Solid rocket satellite launchers are rare due to lower specific impulse and control limitations
the verdict
INSUFFICIENT LEANING
refutedsupported
the weight of evidence
2 sources for · 0 against
AS REPORTEDno primary record reached; this is what the reporting says
Retrieved evidence acknowledges that solid rocket motors suffer from drawbacks such as low specific impulse and limited controllability, but does not provide comprehensive data establishing why complete satellite launchers utilizing solid propulsion are rare.
are the least propellant-efficient (they have the lowest specific impulse). For thermal rockets, pure hydrogen, the lightest of all elements, gives the
A rocket engine, also known as a rocket motor, is a reaction engine, producing thrust in accordance with Newton's third law by ejecting reaction mass rearward, usually a high-speed jet of high-temperature gas produced by the combustion of rocket propellant stored inside the rocket. However, non-combusting forms such as cold gas thrusters, nuclear thermal rockets, and ion engines exist. Rocket vehi
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# Why did the Vanguard rocket use a solid engine for its third stage?
Tags: rockets, history, solid-fuel
- Score: 17
- Views: 2265
- Answers: 3
- Answered: yes
- Asked by: Jacktose (334 rep)
- Asked: 2016-03-24
- Edited: 2016-03-25
- Site: space
## Question
The Vanguard rocket had three stages. The first two were liquid-fueled and the third was solid-fueled.
That struck me as odd, as solid fuel engines are almost exclusively used in atmosphere, and you'd probably want the finest control for your last stage, when placing a satellite into orbit (especially one with no propulsion of its own).
What would have driven that design decision?
## Answers
### Answer by Russell Borogove (score: 17 [ACCEPTED])
Solid fuel motors aren't unknown for upper stage use (e.g IUS, Star-48, among others).
While solids generally have the drawbacks of poor Isp and controllability, their simplicity keeps cost and stage dry mass down on small upper stages. Note that in early launchers such as Vanguard, the specific impulse of the solid stage wasn't much less than that of the liquid stages (248, 271, and 230 seconds respectively for the three stages); there likely weren't any very small, efficient l
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