From: jim rose [james.r.rose@jpl.nasa.gov]
Sent: Tuesday,
March 09, 2004 11:55 AM
To: mmelton@swales.com
Subject: RE:
GLAST Project RFA Response for your Review
Mark
My interpretation of
your response is that I misunderstood the presentation and the change had been
made to the design prior to CDR - so that my impression came from describing the
past; or that after the CDR the change was made. In either case, if the
condition that the instrument itself could get the S/C into a negative power
and/or thermal situation is not now present, then my issue is
resolved.
Jim
At 3/9/2004 11:30 AM, you wrote:
Jim,
Thanks for your
comment. We have updated our response in response to your comment.
Please review and let me know if this adequately addresses your
concern.
Mark
____________________________________________
Mark E. Melton
Systems
Engineer
Swales Aerospace
Bldg 12, Rm N210A
GSFC
(301) 286-7936
(V)
(301) 286-5717 (F)
- -----Original Message-----
- From: jim rose [mailto:james.r.rose@jpl.nasa.gov]
- Sent: Monday, February 23, 2004 3:02 PM
- To: mmelton@swales.com
- Cc: Steven Scott
- Subject: Re: GLAST Project RFA Response for your
Review
- Mark
- My concern was for a case where the instrument would respond to high
flux of Gamma rays with increased power consumption - and if the condition
persisted, would exceed safe temperature limits. The response seems to
indicate that this would not happen. I am not sure if I misunderstood
what was presented at the review, or if a change has been made. The
idea that the increased power consumption would occur due to enabling more
processors seems familiar (this is a long time after the review). The
implication of the response (below) is that the power consumption in NO
LONGER a function of the event rate, and that additional processors are NO
LONGER required - like a change was made. At any rate, if there is NO
on-board function which can autonomously increase the power consumption for
a duration such that the maximum temperature can be reached, and/or there
are adequate safeguards to detect and correct this situation if it could
occur, then my concern is satisfied. Unfortunately, the words in the
response did not clearly demonstrate that these conditions are
satisfied. I would like a further response to these conditions before
I "signed off" on the response.
- Jim
- "This architectural approach was not implemented. The power
consumption is not a function of the event rate. Note that the increased
power consumption was specified when there was a possibility of powering
additional processors to handle high event rates. Those additional
processors are not required."
- Jim,
- Attached is a response to one of the RFAs you
wrote at the GLAST LAT CDR. Mark Goans, the Code 300 Review chair,
has asked that all Project approved RFA responses be reviewed and approved
by the originators prior to official submittal to him.
- Please review the attached response and let me
know if it satisfactorily closes the RFA you generated. You can
provide your approval or comments back to me and I will distribute them to
the appropriate GLAST Project personnel.
- A response is attached for the following
RFA:
- GLAST LAT CDR # 33
- Thank you for your review and
response,
- Mark
- ____________________________________________
- Mark E. Melton
- Systems Engineer
- Swales Aerospace
- Bldg 12, Rm N210A
- GSFC
- (301) 286-7936 (V)
- (301) 286-5717 (F)
-