Space News thread

[DrWilly]

Thanks, I thought it sounded a bit off.

[bsnub]

This is a massive misunderstanding of what redshift means. It does not mean these galaxies look red. It means that spectral lines are not where they are when you look at objects in a lab or nearby, within this galaxy. They are shifted in the direction of red. That's not affected by dust doing blue filtering.

The first sentence in the quote explains that, but then it goes all wrong.

Thanks for pointing that out. Interesting that the author got it so wrong.

[S Landreth]

SpaceX launch

https://www.spacex.com/launches/sl4-23/

[Takeovers]

@S Landreth

SpaceX has presently a very large number of Starlink launches. Four already this month alone, with one more scheduled.

They are presently filling up a second shell of satellites at 53.2°. Satellites with laser links that will enable covering the oceans, where the sats have no groundstations. Very useful for cargo ships, cruise ships and airplanes.

They are also launching satellites to 97.6° polar sun synchronous orbits. By end of the year they can probably serve polar regions. Very useful for ships and planes. Many plane routes are polar over the North Pole region. Also for the South Polar science stations.

Next will be a new constellation of Starlink 2 satellites with almost 10 times the capacity plus low bandwidth direct to cell phone service. Capable of text message service and very low quality telephone service to every location on Earth not served by cell service. These satellites are big and heavy, also thousands of them will be needed. SpaceX is pushing launches with Starship for these. Capacity of existing launch vehicles is not enough.

[S Landreth]

^Thank you for that information.

something most might enjoy watching also.....

Artemis I Launch to the Moon

Liftoff from Launch Pad 39B at NASA's Kennedy Space Center in Florida is currently targeted for 8:33 a.m. EST (12:33 UTC) Monday, Aug. 29, at the start of a two-hour launch window.

7:33 pm Thai Time

[harrybarracuda]

Fuel leaking but within acceptable parameters.

Important timings for today's launch (Times in GMT)

Although we'll be keeping you up to date with the NASA Artemis launch throughout the afternoon, here is a list of key timings to look out.

• 1.33pm - Two-hour launch window opens
• 5pm - NASA post-launch news conference
• 9pm - Coverage of Orion's first outbound trajectory correction burn
• 10.30pm - Orion's first images of earth to appear

[harrybarracuda]

[Takeovers]

Liftoff from Launch Pad 39B at NASA's Kennedy Space Center in Florida is currently targeted for 8:33 a.m. EST (12:33 UTC) Monday, Aug. 29, at the start of a two-hour launch window.

Working two issues presently. We will see how serious they are. Don't sound trivial to me, but that may be just wishful thinking.

[harrybarracuda]

Engine Number 3 isn't playing nicely...

[DrWilly]

They might know in 10 minutes…

[misskit]

Is there any live stream with sound or a commentary or something. Everything I find is silent.

[Cujo]

How the fuck did I not hear about this untill just now?

[Cujo]

[Takeovers]

Is there any live stream with sound or a commentary or something. Everything I find is silent.

I like this one. Sparse commentary but not like the NASA live stream where you get pestered by STEM messages and children singing the national anthem. But that's just me. For most people the NASA stream is good.



NASA stream posted by Cujo.

[Takeovers]

How the fuck did I not hear about this untill just now?

Space News thread

Admit it was not the exact date of today but the chance of launch today was not very good to begin with. This is the opening of the launch window. Launch attempts will continue over the next few days. You can look there for a few more infos.



Launch is scrubbed for today.

[Troy]

Launch has been scrubbed...next opportunity is Friday.

[DrWilly]

Is there any live stream with sound or a commentary or something. Everything I find is silent.

Post 3682 does have commentary, just not constant (I thought I had the same problem too).

[S Landreth]

Launch is scrubbed for today.

Last night before the last note of “live in 3 days” there were over 300,000 people waiting to view the launch at the NASA youtube website.

• First launch of NASA's Artemis Moon rocket delayed by technical issues

NASA's uncrewed Artemis I launch of the Space Launch System rocket and Orion capsule was called off on Monday.

Why it matters: NASA plans to use the SLS rocket and Orion to return people to the Moon for the first time since the end of the Apollo program in the 1970s.

The latest: An engine issue prevented the SLS from getting off the pad in Kennedy Space Center in Florida.

• One of the rocket's four engines didn't get up to the correct temperature, preventing the space agency from launching.
• NASA has backup launch dates on Sept. 2 and Sept. 5, but it wasn't immediately clear whether the space agency would be able to fix the issues and target one of those days.

How it works: For this launch, the SLS is expected to send the Orion capsule on a journey around the Moon before it comes back to Earth, splashing down under parachutes in the ocean.

• The test is expected to prove out all of the capabilities needed to one day send people to the Moon.
• NASA's first crewed Artemis Moon landing is currently expected to occur in 2025.

Edit:

backup launch dates on Sept. 2 and Sept. 5

Both days are forecast for bad weather

[DrWilly]

How bad does the weather have to be to stop a rocket?

[S Landreth]

^I don’t know. But for now, maybe two things.......

1. Lightening – fuel
2. Rain – when I was listening to the news last night some (older) NASA scientist was talking about the two ongoing problems with the Artemis I launch. He said there was a frost on an external line. With rain they might not be able to observe the frost. Think O-ring and cold weather

When Takeovers gets back, I believe he’ll know better

Atlantic 5-Day Graphical Tropical Weather Outlook

[Takeovers]

I never heard of rain as a constraint. It should not be. NASA really should have sensors to pick up things like a cold area due to propellant leaks. But SLS does not have an abundance of sensors like SpaceX has. The NASA ASAP safety panel actually listed as a problem the amount of sensor data SpaceX produces, which can overwhelm NASAs capacity to process them.

Weather concerns mainly are thunderstorms at this time of the year. Florida is thunderstorm central, a problem mainly at certain times of the day. Since the Moon mission has to launch during that time in this window NASA can not move the launch to a more convenient time of day. Lightning rules are quite complex, I never tried to understand them. Especially the connected clouds rule. Which means even if a thunderstorm is quite far away, some kinds of clouds make it possible a lightning could hit during launch.

There are wind limits for launch. They can not launch during a tropical storm.

Another concern is wind shear in the upper atmosphere. There can be layers of wind in different direction close to each other. When the rocket flies through such a boundary the change of wind directions can be quite a hit on the rocket. That's especially bad for SpaceX Falcon rockets because they are tall and slim. Should be less of a problem for SLS.

BTW responsible for weather reports and for range safety during launch is the Florida Airforce, now Spaceforce range. They have massively upgraded their capabilities to accomodate the huge number of launches SpaceX is doing this year. About 1 launch every week on average. For wind shear detection they are launching weather balloons.

[S Landreth]

^Another good lesson. Thank you

• NASA will launch Artemis rocket on Saturday
  

NASA’s Artemis team will take a second shot at a launch on Saturday after the first attempt on Monday was scrubbed.

Team leaders at a media briefing Tuesday said the two-hour launch window for the Space Launch System (SLS) rocket and Orion spacecraft will begin around 2:17 p.m. ET on Saturday (1:17 am Thai time). Weather for Saturday indicates some rainy weather but conditions favorable enough for the team to work with, according to NASA.

The launch team reviewed data from Monday’s launch and settled on a game plan to resolve several issues, including an engine that failed to cool down and led to the launch delay.

John Honeycutt, the manager for the SLS program, said he was confident in the Artemis team’s ability ahead of the second launch attempt.

“We’ve got a path forward,” he said. “We’re in the mode now of processing the data that we got and updating our approach prior to the next launch attempt. I’m confident where the team’s headed.”

If Saturday’s launch at Florida’s Kennedy Space Center is successful, the SLS will rocket into space and plummet back to Earth after shooting the unmanned Orion spacecraft on a six-week journey more than 40,000 miles past the moon.

Through the Artemis program, NASA is trying to send astronauts to the moon for the first time since 1972. Saturday’s launch, if successful, will be the first in a series of tests that will lead to NASA putting astronauts on Orion and landing them on the south pole of the moon sometime in 2025 or 2026.

Monday’s highly anticipated launch faced a number of issues, including lightning strikes near the launch pad in the days leading up, uncertain weather in the two-hour launch window and a hydrogen leak.

NASA ultimately called the launch off after the SLS’s third engine failed to fall to the correct temperature. Launch controllers condition engines by increasing pressure on stage tanks in order to bleed some cryogenic propellant and get them to a proper temperature range for startup.

On Monday, the team was unable to determine what exactly went wrong. NASA officials said Tuesday they believe there could have been a faulty sensor that indicated the engine was not chilling when the hydrogen was flowing properly.

As part of the solution they drafted, the Artemis team created some redesigns and on Saturday will begin the engine bleed earlier with the rocket’s four engines set at an ambient temperature.

Mike Sarafin, the mission manager for Artemis, said the launch team discussed other options besides launching on Saturday, including additional testing. They decided the adjustments to the SLS could be fixed at the pad and in time for a weekend launch.

'Safety Is Always First': NASA Reschedules Artemis Moon Mission To Saturday

_____________

NOAA - Tropical Atlantic 4 hour loop (weather): GOES-East - Sector view: Tropical Atlantic - Band 13 - NOAA / NESDIS / STAR

Because the Artemis is scheduled to launch during the day here is NOAA’s visible loop (weather): GOES-East - Sector view: Tropical Atlantic - Band 2 - NOAA / NESDIS / STAR

One more – Real Time Lightning Map: https://www.lightningmaps.org/#m=oss...;d=2;dl=2;dc=0;

[Takeovers]

On Monday, the team was unable to determine what exactly went wrong. NASA officials said Tuesday they believe there could have been a faulty sensor that indicated the engine was not chilling when the hydrogen was flowing properly.

Yes, that seems their present assumption. Then replacing that sensor seems to be the way to go to a layman like me. But they can probably not replace that sensor on the pad. Rolling back to the VAB for replacement would mean this launch window is gone and the launch would be delayed much more.

[Takeovers]

NASA is setting up a maintenance platform at pad 39-B. Looks like they will attempt replacing that sensor at the pad.

https://twitter.com/SausseImages/sta..._discussion%2F

In the last 45 minutes, a small crane has shown up at pad 39B and lifted something on to the MLP. Possibly the beginning pieces of a platform needed to reach the trouble spots inside of the core stage.

More info in the linked twitter thread. Including pictures.

[misskit]

^^ One of the most amazing things I have ever seen is the VAB and the tractor which transports the rockets from the building. Unbelievably huge.

I did a tour of the space center in the late or early 70’s.