Artemis Moon Program

Flyaway said:
https://twitter.com/x/status/1565688524686376961
View: https://twitter.com/jeff_foust/status/1565688524686376961


Launch weather officer Melody Lovin says weather should trend better through the 2-hour launch window: 60% go at the start to 80% at the end.
For backup day Monday 70% go, but a little more uncertainty.
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https://twitter.com/x/status/1565689190674829314
View: https://twitter.com/jeff_foust/status/1565689190674829314


She adds there could be showers around the time taking starts, but difficult to predict. Any delays in tanking is not necessarily a minute-for-minute launch delay, says Jeremy Parsons, deputy manager of exploration ground systems.
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https://twitter.com/x/status/1565689261550190593
View: https://twitter.com/cbs_spacenews/status/1565689261550190593


SLS/Artemis 1: 1st and 2nd stage tanks should be topped off and in replenish mode by 12:07pm with a final 30m hold at the L-minus 10-minute point starting at 1:37pm; assuming management concurrence, the count should resume at 2:07pm for a launch at 2:17pm
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Melody Lovin . . . you have to love that name
 
I wish that the Hydrogen leak would be sorted out, NASA has yet again detected the leak and are trying hard to solve the issue which is not related to the rocket itself but to a fuel line that feeds the Hydrogen into the tanks, the Oxygen tank is now fully fuelled.
 
Yesterday, SpaceX announced that 2023 will see 100 launches attempts.... NASA should hear that and start taking some risks before any Astronauts life is in danger. Because, it is inevitable now, scheduled missions being what they are, that risks will have to be taken at one time or another.

Better kill a puppy puppet than an intrepid adorable school teacher...
 
TomcatViP said:
Yesterday, SpaceX announced that 2023 will see 100 launches attempts.... NASA should hear that and start taking some risks before any Astronauts life is in danger. Because, it is inevitable now, scheduled missions being what they are, that risks will have to be taken at one time or another.

Better kill a puppy puppet than an intrepid adorable school teacher...
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Yeah. But if Elon blows it up, at worst they laugh at him. If NASA has a big badaboom, then it is all torches and pitchforks.
 
phantonphan said:
Yeah. But if Elon blows it up, at worst they laugh at him. If NASA has a big badaboom, then it is all torches and pitchforks.
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"Failure is not an option." If they attempt a launch, they *could* fail. If they don't attempt a launch, they *won't* fail.
 
Orionblamblam said:
phantonphan said:
Yeah. But if Elon blows it up, at worst they laugh at him. If NASA has a big badaboom, then it is all torches and pitchforks.
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"Failure is not an option." If they attempt a launch, they *could* fail. If they don't attempt a launch, they *won't* fail.
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Same reason they almost didn't do the last X-51 flight (the only one that was actually mostly successful BTW).
 
If it starts like the Shuttle leaks in 1990, we are up for months, not weeks, of delays.

Summer of Discontent: 25 Years Since the Shuttle Hydrogen Leaks (Part 1) - AmericaSpace

Pictured in September 1990, the problem-plagued STS-35 stack is shown in the foreground, on Pad 39A, with the STS-41 stack in the background on Pad 39B. Photo Credit: NASA A quarter-century ago, in the summer of 1990, the shuttle program was in chaos. Less than two years since the resumption of...
www.americaspace.com www.americaspace.com
 
Orionblamblam said:
phantonphan said:
Yeah. But if Elon blows it up, at worst they laugh at him. If NASA has a big badaboom, then it is all torches and pitchforks.
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"Failure is not an option." If they attempt a launch, they *could* fail. If they don't attempt a launch, they *won't* fail.
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A shame the politicians aren't as interested in spinning a failure to attempt as a failure.
 
Archibald said:
Flyaway said:
Don’t forget LH2 leaks were very common during the Shuttle program. Multiple launches were scrubbed due to GUCP leaks.
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Yes. And 1990 truly was annus horribilis, in that regard (nothing sexual hey, you perverted minds !)
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Nothing a good proctologist couldn't take care of . . .
 
https://twitter.com/x/status/1566164410489610241
View: https://twitter.com/jeff_foust/status/1566164410489610241


Mike Sarafin: inadvertent overpressurization of hydrogen line during chilldown. Can’t rule out the quick-disconnect fitting saw some effects of that, but too early to tell.
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https://twitter.com/x/status/1566164783174488064
View: https://twitter.com/wapodavenport/status/1566164783174488064


The hydrogen leak was a "large leak" that persisted despite the various efforts to solve the problem, NASA's Mike Sarafin says. Sounds like they really struggled today.
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https://twitter.com/x/status/1566165232967376898
View: https://twitter.com/jeff_foust/status/1566165232967376898


Sarafin: ruled out doing a demate and remate at the pad. Looking at options to remove and replace the quick disconnect fitting at the pad or in the VAB.
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https://twitter.com/x/status/1566166043529281536
View: https://twitter.com/chrisg_nsf/status/1566166043529281536


"Several weeks" needed to roll SLS back out to the pad after work.

Shocked they're even saying the late-September window is in play. With Crew-5 and "several weeks of work" this can't, from a timeline, align to the end of Sept window. This is most certainly mid-Oct. #Artemis1
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https://twitter.com/x/status/1566167037919076354
View: https://twitter.com/chrisg_nsf/status/1566167037919076354


Ok, they're hedging on "we'd need to talk to the Range [about not going back to VAB and redoing Flight Termination System batteries]." So maybe that's how late-Sept. isn't ruled out. But this is not exactly the "hedge" you want to hear. These limits are there for a reason.
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https://twitter.com/x/status/1566170036708016128
View: https://twitter.com/jeff_foust/status/1566170036708016128


About the overpressurization: the wrong valve was commanded and rectified in about 3-4 seconds. Carefu; to say it is not necessarily the cause of the LH2 leak; more analysis needed.
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https://twitter.com/x/status/1566171212862181377
View: https://twitter.com/jeff_foust/status/1566171212862181377


Free: if FTS is extended and leak can be repaired on the pad, still have to look at issues abut Orion life on the pad to see if can stay there vs rollback.

Sarafin: pros and cons of doing work on the pad. A little early to say what the right path forward is.
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indicisivedivide said:
NMaude said:
indicisivedivide said:
The energy density is so low that the tank will have to be huge in volume. Also liquid hydrogen is very difficult to handle.
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That's why RP-1 is a more appropriate fuel for a first-stage and a major factor why the Saturn 5's S-IC used RP-1 instead of LH2.
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A modernised f-1 would be better than the rs-25 cluster
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That would have been Pyrios:

That should have been Vulcan.

Dynetics could have saved ULA the embarrassment of waiting for Bezos—but noooo.

Still, water vapor exhaust would allow high flight rates with no one screaming about CO2. Hydrogen rocketry deserves its own Musk.
 
publiusr said:
indicisivedivide said:
NMaude said:
indicisivedivide said:
The energy density is so low that the tank will have to be huge in volume. Also liquid hydrogen is very difficult to handle.
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That's why RP-1 is a more appropriate fuel for a first-stage and a major factor why the Saturn 5's S-IC used RP-1 instead of LH2.
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A modernised f-1 would be better than the rs-25 cluster
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That would have been Pyrios:

That should have been Vulcan.

Dynetics could have saved ULA the embarrassment of waiting for Bezos—but noooo.

Still, water vapor exhaust would allow high flight rates with no one screaming about CO2. Hydrogen rocketry deserves its own Musk.
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Could not understand your point about water vapour exaust.
 
jeffb said:
Just a reminder that while scrubs are disappointing, they are just a part of the rocket business, they happen to everyone.

View attachment 683550
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Quite right too jeffb. Things can go wrong with rockets, especially during the fuelling process as we saw yesterday. I only wish that NASA can get the problem sorted out and get the rocket launched come October.
 
Regarding the cubesats aboard Artemis-1.

https://twitter.com/x/status/1566441491853197315
View: https://twitter.com/sciguyspace/status/1566441491853197315


A long thread here that answers your questions about the cubesats tagging along on the Artemis I mission. TL;DR the SLS delays are a risk but seem to be manageable for most of these little guys.
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https://twitter.com/x/status/1566408247350894592
View: https://twitter.com/hardgrove/status/1566408247350894592


Couldn’t help but notice that there were several questions about the cubesat batteries yesterday at the Sept 3rd NASA SLS press conference. Thanks for thinking of us little guys! Given the interest, here’s a bit more info about that… 1 / 24

The cubesats were delivered to NASA KSC in July of 2021. Each uses the same type of batteries (Li-ion 18650). Each cubesat has a different number of them and were charged to different levels depending upon mission requirements & individual design specifications/decisions. 2 / 24

Each mission requires a different amount of charge on the batteries in order to boot the spacecraft and begin operations. 3 / 24

Each mission measured the rate of “self-discharge” on their batteries at some point prior to delivery and most were consistent with rates around (or less than) 2% per month. 4 / 24

There are several unknowns, however, provided that some missions charged to 100% and the cubesats have been stored in the OSA under ambient conditions without temperature control. Both of these incur an unknown penalty on the monthly rate of self-discharge. 5 / 24

If the rate of self discharge stayed around 2% then, at least for @lunahmap, the batteries would not drop below the minimum required to boot the flight computer and deploy the solar arrays until about 30 months after delivery. 6 / 24

If, however, the self discharge rate went up to 5% per month then @lunahmap would drop below the minimum required to boot in about 12 months after delivery. 7 / 24

Without access to the spacecraft, each cubesat program is doing their best to assess the risks to their mission based on the possible charge states after over 1 year in storage. Many assumptions are required and each mission is assessing the risks given their requirements. 8 / 24

To be clear, the SLS program is doing everything they can to provide charge to those cubesats that are able to charge their batteries. For those that can not, the only way for them to be charged would be to remove the cubesats from the OSA, which requires destacking Orion. 9 / 24

Five of the cubesats on Artemis-1 are unable to charge their batteries. The reasons why vary across the missions. Some did not design that capability, some decided not to, and others were not allowed to due to SLS safety concerns. @lunahmap is one of those that can not. 10 / 24

Upon deployment, all the cubesats use solar panels to charge their batteries and/or power their subsystems. In the case of @lunahmap and CuSP, they were designed so that if sunlight hits their solar arrays the batteries will charge even if the spacecraft has not booted up 11 / 24

If these cubesats deploy below the minimum state of charge, then any exposed solar panels will charge the batteries. Each mission is planning their post-deployment operations differently based on their expected state of charge and their overall mission design. 12 / 24

The CuSP mission, for example, is planning a long wait before their first DSN contact to ensure they are sufficiently charged. 13 / 24

@lunahmap needs to execute a set of propulsive maneuvers shortly after deployment, so a DSN contact is planned early on. With only one of LunaH-Map’s eight solar panels getting sunlight, if power is low it may take a few hours to reach the required charge to boot. Or not. 13 / 24

How long it will take to charge sufficiently will depend upon the current battery stage of charge, which is not known with much certainty. We might be fine or need to wait. The time it takes to charge & get into a safe configuration will be a risk for each mission but …14 / 24

SLS launch delays do NOT mean that the cubesat missions are dead, as long as they were designed to charge after deployment when their solar arrays are exposed to the Sun. For these missions, like @lunahmap and CuSP (possibly others), it just adds some risk. 15 / 24

For LunaH-Map, if launch is after December of 2023 we can be pretty sure we will need to spend a few hours (up to a full day) charging after deployment. But the uncertainty about our rate of self discharge means we could reach that point as soon as fall/winter 2022. 16 / 24

For LunaH-Map, deploying below our minimum charge to boot would be a very big risk to our overall mission success because of how little time we have to commission spacecraft subsystems & execute a lunar gravity assist with our propulsion system post-deployment (~3 days) 17 / 24

So while there is increased risk to the cubesats who can not charge, at worst they will deploy into a “dormant” state and spring to life after some Sun hits their solar arrays. The biggest risk to the missions then is lost time. 18 / 24

I can’t speak to the details for each individual mission, and if you are curious about them I encourage you to reach out to find out the details about how they plan to negotiate a low power state upon deployment. We’re all happy to chat about our exiting missions! 19 / 24

… And while you are here, if you’ll allow me a bit of editorializing. The interaction of some of the smallest interplanetary spacecraft ever built with one of the largest rocket programs ever has been very interesting and ground-breaking. 20 / 24

Accommodating tiny high-risk, high-reward spacecraft on big missions will enhance big mission science. Little spacecraft can collect hard-to-reach but exciting datasets. How big missions accommodate tiny ones is a problem worth solving and it doesn’t have easy solutions. 21 / 24

Tiny spacecraft are designed to different sets of requirements than bigger ones (and rockets). SLS has done a great job of working with all of the different cubesat teams and we are still in a position where we can achieve mission success. 22 / 24

Of course there’s always more to learn, but considering we are all doing this for the very first time ever I think we have set out on a good path forward demonstrating we can work together. Let’s go… To the Moon! And beyond! 23 / 24

Tweets and views are my own and do not represent NASA or the SLS Program 24 / 24
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This is hypothetical, but how hard is it to launch Orion or a modified version of Dragon into lunar orbit using Falcon Heavy?
 
siegecrossbow said:
This is hypothetical, but how hard is it to launch Orion or a modified version of Dragon into lunar orbit using Falcon Heavy?
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Falcon Heavy can put a lot of mass into orbit, but its upper stage doesn't have the performance to put something as heavy as Orion into the proper transfer orbit. For getting Orion to Lunar orbit, by design there's no other existing vehicle to do the job. Any option other than SLS falls into the "just start over with a new architecture" bucket.
 
Now there was a quote in the November 7, 2011 issue of Av Week (page 24) that said it would take 36 D-IV Heavy flights or 24 Falcon Heavy flights for a lunar mission…don’t have that issue in front of me. I suppose that was assuming boil-off…

Bohdan Bejmuk of the Augustine Commission said on page 29 of the Aug. 10, 2009 AvWeek that he became more appreciative of the wisdom of the original Ares V…

For whatever those articles are worth…

SD HLLVs were looked at long before Congress’s support. Bill Eoff worked on Magnum decades back.

Here with SLS, the leak took place on the ground… with bolts and one gee keeping everything in place.

Inevitably, Starship will experience a leak in orbit during refueling. No liquid methane isn’t as cold has liquid hydrogen—BUT the differential sunlight heating might make up for that fact meaning you could have the same issues in LEO with that leak being a de-facto thruster…and Starship perhaps being a spinning Agena on steroids. At least hydrazine stays stable…and LH2 won’t form droplets for long.
 
Don't you love it when they use the words "probability" and "almost certainly"?

"Nasa had first tried to launch the rocket on Monday. That attempt was waved off when controllers couldn't be sure the four big engines at the base of the core-stage were at the correct operating temperature.
Frustratingly, subsequent analysis indicated that a sensor was almost certainly outputting inaccurate readings. The power units, in all probability, were in absolutely the right condition to go fly."

From a non-existent NASA fueling manual from 1969:

"It is vital that along with temperature and pressure sensors, that a veeblefitzer unit be installed immediately next to the fueling port and the inlet valve. It will act automatically to ensure no leaks occur."
 
Well, the future generations will remember that their father's 2nd attempt to the moon was made through a strange rolling takeoff :rolleyes:

Some of them will even ask anxiously: but why didn't they put cartwheels at the base? Other will vehemently argue on the Interschmuck that SLS design included a pull and go secret function!
 
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