TexAgs91 said:

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Ag_of_08 said:

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The complete and adamant refusal to consider on orbit refueling or EOR comes back to one person, and his cronies. Senator Richard Shelby has done more to damage US space exploration, and more to endanger US astronauts, than possibly any human left alive.

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Is there a lot of difference between EOR and LOR? (safety-wise, not efficiency-wise)

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Safety wise? None.

Granted, on-orbit refueling of cryogenic propellants is not proven, TRL 9 technology. It's probably more like TRL 5-6. That should not be fatal to the concept and it could be matured pretty rapidly with an inexpensive demo mission relative to the cost of fielding SLS.

It's never really been tried, but not really.

SLS is aiming for a LOR-LOR type mission with no EOR component, and we're seeing the downfall of it now. To be realistically safe at this point, the mass to orbit has to include the transfer, capture, and return stages all have to go up on a single rocket.

With an EOR component, your transfer stage( at minimum) can go up separately. If that launch fails, you have the ability to abort from LEO with the crew return vehicle.

Whats infuriating, we already have a launch vehicle capable of putting the ICPS into orbit fully fueled( centaur is a better stage IMO, but we're playing the "scrap SLS and do it with what we have" game again). The Falcon 9 can put the orion and its SM into orbit manned with the LES from the Antares 1. Unmanned, the Falcon heavy can put a fueled ICPS stack in orbit with no LES, and the dragon can rendezvous and transfer crew to the orion.

The last is our best chance to get a crew quickly an efficiently to the moon imo. Have a dragon waiting in orbit, crewed, and stick the ICPS/orion stack on to heavy. The dragon can maneuver for rendezvous, and let orion/icps make its tli burn after the dragon clears itself. It has huge safety margins, and the only new hardware needed would be the adapter and interstage to mount the icps/orion to falcon heavy. Aerodynamically it works, at least in simulations. It would also cost something like 1.5 billion per mission less.

There are tons of EOR options available now, and once ULA solves it's bezos problem, it will only open up more options. The problem begins and ends with the Shelby cronies, and the make-work program that is/was shuttle and sls.

Ag_of_08 said:

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It's never really been tried, but not really.

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Are we talking about the same thing? Apollo did Lunar Orbit Rendezvous.

They did a full launch, then recovered in LOR.

I'm talking about the first segment of the mission, using EOR to assemble the stack in orbit instead of launching it all at once. LOR-LOR in this case would be placing the lander in orbit then having the manned craft meet it at the moon, separate and land, and rendezvous back in lunar orbit.

I don't see that as a big deal as far as safety goes. We're also going to be rendezvousing with the Lunar Gateway, and doing prolonged missions around the moon. Getting more experience with rendezvous beyond LEO could be a good thing if we're going to start working beyond LEO.

I dont have a problem with LOR-LOR with a lander. What you cannot safety do though, is launch a manned spacecraft at the moon without enough dV to return from its final orbit. Launching with no way home sans a rendevous, especially to lunar orbit, is suicidally reckless. All it takes is a relatively minor set of failures, and you're stuck with a manned spacecraft, watching astronauts slowly die from starvation and oxygen deprivation.

What I'm arguing against is the concept we must launch the TLI transfer stage, and the craft/return vessel aboard the same rocket, which is what Apollo and now SLS are doing. We have a perfectly functional 65ton to LEO launch vehicle, there's no reason we could use it to put a transfer stage into orbit, rendezvous with it to perform TLI, and then make LOR with gateway or a lander.

You would end up with more effective mass to lunar orbit anyway, especially redsigning a stage as a vacumn only vheicle. We talk about Saturn 5 and ~155 tons to LEO, but only 45 or so of that was TLI, SLS will only take about 42 tons, all the rest of the mass is in the transfer stage. Why not focus on a 65 ton transfer stage based on newer rl10s, or a resurrected j2. Take orion and build a better SM to bring the weight up to 65 tons so it has the dV necessary to perform LLO insertion, and either man rate falcon heavy, or have a dragon mission drop a crew off.

You can do EOR with a minimum of new development( an IDA on top of a centaur or ICPS for transfer isn't the most challenging structure to build, let's be honest...) now, and start what, if they're offered as fixed price and not cost + contracts, should be a relatively easy design process of a new transfer stagedesign, and an enlarged SM.

The concept has been around since the 50s, and was the backup plan, using the S1-b, if the combustion instability couldn't be solve in the f1 engines. It was also the plan Glushko was pushing to go lunar when the Soviets shut him down. We're much better at rendevous in LEO now.

As stupid as it sounds, if you do the numbers, the triple launch method is STILL about a billion cheaper than an sls...

Yep.

Ridiculous weird orbit update from Operation Terrible Plan: its orbit has taken it further away from earth than Apollo had to go. Yay!

#Artemis update: @NASA_Orion with its European Service Module is now 401 798 km from Earth, breaking the record for farthest distance from our planet by a spacecraft designed to carry humans and return. This record was previously held by #Apollo13 at 248 655 miles/400 171 km. https://t.co/umRk1g2Cty

— ESA (@esa) November 26, 2022

I wish they would try to pull some better periods of video back. We have a much better video relay ability now, it would have been nice to get some live video, or near live video during launch. One thing NASA has proven absolutely inept on is generating hype with launch coverage on their own.

I laughed, with their "We are going!" campaign. It sounds vaguely like "Yes we can!" or "Change you can believe in." Vacuous head shakers as motivation.

Ag_of_08 said:

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I wish they would try to pull some better periods of video back. We have a much better video relay ability now, it would have been nice to get some live video, or near live video during launch. One thing NASA has proven absolutely inept on is generating hype with launch coverage on their own.

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They've been releasing some of the launch footage afterward. The great part of NASA is it's all public domain.

Their live broadcasts could definitely use some work though, for sure. SpaceX spoiled us.

The live was what I was talking about :-). SpaceX has Def spoiled us badly. For all Musk saying he didn't care for the livestreams, he has 100% recognized how much the do for PR.

It's beautiful photography, but is a composite I'm afraid.

The view from NASA's Artemis mission yesterday is just...words fail me.

HT @JPMajor and the brilliant engineers & scientists who made this happen. #NASA #Artemis #space pic.twitter.com/hAyzRCuW4J

— Corey S. Powell (@coreyspowell) November 29, 2022

FCC, after a year of consideration, just came back and cut down the next wave of starlink satellites by 75 percent.

This is a big deal unless they win something on appeal/an amended application.

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Perhaps the strangest inclusion in the partial grant is a decision by the FCC to subject SpaceX to an arbitrary metric devised by another third-party, for-profit company LeoLabs. In a March 2022 letter, LeoLabs reportedly proposed that "SpaceX's authorization to continue deploying satellites" be directly linked to an arbitrary metric measuring "the number of years each failed satellite remains in orbit, summed across all failed satellites." The FCC apparently loved the suggestion and made it an explicit condition of its already harsh Starlink Gen2 authorization, even adopting the arbitrary limit of "100 object years" proposed by LeoLabs.

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Based on the unofficial observations of astrophysicist Jonathan McDowell, SpaceX currently has more 30 failed Starlink Gen1 satellites at or close to their operational altitudes of 500+ kilometers, meaning that SpaceX would almost certainly be forced to stop launching Gen1 satellites if this arbitrary new rule were applied to other constellations. The same is true for competitor OneWeb, which had a single satellite fail at around 1200 kilometers in 2021. At that altitude, it will likely take hundreds of "object years" to naturally deorbit, easily surpassing LeoLabs' draconian 100-year limit.

In theory, the FCC does make it clear that it will consider changing those restrictions and allowing SpaceX to launch more of its proposed Starlink Gen2 constellation in the future. But the Commission has also repeatedly demonstrated to SpaceX that it will happily take years to modify existing licenses or approve new ones not a particularly reassuring foundation for investments as large and precarious as megaconstellations.

Ultimately, short of shady handshake deals in back rooms, the FCC's partial grant leaves SpaceX's Starlink Gen2 constellation in an undesirable position. For the company to proceed under the current license, it could be forced to redesign its satellites and ground stations to avoid the E-band, or gamble by continuing to build and deploy satellites and ground stations with E-band antennas without a guarantee that it'll ever be able to use that hardware. There is also no guarantee that the FCC will permit SpaceX to launch any of the ~22,500 satellites left on the table by the partial grant, which will drastically change the financial calculus that determines whether the constellation is economically viable and how expansive associated infrastructure needs to be.

Additionally, if SpaceX accepts the gambit and launches all 7,500 approved Gen2 satellites only for the FCC to fail to approve expansions, Starlink Gen2 would be stuck with zero polar coverage, significantly reducing the constellation's overall utility. Starlink Gen2 likely represents an investment of at least $30-60 billion (assuming an unprecedentedly low $1-2M to build and launch each 50-150 Gbps satellite). With its partial license denial and the addition of several new and arbitrary conditions, the FCC is effectively forcing SpaceX to take an even riskier gamble with the billions of dollars of brand new infrastructure it will need to build to manufacture, launch, operate, and utilize its Starlink Gen2 constellation.

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Sigh.

Of course.... Twitter must be protected at all cost.

I would NOT be surprised to see starship stopped from launch at the last minute. The only thing saving it is the HLS contract.

Humanity's only hope is if Elon can somehow get enough Starships off this planet to create a self-sustaining city on Mars and start over.

Ag_of_08 said:

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Of course.... Twitter must be protected at all cost.

I would NOT be surprised to see starship stopped from launch at the last minute. The only thing saving it is the HLS contract.

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Twitter protected? I dunno, but I think the starlink license (substantial) rejection by the FCC is an indication that Elon's endorsement of DeSantis in 24 is going to impact other businesses he owns/runs. This will have more political fall out, in other words, vs. the FAA etc. approvals for starship launches.

I don't think 'they' will stop starship from launching once or many times, but keep in mind SpaceX needs to hit some incredible cadence of launches to really refine/make the economics work as desired. And there will be some starship RUD's, leading to more worrisome 'oh no some debris hit a sea turtle 100 miles out at sea, let's review this for a year or two.'

SpaceX will need approval for 6 or more per day (I think their goal is 12). Anyone who thinks that will be allowed to happen with a Democrat in the white house now would have their head in the sand, imho.

Meanwhile, who knows how close to 'ready' spacex even is to go for a launch...

Of note, they are currently swapping Raptors on Booster 7 at the orbital launch mount, so I do not think Booster 7 has been de-manifested from the orbital flight test. That said, I still predict that that day may come sometime soon (it is a pretty old booster at this point).

— Michael Baylor (@nextspaceflight) December 2, 2022

Well, there is some merit to this "arbitrary" metric. Failed satellites that stay in orbit are essentially orbital pollution, and there's quickly becoming enough crap in orbit that it needs to be addressed if commercial spaceflight is going to continue to progress. The more we launch, the more crowded it gets. You don't want to hit anything in your way to orbit, you don't want anything hitting you while you're in orbit, and you don't want to have to burn energy avoiding things in orbit. The idea of object years for failed or defunct satellites is a good measure of how much and how long something like starlink would contribute to unnecessary junk in orbit. It's not much different than regulating waste disposal here on the ground and ensuring it doesn't damage the environment or pose a threat to other people

Ag_of_08 said:

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It's beautiful photography, but is a composite I'm afraid.

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Aren't all videos/gifs a composite by definition? Seems like he used the gyroscope to maintain orientation to the sky instead of the ground and did a time lapse. It doesn't look like he overlayed anything at all.

While true as a general statement, starlink in particular is designed w/ a relatively short life span. Multiple earlier generation satellites renter & burn up monthly. If it helps you sleep better at night, the 18 SDS does a pretty good job at monitoring all of this. The mission is slated to eventually go to the commerce dept but I can't remember the timeline on that.

It's not a gyroscope you'd use, it's usually a German equatorial mount, although you could achieve similar with an alt/AZ mount

The sky is a stacked static photo of the milky way, and the video segment is shot separately with some of the air traffic left in it if I'm not mistaken. To produce a shot like that showing the nebulae in a video is night on impossible with a consumer setup. Most images like that one are shot with dozens of frames stacked on top of one another and post processed. I do a little but of astrophotography... the shot is impressive, but it's not just a camera that someone pressed record on and tracked a full night.

ETA: A really good tutorial on how this is done shooting 30 second subs. https://astrobackyard.com/how-to-photograph-milky-way/

Ag_of_08 said:

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It's not a gyroscope you'd use, it's usually a German equatorial mount, although you could achieve similar with an alt/AZ mount

The sky is a stacked static photo of the milky way, and the video segment is shot separately with some of the air traffic left in it if I'm not mistaken. To produce a shot like that showing the nebulae in a video is night on impossible with a consumer setup. Most images like that one are shot with dozens of frames stacked on top of one another and post processed. I do a little but of astrophotography... the shot is impressive, but it's not just a camera that someone pressed record on and tracked a full night.

ETA: A really good tutorial on how this is done shooting 30 second subs. https://astrobackyard.com/how-to-photograph-milky-way/

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Jock 07 said:

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While true as a general statement, starlink in particular is designed w/ a relatively short life span. Multiple earlier generation satellites renter & burn up monthly. If it helps you sleep better at night, the 18 SDS does a pretty good job at monitoring all of this. The mission is slated to eventually go to the commerce dept but I can't remember the timeline on that.

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I get that they're short lived, but that doesn't exactly address the measure. A dead object in orbit for 100 years is presenting as much of a problem over its dead orbit lifespan as 100 dead objects in orbit for 1 year. It's analogous to man hours for production. The starlink satellites may have a short lifespan and burn up, but there's also a lot of them. How starlink as a whole stacks up to other launches and systems is determined by that overall contribution of how much total time dead or failed objects stay in orbit, and that's the metric proposed.

ETA 100 years of dead orbit time = 1200 months
1200 months / 3300ish starlink satellites = .36 months per satellite
If a dead starlink satellite is in orbit for about 10 days after failing, the entire network contributes about the same pollution as a single dead object stuck in orbit for 100 years.


Yes, all of these things are tracked, but that doesn't mean they're not there and don't force people to avoid them. Would you rather launch into a relatively clean sky, or have to plan very carefully and have extra fuel/systems on board for object avoidance?

Gotcha. Thanks for the explanation!

The starlinks aren't necessarily dead when they're disposed of. Even with mega constellations like starlink, space is still a massive AOR.

Jeez

I am, in fact, that nerdy

Very nice!

Some interesting stuff about Artemis' trajectory

Was bored and started rewatching some of these, his alternate histories are as interesting as his historical recreations.

I've wondered a bit about these since watching/reading about the ludicrous things nasa has done to keep the old saturn V transporters in operation for SLS (though over-worked). SpaceX uses these for starship and falcon I believe, though I think they generally use the 'Sarens' brand.



Kind of interesting, anyway, if not exactly rocket science. At some point, they'll have to come up with a plan to assemble/build such a transporter on Mars I would guess, to move stuff about.

TexAgs91 said:

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Humanity's only hope is if Elon can somehow get enough Starships off this planet to create a self-sustaining city on Mars and start over.

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Trapped in a metal box on an inhospitable rock, devoid of life, voids any humanity and will crush that hope. You will need to hoard the canned food and smuggle enough bullets with a gun to be the last to survive to die alone.

Advantage Earth.