
Nasa Establishes Contact with STEREO Mission - cjdulberger
http://www.nasa.gov/feature/goddard/2016/nasa-establishes-contact-with-stereo-mission
======
spuz
The linked article that gives the background on this mission and its recovery
is definitely worth reading [0]. In particular, it's worth noting that the
STEREO mission was only supposed to last until 2008 and part of the reason it
was lost was due to NASA's attempts to reconfigure it to survive the unplanned
period it would be out of contact from Earth as it passed behind the Sun. It
would be pretty impressive if they were able to get it back in service so long
after its planned end-of-life.

[0] [http://www.nasa.gov/feature/goddard/saving-nasas-stereo-b-
th...](http://www.nasa.gov/feature/goddard/saving-nasas-stereo-b-
the-189-million-mile-road-to-recovery)

~~~
codezero
I imagine this happens more often than most people realize.

I worked on a satellite that was launched in 2003 and had a lifetime of 3
years. It operated until at least 2012 when the Air Force decided it was done
paying for the downlink, but the satellite itself was still in pretty good
condition.

~~~
mikeash
I always assumed this happened because the official lifetime is defined in
terms of some high probability of surviving that long, maybe 95%. And if you
have a 95% chance of lasting 3 years, you probably have something like a 50%
chance of lasting a decade or two. Is that assessment vaguely correct?

~~~
mturmon
That's true ("ability to operate") but another large factor (for scientific
space missions) is the demonstrable benefit to continuing -- even if the
spacecraft is fully operable. For instance, New Horizons, once it flew by
Pluto, had accomplished its primary science mission, and an end could have
been declared at that time.

But then the NH science team put together a rationale for an "extended
mission" with the new objective of visiting a Kuiper Belt Object, which was
accepted by NASA.

But on the other hand, at the same time, the Dawn spacecraft's proposed
extended mission to leave Ceres and visit Adeona, was denied, and it is
expected to just orbit Ceres for the rest of its lifetime. (More:
[http://spaceflightnow.com/2016/07/02/pluto-probes-
extended-m...](http://spaceflightnow.com/2016/07/02/pluto-probes-extended-
mission-approved-but-new-dawn-destination-denied/))

So the surplus lifetime might not be used if the further science benefit can't
be justified -- against engineering effort, downlink, etc. Sometimes portions
of a spacecraft are turned off but the low-bandwidth observations are still
taken and downlinked.

Or, sometimes a spacecraft is kept operating, with great engineering effort,
even though it is not in great shape.

------
gammarator
My favorite story about this mission: the engineers bought a (human) casket to
ship one of the antennas! [https://astroanecdotes.com/2015/12/27/the-casket-
with-an-imp...](https://astroanecdotes.com/2015/12/27/the-casket-with-an-
impact/)

------
kylek
Slightly off-topic, but if you're in to solar/space weather news, I highly
recommend you take a look at the suspicious0bservers channel on youtube. Ben
does a daily 5-minute blurb on this science-y kind of stuff (stereo has been
mentioned a bit of the last few days). Very interesting and not a big time
commitment.

[https://www.youtube.com/user/Suspicious0bservers](https://www.youtube.com/user/Suspicious0bservers)

(Today's news, mentioning the return of stereo
[https://www.youtube.com/watch?v=MhSCMR0YP8Q](https://www.youtube.com/watch?v=MhSCMR0YP8Q)
)

------
dmix
> Mission Operations team over several hours to characterize the _attitude_ of
> the spacecraft

> The STEREO Missions Operations team plans further recovery processes to
> assess observatory health, re-establish _attitude control_

Did they mean altitude? What does attitude mean?

~~~
kerbalspacepro
Attitude is the orientation of a spaceship. It is where a spaceship is
pointing in space relative to other things.

