衛星SO-33(SEDSAT-1) リセットデータ


● (No.203) 衛星SO-33(SEDSAT-1) リセットデータ (2000年4月19日)
 -------------------------------------------------------------

今から1年半前の 1998年10月24日に打ち上げられた衛星SO-33(SEDSAT-1)が、
弱ってきているようです。この衛星は、アマチュア無線と宇宙工学の教育目的
にアメリカのアラバマ大学の学生と指導者を中心に製作されたもので、初期の
頃よりデジタル送信機が不調で、数十時間ごとにハードリセットを繰り返して
いました。 (このホームページの過去の記事を参照)

http://www.asahi-net.or.jp/~EI7M-WKT/


先日(4月13日)、そのデジタル送信機が リセットする瞬間のデータを、偶然に
受信することができました。(下記データ UpDays,UpHours,UpMinutes に注目)
アリゾナ大学の衛星プロジェクトマネージャの Lewicki氏らの指摘によると、
このデータの中の CDS_Boot と、SEASIS_State の数値変化が 注目すべき箇所
のようです。 (全データは次に登録済み)

http://www.ne.jp/asahi/hamradio/je9pel/


-----
Date: Sat, 15 Apr 2000 19:41:45 +0900
From: "M. Wakita" [je9pel@jamsat.or.jp]
To: telemetry@seds.org
Subject: SEDSAT telemetry Apr 13,15

000413-JE9PEL.tlm with SGS20.EXE   http://uah.seds.org/projects/sedsat/

Month, Day, Year, Hour, Minute, Second,  CDS Boot, SEASIS State,
    4,  13, 2000,    1,     43,      2,         1,            0,
    4,  13, 2000,    1,     46,      1,         1,            0,
    4,  13, 2000,    3,     30,      1,         0,            1,
    4,  13, 2000,    3,     31,      1,         0,            1,

                   ....., UpDays, UpHours, UpMinutes, UpSeconds
                   .....,    001,      01,        46,        00
                   .....,    001,      01,        49,        00
                   .....,    000,      00,        19,        00
                   .....,    000,      00,        20,        00


-----
Date: Sat, 15 Apr 2000 07:20:30 PDT
From: "Jason Rupert" [jkrupert@hotmail.com]
To: je9pel@jamsat.or.jp
Subject: Re: SEDSAT telemetry Apr 13,15

Mineo,

Many thanks for the SEDSAT telemetry. We greatly appreciate your 
continuing efforts. Was the signal strong or weak? Our station is
still minus one TNC so we are dependent upon the kindness of other
amateur radio operators for telemetry.
Again thank you for your support.

Sincerely,
Jason Rupert


-----
Date: Sat, 15 Apr 2000 23:13:33 -0700
From: Chris Lewicki [chrisl@seds.org]
To: "M. Wakita" [je9pel@jamsat.or.jp]
CC: telemetry@seds.org,
    UA-SEDSAT [uasedsat@seds.org],
    SEDSAT [sedsat@seds.org]
Subject: Re: SEDSAT telemetry Apr 13,15

Hi Mineo,

Thanks for the data!  I hadn't seen SEDSAT data and was starting to
wonder if it had finally gave in, but your data shows otherwise!  
539 days (and maybe as many resets) and still going!

There are some interesting items in the April 13 data. I'm not the 
best to interpret them, but "CDS Boot" switches between 0 and 1 
(I think its usually 0).  The "SEASIS State" does the same.

From what I could quickly gather from a look at data from the 
beginning of the mission it looks like most of the temperatures,
voltages and currents are all mostly the same.

Anyway, thanks for the data and keep sending it when you get it.
I'd appreciate taking a look at a period of time since we haven't 
done that in a while.  It'd be nice to get an idea of how often its
rebooting, etc...

For those of you still interested in SEDSAT, the SEDSAT homepage has
moved to http://uah.seds.org/ -- However, the UAH folks are having 
network problems, so its not always accessible.

Christopher A. Lewicki  KC7NYV   626.230.6662
A Maintainer of SEDS.ORG
No project, no plan, just a graduate student and his thesis...


-----
Date: Tue, 18 Apr 2000 09:14:32 -0500
From: "Chris Bond" [Chris.Bond@oarcorp.com]
To: "'Chris Lewicki'" [chrisl@seds.org],
    "'M. Wakita'" [je9pel@jamsat.or.jp]
Cc: telemetry@seds.org,
    "'UA-SEDSAT'" [uasedsat@seds.org],
    "'SEDSAT'" [sedsat@seds.org]
Subject: RE: SEDSAT telemetry Apr 13,15

Chris, Mineo, et. al.,

  Sorry if anyone gets multiple copies of this... not sure who's on 
which list anymore...

  Just thought I'd toss my 2 cents in on interpreting the SEDSAT data.
First of all, I continue to be amazed that she's made it this long,
considering she was only built for a 1 year mission, and even that 
assumed some power management by the ground team.

  Now, about the SEASIS and CDS Boot flags... here's the interpretation
(This is represented in SGS20, also):

CDS Boot
0 - The last boot was a reset
1 - The last boot was due to a power cycle
2 - The last boot was the start of the mission

SEASIS Boot
0 - The SEASIS boot codes (From CDS) did not transfer properly
1 - The SEASIS boot codes were transfered by CDS, but CDS has not yet
    heard a response from SEASIS
2 - SEASIS booted normally
3 - SEASIS was not booted because CDS detected a reset or power cycle
    on last boot

So, we can expect CDS Boot to waffle between 0 and 1, depending on the
orbit conditions. We'll never see a 2, because I doubt the voltage will
ever be high enough on a power cycle for CDS to think it's the start of
a mission. For what it's worth to other satellite programs, this system
seems to work.

SEASIS boot should probably always be 3, because SEASIS is not booted 
on power cycles or resets.  SEASIS controls the cameras and filter
wheels, and without an uplink is fairly useless. I probably should have
anticipated the scenario of no uplink at all and thought of a way to
get at least a single picture down, but hindsight is 20/20, after all.

Finally, let me say congratulations and thank you to Mineo, for
continuing to send us data.

-Chris Bond


-----
Date: Tue, 18 Apr 2000 07:57:32 -0700
From: "Dennis Ray Wingo" [wingod@mailcity.com]
To: "'Chris Lewicki'" [chrisl@seds.org],
    "'M. Wakita'" [je9pel@jamsat.or.jp],
      Chris.Bond@oarcorp.com
Cc: telemetry@seds.org,
    "'UA-SEDSAT'" [uasedsat@seds.org],
    "'SEDSAT'" [sedsat@seds.org]
Subject: RE: SEDSAT telemetry Apr 13,15

Folks and Especially Mineo

Thanks again for sending in this data.  The core mission of SEDSAT
was to build the bird and get the engineering data that you folks 
are so kindly supplying.  I spoke with Dr. Charles Lundquist 
yesterday and there are some students who are trying to take this
data, interpret it, and present it at the Small Satellite conference
in Logan Utah in the late summer/fall.

SEDSAT 1 is a success, in spite of the receiver problems. The fact
that the bird is still working at all is amazing with all of the 100%
battery discharges. Also, the bird is going through 1180 km several
times a day which is the bottom of the radiation belts and is still
working.  This is far in excess what the statistical predictions were
for the radiation tolerance of the bird's integrated circuits, 
especially the analog chips.

Again, Mineo thank you for your valuable data that you are sending 
to us. Chris Bond/Lewicki a question.  Is this data being archived?
If not can I get access to the entire suite of data files so that I
can archive them on CD ROM.

Thanks!
Dennis Wingo
KD4ETA


-----
Date: Tue, 18 Apr 2000 12:42:41 -0700
From: "Chris Lewicki" [chrisl@seds.org]
To: wingod@mailcity.com,
  "'M. Wakita'" [je9pel@jamsat.or.jp],
    Chris.Bond@oarcorp.com
Cc: telemetry@seds.org,
  "'UA-SEDSAT'" [uasedsat@seds.org],
  "'SEDSAT'" [sedsat@seds.org]
Subject: Re: SEDSAT telemetry Apr 13,15

> Thanks again for sending in this data.  The core mission of SEDSAT
> was to build the bird and get the engineering data that you folks 
> are so kindly supplying.  I spoke with Dr. Charles Lundquist 
> yesterday and there are some students who are trying to take this
> data, interpret it, and present it at the Small Satellite conference
> in Logan Utah in the late summer/fall.

I would be happy to provide my SQL expertise in helping them get
at the information they're looking for (maybe I'd be interested 
in being a co-author!).  There's almost 20,000 lines of telemetry
in the database, spannign 18 months, and the globe, so there's a
pretty good data set there.

> Again, Mineo thank you for your valuable data that you are sending 
> to us. Chris Bond/Lewicki a question.  Is this data being archived?
> If not can I get access to the entire suite of data files so that I
> can archive them on CD ROM.

Yes -- I had been mainting the archive on SEDS.org until I handed
it back over to UAH for care and feeding, however, we haven't gotten
much data since then, so the UA Database is for the most part current.
Probably would just take me a few minutes to get it back into check,
the UAH server continues to be inaccessible.  All the data (including
many screen captures) is only 10MB, so its not that large of a data
volume.

--
Christopher A. Lewicki  KC7NYV     626.230.6662
A Maintainer of SEDS.ORG
No project, no plan, just a graduate student and his thesis...


-----
Date: Wed, 19 Apr 2000 06:55:15 -0700
To: telemetry@seds.org, "M. Wakita" [je9pel@jamsat.or.jp]
From: "Dennis Ray Wingo" [wingod@mailcity.com]
Cc: Chris.Bond@oarcorp.com, chrisl@seds.org, wingod@mailcity.com,
    jkrupert@hotmail.com
Subject: Re: SEDSAT telemetry 13,15

>Thank you to many informations on CDS and SEASIS Boot.
>What are the initials of these words 'CDS and SEASIS' ?
>And what is the work of CDS ?

Mineo

The Acronym CDS stands for the Command Data System.  This is the
system controller board and consists of an Intel 80C186 embedded
microprocessor running UAH developed tasks under Harold Price's SCOS
(Spacecraft Operating System).

The Acronym SEASIS (Pronounced SEA-SIS) stands for the SEDS Earth
Atmosphere and Space Imaging System. The Term SEDS stands for the
Students for the Exploration and Development of Space.

The CDS controls the power system and interfaces to the SEASIS Image
processor and the transponders.

Thanks again for your kind assistance.

Dennis


-----
Date: Wed, 19 Apr 2000 08:56:44 -0500
From: "Chris Bond" [Chris.Bond@oarcorp.com]
To: je9pel@jamsat.or.jp
Subject: RE: SEDSAT telemetry Apr 19

Mineo,

CDS = Command Data System, is a 16mhz, 80186c processor board with
32 megabytes RAM. It's primary responsibility is housekeeping
(keeping the batteries charged, reading temperatures, etc), and
communications. It's the system which sends the telemetry you've
been receieving.

SEASIS = SEDSAT Earth And Space Imaging System, is a SCC-100 
transputer based board, also with 32 megabytes RAM. It's responsible
for running the cameras, filter wheels (for the cameras), and the
magnetorquers (for stabilization and orientation control).

Unfortunately, the only code we had time to develop for it prior to
launch was to snap 80 images on start of mission... which have since
been lost due to power cycles. It was intended to upload programs to
it post-launch, but without an uplink this is impossible...

I'm always glad to answer questions....

-Chris Bond


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