[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[jamsat-news:961] * SpaceNews 02-Nov-98 *
SB NEWS @ AMSAT $SPC1102
* SpaceNews 02-Nov-98 *
MONDAY NOVEMBER 2, 1998
SpaceNews originates at KD2BD in Wall Township, New Jersey, USA. It
is published every week and is made available for non-commercial use.
* FUJI-OSCAR-29 NEWS *
The present JA mode operation of FUJI-OSCAR-29 will continue to investigate
the frequency of bit errors experienced by the on-board-computer. Reports
received from radio amateurs who observed that the value of CW TLM channnel
2A changed '00' are still appreciated. The position of channel 2A is the
fifth item after 'HI HI' in CW telemetry. The normal value is '00'.
Reports should be sent to: email@example.com.
FO-29 has entered a period of "full illumination" (always illuminated from
the Sun). This period will continue for 3 months, and end in December.
The satellite's on-board-computer has responded well to groundstation commands
while the satellite experienced eclipses in August. As a result, the command
team expects to resume digital transponder operation in December or early
next year. A period of Digitalker operation is also being considered.
[Info via Kazu Sakamoto, JJ1WTK]
* SEDSAT-1 TROUBLE *
Chris Lewicki reports that two of the primary "experiments" on board SEDSAT-1
are not performing to spec (solar panels and batteries), and sometime around
orbit 22, the spacecraft power cycled. Due to the power cycle, the 89
deployment images were lost, and due to the low power available, the
spacecraft is in a reduced state of operation.
This lack of telemetry was first noticed by John Melton from AMSAT-UK
on orbits 23-25 and Chris noticed it in Tucson on orbit 26 at 7:23 UTC
on 1998-Oct-26. On orbit 27, in Tucson, the SEDSAT team heard 5 telemetry
bursts, spaced at 1 minute apart, and they captured and decoded 3 of them,
indicating that the spacecraft had gone to zero power and cycled. The
satellite went quiet again about half way through the 16 minute pass,
and was quiet on orbit 28, indicating that it had gone into its "power
cycle" mode, whereby it notices that it is in extremely low power
conditions, and waits 10 hours until attempting to transmit again.
According to Chris, it was evident from the orbit 13-16 telemetry that the
spacecraft was in a "power negative" situation, but even under the worst
power generation circumstances, the satellite should not have cycled as
early as it did (nearly twice as fact as expected), which indicates that
the batteries are not storing their specified 8 A-h, and are likely
somewhere around half that capacity.
The solar panels are producing about as much power expected, but are slow
to react when exiting an eclipse period, so charging of the batteries doesn't
occur until at least 10 minutes into a daytime cycle.
Stations with 9600 baud satellite receive capability are asked to copy any
telemetry they receive from SEDSAT-1 on 437.910 MHz. and forward it to the
SEDSAT-1 team. A telemetry program for SEDSAT-1 is available at the SEDSAT
[Info via Chris A. Lewicki, KC7NYV]
* PHASE 3D NEWS *
Dan Schultz, N8FGV, reports that AMSAT's Phase 3D spacecraft has come one
step closer to being ready for space after it completed its thermal vacuum
test on the morning of 1998-October-29. After nearly a week under vacuum
and five cycles of alternately broiling and freezing the satellite, the
temperature was allowed to stabilize and the test chamber was brought up
to atmospheric pressure. On initial inspection, the satellite does not
appear to be any worse for its ordeal.
Before returning to Germany, Karl Meinzer, DJ4ZC, president of AMSAT-DL,
said that "The test has been extremely successful at this stage. We
identified a few things that need to be corrected- that was the purpose
of the test- to find things before the satellite is launched into space.
There were no major failures, no irreversible problems. It really is a
spacecraft now, it has its personality and its quirks- before it was just
a collection of parts."
A thermal vacuum test is an intense experience in which a lot of work must
be accomplished in a short period of time. AMSAT's engineering team will
be analyzing their test data over the next few weeks to fully understand
the spacecraft's performance during the test. This effort will ultimately
insure that Phase 3D will be a more reliable spacecraft when it finally
does reach orbit.
The RUDAK team reports that most of their test objectives have been
accomplished and that they consider the test to be a "resounding success".
RUDAK's command center was set up in their hotel room about one mile from
the Orbital Sciences facility, and all of their testing was accomplished
via line of sight radio links to and from the antennas on OSC's rooftop,
just as it will be done when P3D is in space. RUDAK successfully collected
data from the SCOPE camera, the RF monitor experiment, and the CEDEX cosmic
ray experiment during both the hot and the cold parts of the temperature
cycle. Improvements were made in the software which RUDAK will use for
experiment control, telemetry, and whole orbit data collection. Both of
the SCOPE cameras took pictures inside the vacuum chamber, these can be
seen at: http://www.jamsat.or.jp/scope/index_e.html
Steve Greene, KA1LM, and Eric Rosenberg, W3DQ, reported successful
reception of P3D's beacon signal from Northern Virginia and Washington, D.C.
Local AMSAT volunteers spent most of 1998-Oct-29 assisting the Phase 3D
team in packing several hundred items of equipment into dozens of boxes
and shipping containers for loading onto the rental truck, with all items
carefully inventoried for easier unpacking upon return to Orlando. The
satellite and a fair portion of the Orlando lab will be returning to
Florida this weekend.
In the coming months, the electronic modules will be potted to increase
their vibration resistance, wire bundles will be "finalized", antennas
and solar arrays will be attached, and the satellite will be buttoned
up for flight. It will return to Maryland in a few months for the
vibration test, which will verify its ability to survive the stress
of launch without falling apart and possibly damaging the rocket and
other payloads. This is a necessary and important certification that
will assure a potential launch agency that the satellite is fit for
flight and will not pose a threat to the launch vehicle or its primary
payload. The local Washington area AMSAT members are looking forward
to another chance to see and work on this remarkable satellite.
[Info via Dan Schultz, N8FGV]
* FEEDBACK/INPUT WELCOMED *
Comments and input for SpaceNews should be directed to the editor
(John, KD2BD) via any of the paths listed below:
WWW : http://www.njin.net/~magliaco/
PACKET : KD2BD @ KS4HR.NJ.USA.NA
INTERNET : firstname.lastname@example.org, email@example.com
SATELLITE : AMSAT-OSCAR-16, KITSAT-OSCAR-25
<<=- SpaceNews: The first amateur newsletter read in space! -=>>
<<=- Serving the planet (and beyond) since 1987 -=>>
-=-=-=-=-=-=-=-=-=-=-=-=- John A. Magliacane, KD2BD -=-=-=-=-=-=-=-=-=-=-=-=-
Internet : firstname.lastname@example.org | Voice : +1.732.224.2948
Satellite : AO-16, LO-19, KO-25 | Morse : -.- -.. ..--- -... -..
Packet : KD2BD @ KS4HR.NJ.USA.NA | WWW : http://www.njin.net/~magliaco/
Video : 426.250 MHz/439.250 MHz | FAX : +1.732.224.2060
-=-=-=-=-=-=-=-=- Linux: Because Failure is NOT an Option -=-=-=-=-=-=-=-=-=-
Via the ans mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe ans" to Majordomo@amsat.org