147
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Jonathan McDowell @planet4589
LAUNCH at 0228 UTC Mar 19 of 22 more Group 7 Starlink sats from Vandenberg Space Force Base, California
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Other US Launchers / Re: US Launch Schedule
« Last post by Salo on Today at 05:57 am »
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SpaceX is targeting Monday, March 18 for a Falcon 9 launch of 22 Starlink satellites to low-Earth orbit from Space Launch Complex 4 East (SLC-4E) at Vandenberg Space Force Base in California. Liftoff is targeted for 7:28 p.m. PT, with backup opportunities available until 11:10 p.m. PT. If needed, additional opportunities are also available on Tuesday, March 19 starting at 7:38 p.m. PT.

A live webcast of this mission will begin on X @SpaceX about five minutes prior to liftoff. Watch live.

This is the 10th flight for the first stage booster supporting this mission, which previously launched SDA-0A, SARah-2, and seven Starlink missions. (=B1075-10) Following stage separation, the first stage will land on the Of Course I Still Love You droneship, which will be stationed in the Pacific Ocean.

https://www.spacex.com/launches/mission/?missionId=sl-7-16
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I have many thoughts on this.  I will also tell you I have worked in the field of electroplating for nearly 30 years.   I think SpaceX & others are right to pursue alternate methods of building up rocket engine parts vs. electroplating.   Technology always evolves, and what can be done with other methods like 3-D printing can oftentimes be better.  I'll also let you know that somewhere out on YT is a great video of either the Vulcain or Vinci jackets for A5 being nickel plated.

Having said that, I think Musk is incorrect in his expressed understanding of how electroplating builds up the engine part one atom at a time.   ( 6 minute mark)  That misunderstanding may color his judgement on electroplating as a tachnology.   

The rate of metal deposition with electroplating is primarily a function of current density at the cathode (workpiece).  The current density ( amps per unit area) can be increased by increasing the mass transport of metal ions ( Cu+2, Ni+2, Au+1) to the cathode.  This is mainly done with solution agitation, metal ion concentration,  temperature, and careful design of the anode/cathode geometry.  Modern electrochemical processes also benefit from proprietary additives that can also improve the rate of deposition, and overall material properties.

I have about a 99% confidence level ( some inside knowledge) that SpaceX's process for making the electroplated Merlin parts were not state of the art.   They were run of the mill "rack plating" tanks.  Nothing wrong with that, they produce good work, they are just slow.  Think of a rack plating tank as a big kitchen sink with maybe a good pump moving solution around.  Rack plating tanks are OK at pumping out parts that need maybe anywhere from 2 to 50 microns of whatever metal is being plated.  A rocket jacket/liner may need 10,000 microns.   Rack lines operate at current densities probably not exceeding 20-40 amps per square foot (2-4 ASD if you want a metric system unit) At that rate it would take over a week to plate 1 cm of copper or nickel.  That is pretty slow.

If you compare those rack plating tanks to state of the art in other industries, you will see rack lines are primitive.  They are the proverbial "Jack of all trades, master of none".   In semiconductor packaging applications, there are copper plating tools that can operate at +250 amp/square foot.  ( 10 X faster).  These plating tools are made by companies like LAM Research, AMAT, ASM, & ClassOne. Price points are probably between $1.5M to +$10M per tool.  I have personally worked on wire platers that used over 1400 amps per square foot for plating tin. ( the wire was moving through the plating tank at over 100 feet per second)

So why does all this matter?  Well who is going to make customized & optimized plating tools for rocket engine builders?   The global market is....SpaceX, Rocketdyne/L3, ISRO, ARIANESPACE, + few others?.  It's a very small market, maybe two or three tools per yer, and competing technologies like 3-D printing, sintering, explosive forming, etc. all basically compete better.   

Circling back to Musk saying that electroplating builds the part one atom at a time.   Define time please.  Nothing happens instantaneously.  In electroplating we use the Faraday constant of 96485 Coulombs per mole e-.  Also 1 amp = 1 coulomb/second.   Both nickel & copper ( the metals common to rocket engine jacket/liners) exist at a valence of +2 in the respective electrolytes.  So 2 x 96485 =192170 coulombs per mole of Ni or Cu metal deposited.  Crunch these numbers for a jacket/liner that has around 10 square feet of area, and drawing 40 ASF gives a total of 400 amps.  That would equate to depositing roughly 438 grams Nickel or 7.46 moles of Nickel per hour.  Multiply that by Avagadro's number and it is 4.5E24 atoms per hour, or 1.25E21 atoms per second, or 1.23 million Ni atoms per femtosecond.  First principles Mr. Musk!  :-)

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This screen shot from the newest RGV aerial Photography video shows how fast the village expansion is building up. Anything with construction on it is almost certainly SpaceX property even if the county records have not caught up yet.

Of the 10 green vacant lots between Weems and the bay, 4 are owned by Texas Parks and are part of the proposed land swap. Based on recent county records of family transactions I expect one of the others to be assimilated soon-ish.

What I still find amazing is all this investment in housing that needs to be regularly, completely, evacuated for testing and launches...

I've been wondering for a while if they're going to allow any of the general public to rent/buy; or just use it all as temporary housing for star factory workers.  The original airstream trailers and old village houses were used that way for people coming in from California on a temporary basis.  It's what I initially assumed the plan was for new construction, but the current scale has me wondering.  I counted 78 air streams, 153 tiny houses and 83 normal houses or house size lots being cleared in the village area (fast counts so I wouldn't be surprised if I'm off by a few).  That's 300+ homes which seems like a lot unless they're also offering medium term rentals for people working in the BC area on a semi-permanent basis.
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1 mSv/yr refuge for pregnancy

Background dose on Earth is 2.4 mSv/yr.   ???

At this point this has gotta be some sort of performance art piece ala Sacha Baron Cohen, right LMT?   :o

Dose in mGy/day.

So, useless. Sieverts or bust.   ::)

He doesn't grasp "radiation weighting factor", where mSv numbers are calculated, very simply. 

I grasp it fine. ::)  We both know there is no simple, universal conversion from grays to sieverts.

Naturally if the sieverts curve didn't disprove your (supposed) point, you would already have posted it...

And he laughs at the ICRP pregnancy dose limit

Please give any evidence of this alleged "laughter."   ???

Coastal Ron is right, of course. Pregnancy is not "near term." The simplest option for your "in case of pregnancy" scenario is, of course,  return to Earth.


  If he lectures again on magical Ramsar radiation pregnancies, posters can check that, too.

"Magical" Ramsar pregnancies? Are you claiming nobody gives birth in Ramsar?

You cite only one paper for the mean dose, but still haven't cited any medical effects for the high-dose population living in Ramsar, Iran. Even if the mean dose is small, we would still expect a significant uptick.

Such psych

Is this English?  :-\  I mean I know it's "lame attempt at armchair psychology gocha-ism," but is it actual human speech?

for 30 cm of plastic...

30 cm of plastic is the only thing that's actually economical.

Them's the facts. Sorry Ace. Don't blame the messenger.

If you believe you can demonstrate a better cost/benefit ratio, I of course welcome your correction in this matter. ;D
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My biggest peeve with the MSR plan of record is that it assumes that an SEP-driven vehicle is going to be the active RPOD element for catching an unpropelled volleyball, out of a fairly loosely determined orbit, and the cumulative risk of that comes out to be anything close to the proper profile for a Class A mission.

If they can't find a way to make a bigger MAV, with a real orbital maneuvering system, then the mission should be shelved until they find a way.  But if they insist on pushing this, give me a 200t spacecraft with a sustainable RCS system (an admittedly sore point after Thursday) over the thing with the Hall thrusters.
MEV already performed RPOD with a non-cooperative target vehicle - albeit one with a low 0.25°/minute rotation rate - with electric propulsion. And it's not like the Earth Return Orbiter does not already have a biprop RCS system, just like MEV.

A somewhat fair point, but an MEV knows where it's going, and has ground tracking to help it out.  Neither of these is true for the ERO.
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