- From: James Cutler <jwc@Stanford.EDU>
- Date: Fri, 11 Feb 2000 09:41:05 -0800 (PST)
Opal Update: 2/11/2000
-----------------------
- Last night, fire commands were sent to Opal to launch
tube 4 containing JAK and STENSAT. Opal telemetry
did not confirm or deny the launch. Difficulities in
the connection resulted in corrupted data downloads.
During the AM pass today, we established a connection
and downloaded pico launch tube telemetry. Data
indicates SUCCESSFULL PICO LAUNCH! Two data sets
confirm this. Sorry for the long URLs.
ROS 11:
http://ssdl/opal/Operations/data/contacts/Feb_11_2000_06.39.46_PST/images/raw.1_
jak.oth.gif
Solar panel:
http://ssdl/opal/Operations/data/contacts/Feb_11_2000_06.39.46_PST/images/raw.1_
jak.cur.gif
ROS 11 is a reflective object sensor in tube 4 that
detects the pico. A high voltage indicates absence
of picos, a low indicates presence of picos. You'll
notice the plot starts high and they dips down.
This is a "feature" that we fully expected. Light from
the sun produces a reflection signal thus tricking our
sensor. The solar panel plot confirms that the pico
doors are in the sun at the time of the decreased signal.
The doors are on side 2. Solar panel 7 and 8 are top
and bottom respectively. 1 and 3 are on either side of
the doors.
We are confident this data indicates pico launch. We hve
not checked with sensors in Tube 1 and 2 that still house
picos. If we have time, we will.
Space Command is monitoring Opal and looking for picos.
We should have the data within several hours.
So, JAK and STENSAT are space-borne! Go get em guys.
- We are complete pleased at the contacts these past two
days. However, we are concerned about battery temperature
data. Our recent data indicates temperatures in the range
50-70C. This far exceeds their ratings and could result
in premature failure. We believe this is due to over-
charging of the batteries. We have turned on several Opal
payload systems to increase our consumption of power.
On the next pass, we will download more spacecraft telemetry
to that will aid us in characterizing Opal. Our recent
data sets are only several point measurements, rather
than continuous data measurements. We hope to download some
10 hour data sets tonight.
- The spurious tone is still periodically present on Opal's
transmissions. However, the transmissions are appearing
at hte appropriate times and lengths. This week we entered
a mode where the AX 25 beacon reduced its frequency from
6 times a minute to once a minute. This was due to a
decrease in battery voltage. The CPU no longer was alarmed
and therefore decreased the frequency of beacons. We lowered
the threshold alarm voltage to enable the increased beacon
frequency. This will help us in tracking and also in
dissipating power. Unfortunately this could mask the SCU
picos that are on the same frequency. We will attempt to
lower the frequency again when we launch the last two.
What's interesting is that this morning we were able to
connect and talk to Opal despite the presence of the spurious
tone. It seemed to be higher pitch than before. In fact,
the signals from Opal sounded quite bad but we decoded them
perfectly. Gotta like that big dish. Howevery, other
people were also able to decode packets this AM.
- Two more SCU picos are still housed in Opal. These are the
VLF lightning picos. We expect to launch them this PM or
tomorrow AM.
- Our time at the dish ends tomorrow evening. We will return
our equipment to Stanford an attempt to establish contact
from here. Several HAMs have been decoding our recent
contact sessions from the dish and have heard Opal clearly.
This gives us hope that our station will indeed be able
to comm with Opal. It's goign to take a lot of work though.
Too bad we can't use the dish on a continued basis.
- Thanks for your continued support and encouragement. I think
we're all amazed that the mission is progressing so well!
----
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