M
Mceglowski
mceglowski.substack.com · Personal blog · on HN since 2026
Maciej Cegłowski, creator of Pinboard, writes a newsletter about Mars, Starship, radiation and space policy.
What HN saysCommenters subscribe eagerly and say he could make any topic worthwhile; they also discuss his radiation vest and Starship cost claims.
15HN people shared it
5linked it in comments
22stories submitted
45story points
3 months agolast shared
2026people per year2026
Most-shared posts
- 1How should we think about Starship?4 people · 5 points · first shared 2026 · discussion on HN
- 2L'Affaire Siloxane3 people · 3 points · first shared 2026 · discussion on HN
- 3Bitter Lessons from the ISSpresso2 people · 4 points · first shared 2026 · discussion on HN
- 4What Happened with Mars Sample Return?2 people · 3 points · first shared 2026 · discussion on HN
- 5More Bounce to the Ounce – By Maciej Cegłowski2 people · 3 points · first shared 2026 · discussion on HN
- 6Mars for the Rest of Us2 people · 3 points · first shared 2026 · discussion on HN
- 7Who Is the Villain in Mars Sample Return?2 people · 2 points · first shared 2026 · discussion on HN
- 8Radiation Tradeoffs for Mars – How to get by when the sky wants you dead2 people · 1 points · first shared 2026 · discussion on HN
- 9A Primer on Long-Duration Life Support2 people · 1 points · first shared 2026 · discussion on HN
- 10The Plight of the Martian Farmer1 people · 15 points · first shared 2026 · 3 comments on HN
- 11Microbial Dark Matter and the Search for Life on Earth1 people · 1 points · first shared 2026 · discussion on HN
- 12Let's Talk Space Toilets1 people · 1 points · first shared 2026 · discussion on HN
- 13Musk on Mars1 people · 1 points · first shared 2026 · discussion on HN
- 14Why Not Venus?1 people · 1 points · first shared 2026 · discussion on HN
- 15A Diner's Guide to Mars1 people · 1 points · first shared 2026 · 1 comments on HN
What HN people wrote when they linked it
dmazin · 2026-03-31
Maciej now has a Mars newsletter, which I obviously subscribed to immediately: https://mceglowski.substack.com/
I didn’t even have a strong interest in space before the dude started writing about it. Maciej could write about literal rocks and make it worthwhile to read.
Sniffnoy · 2026-08-18
It's kind of buried in the article, but it's worth noting that this vest is meant only to guard against solar storms, not cosmic rays; those remain a significant problem.
> The vest, though, does nearly nothing against galactic cosmic rays (GCR), which are the other major radiation source astronauts face. Unlike solar storm radiation, GCR arrive continuously at much higher energies, which makes them harder to shield against. “Using the vest against these rays would not be reasonable,” Houri says. “You’d have to wear it at all times.”
See for instance this article on how the cosmic ray problem would affect a Mars mission: https://mceglowski.substack.com/p/radiation-tradeoffs-for-mars
jodrellblank · 2026-07-03
from L'Affaire Siloxane? ( https://mceglowski.substack.com/p/laffaire-siloxane )
skybrian · 2026-06-17
Why should we believe that Starship launch costs will be that cheap when we don't believe Musk's other numbers? Where does that number come from? Has anyone looked into it?
It doesn't cover launch costs directly, but here's a bearish take on reusability of the second stage:
https://mceglowski.substack.com/p/how-should-we-think-about-starship
palata · 2026-04-02
> The distinction is kind of meaningless
Only if it helps you to call this "science", I would say.
> advancing our engineering capabilities in space is advancing the science
In this case, we are advancing our engineering capabilities to make humans survive in space, which is arguably completely useless.
Not only that, but we keep focusing on the easier and fun part for engineers. A real problem for surviving in space is life support, see e.g. this: https://mceglowski.substack.com/p/a-primer-on-long-duration-life-suppo…
But it is a lot less fun than sending humans around the moon in a ship that doesn't need them at all, isn't it?