Apollo Launch Abort System Test

The tower style launch escape system works in flight as well. Here's a video explaining how it works, with footage of it being tested during the Apollo era. ▶ this video

in “SpaceX Crew Dragon Splashes Down After Historic Test Flight” · View on HN

> how come people with sliding rulers and navigation computers 'knitted' by local grannies have lost 0 Saturn rockets. The fuck? NASA lost people in production hardware multiple times. [link] [link] "The damaged third-stage engine failed to restart for trans-lunar injection... Despite the engine failures, the flight provided NASA with enough confidence to use the Saturn V for crewed launches..." [link] [link] [link] Here's a fun one: They tested the Saturn crew escape system. The booster was supposed to blow up, and demonstrate the crew would survive... but the test went wrong , and it blew up early , when it shouldn't have. The crew abort worked, so test failed successfully . ▶ this video

in “SpaceX's next Starship flight could test refueling tech” · View on HN

> If a test flight doesn't achieve the testing objectives, that's a failure. Incorrect. Examples: ▶ this video is a Saturn launch abort test that failed. It failed in a way that they were able to determine that intended test would have worked, though. [link] also failed to achieve its objectives; "Despite the engine failures, the flight provided NASA with enough confidence to use the Saturn V for crewed launches; a potential third uncrewed flight was cancelled." All that aside, SpaceX was quite clear that the latest Starship test had multiple objectives, and that "successfully splashdown near Hawaii" was deemed quite unlikely. It successfully demonstrated a number of items, including fairly critically the launchpad changes.

in “SpaceX's next Starship flight could test refueling tech” · View on HN

It might seem a little sketchy but it worked well. When they flew it on a small rocket to test it, the rocket accidentally broke apart but the escape tower system then performed perfectly: ▶ this video

in “Boeing has now lost $1.1B on Starliner, with no crew flight in sight” · View on HN

Red is kerosene, blue is liquid oxygen, orange is liquid hydrogen, the fuel that looks like fire is solid fuel (think compressed gunpowder). Left to right: Saturn V, Space Shuttle, Falcon 9 Heavy, SLS (still under construction). 2:22, you hear Neil Armstrong say "inboard cutout," that is the center engine shutting off to limit the thrust, and therefore G-forces the astronauts felt. As fuel ran out, the rocket stack would weigh less and so the rocket would push harder. By the time the main engine cutoff, the Saturn V was pulling 4 and a half Gs. Also, just noticed the SLS keeps its launch escape tower (the big needle on the top of the rocket - see this: ▶ this video ) - this wouldn't happen in a real flight. The flight plan calls for ditching than when it's not longer useful - you can hear the Apollo 11 call saying, "tower jettisoned."

in “If Rockets Were Transparent [video]” · View on HN

Satellites usually need to point their solar panels and high-gain antennas properly in order to stay powered to be able to communicate with ground stations, although this particular satellite seems to have been unable to use its high-gain antenna anyway and relied on an omnidirectional one anyway. Another issue would be thermal management as it is possible that not all parts of the satellite were designed to deal with direct sunlight. I would be more worried about all the sensors, though. The days of secondary electron conduction tubes [1] might be long over, but many instruments still prefer not to be pointed directly at the sun. Speaking of those other sensors, spinning the satellite would mean pointing all of them away from where they are supposed to be looking – not necessarily a net win. Finally, trying to spin the satellite at anything approaching 360 RPM might end up dramatically shortening the mission [2]. [1] [link] [2] ▶ this video EDIT: In case you do not feel like watching the video, [2] shows a Little Joe II rocket ( [link] ) breaking up due to an excessive roll rate (around 56 RPM) ( [link] ).

in “The death of a weather satellite as seen by SDR” · View on HN