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Comment by perihelions | Hacker News Reader

There was an anomaly in the second stage deorbit burn (which did not impact the payload). Falcon is apparently grounded.

https://www.space.com/spacex-pause-launches-crew-9-falcon-9-... ("SpaceX pausing launches to study Falcon 9 issue on Crew-9 astronaut mission")

- "After today’s successful launch of Crew-9, Falcon 9's second stage was disposed in the ocean as planned, but experienced an off-nominal deorbit burn. As a result, the second stage safely landed in the ocean, but outside of the targeted area. We will resume launching after we better understand root cause"

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FAA pedantry will tell you they are not ground, they merely may not have a license to fly more missions.

Also, it's unclear yet whether the FAA has pulled the license - SpaceX has potentially paused voluntarily.

For anyone out of the loop, the aforementioned FAA pedantry: https://www.youtube.com/watch?v=3TobeGL4Ma8&t=80

For those not familiar with the launch profile of the Falcon 9, the second stage de-orbit burn occurs after the crew/service module separates from the second stage.

If something happens to Dragon (non-zero chance) they are going to regret not coming back on Boeing's space-Yugo.

They would also regret if something went wrong while returning on a Starliner that everyone knew wasn't working as it should. Returning on a Dragon was the safest choice available.

"the second stage safely landed in the ocean, but outside of the targeted area. We will resume launching after we better understand root cause"

reality: "It crashed somewhere in the ocean, we don't know why but we pretend it was safe, though we just got lucky"

Uncontrolled reentry has been the norm for most of the space age (and is still standard practice for the Chinese, and their boosters). The far more important issue is that this a human-rated booster, and an unidentified defect impacts the safety of crew launches. This issue showed up on a de-orbit burn, but it's unlikely to be limited in scope to de-orbits only.

edit: Turns out this isn't accurate; it's still actually normal for US rocket *upper stages* to do uncontrolled reentries [0]. This is a subject of ongoing FAA rulemaking [1]. The Chinese examples are still exceptional because they involve far larger first-stage/core-stage boosters (>50 meters in length).

edit 2: If anyone was curious about the Europeans, the answer is that Ariane 5/ECA has actually *never* done a controlled upper-stage deorbit, because its LH2/LOX engine isn't designed to be able to ignite twice (deorbit burns are excluded)[2].

[0] https://outerspaceinstitute.ca/osisite/wp-content/uploads/OS... ("Uncontrolled reentries are currently used for 35% of U.S. missions (62% if we exclude SpaceX)") (as of 2023?)

[1] https://spacenews.com/new-upper-stage-disposal-rules-help-no...

[2] https://www.sciencedirect.com/science/article/abs/pii/S00945... ("it is not possible to perform a controlled reentry of the Upper Composite")

China also often launches from far-inland locations which puts large terrestrial populated regions beneath the booster (and booster landing) track. Perhaps less so for nominal launches, but not all launches are nominal:

<https://yewtu.be/watch?v=ys0DOsZmr7g>

<https://yewtu.be/watch?v=peJ6gErODic>

<https://yewtu.be/watch?v=-SFRNImP7p8>

China operates four launch facilities, three of which, Jiuquan, Taiyuan, and Xichang are inland. The fourth, Wenchang, is on the island of Hainan, in the South China Sea between China, Vietnam, and the Philippines.

<https://en.wikipedia.org/wiki/China_National_Space_Administr...>

Russia's Baikonur Cosmodrome, located in the independent country of Kazakhstan, is similarly an inland location and has seen launch debris fall over populated areas.

Is it "luck" if you intentionally chose a place smack in the middle of nowhere, such that even an off-nominal reentry will overwhelmingly occur in an extremely sparsely populated area (ie the middle of the ocean)?

Sounds like planning, not luck.

Landing area is one thing, but more important and dangerous is reentry profile. Too steep, and the capsule melts down or crew inside becomes very flat from the deceleration.

This isn't the capsule; it's the second stage.

There are no humans on the second stage reentry. It burns up.

All rockets before Falcon always crashed in the ocean.

There's a nuance here: non-SpaceX rocket *first*-stages typically fall into the ocean, but they do that within controlled exclusion zones, which are notified and restricted for air- and marine- traffic. *Upper*-stages are a different beast. Most (see my sibling comment) deorbit uncontrollably and impact somewhere at random.

with the scale of the planet, it would be more like really unlucky if it actually hit someone

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