4 ms·
The speed of that take off, or lack of, was wild. I don't think I've ever seen a rocket build up its speed so slowly. The methane blue looked spectacular.
by roskelld 2y ago
The speed of that take off, or lack of, was wild. I don't think I've ever seen a rocket build up its speed so slowly.
The methane blue looked spectacular.
- mkl 2y agoYes, those seven blue spikes were pretty amazing.
- roskelld 2y agoDoesn't show the diamonds, but sure shows that blue glow. https://xcancel.com/JerryPikePhoto/status/1879793792536158606#m https://xcancel.com/JerryPikePhoto/status/187979379253615860...
- mkl 2y agoHere's a good view: https://youtu.be/KXysNxbGdCg?t=6935 https://youtu.be/KXysNxbGdCg?t=6935
- nyokodo 2y ago> I don't think I've ever seen a rocket build up its speed so slowly. New-Glenn has a low thrust to weight ratio vs other rockets and lower engine chamber pressure than some other engines to put less stress on the rocket and engines for greater reusability.
- tankenmate 2y agoBut the obvious cost here is less mass to orbit. But I suspect it's a given that they'll tweak up the margins once they have more flights under their belt.
- marze 2y agoThat is a trajectory optimized for payload mass, with a set amount of first stage thrust. It is quite typical, historically. It just looks extra slow since the New Glenn rocket is quite enormous relative to historic rockets. An impressive first flight by any measure!
- idlewords 2y agoNo, that's not true. Back of the envelope estimates for New Glenn's launch tonight give a thrust to weight ratio of 1.2. For the Space Shuttle, t/w at launch was 1.5, the same is true for Falcon and Starship. Delta Heavy was around 1.3. Saturn V was 1.2. None of this has anything to do with optimizing the trajectory.
- marze 2y agoHistoric rockets around 1.2, including Shuttle, check your numbers. Starship is not a "historic rocket". It and Falcon 9 fly a trajectory that is optimized for something else, not max payload for a set first stage thrust.
- echoangle 2y agoThis SE answer also calculates shuttle liftoff TWR to around 1.5: https://space.stackexchange.com/a/58800 https://space.stackexchange.com/a/58800
- idlewords 2y agoThe shuttle stack weighted 4.5 million lbs at takeoff and had a total thrust of about 6.8 million lbf, giving a thrust to weight ratio of 1.5.
- marze 2y agoThat is incorrect. Shuttle liftoff thrust was 5.7 million pounds, giving a ratio of 1.25. At liftoff, each SRB produces 2.65 million pounds thrust [1]. Using Wikipedia numbers instead (2.8 million pounds for SRB thrust at liftoff [2]) gives a liftoff thrust to weight ratio of 1.33. The 3xSME produce 0.4 million pounds thrust at liftoff. The SRB thrust did increase as the burn progressed, then ramped down for max Q. People are accustomed to SpaceX rockets rapid acceleration, since they conduct most launches these days, but historic rockets (and New Glenn) accelerated more slowly off the pad. [1] https://www.nasa.gov/reference/the-space-shuttle/ https://www.nasa.gov/reference/the-space-shuttle/ [2] https://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Booster https://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Boo...
- deleted 2y ago[deleted]
- baq 2y agoIf my KSP experience tells me something it needs more boosters
- holler 2y agoStarships first flight felt similarly slow, watched in person.