[Cerowrt-devel] spacebee

Tue Mar 13 13:31:02 EDT 2018

On Tue, Mar 13, 2018 at 10:03 AM, Jim Gettys <jg at freedesktop.org> wrote:
>
>
> On Tue, Mar 13, 2018 at 12:52 PM, Dave Taht <dave.taht at gmail.com> wrote:
>>
>> A couple things on the spacebee.
>>
>> 0) I LOVE the concept. Of late (due to my boat) I'd been digging into
>> the evolution of AIS repeaters, and that insanely primitive protocol,
>> and the hacks to make that scale over two channels of VHF up into
>> orbit.
>>
>> 1) The costs of launching cubesats has dropped dramatically. I believe
>> this particular launch cost about $.5m per 1u device. (I was paying
>> attention due to my interest in Planetary Resources' work. Their 6u
>> arkyd-3 spacecraft was in this payload and is functioning nominally.)
>>
>> Spacebee - Having a payload 1/4th the size of a cubesat *work* and be
>> useable! is a major advance. And is 1/4th the space junk. Worrying
>> about something smaller than baseball hitting anything strikes me as
>> control freakery at the FCC.
>>
>
> Something that size, hitting at thousands of miles/hour, will destroy what
> it hits.

You don't get relative velocity numbers for sats that large unless the
orbit is asymmetric. I'd have to go look up the numbers for this
launch...

Certainly you have to worry a bit about launches through zones like this.

> Size, until the object gets really small, really doesn't matter.

The odds of a collision drop proportionally (what's the math?) to
size. Imagine useful sats this small, or smaller, in lower orbits that
burn up in a few years, and constant replacement and technological
refreshment...

>
>
>>
>> 2) Although the FCC denied the application based on having inadaquate
>> radar reflectivity, according to their standards, the article states:
>>
>> "Websites dedicated to tracking operational satellites show the
>> SpaceBees in orbits virtually identical to those specified in Swarm’s
>> application." Ground stations can only get better.
>>
>> 3) most (all?) 1u spacecraft have no maneuvering capability and half
>> of cubesats tend to fail quickly, so there will be an increasing
>> amount of space junk in low orbits regardless. But there's nothing to
>> explode on board ('cept maybe a battery?), and probably the biggest
>> source of space junk has been explosions. Yes, there have been
>> collisions, but the smaller the device, the smaller the chance of
>> collision.
>
>
> Objects in low earth orbits don't last very long; they decay quickly
> due to drag.
>
> So low earth orbit just doesn't have much to hit in the first place, and
> a satellite there doesn't live very long either.
>
> Higher orbits are much more problematic.

Higher orbits have been classically useful due to large sat size and
difficulty in aiming antennas. Being so high up compounds the problem
with gain and latency. If we instead start using constellations in LEO
(as per the 4800 sats spacex intends to launch), we cut latency down
to *better* than what can be achieved via fiber on earth (because we
don't have any surface features to warp around). As for bandwidth...
don't know!

Sure hope spacex has paid attention to the bufferbloat effort for that design.

>
>>
>> 4) Flat out bypassing a staid and boring agency, getting the thing
>> launched, and proving the concept is just so american! but unless the
>> regulations are reformed I could certainly see more and more sats
>> created outside the USA. ITAR is a real PITA, and now testing,
>> development, and regulation now dominate over launch costs.
>
>
> Read the wikipedia article, and the analysis of the Chinese collision.
> https://en.wikipedia.org/wiki/2009_satellite_collision
>
> The Kesseler syndrome is a real problem.

>From the wikipedia article: "even a catastrophic Kessler scenario at
LEO would pose minimal risk for launches continuing past LEO".

Go, Spacebee!
>>
>>
>> 5) I'd misread the article, and interpreted part of the denial based
>> on some longstanding issues they've had with not allowing spread
>> spectrum radio in orbit.
>>
>> I'd love to see an independent, fast-moving, external and
>> international group just start ignoring the FCC on certain matters, or
>> acting in concert to help push small sats forward, faster.
>
>
> Again, there are limitations on how small an object they can track via
> radar.
>                                      - Jim
>>
>>
>>
>>
>> On Tue, Mar 13, 2018 at 9:12 AM, Jim Gettys <jg at freedesktop.org> wrote:
>> > The issue is that they can't track satellites that small using current
>> > radar
>> > technology.  They literally move satellites out of the way
>> > if there is some possibility of collision.  If there is a collision,
>> > then
>> > you get lots of debris, that just makes the debris
>> > problem worse.
>> >
>> > See: https://en.wikipedia.org/wiki/2009_satellite_collision
>> >
>> > Certain orbits are much more of an issue than others; for example, low
>> > earth
>> > orbits decay quickly enough that there is little issue, as the
>> > satellites
>> > will
>> > reenter quickly enough that there is unlikely to be a problem.  Other
>> > orbits
>> > are seldom used, so there isn't much to run into.
>> >
>> > The satellite's vendor proposed using on-board GPS to send its location.
>> >
>> > The problem is that if the satellite fails, they would get no
>> > information.
>> > The FCC was unhappy with that.  Launching without solving that
>> > objection is a real "no-no".a
>> >
>> > Jim
>> >
>> >
>> >
>> >
>> > On Mon, Mar 12, 2018 at 4:29 PM, Christopher Robin <pheoni at gmail.com>
>> > wrote:
>> >>
>> >> Now I'm not defending the FCC thinking it has global launch control,
>> >> but
>> >> I've actually done some academic reading on space debris and usable
>> >> orbits.
>> >> The experts in the field have shown concern for how to handle the
>> >> growth of
>> >> space traffic for decades, and not just in GEO space. Someone "going
>> >> rogue"
>> >> could have large scale impacts. This is different than flying planes or
>> >> setting up a new radio tower without following the "rules of the road".
>> >> Space also has the additional factors that:
>> >>
>> >> 1) there is currently no way (realistic) to clean up after an event in
>> >> space
>> >> 2) any collision events in space tend to cascade into a much larger
>> >> problem
>> >>
>> >> There are some awesome technologies on the horizon, and I want to see
>> >> them
>> >> come about. But unlike terrestrial radio, fixing a mistake isn't
>> >> currently
>> >> feasible for small scale companies. Until that changes, we really need
>> >> an
>> >> independent, international organization that will verify that these
>> >> small
>> >> startups didn't miss something in their planning. Personally I'd rather
>> >> be
>> >> stuck with sub-par terrestrial signals than increasing risk to GPS &
>> >> weather
>> >> imaging.
>> >>
>> >> On Mon, Mar 12, 2018 at 3:10 PM, dpreed at deepplum.com
>> >> <dpreed at deepplum.com>
>> >> wrote:
>> >>>
>> >>> To me that is analogous to the idea that since ancient TV sets would
>> >>> show
>> >>> weird ghosts when various kinds of radio transmitters were placed
>> >>> nearby (or
>> >>> even be disturbed by power-line noise) that the entire effort and
>> >>> rulemaking
>> >>> of the FCC should be forever aimed at protecting those TV sets,
>> >>> because
>> >>> someone's grandmother somewhere might still own one.
>> >>>
>> >>>
>> >>>
>> >>> It's a technologically backwards idea. It's the kind of idea that made
>> >>> it
>> >>> next to impossible to legalize WiFi [I know, I was there]. Only a very
>> >>> key
>> >>> person (named M. Marcus, now retired from FCC OET, and a friend) was
>> >>> able to
>> >>> enable the use of WiFi technologies in the ISM bands. Otherwise, the
>> >>> idea
>> >>> that all current poorly scalable systems ought to be allowed to
>> >>> "block" new
>> >>> technologies takes over.
>> >>>
>> >>>
>> >>>
>> >>> All I can say is that if you really think about sharing orbital space
>> >>> in
>> >>> a scalable way, there is a lot more "space" available. Which is why I
>> >>> suggested "rules of the road" that operate in everyone's interest and
>> >>> privilege no one use over another are almost certainly feasible. As
>> >>> satellites get more capable (smaller, lighter, more maneuverable, as
>> >>> they
>> >>> follow the equivalent of Moore's Law for space) avoidance becomes
>> >>> feasible,
>> >>> *especially if all satellites can coordinate via low energy networking
>> >>> protocols*.
>> >>>
>> >>>
>> >>>
>> >>> I know all the scare stories. Planes will fall out of the sky if
>> >>> someone
>> >>> accidentally uses a WiFi device or cellphone on airplanes. The
>> >>> Internet will
>> >>> be inhabited only by criminals. Encryption is something no one with
>> >>> "nothing
>> >>> to hide" needs to use.
>> >>>
>> >>>
>> >>>
>> >>> Please. Think harder. Become an expert on space technology, etc. Not
>> >>> just
>> >>> someone who "knowledgably repeats lines from news media articles" as
>> >>> so many
>> >>> do.
>> >>>
>> >>>
>> >>>
>> >>> My point is that while it may be that *geosynchronous equatorial
>> >>> orbit*
>> >>> is very tightly occupied, most MEO and LEO space is not densely
>> >>> occupied at
>> >>> all.
>> >>>
>> >>> -----Original Message-----
>> >>> From: "Christopher Robin" <pheoni at gmail.com>
>> >>> Sent: Monday, March 12, 2018 1:34pm
>> >>> To: "dpreed at deepplum.com" <dpreed at deepplum.com>
>> >>> Cc: cerowrt-devel at lists.bufferbloat.net
>> >>> Subject: Re: [Cerowrt-devel] spacebee
>> >>>
>> >>> The portion of space with usable orbital paths is much, much smaller.
>> >>> One
>> >>> rogue rocket with a poor/flawed understanding of that could endanger
>> >>> several
>> >>> other satellites. Many systems already in orbit lack the redundancy to
>> >>> handle a major collision. And any collision in orbit could ruin the
>> >>> usability of a much larger section of space.
>> >>>
>> >>> On Mon, Mar 12, 2018 at 1:18 PM, dpreed at deepplum.com
>> >>> <dpreed at deepplum.com> wrote:
>> >>>>
>> >>>> Well, that may be the case, but it's a non-scalable and highly
>> >>>> corruptible system. IMO it's probably unnecesary, too. Space is
>> >>>> actually
>> >>>> quite big.
>> >>>>
>> >>>>
>> >>>>
>> >>>> -----Original Message-----
>> >>>> From: "Jim Gettys" <jg at freedesktop.org>
>> >>>> Sent: Monday, March 12, 2018 12:26pm
>> >>>> To: "Dave Taht" <dave.taht at gmail.com>
>> >>>> Cc: cerowrt-devel at lists.bufferbloat.net
>> >>>> Subject: Re: [Cerowrt-devel] spacebee
>> >>>>
>> >>>> I do believe that the international space treaties require our
>> >>>> government to control all launches.
>> >>>> Launching satellites without permission is a big no-no.
>> >>>> Note that according to the article, it is collision risk, rather than
>> >>>> radio radiation, that is the issue here.
>> >>>> Jim
>> >>>>
>> >>>> On Mon, Mar 12, 2018 at 12:13 AM, Dave Taht <dave.taht at gmail.com>
>> >>>> wrote:
>> >>>>>
>> >>>>> This is awesome. The FCC (whic still doesn't "get" spread spectrum
>> >>>>> radio) just discovered it doesn't have authority over the airwaves
>> >>>>> of
>> >>>>> the whole planet.
>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>> https://spectrum.ieee.org/tech-talk/aerospace/satellites/fcc-accuses-stealthy-startup-of-launching-rogue-satellites
>> >>>>>
>> >>>>> --
>> >>>>>
>> >>>>> Dave Täht
>> >>>>> CEO, TekLibre, LLC
>> >>>>> http://www.teklibre.com
>> >>>>> Tel: 1-669-226-2619
>> >>>>> _______________________________________________
>> >>>>> Cerowrt-devel mailing list
>> >>>>> Cerowrt-devel at lists.bufferbloat.net
>> >>>>> https://lists.bufferbloat.net/listinfo/cerowrt-devel
>> >>>>
>> >>>>
>> >>>> _______________________________________________
>> >>>> Cerowrt-devel mailing list
>> >>>> Cerowrt-devel at lists.bufferbloat.net
>> >>>> https://lists.bufferbloat.net/listinfo/cerowrt-devel
>> >>>>
>> >>
>> >>
>> >> _______________________________________________
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>> >> Cerowrt-devel at lists.bufferbloat.net
>> >> https://lists.bufferbloat.net/listinfo/cerowrt-devel
>> >>
>> >
>> >
>> > _______________________________________________
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>> > https://lists.bufferbloat.net/listinfo/cerowrt-devel
>> >
>>
>>
>>
>> --
>>
>> Dave Täht
>> CEO, TekLibre, LLC
>> http://www.teklibre.com
>> Tel: 1-669-226-2619
>
>

-- 

Dave Täht
CEO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-669-226-2619