ARISSat-1 re-entry prediction

(1) Download and Install '' to calculate the hight from the earth.

(2) Request the past orbital element of the satellite to NORADO.
    (Catalog Number of ARISSat-1 is 37772.)

    The text file as follows has been sent by an email of zip format several hours later.

      37772 1998-067CK  RADIOSCAF-B (KEDR)                               
      Launched: 1998-11-20 (324)           Start Date: 2011-08-04 (216)  
       Decayed:                             Stop Date: 2011-10-31 (304)  
    1 37772U 98067CK  11216.75158638  .00033717  00000-0  40433-3 0    12
    2 37772  51.6382 276.2984 0012892  43.5724 316.6246 15.60501122    76
    1 37772U 98067CK  11217.21207942  .00016502  00000-0  20151-3 0    26
    2 37772  51.6391 273.9819 0013128  45.8900  22.9677 15.60501782   146
    1 37772U 98067CK  11217.41309442  .00015548  00000-0  19021-3 0    30
    2 37772  51.6392 272.9690 0013085  46.7791  72.0942 15.60506459   173
    1 37772U 98067CK  11217.72992057  .00017961  00000-0  21855-3 0    44
    2 37772  51.6393 271.3741 0013139  48.1304  51.8180 15.60521963   222
    1 37772U 98067CK  11218.16773367  .00019609  00000-0  23780-3 0    55
    2 37772  51.6393 269.1699 0013099  49.9392 351.2537 15.60542636   290

(3) Input the value of 'Eccentricity' and 'Mean Motion' into the cells of 'satrange.xls'.
    And input 128 in 'MA' because it is approximately the circular orbit satellite.

(4) Following Distance is the height from the surface of the earth. 

As above, I calculated the current 'ARISSat-1 Height' using Excel software.
Then, I predicted the day of the re-entry into the earth's atmosphere of ARISSat-1.

Algorithm to calculate the hight of the satellite

Re: ARISSat-1 Re-entry Prediction

There was the report that an article 'Predictions of the Orbital Lifetime of ARISSat-1'
was placed in 'Amsat journal, March/April 2011' for my 'ARISSat-1 Re-entry Prediction'
a half year before the launching of ARISSat-1 ago. Actually I, JE9PEL think that there
is a little more life according to the calculation mentioned above, because the initial
height of the satellite was approximately 395km. Therefore I think the re-entry will be
about April 9, 2012. (Thanks the information of PDF to John, G7HIA)

ARISSat-1 Orbit Decay Prediction

Subject: ARISSat-1 (37772) decay
From: DeYoung James
To: amsat-bb
Date: Tue, 15 Nov 2011 09:29:31 -0800 (PST)

First, thank you Mineo for reading the AMSAT Journal and making several of
my papers available on your web site. My AMSAT Journal paper published in
the March/April 2011 issue is actually still fairly valid for the scenarios
shown in the paper. The solar flux has turned out to be somewhat higher than
was used/predicted in the paper. This has caused the atmospheric densities
to be higher which results in higher decay rates. When I wrote the paper I
had this nagging feeling that stopping the release height scenarios at 370
-km was not going to be high enough. We are very fortunate that the ISS was
boosted to such a height before release of ARISSat-1 and not after release!

There is a valuable lesson, I think, to be made with respect to predicting
satellite decay dates far into the future. The future state of the atmosphere,
i.e. the atmospheric density that the satellite will pass through is poorly
predictable in the long-term, say starting greater than a week or two into
the future. Predictions of satellite decay dates months in the future should
be evaluated with the understanding that your date of prediction errors may
be large. The errors are due to the future uncertainties of the orbital path
which grow quickly with time in a prediction. The atmospheric density is not
the only source of error. Your orbit model, the integrator, and the accounting
of the gravitational and drag forces among others will affect your results.

Predictions of satellite decay dates are not do-and-forget. The general
process is to make a prediction, get new measured observations of the height
in the future, and at some point re-do your prediction when the errors become
significant to you. With that all said here is my current prediction using
the same tools used in the AMSAT J. paper and produced as of 2011 November
13th. The decay of ARISSat-1 (37772) will happen nominally on 2012 January
30th with a 10% rule-of-thumb error allowance of 18 days around this date.
The errors may be larger than the rule-of-thumb indicates!

Jim, N8OQ


Subject: Re: ARISSat-1 (37772) decay
From: Mineo Wakita
To: amsat-bb
Date: Wed, 16 Nov 2011 20:36:44 +0900

Hello Jim, N8OQ.
Thanks for your very valuable reply.

Because it has the effect of the atmosphere density, I think that
the re-entry into the earth's atmosphere of ARISSat-1 will be
really earlier than April 9, 2012.

Thank you.
JE9PEL, Mineo Wakita

ARISSat-1 count down

31  Dec 2011, 19:16 JST, 238km
1st Jan 2012, 00:15 JST, 225km

ARISSat-1 New Year SSTV/VOICE, 2012
10:01-10:07 JST, 1st Jan 2012, Ele 22 WS-E-EN, 145.950MHz FM

ARISSat-1 Re-entry!

23:50-23:56 UTC, 3 Jan 2012, Ele 22 S-SE-E, 145.950MHz FM over Japan

01:22-01:27 UTC, 4 Jan 2012, Ele 7 W-WN-N, 145.950MHz FM over Japan

07:30-07:36 UTC, 4 Jan 2012, Ele 53 WN-E-ES, 145.950MHz FM over Japan
At last, the whole this path was long silence all the time.
It seems to re-entry in the atmosphere at past about 06:00 UTC, 4 Jan 2012.

ARISSat-1 The last official report [AMSAT-NA]


ARISSat-1 summary [AMSAT-UK]

ARISSat-1 voice messages

All audio files of the message by children of all the countries of the world
sent to by ARISSat-1 and the translated sentence were uploaded in SatBlog of
the DK3WN station. A Japanese message is introduced by the top. I can guess
that it would be hard to collect these messages. This is a laborious work.
Please hear all once. A password appears in the last of the message of each
country, but already I thinks this to be statute of limitations.

International Greetings
ARISSat-1 japanese

Sekai no minasan kon_nichi wa. Boku-tachi, watasi-tachi wa Iruma-si jidou sentaa
de musen ya tenmon no katsudou wo site imasu. Itsuno hi ka boku-tachi kodomo demo
kokusai-utyuu-suteisyon ni ikeru hi wo, tanosimi ni siteimasu. Ai-kotoba wa 'Kibou'.

Hello, all of you of the world. We are doing activity of radio and astronomy in
"Children center" in Iruma-City. The day when even we child can go to International
Space Station looks forward to coming sometime or other. The secret word is HOPE.

[thanks Mineo san, JE9PEL]

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