[ExI] nasa's solar sail has deployed

[spike at rainier66.com]

-----Original Message-----
From: extropy-chat <extropy-chat-bounces at lists.extropy.org> On Behalf Of BillK via extropy-chat
Sent: Saturday, 27 April, 2024 3:37 AM
To: ExI chat list <extropy-chat at lists.extropy.org>
Cc: BillK <pharos at gmail.com>
Subject: Re: [ExI] nasa's solar sail has deployed

On Sat, 27 Apr 2024 at 05:45, spike jones via extropy-chat <extropy-chat at lists.extropy.org> wrote:
>
> Hey cool!  This is one I have long been waiting for: a solar sail.  NASA launched a CubeSat with an 80 square meter sail:
>
> https://www.sciencealert.com/nasas-advanced-solar-sail-has-successfull
> y-deployed-in-space
>
> Information on the control system is hard to find.  If anyone has a link, specifically about the ACS3 control system, that’s what I am looking for.
>
> spike
> _______________________________________________


This might be what you are looking for?
<https://ntrs.nasa.gov/api/citations/20210017923/downloads/SmallSat_2021_ACS3_overview_20210620_rev_b_for_review.pdf>
BillK

_______________________________________________


Thanks BillK!  You are really good and finding out stuff.

Notice on that first chart in that link you sent, the photo in the top left, and that photo top right.  That device is called a lenticular strut, which is really cool because it forms the lightest deployable compression element we have in our bag of aerospace magic tricks.

Perhaps you have played with a carpenter's metal tape measure so you know how a strip of curved metal can bend one way easily but resists bending backwards.  You can roll it up, as it is inside the device, without going anywhere near the yield limit of the metal: it is good as new.  OK, now imagine taking two of those and putting them in parallel, so if you looked down along the end, the shape it makes is a lens shape, or American football shape (whassup with you British guys and your odd shaped "football"?  (that's not a football (it looks like a rugby ball (and what's with calling rugby "football?" (BillK, you know I think the world of you pal, but that unpleasantness in the 1770s was inevitable (if it hadn't been over the tea in the harbor, it would have started over the whole "football" business.))))))

But I digress.  The two metal tapes facing each other and their edges welded together form a lenticular strut, which is really cool because you can make a long very low weight strut which can be folded into a Z pattern (or fan folded) so it can fit into a small Cubesat box.  Then when it is unfolded, it pops out and makes a strong strut as shown in the slides.  You can cantilever those things horizontally for an absurd length.  I worked with a subcontractor who made those things, which I might post about later but now I am watching the robot races and those are cool as all hell.

https://www.youtube.com/watch?v=TPzBH-7ckO0

spike