kendrix_j@mims.enet.dec.com (John R. Kendrix) (05/17/91)
I've seen a few posts which have mentioned in passing that NASA derives some benifit from launching close to the equator due to a 'Sling shot effect'?!?! I understand that there is centrifugal force involed with the earths rotation, but I don't see how that can act as a booster to help the shuttle get into orbit. Would someone be so kind as to give me a bit more through explanation as to how this works?? Thanks!! JK ******************************************************************************** * John R. Kendrix * Disclaimers: The opinions expressed here * * Digital Equipment Corporation * aren't likely to be claimed * * * by me, much less my employer. * * * * * Phone: 404-343-1739 * E-Mail: Kendrix_J@mims.enet.dec.com * ********************************************************************************
henry@zoo.toronto.edu (Henry Spencer) (05/17/91)
In article <22727@shlump.lkg.dec.com> kendrix_j@mims.enet.dec.com (John R. Kendrix) writes: >I've seen a few posts which have mentioned in passing that NASA derives some >benifit from launching close to the equator ... >I understand that there is centrifugal force involed with the earths rotation, >but I don't see how that can act as a booster to help the shuttle get into >orbit. Centrifugal force is what keeps spacecraft in orbit. [Pedantic Physics 101 students wanting to quibble about whether this is a real force should study some general relativity before making pronouncements on the subject.] Nature does not care whether the velocity needed to get into orbit comes from rocket boost or from Earth's spin. If you launch due east from the equator, you already have about 500m/s out of the 8000m/s or so of eastward velocity you need to get into orbit. Another way of putting this is that Earth's equator is already about 1/16 of the way to orbital velocity. That may not sound like a lot, but it's enough to make a noticeable difference in payload. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry