
LightSail Test Mission Declared Success; First Image Complete - gokhan
http://www.planetary.org/blogs/jason-davis/2015/20150609-lightsail-test-mission-success.html
======
devindotcom
Love this. I'm happy to say I just talked to Bill Nye on Friday (LS was still
AWOL) about this and a recent science competition for kids and I love his
enthusiasm for everything. He thinks of it as carrying on work that Carl Sagan
started. Just gonna hijack this thread to share a couple quotes from my notes
that didn't make it into my article[1], since you guys might appreciate them:

"for me it's [lightsail is] really personal. i had carl sagan for one class,
and it changed my life. and so i'm really excited to get this thing working.
if not this mission, the next mission. oh god, the concept is just cool, to
just be sailing around the solar system essentially for free. It's elegant."

"there are two questions we all ask, and if you meet somebody who claims
they've never asked these questions they're lying and that's all there is to
it: where did we come from and are we alone in the universe? if you want to
answer those questions, you have to look at the past and the future. You have
to look at paleontological evidence, and you have to explore space."

"talk to younger people. they expect great things from technology. that
expectation i believe will carry over to every aspect of life - that we can do
technological things to prevent climate change. that for any problem there's a
technological solution."

"this is what we talk about all the time in science ed. we want science every
day in every grade. this is obvious to me and my colleagues in science ed.
what's amazing is it's not amazing to everybody. science is as important a
topic as writing and reading and arithmetic. if you want to have innovation,
if you want to have the engineers of tomorrow, you have to have science."

"kids have no trouble understanding climate change - it's grown-ups that are
confused. climate change denial is almost entirely a generational issue."

[1] [http://www.nbcnews.com/science/science-news/bill-nye-
boosts-...](http://www.nbcnews.com/science/science-news/bill-nye-boosts-
future-science-guys-girls-kids-are-natural-n370706)

~~~
monk_e_boy
"climate change denial is almost entirely a generational issue" ...

I do wonder if this is a US thing. I've not seen a denier over here in the UK.
Sure, on the TV they have debates about climate change with scientists. They
argue and present data and talk about change. They may argue about the rate of
change and the potential effects. But everyone agrees that change is
happening.

Just take a look at the G7 fossil fuel pledge by the Germans. That's pressure
from everyday people over here in Europe, that's millions of us who
understand.

~~~
pjc50
James Delingpole in the Telegraph is probably the leading UK denier. But there
are quite a lot of "silent" denialists who won't make a big noise about
climate itself but will attack environmental, energy or "green" projects on
spurious grounds.

~~~
monk_e_boy
Meh. History will judge them (and us.) Let's hope we win, else our history
will be written by an off-earth entity.

------
mod
Does anyone know the actual purpose of the LightSail?

The article doesn't seem to mention it, just the details of this successful
mission.

~~~
TheLoneWolfling
It's a solar sail, or rather a test thereof.

Long story short, photons (and solar wind) impart a small amount of momentum
on the sail. This can be used instead of rockets - as long as you don't mind
it taking an absurd amount of time to get you anywhere, that is. And its a
whole lot lighter.

~~~
fixermark
An absurd amount of time can be a workable tradeoff depending on the purpose
of the mission.

Historically, both thrust and delta-V have been sorely constrained on
spacecraft. This is trading a lot of thrust for an infinite* amount of dV,
which is a really valuable trade.

(*Practically infinite. It runs out when the sun stops giving solar pressure
;) ).

~~~
TheLoneWolfling
I am well aware of the potential advantages of solar sails for many things.

I'm just saying they aren't the be-all and end-all. There are many things
where they aren't particularly useful (for instance: anything time-
constrained. Or anything that requires largeish maneuvers to be done in the
outer solar system. And there are certain maneuvers that are... difficult...
with a solar sail.)

Also, it's not infinite, nowhere near. Among other things, solar radiation and
solar wind will degrade the sail over time. Especially with a lot of the
materials they suggest using (mylar, etc.)

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kolev
Let's give it one last push! A bit more than 2 weeks and $150K to go:
[https://www.kickstarter.com/projects/theplanetarysociety/lig...](https://www.kickstarter.com/projects/theplanetarysociety/lightsail-
a-revolutionary-solar-sailing-spacecraft)

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magicmu
This is absolutely amazing!! Pardon my ignorance, but how does this compare to
ion thrust? Unless that's still theoretical, that is -- this seems like an
even more elegant solution that ion thrusters.

~~~
jameshart
Ion propulsion is not purely theoretical - the Dawn mission currently entering
orbit around Ceres got there under ion propulsion, having previously
rendezvoused with Vesta.

~~~
magicmu
Wow! Thanks for the info, looks like I've got some reading to do.

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tomphoolery
"Mirab, his sails unfurled!"

~~~
aaronharnly
So this comment is not a substantive engagement with the topic of the article;
instead, a reference to a familiar (to a nerdy in-group) pop culture
touchpoint.[1] As such, it is more of an /r/ comment than an HN comment.

Nevertheless, it made me happy to read it, and I welcome it :-)

(One could note the pleasing irony of the comment itself being an instance of
the type of communication-by-reference-to-shared-myth that occurs in the
episode. However, since its contribution to _this_ conversation is not about
that mode of communication, it's ultimately a distraction .)

[1]
[http://www.theatlantic.com/entertainment/archive/2014/06/sta...](http://www.theatlantic.com/entertainment/archive/2014/06/star-
trek-tng-and-the-limits-of-language-shaka-when-the-walls-fell/372107/)

~~~
TeMPOraL
> _As such, it is more of an /r/ comment than an HN comment._

The river Temarc in winter. Kiteo, his eyes closed.

;).

Honestly, this "familiar pop culture touchpoint" inspired a big part of a
generation of scientists and engineers. As someone who thinks it has a
significant impact on his life, I too appreciated the comment :).

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Adam_O
Minor side note for the audio-curious.. Neil DeGrasse Tyson's podcast had an
episode recently where Bill Nye talked all about the LightSail..

[https://soundcloud.com/startalk/cosmic-queries-lightsail-
wit...](https://soundcloud.com/startalk/cosmic-queries-lightsail-with-bill-
nye)

------
aswanson
Am I the only one who thought, on first read, Danifong pivoted to space
imaging?:[https://news.ycombinator.com/user?id=DaniFong](https://news.ycombinator.com/user?id=DaniFong)

~~~
DaniFong
Thanks for the H/T. ;-) We're fans of the project too

