[Isocops] Hawaii 21 March 1710

[Ryan Tyler]

Chelle,

1&2 and 3&4 are the pairs for precession maneuvers, but 1&4 are the pair
for spin-up and 2&3 are the pair for spin-down. So if 1 and 4 have the same
number of pulses then the precession probably took the same number of
pulses from each precession thruster pair (since 2 and 3 show the same
number) and the additional pulses on 1 and 4 would then be for spin-down,
and the spin rate reading from the accel (ignoring the star tracker due to
the outage) should have decresed from, say, 4.2 to 4.14 rpm.

You can add the number of pulses from thrusters 2 and 3 (dividing the total
on-time for 2 and 3 by 16 to get the number of pulses) to get the total
number of pulse pairs used for spin axis precession. That number should be
somewhere in the low-to-mid 50's, I would expect.

Ryan


|------------>
| From:      |
|------------>
  >--------------------------------------------------------------------------------------------------------------------------------------------------|
  |"Reno, Michelle" <mreno at swri.edu>                                                                                                                 |
  >--------------------------------------------------------------------------------------------------------------------------------------------------|
|------------>
| To:        |
|------------>
  >--------------------------------------------------------------------------------------------------------------------------------------------------|
  |"Tim Perry" <Perry.Tim at orbital.com>, <IBEX.fdg at applieddefense.com>, <ibexops at gmail.com>, "John Cavallo" <Cavallo.John at orbital.com>, "Ed Fleming"  |
  |<Fleming.Ed at orbital.com>, "Thomas Regiec" <Regiec.Thomas at orbital.com>, "Robert Lockwood" <Lockwood.Robert at orbital.com>, "Bret Hautamaki"          |
  |<Hautamaki.Bret at orbital.com>, <isocops at lists.sr.unh.edu>, "Ryan Tyler" <Tyler.Ryan at orbital.com>                                                   |
  >--------------------------------------------------------------------------------------------------------------------------------------------------|
|------------>
| Date:      |
|------------>
  >--------------------------------------------------------------------------------------------------------------------------------------------------|
  |03/21/2011 03:29 PM                                                                                                                               |
  >--------------------------------------------------------------------------------------------------------------------------------------------------|
|------------>
| Subject:   |
|------------>
  >--------------------------------------------------------------------------------------------------------------------------------------------------|
  |RE: [Isocops] Hawaii 21 March 1710                                                                                                                |
  >--------------------------------------------------------------------------------------------------------------------------------------------------|





Ryan, Bret -

The number of pulses cited here are very different than the expected values
for the maneuver I cited in the checklist. I got my numbers from the
monthly trending. What are reasonable ranges to expect for a sun pointing
maneuver due to an outage at perigee (~8.5 degree maneuver)?

Can you explain what we should be looking for in the thruster pulses to
verify the maneuver magnitude roughly? In an earlier email it was
designated that 1&2 were a pair and 3&4 were a pair, but 2&3 have the same
number of pulses as do 1&4. Are we looking for the total number of pulses,
or the difference between the number of pulses in each pair?

Thanks,
Chelle


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

From: isocops-bounces at lists.sr.unh.edu on behalf of Tim Perry
Sent: Mon 3/21/2011 1:27 PM
To: IBEX.fdg at applieddefense.com; ibexops at gmail.com; John Cavallo; Ed
Fleming; Thomas Regiec; Robert Lockwood; Bret Hautamaki;
isocops at lists.sr.unh.edu; Ryan Tyler
Subject: [Isocops] Hawaii 21 March 1710




All,
   The Hawaii support was failed due to a poor signal quality.  The Eb/No
ranged from 1 to 17 db. Spacecraft looked nominal and the maneuver was
successful.
Eb/No: @ 1710  2k    3 to 14 db
               @ 1715  2k    1 to 17 db
               @  1732 2k    1 to 12 db
USN PR 10,000
Razor Issue I100-450   Intermittent data Hawaii 21 Mar 11 1710



(Embedded image moved to file: pic05436.gif)

Timothy E. Perry
IBEX, GEMS Mission Ops Lead
Orbital Sciences Corp
Space Systems Group
Office: (703) 406-5976
Cell: (301) 606-1430
perry.tim at orbital.com


-----------------------------------------
Notice:  This e-mail is intended solely for use of the individual
or entity to which it is addressed and may contain information that
is proprietary, privileged and exempt from disclosure under
applicable law.  If the reader is not the intended recipient or
agent responsible for delivering the message to the intended
recipient, you are hereby notified that any dissemination,
distribution or copying of this communication is strictly
prohibited.  This communication may also contain data subject to
U.S. export laws.  If so, that data subject to the International
Traffic in Arms Regulation cannot be disseminated, distributed or
copied to foreign nationals, residing in the U.S. or abroad, absent
the express prior approval of the U.S. Department of State.   If
you have received this communication in error, please notify the
sender by reply e-mail and destroy the e-mail message and any
physical copies made of the communication.  Thank you.