4 ms·

"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 cr

by rvnx 2y ago

"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"

schiffern 2y ago
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.
- deepsun 2y ago
  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.
  - ceejayoz 2y ago
    There are no humans on the second stage reentry. It burns up.
  - HPsquared 2y ago
    This isn't the capsule; it's the second stage.
perihelions 2y ago
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/OSI_response_to_FAA_NPRM.pdf 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-not-harm-us-leadership-space/ https://spacenews.com/new-upper-stage-disposal-rules-help-no... [2] https://www.sciencedirect.com/science/article/abs/pii/S0094576520302241 https://www.sciencedirect.com/science/article/abs/pii/S00945... ("it is not possible to perform a controlled reentry of the Upper Composite")
- dredmorbius 2y ago
  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=ys0DOsZmr7g> <https://yewtu.be/watch?v=peJ6gErODic https://yewtu.be/watch?v=peJ6gErODic> <https://yewtu.be/watch?v=-SFRNImP7p8 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_Administration#Launch_facilities 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.
whimsicalism 2y ago
with the scale of the planet, it would be more like really unlucky if it actually hit someone
api 2y ago
All rockets before Falcon always crashed in the ocean.
- perihelions 2y ago
  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.

by rvnx 2y ago

schiffern 2y ago

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.

deepsun 2y ago
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.
- ceejayoz 2y ago
  There are no humans on the second stage reentry. It burns up.
- HPsquared 2y ago
  This isn't the capsule; it's the second stage.

perihelions 2y ago

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/OSI_response_to_FAA_NPRM.pdf 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-not-harm-us-leadership-space/ https://spacenews.com/new-upper-stage-disposal-rules-help-no... [2] https://www.sciencedirect.com/science/article/abs/pii/S0094576520302241 https://www.sciencedirect.com/science/article/abs/pii/S00945... ("it is not possible to perform a controlled reentry of the Upper Composite")

dredmorbius 2y ago
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=ys0DOsZmr7g> <https://yewtu.be/watch?v=peJ6gErODic https://yewtu.be/watch?v=peJ6gErODic> <https://yewtu.be/watch?v=-SFRNImP7p8 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_Administration#Launch_facilities 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.

whimsicalism 2y ago

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

api 2y ago

All rockets before Falcon always crashed in the ocean.

perihelions 2y ago
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.