
NASA’s IMAGE satellite, lost since 2005, is alive - sohkamyung
https://skyriddles.wordpress.com/2018/01/21/nasas-long-dead-image-satellite-is-alive/
======
quotemstr
The failure analysis is interesting:
[https://image.gsfc.nasa.gov/publication/document/IMAGE_FRB_F...](https://image.gsfc.nasa.gov/publication/document/IMAGE_FRB_Final_Report.pdf)

Basically, the spacecraft needs a transponder to communicate with Earth. The
transponder is attached to a circuit breaker. For various reasons, the circuit
breaker can flip off. When this happens, it sends an "I'm off" status bit to
the spacecraft's power control computer, which in turn flips the circuit
breaker back on.

The problem is that the transponder circuit breaker, if it switches rapidly,
turns itself off without setting the "I'm off" status bit. Since the
spacecraft computer doesn't know the transponder circuit breaker is off, it
never commands it back on. Consequently, the spacecraft can't send or receive
commands and becomes useless.

The paper speculates that one way to break out of this state might be to wait
for an eclipse that lasts long enough to drain the onboard batteries, causing
the whole spacecraft to lose power. When the spacecraft boots up again after
exiting the eclipse restores power, the power control computer will
unconditionally command the transponder circuit breaker on, restoring
connectivity --- basically, waiting for orbital geometry to turn the whole
thing off and on again.

There's more. You might think: "Well, just add a bit of code to the main
onboard computer to unconditionally reset the circuit breaker every so often.
Hacky, but it works, right?"

Nope. If I'm understanding this right, the power display computer (which
doesn't appear to be programmable) is designed to ignore transponder power
control commands from the main computer. The paper doesn't explain the
reasoning for this resign, but I suspect it's probably to guard against
software bugs causing exactly the scenario that the circuit breaker hardware
bug caused. So in an attempt to guard against a software bug, the designers
lost the ability to work around a hardware bug.

Maybe you could program the software to notice that it hasn't gotten commands
for a while and deliberately rotate itself into an orientation that causes a
power loss and reset? I'm guessing that the solar panels are arranged in such
a way that it wouldn't work, and the attitude control fuel consumption might
be excessive.

~~~
mLuby
Wonder if the power display computer might be susceptible to Meltdown, Spectre
or Rowhammer? Or is it not programmable in the sense that everything is
hardwired…

~~~
simias
Why would it matter? It's not like it's running any untrusted code.

~~~
petee
I believe the suggestion was that NASA could update the main computer with
their own 'untrusted' to exploit the flaw in the power system, side stepping
their own protections. But as mentioned below in other comments, these vulns
are likely not present on this hardware

~~~
simias
That doesn't make sense to me, aren't we talking about two different pieces of
hardware talking together? If they could reflash the "display computer" then
the problem would be solved if I understand correctly.

Even if it's really two "applications" running on the same CPU I don't see how
spectre/meltdown would help since it's all about getting read-only access to
"forbidden" memory. Clearly they don't need that (they know full well what's
in memory), they want to be able to modify it.

In such a situation RowHammer _might_ be used to modify the state of an other
program sharing the same RAM in the right conditions but if there's one piece
of hardware I expect to be hardened against spurious bitflips it's a space
probe. We're talking about radiation-hardened ECC-protected RAM after all.

------
dirktheman
This isn't the first time amateur astronomers are helping NASA: in 2014 a
group of amateur astronomers rebooted a long-lost satellite from the 1970s
(ISEE-3). They even managed to fire the thrusters for the first time since
1987 but sadly, contact was lost again later that year:

[https://en.wikipedia.org/wiki/International_Cometary_Explore...](https://en.wikipedia.org/wiki/International_Cometary_Explorer#Reboot_effort)

~~~
rando444
They refer to this in the article.

------
JKCalhoun
Wow, I didn't know there was such a cool hobby out there waiting for me. I
know nothing about modern radio scanning but I'm suddenly fascinated to learn.

~~~
cjsuk
Have a look at amateur radio and satellite operations as a whole. You can,
with some persistence and brains have a chat with someone a vast distance away
via satellite repeater with nothing but a cheap handheld radio.

I’ve only managed to receive so far due to a cruddy antenna but that was with
a $30 Baofeng radio from Amazon.

Note: you need a license but it’s pretty easy to get, at least in the UK and
you learn a lot while getting it. It also tends to cost you a lot of money in
the end because it’s really interesting :)

~~~
godelski
A HAM license is easy to get in the US. There are three main classes, and I
would expect most people on HN could get the Technician license with little to
no studying. Won't provide you world wide communications, but it is still good
to have. Most places charge $10 and are done by the local HAM group. Here's a
practice test for the levels if anyone is interested. [1] The questions are
from a pool, so worst case you could just memorize them.

[1] [http://aa9pw.com/radio/](http://aa9pw.com/radio/)

~~~
UncleEntity
Yep, read a couple books I got off the internets, mostly memorized the pool
questions and got an expert license I never really used (probably doesn't help
I'm not the most social creature) so didn't renew last year. Really easy to
get a license since they got rid of the Morse code requirement -- just need to
learn a few formulas really.

\--edit-- Not in one sitting, IIRC went from tech to expert on the second
trip.

~~~
cjsuk
Data modes and CW are there for us unsociable individuals :)

------
ggm
Hooray for gifted amateurs. This post made me very happy. I especially liked
the scientist who replied to the article saying they have experiment on the
sat, and would love to see it wake up.

~~~
dmix
Here's a good article about these guys:

"Meet the amateur astronomers who track secretive spy satellites for fun"

[https://www.popsci.com/zuma-spy-satellite-amateur-
astronomer](https://www.popsci.com/zuma-spy-satellite-amateur-astronomer)

~~~
c12
That actually does sound like fun... but I don't personally have the resources
to get into a hobby like that :(

~~~
brians
It takes $50 in parts: half for a radio (new Baofeng, used Yaesu or Alinco),
$10 for antenna parts for a “tape measure Yagi,” and $5 for a cable. The last
$10 can buy some hot coffee for long nights of cold.

~~~
godelski
An additional $10 will get you the license to transmit and be able to talk to
your _local_ HAM group.

------
oh_sigh
Wow...according to wikipedia(so who knows in this case), NASA is trying to
communicate with IMAGE via the DSN 4 days after this blog post.

If it is the case that no one remembered about this satellite, then this
really is an amazing find.

~~~
quotemstr
Yep. I wish I'd caught the communication attempt on DSN Now:
[https://eyes.nasa.gov/dsn/dsn.html](https://eyes.nasa.gov/dsn/dsn.html)

I have a sudden urge to somehow make DSN Now my desktop background.

~~~
fjarlq
According[1] to NASA's Richard J. Burley, as of just after midnight UTC Jan 25
2018, they haven't yet attempted communication using DSN, but they're working
on it:

> _I have attached the TLE I got this morning from JSPoC /CARA. Looks like a
> close match. We are in the process of engaging the Deep Space Network to see
> if they can get a signal lock. They (JPL/DSN) are in the process of digging
> up 13-year old configuration files for that attempt. The DSN has evolved
> since then so some adjustments to their system setups will be required._

> _I have no schedule estimate yet for when that first attempt will be made.
> If we are able to get signal lock and verify that it is IMAGE, we will setup
> a MINIMAL ops setup to verify telemetry /command and make an initial
> assessment of the health and viability of the spacecraft bus. I don't have a
> credible schedule prediction yet for that step either._

> _Thank you for all of your efforts for IMAGE. IMAGE made ~39 new discoveries
> about the Earth 's magnetosphere and plasma-sphere. At the time it stopped
> radiating, NASA HQ ranked IMAGE as the 2nd most valuable space-physics
> mission flying. A follow-on mission called MMS, with a 4-spacecraft
> constellation is currently flying, in part, to follow up on these
> discoveries._

[1]:
[http://www.satobs.org/seesat/Jan-2018/0192.html](http://www.satobs.org/seesat/Jan-2018/0192.html)

~~~
Maxious
Follow up!

> I just received official confirmation from NASA that IMAGE is indeed alive!
> See Below!

> Engineers at GSFC have acquired the suspect S-band source using the 4m CTA
> (Compatibility Test Antenna) here at GSFC (.jpg attached and no I’m not in
> the picture). They acquired the signal while the target was on ascent at
> about 2RE. Center frequency (CF) was between 2272.478 and 2273.418. The
> difference between IMAGE documented CF of 2272.5Mhz can be attributed to
> expected Doppler. Subcarriers are visible as well 1.7Mhz from CF as
> expected. The signal strength was oscillating. Plots will be forthcoming.
> The oscillation is not unexpected given IMAGE’s loss of spin balance.

> All indications so far suggest that this is, in fact, IMAGE.

[http://www.satobs.org/seesat/Jan-2018/0203.html](http://www.satobs.org/seesat/Jan-2018/0203.html)

------
mirimir
IMAGE: [https://image.gsfc.nasa.gov/](https://image.gsfc.nasa.gov/)

------
AnnoyingSwede
What are the technical and geographical requirements to do two-way
communitcation with low-orbiting satelites? A directional antenna, an SDR-card
and a decent amplifier i assume, but what about geography? Would i be able to
pull this off in a European capital with surrounding electromagnetic/radio-
wave pollution one can expect in a capital?

~~~
brians
Yes, absolutely. The trick is to use a very directional antenna—it listens to
what you point it at and blocks out noise from the sides. The canonical tool
for this is a handheld Yagi, either home made for a few dollars in tubing and
screws or ordered from Arrow Antenna.

What replaces the expensive satellite tracking system? A top notch neural
network with high endurance myelin-actuated 6-dof arm. You.

~~~
UncleEntity
Every so often I wonder what kind of shenanigans I could get up to with the
"complementary" satTV dish that came with my apartment if I rigged up some
sort of tracking system and messed with the feed head for different
frequencies. Those things are everywhere, a real untapped resource.

------
vvanders
Official confirmation:
[http://www.satobs.org/seesat/Jan-2018/0203.html](http://www.satobs.org/seesat/Jan-2018/0203.html)

------
zmix
This is so cool! :-) Not that I would understand the slightest of the
technical mumbo-jumbo, but it is fascinating, that hobbyists can do such
things, these days.

------
ProAm
This is amazing. Great post for HN.

------
SubiculumCode
This is just a great post. Very inspiring. And now confirmed by several
others, and the original IMAGE teams are all excite.

------
FourSigma
I haven’t seen PGPlot in ages! I didn’t realize it is still being used!

~~~
joshumax
We (I) use it a lot in the Amateur Radio and Amateur Radio Astronomy community

------
bhhaskin
Thank you for posting this! It was a great read and can't wait to see what it
leads to.

------
zdw
Dupe:
[https://news.ycombinator.com/item?id=16231252](https://news.ycombinator.com/item?id=16231252)

------
tzfld
How the hell can I google it after it's abbreviation?

~~~
zingmars
"NASA IMAGE satellite" seems to find the project page for me. IMAGE satellite
also finds a lot of news entries regarding this incident that you can probably
use to find out more.

------
chatmasta
It’s cute that amateur astronomers can find this satellite, but aren’t we
paying NASA billions of dollars to figure these things out themselves?

~~~
kawfey
[https://www.nasa.gov/sites/default/files/atoms/files/fy_2018...](https://www.nasa.gov/sites/default/files/atoms/files/fy_2018_budget_estimates.pdf)

No.

------
orionblastar
This is good news. NASA does not always tell us everything. They keep it a
secret stuff like intergalactic drive research, ECT until they can prove it
works, so it does not fall into the wrong hands.

~~~
jacquesm
> They keep it a secret stuff like intergalactic drive research, ECT until
> they can prove it works, so it does not fall into the wrong hands.

And who might 'the wrong hands' be?

And how does proving that it works prevent it from falling into the wrong
hands?

