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Electric turbopumps are an answer to the question: "how small can you make a commercially viable orbital rocket?" Atmospheric drag effects rocket performance l
by neaanopri 8y ago
Electric turbopumps are an answer to the question: "how small can you make a commercially viable orbital rocket?"
Atmospheric drag effects rocket performance less and less the larger a rocket gets (square-cube law), so that a rocket like the Space Shuttle can effectively ignore the atmosphere. Conversely, the smaller a rocket gets, the harder and harder launch gets. This is the problem Rocket Lab has decided to attack.
A decade ago, SpaceX launched the very similar Falcon 1. Falcon 1 was designed a decade ago, and you can see a large amount of the tech advancements in the last decade in Rocket Lab's design:
1. Cheap, lightweight Lithium Polymer (LiPo) batteries.
2. Cheap and performant brushless motor controllers.
3. Additive manufacturing for cheaply making complex parts without significant labor costs.
4. Advances in composites to enable the first orbital-class composite-bodied rocket.
Without any one of these advances, Rocket Lab would not be viable. It still may end up not being viable. Rocket Lab can never compete on bulk orbital cargo pricing. However, Rocket Lab's vision of applying recent tech advancements to bring down the smallest possible launcher size is extremely commendable.
- mmirate 8y ago> Cheap and performant brushless motor controllers. Moreso than the good old 8-bit (in both senses iirc) AVR? > Additive manufacturing for cheaply making complex parts without significant labor costs. Who, when, and how, has 3D printing ever been used for materials stronger than ABS plastic?
- Gibbon1 8y ago> Rocket Lab can never compete on bulk orbital cargo pricing. Rocketlab business model is to compete with SpaceX on scheduling and orbits for small satellites. Not on price per Kg to orbit. That fits in with the trend to make satellites smaller.
- trainingaccount 8y agoA variation of a couple of degrees during launch would rip the Shuttle's wings off, so "ignore" is not the right word here.
- stcredzero 8y agoWithout any one of these advances, Rocket Lab would not be viable. It still may end up not being viable. Rocket Lab can never compete on bulk orbital cargo pricing. However, Rocket Lab's vision of applying recent tech advancements to bring down the smallest possible launcher size is extremely commendable. Without a number of advances, the iPad and iPhone wouldn't have been viable. (As evidenced by the appearance of tablets and smartphones many years before.) Tablets can't compete with larger form factors on bulk pricing of computation. However, there is a technology inflection point where smaller and more flexible becomes usable enough. I guess that's what RocketLab is aiming for.