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Unmanned _ Hayabusa2 _ PROCYON

Posted by: Explorer1 Dec 7 2014, 07:58 PM

PROCYON is in the right trajectory too; the initial operations phase has begun.

Posted by: Weywot Dec 9 2014, 11:01 PM

Maybe PROCYON soon needs its own thread.
Next to the, already mentioned above in the spacedaily article, it also has a

Some posts are in english, but goole translate helped me with the interesing other statements the last days, that the three-axis attitude control system was successfully tested by starting the RCS. The post is illustrated with some nice that shows housekeeping data.

The last post shows the calibration test for the attitude control, with an initial "oversteering" of a deliberate change of 10 from the sun orientation and then as google translate says: "I was able to direct the clean attitude of goal without having to vibration as "After" in Figure!!!" smile.gif Picture

I think it's really nice to have such direct reports from the team and the spacecraft. I remember that from other japanese missions, like the blog from the IKAROS mission.

Posted by: elakdawalla Dec 9 2014, 11:05 PM

Good idea for a separate thread for PROCYON; I've made one here., as well as 2000 DP107, 2010 LJ14 and 2002 AJ29. Via Twitter, radio astronomer Michael Busch says that 2000 DP107 is a binary asteroid studied extensively by radar in work led by Shantanu Naidu and Jean-Luc Margot.

Posted by: Weywot Dec 9 2014, 11:21 PM

Can't even edit my post, already a new thread wink.gif

What I wanted to add:

I somehow miss the LAICA camera system in all PROCYON images and articles. It only shows in some functional block diagrams. Was the "Observation of Geocorona using Lyman Alpha Imaging CAmera" just a proposal, or is it on board the spacecraft? I wonders, since the observation time is said to be 1-2 weeks afer launch in the translated by pandaneko. Thanks btw.

Some other good articles about PROCYON on (also about ArtSat and Shin'en2) and very extensive one on, but all are missing LAICA.

Posted by: charborob Dec 10 2014, 01:08 AM

I tried searching for information about the camera carried by PROCYON, but I couldn't find anything too clear about it. What resolution does it have?

Posted by: pandaneko Dec 15 2014, 02:19 AM

QUOTE (Weywot @ Dec 10 2014, 08:21 AM) *
Lyman Alpha Imaging CAmera" just a proposal, or is it on board the spacecraft?

I have been away in Taipei, paying my respect to Teresa Teng, an Asiawide famous female singer,
who died at the age of 41. I do not carry IT things (or for that matter even a camera). So,
that is for the delay in my response.

I think the camera is on. That is my gut feeling. I will start translating the gist of what the
control team is saying. By looking at what they have said to date the probe may not yet be
far out enough to look at the earth.

If the camera is installed they will have to be saying something about what our hydrogen extent
is looking like. So far, no mention of it.

I am personally more interested in asteroids. Will this probe be reaching one a lot sooner
than Hayabusa 2? P

Posted by: pandaneko Dec 15 2014, 06:06 AM

PROCYON status digest from FB as follows. P

9 December

Reporting on status on 8th.

Travelling at 2.2 million km from earth, it takes 7 seconds for the signals
to reach PROCYON.

We made adjustments to the 3 axix attitude control system and
we are now able to point PROCYON in any ditrection we want, like
pointing the medium gain antenna to earth.

10 December

Almost a week from launch. PROCYON is healthy, but far away. Unless we communicate slowly line is
corrupted by noise. Comms. rate has been 2kbps, from PROCYON.

Today's testing was on the medium gain antenna. We made it and are now able to use
16kbps, still as slow as 1/1000 of smart phone comms.


PROCYON operation stopped during 12-14 December. During this period PROCYON passed through
a region of very strong solar winds. You can get information on solar winds on

PROCYON is currently at 4 million km from earth.

Posted by: Weywot Dec 15 2014, 05:05 PM

QUOTE (pandaneko @ Dec 15 2014, 03:19 AM) *
Will this probe be reaching one a lot sooner than Hayabusa 2?

As Hayabusa2's arrival at 1999 JU3 is planned for June 2018, PROCYON will make its fly by earlier. In the above mentioned by Ozaki et al., all possible target asteroids will be reached mid to end of 2016.
The paper was written prior to the launch and as the launch day was not clear, the target asteroid was not selected. Table nr. 4 on page 9 of the paper lists some of the target astroids, of which all require an earth gravity assist. The ones that can be reached directly in a shorter time result in a too short phase of only about one day where the probe can steer by optical navigation. This time sould be more than 3 days, which is only possible for the asteroids reached by the gavity assist scenario.

So we will know the exact fly by date, when the asteroid will be selected and announced by JAXA.

Posted by: katodomo Apr 8 2015, 04:49 PM

If I get that right in this Japanese article 2000 DP 107 has been offically announced as the primary candidate target asteroid:

Posted by: Explorer1 Apr 8 2015, 05:33 PM

Two for the price of one, nice! Short rotation rate on the primary too; it should be possible to see the whole area during the flyby?

Posted by: Paolo Apr 9 2015, 04:17 PM

everything you wanted to know about PROCYON's target:

Posted by: pandaneko Apr 10 2015, 11:29 AM

I have been looking at PROCYON's FB, at least once/week to see what is going on.

I must say I am very unhappy. Only today I learnt through my GOOGLE alert that
JAXA and Tokyo University had a joint press meeting on 6 April to say that
the engine had stopped running.

No mention of when the engine stopped. Does anybody know anything?

No wonder no progress report in their FB. P

Posted by: PaulH51 Apr 10 2015, 12:09 PM

QUOTE (pandaneko @ Apr 10 2015, 07:29 PM) *
....JAXA and Tokyo University had a joint press meeting on 6 April to say that the engine had stopped running.

Let's hope they can solve the issues and restart the engine ASAP

Posted by: Paolo Apr 10 2015, 12:15 PM

the link that katodomo posted above says engine stopped in mid-March after 223 hours in total. they expect (hope for?) recovery by end of April

Posted by: Paolo Apr 10 2015, 03:02 PM

from this image of the press event, flyby would be on 12 May 2016
there is also, but with little or no new informations

Posted by: pandaneko Apr 11 2015, 12:42 AM

Thanks, Paolo and Katodomo

What follows has been extracted from Katodomo's Senews and Paolo's Monoist. Only portions
new to me.

The target of PROCYON is now set to "2000 DP107" which is a doublet. 800m and 300m.
Consequently, PROCYON will not be able to return to near earth orbiut to perform a
swingby. So, only chance of asteroid approach. The earth swingby is December 2015 and
asteroid passby is May 2016.

Norminal mission has been accomplished. Solar pannels are OK, temps are OK,
triaxial control is OK. It is very much alive.

Ion engine stopped in midMarch 2015, trying to restart, but no indication yet of
recovery at the moment.

The cause of this has not been identified yet, but the most likely reason is thought to be
that minute metal piece has migrated into the gap between the 2 ion grids of the ion source.

Therefore, several options have been identified, as follows.

1. Give this grid a thermal cycle of expansion and contraction.
2. Give the probe an acceleration and rotate, stop, rotate, stop etc.
3. Apply high voltage and brun out the meal piece.
Theseoptions will be tried carefully. However, the deadline for recovery is currently
end April 2015 in time for the earth swingby in December 2015. This deadline is
also being re-evaluated for accuracy.

In the meantime, geo-corona image aqquisition has been successful.
The image has not been made available as theses are being written at the moment.

Above are the gists of what are available at the moment. P

Posted by: Paolo Apr 11 2015, 06:10 AM

thanks a lot pandaneko! I always value you translations. a lot of these informations were lost when trying to make sense of the machine translation!

Posted by: Paolo May 8 2015, 06:21 PM

asteroid flyby abandoned sad.gif

Posted by: Explorer1 May 10 2015, 02:53 AM

What about the Earth flyby in December, is that still happening? Even distant observations would be a good test of the systems (and look cool too).

Posted by: Paolo May 10 2015, 07:01 AM

I guess they are in an orbit that will get PROCYON somewhere near Earth in December anyway (a few million km, probably). If I understand this other news report, observations of the Earth's geocorona are to continue

Posted by: Paolo Oct 14 2015, 07:08 AM

here is some work for Pandaneko! PROCYON observes the hydrogen coma of Churyumov-Gerasimenko

Posted by: Paolo Nov 18 2015, 11:48 AM

Procyon has been observing the Earth recently, heading for a distant flyby in early December. A couple of images from


Posted by: Paolo Dec 11 2015, 07:30 AM

contact with PROCYON has apparently been lost after the distant Earth flyby

Posted by: Explorer1 Jan 25 2017, 04:49 PM

Luckily, some distant observations were made of 67P before, not bad for a tiny spacecraft! (link to new paper at the bottom)

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