You are not logged in.
Today's "Daily Launch" from AIAA finally brings up the heat shield issue facing Artemis-2 as it heads to re-entry. The link was to a Scientific American article of some kind. Not all the supposed facts quoted in it were correct, but the concern over char cracking leading to the shedding of chunks of char was correctly pointed out.
Myself, I think the odds are good that the crew will come home just fine. Where I differ with NASA is that I think the same damage seen on Artemis-1 will happen to Artemis-2's heat shield, despite switching to a non-skip, single heating pulse entry. It might be less than what happened to Artemis-1, or it might not. But if ANY chunks at all get shed, then NASA was wrong and I was right!
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
This post is reserved for a set of files GW Johnson sent by email on Tuesday 2026/04/21
I'll return to this post later today, Wednesday 2026/04/22
Work plan:
1) three pdf's in HeatShieldArtemisII folder to Dropbox
The three pdf's were stored in Dropbox
2) Link three pdf's from Dropbox to this post
https://www.dropbox.com/scl/fi/sp0kxa1o … w1mzq&dl=0
Above is Entry By Hand Article using spreadsheet from Orbits Course
https://www.dropbox.com/scl/fi/udi4mzuk … 0ptpm&dl=0
See notes below for content
https://www.dropbox.com/scl/fi/auanvzc5 … nnabe&dl=0
Study of Orion heat shield after Artemis II flight
3) Add text from email to explain links
Test from email:
First: there is "Entry By Hand Article.pdf", which shows exactly how to
use my entry spreadsheet and do really interesting things with it. There
are slides and presentation notes for this.Second: there is "Entry Study.pdf", which shows results and comparisons
for a small probe with either a conical heat shield or a blunt heat
shield, at Earth from LEO and lunar return, and at Mars from direct entry
off a fast interplanetary trajectory. All of that gets compared to an
Apollo returning from the moon, or from low circular orbit, at Earth.There are slides and presentation notes for this, too.
Third: there is "Quick First Look at Orion.pdf, where I ran a spread of
entry angles for an Orion lunar return, trying to figure out how to use my
simple tools to at least bound what Artemis-2 really just did. No slides
yet, but there will be.If you want to post any of this stuff on the forums, be my guest.
Updates completed 2026/04/22 at 23:27 UTC
(th)
Offline
Like button can go here
This post offers a link to a document prepared by GW Johnson:
https://www.dropbox.com/scl/fi/s3r092rt … scnaw&dl=0
Preliminary Evaluation of Artemis II heat shield performance.
(th)
Offline
Like button can go here