[Isocops] Fwd: STF for Orbit 0118 - v002 done.

Mon Mar 7 18:39:22 EST 2011

FYI - I will be sending out the updated checklist prior to tomorrow's meeting. Stay tuned. 

Sheral, please hold off on generating the o118 ATS until after the call.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Chelle Reno
Austin Mission Consulting
(210) 478-7337 (c)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

________________________________

From: isocops-bounces at lists.sr.unh.edu on behalf of Reno, Michelle
Sent: Mon 3/7/2011 5:35 PM
To: Mark Tapley; IBEX Operator; isocops at lists.sr.unh.edu; IBEXOPS at gmail.com; wesley.sheral at orbital.com; perry.tim at orbital.com; ibexops at orbital.com
Subject: Re: [Isocops] Fwd: STF for Orbit 0118 - v002 done.

The sun precession maneuver will be at 14Re ascending.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Chelle Reno
Austin Mission Consulting
(210) 478-7337 (c)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~

________________________________

From: isocops-bounces at lists.sr.unh.edu on behalf of Mark Tapley
Sent: Mon 3/7/2011 5:22 PM
To: IBEX Operator; isocops at lists.sr.unh.edu; IBEXOPS at gmail.com; wesley.sheral at orbital.com; perry.tim at orbital.com; ibexops at orbital.com
Subject: [Isocops] Fwd: STF for Orbit 0118 - v002 done.

All,
        the v001.stf for orbit 118 has been
modified to include -Lo O-mode commands and to
scoot the descending time back by 12 hours,
producing:

IBEX_2011_079_19_43_v002.stf

        which is attached, and has been copied
from my directory on ena.unh.edu to:

/usr/local/IBEX/ops/SFTP/ibex/moc/Soc-Moc/stf/IBEX_2011_079_19_43_v002.stf
/usr/local/IBEX/raw/o0116/IBEX_2011_079_19_43_v002.stf
/usr/local/IBEX/work/ops/hvscistf/IBEX_2011_079_19_43_v002.stf

        it has also been placed on the SFTP server at:

/ibex/moc/Soc-Moc/stf/IBEX_2011_079_19_43_v002.stf

        Changes include:

1) scooted back descending commands to occur
before 2011-03-27T02:32:51.089Z, to prevent
sun-angle > 7.25° even with a 1° deadband on the
sun-pointing maneuver at the end of O117/begin
0118.

        Notes:

        Since the ATS has not been produced, I
don't know when the sun-pointing maneuver will
take place. I assumed it would be close to the 10
Re ascending time, which is:
2011-03-20T19:43:32.131Z per
IBEX_2011_Orbit117_v001.oef.

        **** ATTENTION **** If the sun-pointing
maneuver is not very close to or after this time,
this STF will need to be modified!!

        At this time, the sun vector will be R.A.
+359.737 Decl.  -0.103 (ibex-sun):

[tapley at ena ~]$ ibex_rotate -o -w ibex-sun -t 2011-03-20T19:43:32.131Z
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
  points axis  +1.000000,+0.000000,+0.000000
  towards ECI  +1.000000,+0.000000,+0.000000
  which is     R.A.   +0.000 Decl.  +0.000
  missing      R.A. +359.737 Decl.  -0.103 (ibex-sun)
  error is     R.A. +359.737 Decl.  +0.103
  for a total  0.283 deg

        If the maneuver points us perfectly at
the sun, the sun angle at the maneuver (should be
zero), ascending time (should be small) and
descending time will then be:

[tapley at ena ~]$ ibex_rotate -o -r +359.737 -d
-0.103 -w ibex-sun -t 2011-03-20T19:43:32.131Z
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
  points axis  +1.000000,+0.000000,+0.000000
  towards ECI  +0.999988,-0.004590,-0.001798
  which is     R.A. +359.737 Decl.  -0.103
  missing      R.A. +359.737 Decl.  -0.103 (ibex-sun)
  error is     R.A.   +0.000 Decl.  +0.000
  for a total  0.000 deg
[tapley at ena ~]$ ibex_rotate -o -r +359.737 -d
-0.103 -w ibex-sun -t 2011-03-20T23:39:51.926Z
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
  points axis  +1.000000,+0.000000,+0.000000
  towards ECI  +0.999988,-0.004590,-0.001798
  which is     R.A. +359.737 Decl.  -0.103
  missing      R.A. +359.895 Decl.  -0.034 (ibex-sun)
  error is     R.A.   +0.158 Decl.  +0.069
  for a total  0.172 deg
[tapley at ena ~]$ ibex_rotate -o -r +359.737 -d
-0.103 -w ibex-sun -t 2011-03-27T14:32:51.089Z
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
  points axis  +1.000000,+0.000000,+0.000000
  towards ECI  +0.999988,-0.004590,-0.001798
  which is     R.A. +359.737 Decl.  -0.103
  missing      R.A.   +5.903 Decl.  +2.530 (ibex-sun)
  error is     R.A. +353.834 Decl.  +2.633
  for a total  6.703 deg

        maneuver sun angle is zero as expected
and ascend sun angle is very small, but descend
puts the angle including a 1-degree deadband
outside the 7.25 degree safe limit. Trial and
error finds a descend time that would be safe:
2011-03-27T02:32:51.089Z producing a sun angle <
6.25 degrees:

[tapley at ena ~]$ ibex_rotate -o -r +359.737 -d
-0.103 -w ibex-sun -t 2011-03-27T02:32:51.089Z
Quaternion    +0.000000,+0.000000,+0.000000,+0.000000
  points axis  +1.000000,+0.000000,+0.000000
  towards ECI  +0.999988,-0.004590,-0.001798
  which is     R.A. +359.737 Decl.  -0.103
  missing      R.A.   +5.465 Decl.  +2.333 (ibex-sun)
  error is     R.A. +354.272 Decl.  +2.436
  for a total  6.223 deg

        The Descending macros are backed up by 12
hours to finish at approximately this time.

2) Commented out the Moon-in-FOV commands which
all take place after the new, earlier time for
the descending commands and are therefore not
needed.

        Please check this over very carefully,
since there are many hand-edits and mental time
arithmetic imbedded in here.

Sheral,
        I think this is ready to go for the Orbit
118 ATS, unless one of the isocops says otherwise.

All others,
        comments/corrections welcome.

--
                                                - Mark     210-379-4635
-----------------------------------------------------------------------
Large Asteroids headed toward planets
inhabited by beings that don't have
technology adequate to stop them:

                                Think of it as Evolution in Fast-Forward. 

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