# How fast can we go with existing technology?

**URL:** <https://boards.straightdope.com/t/how-fast-can-we-go-with-existing-technology/528853>\
**Category:** Factual Questions\
**Created:** [February 13, 2010, 1:24pm UTC](https://boards.straightdope.com/t/how-fast-can-we-go-with-existing-technology/528853 "2010-02-13T13:24:13Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![AllFreedomUnlessDefyingScience](https://avatars.discourse-cdn.com/v4/letter/a/e36b37/32.png) [@AllFreedomUnlessDefyingScience](https://boards.straightdope.com/u/AllFreedomUnlessDefyingScience)\
**Post date:** [February 13, 2010, 1:24pm UTC](https://boards.straightdope.com/t/how-fast-can-we-go-with-existing-technology/528853/1 "2010-02-13T13:24:13Z")

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Hiya folks,

The fastest speed ever attained by a spacecraft was 252,792 km/h (157,078 mph) by the Helios 2 probe in the 70’s. What I’d like to know is this, using rocket technology that exists (at least as plans for proved technology if not as parts on a shelf) and the gravitational assist effect from diving into gravity wells of multiple planets to build up speed as much as possible, what is a general estimate for how fast we could get something to leave the solar system right now? I know that the actual calculations of something like this would require some serious, probably heavy duty computer calculations to figure out a highly accurate figure here. I’m just interested in a general estimate. This is just to satisfy my curiosity, I offer you my thanks in advance should you do so.

with gratitude,  
AllFree