[ExI] Breakthrough Starshot - To The Stars!

[Adrian Tymes]

On Apr 14, 2016 12:41 PM, "Rafal Smigrodzki" <rafal.smigrodzki at gmail.com>
wrote:
> Why would they need the beam on for 20 years? The proposal calls for a
boost phase lasting only a few hours, after launching a sufficient number
of probes the facility can be dismantled.

How do they plan to decelerate?  (If they will detach something to stay,
that will need deceleration.)

And if they don't, what meaningful interaction can be accomplished over
there?  Even just measurement and observation would be better done by
something that sticks around (see how much data a certain Mars rover has
generated).  We've seen how sustainable "flags and footprints" is: some
decades later, we can't even rebuild the rockets that took people to the
Moon.

Further, accelerating to even just 0.1 c (about 3 * 10^7 m/s) over a few
hours (call it 10,000 seconds, roughly 3 hours) comes to about 300 Gs.  And
they're just launching nanocraft.  I do not think they will be able to come
up with a design that would not shatter, breaking the reflector so they
don't even wind up accelerating dust, let alone functioning spacecraft, to
nearly the speed desired.  Granted, 90 hours - just shy of 4 days
continuous - would drop this to around 10 Gs, which may be feasible
depending on spacecraft design.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20160414/41aad021/attachment.html>