You are not logged in.
- Topics: Active | Unanswered
Announcement
#51 2024-11-27 09:42:36
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 24,313
Re: Artemis I unmanned Flight Coverage
This web site offers an overview of the Artemis missions. It includes diagrams of the actual or planned flight paths.
https://www.rmg.co.uk/stories/topics/na … aunch-date
rmg stands for Royal Museums Greenwich
(th)
Offline
Like button can go here
#52 2024-11-27 11:57:42
- GW Johnson
- Member
- From: McGregor, Texas USA
- Registered: 2011-12-04
- Posts: 6,199
- Website
Re: Artemis I unmanned Flight Coverage
Those trajectories are exactly what I previously understood about SLS/Orion Block 1, and amazingly close to what I analyzed for modeling propellant return via Gateway to LEO. My 60,000 km apoapsis halo is gravitationally stable, but required a slightly-higher dV burn to enter it at periapsis.
Apparently that slight dV increase is too much for SLS/Orion Block 1, so they went to the gravitationally-unstable 70,000 km apoapsis halo, which requires frequent course corrections by Gateway just to stay in that orbit. Without them, it leaves the moon, going into a far orbit about the Earth.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
Offline
Like button can go here
#53 2024-11-28 15:32:52
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 24,313
Re: Artemis I unmanned Flight Coverage
Gemini is an extension of Google Search...
I asked Gemini for information about Artemis. I was looking for specifications of the docking port.
Hi Gemini! By any chance can you find specifications for the docking port on the Orion capsule? It is thought to be similar to the one on the Apollo capsule, but with decades of progress in space systems design, there may be some differences.
The Orion capsule's docking port is based on the Apollo capsule's design but has been significantly improved with modern technology. Here are some key differences and specifications:
Key Differences:
Enhanced Docking Mechanism: The Orion uses a more advanced docking mechanism called the "NASA Docking System (NDS)." This system allows for automated docking and provides greater flexibility in docking with different spacecraft.
Improved Sealing: The Orion's docking port has a more robust sealing mechanism, ensuring a tighter and more airtight connection between spacecraft.
Data and Power Transfer: The NDS enables faster and more efficient transfer of data and power between docked spacecraft.
Future Expansion: The Orion's docking port is designed to be compatible with future spacecraft and modules, allowing for potential expansion of the spacecraft's capabilities.Specifications:
Diameter: The docking port has a diameter of 800 millimeters (31 inches).
Interface: The NDS interface can transfer power, data, and air. Future implementations will be able to transfer water, fuel, oxidizer, and pressurant as well.Crew and Cargo Transfer: The passage for crew and cargo transfer has a diameter of 800 millimeters (31 inches).
Additional Information:
The Orion's docking port is located at the forward end of the spacecraft.
The NDS is compatible with the Shuttle/Soyuz APAS-95 mechanism used on the International Space Station.The Orion's docking port is not compatible with the larger common berthing mechanism used on the US segment of the ISS, the Japanese H-II Transfer Vehicle, the original SpaceX Dragon, and Orbital Sciences' Cygnus spacecraft.
Sources:
NASA Docking System
Orion (spacecraft)
Crew Transportation With Orion Educator Guide
Orion ComponentsI hope this information is helpful!
en.wikipedia.org
en.wikipedia.org
NASA Docking System - Wikipedia
Source icon
en.wikipedia.org
profile pictureThank you! That is ** very ** helpful! (th)
You're welcome! I'm glad I could help. Let me know if you have any other questions.
(th)
Offline
Like button can go here
#54 2025-01-01 19:57:54
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 24,313
Re: Artemis I unmanned Flight Coverage
GW Johnson has been warning the public about the risks of flying Artemis II with the suspect heat shield that failed during the Artemis I test flight with three dummy astronauts on board. Members of NewMars are well aware of the problems identified by GW Johnson.
It is with some surprise that I am able to provide this quote from an Internet news feed:
Space
NASA delays Artemis missions again. What could this mean for the moon, Mars and space leadership?
Andrew Jones
Mon, December 23, 2024 at 10:00 AM EST
The latest delays stem, in part, from an issue with the Orion crew spacecraft and its heat shield which was detected after a "skip reentry" during the uncrewed Artemis 1 mission in late 2022.
"We have since determined that while the capsule was dipping in and out of the atmosphere as part of that planned skip entry, heat accumulated inside the heat shield outer layer, leading to gases forming and becoming trapped inside the heat shield," NASA Deputy Administrator Pam Melroy said during a Dec. 5 press conference. "This caused internal pressure to build up and led to cracking and uneven shedding of that outer layer."
Related: NASA delays Artemis 2 moon mission to 2026, Artemis 3 astronaut landing to mid-2027
Artemis 2 will still use Orion, but with a different reentry trajectory to better manage the resulting heat. "The safety of our astronauts is always first in our decisions," NASA Administrator Bill Nelson said.
It sure would be interesting to know the behind-the-scenes thought process that led to this decision.
A possibility is that Mr. Nelson decided to give the new incoming NASA Administrator plenty of room to maneuver. An option is to kill the over-budget program altogether. Another (less likely) option is to replace the suspect heat shield with an Apollo Era version that has already flown with success in a flight before Artemis I.
(th)
Offline
Like button can go here
#55 2025-01-02 11:38:15
- GW Johnson
- Member
- From: McGregor, Texas USA
- Registered: 2011-12-04
- Posts: 6,199
- Website
Re: Artemis I unmanned Flight Coverage
The influence of the skip re-entry is the true part, the notion of gas pressure building up and pushing chunks of char off, does not ring true at all, because polymer char is inherently porous! How can you build up gas pressure beneath something porous? Makes no physical sense. But most people would not know about that porosity of char.
I personally think the cooling during the skip between heating pulses embrittled the unreinforced char, so that it cracked and was more vulnerable to fluid shear forces tearing out chunks erratically. I've seen that behavior up close and personal, testing experimental ablatives in ramjet combustors. It was already vulnerable because it was unreinforced, there being no hex in the tiles they made. Cooling embrittlement during the skip just makes that worse.
Doesn't matter, the fixes are the same: either (1) put the fiberglass hex back into the heat shield, or (2) do not fly skip re-entries (what they chose to do for Artemis-2, using the already-installed heat shield that proved faulty on Artemis-1). They have been assuming that EITHER they had to go back to hand-gunning the Avcoat into the hex cells bonded to Orion the way they were in Apollo and the first Orion flight test, OR that they just fly the unreinforced bonded Avcoat tiles that they wanted, and which they built for Artemis-1 and Artemis-2.
They got into trouble by building Artemis-2 that way before actually flying the Artemis-1 unmanned test, which (unexpectedly) so very clearly said that their preferred design was the wrong heat shield for doing the skip entries they wanted to do. That was a simple management mistake: do not commit your design to a process until AFTER you have tested it. But they jumped ahead to save money and time, which they lost anyway, because it was a bad bet.
I gave them a way to make their preferred Avcoat bonded tiles with the hex incorporated into those tiles. So there really are now 3 alternatives, not just two. But to install it on the Artemis-2 Orion would cause further costly delay. So I understand the decision to fly anyway, but delete the entry skip. Not that it is the right decision, but I do understand. The "right" decision would be to fly Artemis-2 unmanned with a reinforced heat shield, to prove that it works right, before risking a crew's lives on it. But they would have to renegotiate contracts with the makers of the heat shield tiles, almost from scratch. And nothing ever takes place in a timely fashion, dealing with "old space" on a government contract. So, time and money trump crew's lives yet again, when it does not have to.
What I think we are seeing here is the same upper-echelon management resistance to admitting they made a mistake, that we saw with two fatal shuttle disasters. In the case of Challenger, this even led to an attempted cover-up, but which was exposed during the Rogers commission hearings by the physicist, an astronaut, and an actively-serving air force general.
If you fail to learn from history, you end up repeating it. And they are repeating it.
GW
Last edited by GW Johnson (2025-01-02 11:52:58)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
Offline
Like button can go here
#56 2025-01-02 14:16:33
- Oldfart1939
- Member
- Registered: 2016-11-26
- Posts: 2,494
Re: Artemis I unmanned Flight Coverage
Given the amount of time and money spent on Artemis II to date, it's unconscionable for the contractors to green light a faulty heat shield, as well as the administrators. I would think that Jared Isaacman will tell the contractors to FIX THE HEAT SHIELD! I wouldn't want to be in the shoes of the next NASA administrator, who will be under pressure to get this damned thing flying around the moon!
They are saying that it will take a year to made a new shield, but I suspect that it could be done by someone other than Lockheed Martin in a significantly shorter time by working 24/7 in order to maintain the schedule?
Offline
Like button can go here
#57 2025-01-02 18:49:34
- GW Johnson
- Member
- From: McGregor, Texas USA
- Registered: 2011-12-04
- Posts: 6,199
- Website
Re: Artemis I unmanned Flight Coverage
I sent them the how-to to put the hex back into the Avcoat tiles they want to bond onto the capsule substrate. Initially I thought they were casting tiles to near net shape, but it turned out they cast big blocks of Avcoat, and then "machined" the various tiles out of those blocks.
You could still put the hex back in, either way, using a plastics industry extrusion press. Cut hex to fit the mold of the big blocks (there has to be one). Extrude the Avcoat through all the cells in that chunk of hex all at once, which precludes any voids, and eliminates all the variation in hand-gunning expertise, plus all the hand-gunning labor. Then line the box mold with some Avcoat, and drop the loaded hex core into it. Anything you cut from that cured block will have hex reinforcement in it.
The problem is who has Avcoat and who does not. I suspect Lockheed-Martin and Boeing have it, but nobody in "new space" is allowed to use it. Lawyers make a lot of money making sure these things happen that way.
Avcoat is an epoxy novolac resin loaded with microballoons to lower its density in a controllable manner. You can adjust the ablation rate somewhat by varying the finished density. This also varies finished heat shield weight: lower density is lower weight but higher ablation rate (it's a tradeoff you must make for the mission). But Avcoat ablative as defined during Apollo always without exception was hand-gunned into the hex cells of a fiberglass hex honeycomb previously bonded to the capsule substrate. That produced a monolithic hex-reinforced heat shield integrally bonded to the capsule. But on Orion, there are almost 400,000 such cells to fill.
There is nothing wrong with wanting to do this as pre-made tiles bonded separately to the capsule substrate. The integrity of the bonds and the integrity of the between-tile gap fillers is not in question on Artemis. But, they cast the big blocks of Avcoat without any fiberglass hex reinforcement, and then expected it to perform the same, without any prior flight test experience to show that it would work.
It was no skin off Lockheed's nose when it did not work, they got paid anyway, as was (and still is) typical for "old space". It was the upper echelons of NASA management that made that mistake, now compounded by building both Artemis-1 and Artemis-2 in that very same way, BEFORE flying Artemis-1 to verify it would work (which it did not). This mistake was further compounded by adding the skip re-entry. The original pre-Artemis Orion flight test used the Apollo hand-gunned approach identical to Apollo, and did not fly a skip re-entry. Too many variables from test to test. That's a lesson they either forgot or never learned, over time and personnel changes.
GW
Last edited by GW Johnson (2025-01-03 10:25:58)
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
Offline
Like button can go here
#58 2026-04-10 09:24:14
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 24,313
Re: Artemis I unmanned Flight Coverage
This post is about the planned landing (splash down) Friday 2026/04/10
Per Google:
Key Facts
NASA is targeting 8:07 p.m. EDT (5:07 p.m. PDT) on Friday, April 10, for the splashdown of Artemis II in the Pacific Ocean near San Diego. Live coverage on NASA+ begins at 6:30 p.m. EDT (3:30 p.m. PDT).
Just before re-entry, the Orion capsule will separate from the European Service Module, its life-support system, built by the European Space Agency. After the 16-minute blackout, parachutes will deploy to slow the capsule, and waiting cameras will scan the sky for the first glimpses of “Integrity.”
The recovery process is expected to take several hours, with U.S. Navy teams due to secure the Orion capsule and assist the crew aboard the USS John P. Murtha, which departed San Diego on Monday, April 6. The crew will be flown by helicopter to the Murtha for medical evaluations before traveling to Houston.
The crew includes Commander Reid Wiseman, Pilot Victor Glover, Mission Specialist Christina Koch and Mission Specialist Jeremy Hansen. Selected in April 2023, the four astronauts have trained together for three years in preparation for this mission.
(th)
Offline
Like button can go here
#59 2026-04-10 10:27:52
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 24,313
Re: Artemis I unmanned Flight Coverage
Spash Down is predicted for 18:07 EST ...
I asked Google about entry to the atmosphere:
AI Overview
The Artemis II Orion capsule is scheduled to enter the Earth’s atmosphere at approximately 7:54 p.m. EST (13 minutes before splashdown) on Friday, April 10, 2026. The capsule will splash down at 8:07 p.m. EST in the Pacific Ocean off the coast of San Diego, initiating a 6-minute communication blackout due to high heat.Entry Interface: Approx. 400,000 feet altitude.
Velocity: ~25,000 mph (approx. 24,000 mph mentioned in other reports).
Re-entry duration: 13 minutes.
7:54 p.m. EST
(th)
Offline
Like button can go here
#60 2026-04-10 17:21:31
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 24,313
Re: Artemis I unmanned Flight Coverage
Splash down is just 40 minutes (or so) away....
Coverage is live on multiple channels...
Update after splashdown ... The view from the capsule window just before communications blackout was ** really ** impressive.
The landing looked perfect from my perspective, and Mission Control seemed to think so as well.
The milling around on the water afterward was surprising to me.
It seemed to me that the United States is out of practice after 70 years of just doing LEO returns.
However, I don't remember how long the recovery operations took for the Apollo missions, so they may have been just as confused looking. It was clear from the transcript that equipment meant to allow communications between the Navy and the capsule were not working.
NASA gave the Navy 2 hours to work with, and they used just about every minute of it. Part of the delay was due to the need to clear hydrazine from the capsule. I did notice what appeared to be hydrazine firings as the capsule descended under the parachutes. That might have been intended to exhaust the supply before the capsule landed.
I did learn (through subsequent reporting by someone at the NASA feed) that the crew had been rehearsing that convoluted procedure so they knew what to expect. One thing I ** didn't ** see was how the capsule itself was collected. Hopefully there will be reporting on that at some point. It is understandable that securing the crew and presenting them to the public was the highest priority.
(th)
Offline
Like button can go here
#61 2026-04-11 09:05:51
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 24,313
Re: Artemis I unmanned Flight Coverage
Update regarding capsule after crew was removed...
Per Google:
After the Artemis II crew splashed down and was extracted by Navy divers near San Diego on April 10, 2026, the Orion capsule was secured and hoisted out of the Pacific Ocean by the USS John P. Murtha. The capsule is now undergoing post-flight inspection and analysis of its heat shield and systems before returning to NASA's Johnson Space Center.
NBC News+4
Key post-landing actions for the Orion capsule include:Safe Extraction: Navy divers secured the craft, and the crew was plucked by helicopters from the capsule's exit, known as the "porch".
Ship Recovery: The capsule was hoisted from the ocean onto the U.S. Navy ship.
Evaluation: NASA technicians are inspecting the capsule's heat shield and overall structural integrity following its high-speed, 3,000-degree Fahrenheit re-entry.
Payload Unloading: Remaining equipment and data are removed for analysis to prepare for future missions.
NBC News
+2
(th)
Offline
Like button can go here
#62 2026-04-11 09:47:03
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 24,313
Re: Artemis I unmanned Flight Coverage
As a follow up regarding the recovery operations...
Via email, GW Johnson pointed out that the Apollo era capsules only weight a couple of tons, but this craft weighed 5 tons.
According to Google, a Sikorsky Skycrane can lift up to 11.5 tons, and there are 41 operating around the world.
The cost per hour of flight is significant.
The Navy already had a fully operational helicopter carrier, so that solution made sense.
However, if the US is going to get into the Moon trip business, investment in a heavy lift helicopter would save a lot of time.
(th)
Offline
Like button can go here
#63 2026-04-11 09:52:02
- GW Johnson
- Member
- From: McGregor, Texas USA
- Registered: 2011-12-04
- Posts: 6,199
- Website
Re: Artemis I unmanned Flight Coverage
The Navy does not operate Sikorsky Skycranes. The Army did fly a few, but most of them serve commercially now.
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
Offline
Like button can go here
#64 2026-04-11 10:03:15
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 24,313
Re: Artemis I unmanned Flight Coverage
For GW Johnson re #63!
Thank you for your observation about the Sikorsky heavy lift helicopters. There are 41 of these operating around the world, and all are expensive to rent. According to Google, a rental of a million USD is typical. These machines are (apparently) used for logging and fire fighting, but ** also ** for lifting heavy HVAC equipment to the top of tall buildings.
Since the US Navy already ** had ** a helicopter carrier, it was a logical choice for this operation.
Here is a Google snapshot about the USS John P. Murtha:
USS John P. Murtha Completes Orion Spacecraft Recovery Tests ...The USS John P. Murtha (LPD-26), a San Diego-based San Antonio-class amphibious transport dock ship, was designated as the primary recovery vessel for the NASA Artemis II mission in April 2026. The ship retrieved the Orion capsule and its four-astronaut crew in the Pacific Ocean after their lunar flyby mission.
+2
Key Details About the Recovery:Mission Role: The Murtha and its crew, along with Navy helicopters and special boat teams, performed the "at-sea" recovery, which involved securing the crew module test article and the astronauts after splashdown.
Experience: The vessel previously supported the Underway Recovery Test (URT) for the Orion capsule in 2023.
Process: The ship utilized its well deck to recover the capsule, and helicopters were used to transport astronauts for medical evaluations.www.navy.mil
+5
The USS John P. Murtha (LPD-26) was specifically selected by the US Navy to recover the first crewed Artemis mission beyond the Moon since 1972.
+1
Here is a bit more information about the Murtha, which is one of a class of ships:
Per Google:
AI Overview
The USS John P. Murtha (LPD 26), a San Antonio-class amphibious transport dock, was constructed under a contract worth approximately $1.5 billion awarded to Huntington Ingalls Industries in 2011. The ship, commissioned in 2016, is designed to transport and land Marines, with recent modernization contracts for maintenance valued in the tens of millions.Wikipedia
+1
Initial Construction Cost: The 10th San Antonio-class ship contract, which included the John P. Murtha, was valued at $1.5 billion.Maintenance & Modernization: In 2023, BAE Systems was awarded a contract valued up to $42.4 million for modernisation and maintenance, slated for completion in 2024.
Post-Shakedown Availability: Earlier, in 2017, a similar maintenance contract was estimated at roughly $21.2 million to $61.1 million.
US Carriers.net
+2
The ship is officially part of the U.S. Navy fleet, tasked with various missions, including recovery operations for the Artemis II mission.
YouTube+1
(th)
Offline
Like button can go here
#65 2026-04-11 10:07:06
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 24,313
Re: Artemis I unmanned Flight Coverage
The Russians are unlikely to get into the Moon game, but the Chinese certainly are.
The Chinese must surely be studying the US example.
I'll bet they go with Apollo style heat shields.
They may skip the capsule stage entirely.
A ship that can land on wheels like the Space Shuttle would seem likely to appear on the scene some time this century.
(th)
Offline
Like button can go here
#66 2026-04-11 14:17:15
- SpaceNut
- Administrator
- From: New Hampshire
- Registered: 2004-07-22
- Posts: 30,700
Re: Artemis I unmanned Flight Coverage
indication of the heat shield is indicated to have simular results thou that how the shield was made had been altered.
interesting inside view of the shield
Offline
Like button can go here
#67 2026-04-11 14:57:28
- GW Johnson
- Member
- From: McGregor, Texas USA
- Registered: 2011-12-04
- Posts: 6,199
- Website
Re: Artemis I unmanned Flight Coverage
Forgive me, but why is the Artemis-2 stuff listed under "unmanned probes"? There were 4 people aboard!
GW
GW Johnson
McGregor, Texas
"There is nothing as expensive as a dead crew, especially one dead from a bad management decision"
Offline
Like button can go here
#68 2026-04-11 16:30:04
- tahanson43206
- Moderator
- Registered: 2018-04-27
- Posts: 24,313
Re: Artemis I unmanned Flight Coverage
For GW Johnson!
Thanks for pointing out the discrepancy!
When this topic was created, Artemis I was the subject and it was an unmanned expedition.
For SpaceNut ... none of the four topics about Artemis seemed a good fit for posts about the unmanned test flight
This topic is offered for anyone who might wish to report events as they unfold over the several weeks of the Artemis I test flight.
The change to "Flight Coverage" happened without paying attention to the higher level!.
Fortunately, we can fix this!
I'll rename the topic and create a new one for the manned flights.
This topic is closed except for such updates as members may contribute about Artemis I.
(th)
Offline
Like button can go here