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Chinese Launchers / Re: The Chinese NOTAMs thread
« Last post by mikezang on Today at 01:17 am »
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A0676/24 NOTAMN
Q) ZPKM/QRDCA/IV/BO/W/000/999/2649N10742E012
A) ZPKM B) 2404022247 C) 2404022312
E) A TEMPORARY DANGER AREA ESTABLISHED BOUNDED BY:
N265200E1075500-N264100E1075100-N264600E1073000-N265700E1073400
BACK TO START. VERTICAL LIMITS:SFC-UNL.
F) SFC G) UNL

A0677/24 NOTAMN
Q) ZGZU/QRDCA/IV/BO/W/000/999/2504N11201E022
A) ZGZU B) 2404022248 C) 2404022318
E) A TEMPORARY DANGER AREA ESTABLISHED BOUNDED
BY:N250600E1122500-N244900E1121800-N250300E1113900-N252000E1114500
BACK TO START. VERTICAL LIMITS:SFC-UNL.
F) SFC G) UNL
The NOTAM for CZ-2C from Xichang.
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Would a Project Mercury Retro-Pack style set of solid fuel motors 'rippling' be a possibility for ullage? They'd be more efficient than hot or cold gas, and there would be zero plumbing.

For a temporary fix, yes.  Long term not usable for going to Mars, though maybe one could over-provision the number needed, make them replaceable by space-walk.
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Not necessarily, if you were to use the booster as a kick stage in conjunction with the Moon for a slingshot maneuver for a high energy departure into the system, you could use the Moon to help bring the booster back to low Earth orbit. Unfortunately, the outer 20 engines would be useless dead weight without modifications to make them restartable or have them drop off above the Karman line.

This has all been endlessly mathed out in this thread:

https://forum.nasaspaceflight.com/index.php?topic=55550.0

TL;DR - booster is designed for boosting from a high gravity well with an atmosphere.  It's not efficient for anything else.

Starships are for 60km and above,  They are great at it, efficient, and sending a bunch in parallel is more efficient than anyone could come up with, including Nuclear Rockets.  (see that thread if you want the details on that)

(My own fault for not being more specific)
I was specifically responding to XVEL’s comment:
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generally in ideal case it is probably equivalent but this is not ideal case and even if booster would be modified to be able to do that it would be still expendable one use only

I was just disagreeing that the booster had to be disposable.  This had nothing to do with the  efficiency of sea level  engines in a vacuum.
 Personally, my stupid wild idea involves modifying a StarShip as a full sized vehicle kick stage. I imagined a stripped down ship (like Ship 26), since there would be no cargo section, stretch the fuel tanks, and have a truncated nose cone fairing which would be dropped just like F9 fairings. The bow would have both a payload/docking adapter and a ship clamp adapter (just like the boosters currently have to mate with the StarShips).
At the stern, have 6 Raptor Vac.(just like what is supposed to be done soon), but remove the 3 center sea level engines and install 4 of the smaller lunar landing engines with vacuum bells in their place.
I know we don’t know much at all about the Lunar landing engines but I figured since they will be so much smaller, and probably only about 10% the thrust as a standard raptor, they would be pretty much for vector control and propellant settling. 
In order for it to be “practical in reusability” :o , I imagined that it would remain in Earth system providing Oberth maneuvers up to slingshot maneuvers utilizing the moon. 
Where things get really iffy is trying aero braking to bring it back down to LEO without heat shield tiles.

Why not just fill two Starships full of fuel in LEO, boost them to a near GTO elliptical orbit (whatever uses half the fuel), do the fuel transfer, and Oberth boost with a full Starship?  The near empty one aerobrakes back to LEO and/or direct to landing.

Nothing is thrown away except the one  Starship doing the Oberth burn with 150t of cargo.  You end up with a Vinf that gets you anywhere you want in the solar system (enough to barely exit the solar system in fact) with 5x-10x the mass of any to-date science mission.

For very deep space fast missions that 150t of Starship cargo has fuel + science payload to do an oberth burn + gravity assist at Jupiter, which allows escaping the Solar system at a decent clip.

You can scale this up to have multiple starships do the elliptical Oberth burn at Earth, then refuel to a full Starship in deep space, and do a full Starship Oberth + gravity assist at Jupiter, and eventually the empty ones make their way back to Earth and reuse via gravity assists and aerobraking at various locations with an atmosphere in the solar system.  If you really wanted 150t of full cargo moving at 50+km/sec while exiting the solar system it's the way to go with no new tech, just standard operations done in deep space instead of LEO.   But there are extremely few missions that need this.  On that thread link I provided someone made a full spreadsheet for this scenario.  Look for the keyword "ladder".   You can "ladder" as many refuel stages as you wish, though it's a waste to not do burns deep in a gravity well, which limits you to two further burns (Jupiter and Saturn), a somewhat rare time window in the planetary orbits.

That aerobraking gives you tons of free deltaV, why would you throw that away?  Use standard starships for everything but the throw-away final stage that goes into the deep space never to return.
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Brady Kenniston
@TheFavoritist
I’ve been working with NSF since 2016-2017ish. Never thought I’d see the site grow so much in those years. Crazy to be apart of this wild ride.

https://twitter.com/TheFavoritist/status/1773425114039623698
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Space Science Coverage / Re: ESA - Voyage 2050
« Last post by matthewkantar on Today at 01:03 am »
I think it’s best to design for what exists. Europa Clipper was going to launch on SLS, a cheaper gentler ride came along, it’s going to go on FH. No need to clog up all the threads with future launchers.
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Tyler Gray
@TylerG1998
In other news… 🎉

What a huge milestone this is. Thanks to each and every person who’s followed Team NSF on our YouTube journey — we are eternally grateful.

Really, really proud to be a part of this. ♥️

https://twitter.com/TylerG1998/status/1773427678512574909
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Andrew C - Rocket Future
@TheRocketFuture
Congrats on your first 1M milestone @NASASpaceflight! You've got a great team and it shows. Onwards and upwards to 2M!

https://twitter.com/TheRocketFuture/status/1773429142970659323
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Quote
Tyler Gray
@TylerG1998
In other news… 🎉

What a huge milestone this is. Thanks to each and every person who’s followed Team NSF on our YouTube journey — we are eternally grateful.

Really, really proud to be a part of this. ♥️

https://twitter.com/TylerG1998/status/1773427678512574909
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Elisar Priel
@ENNEPS
It has been a honor to take a small part over the last two years in the team and see that amazing community from around the world that has been build around our mutual love for space.

https://twitter.com/ENNEPS/status/1773439682862272615
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