AMSAT-NAAMSAT News Service

February  4, 2001

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Phase 3D/AO-40 Update

The month of February begins with command stations continuing their on-going recovery efforts of AMSAT OSCAR 40.

The AMSAT-DL web site is currently featuring the following statement:

AO-40 is currently like a ship on a sandbank at low-tide and in the fog. In the fog because of the high solar-angle (maximum of 77 degrees) where the onboard sun sensor(s) temporarily cannot see. At low-tide because the increasing solar-angle leads to less illumination (minimum of 23 percent) -- thus less energy is produced. AO-40 is stuck on a sandbank because the satellite cannot be maneuvered out of this situation very easily. The 'de-spinning' software routine may help. This program should work without sun sensor data and will use on-going measurements from the solar panels as an attitude indicator. Intensive work on this software is currently taking place.

Even if this routine doesn't work immediately, there is no reason to panic. The 'fog and low-tide' orbit will disappear with further seasonal Sun movements around the spacecraft. By April the sensors will see the Sun again and active attitude control can be restarted. After lowering the current spin rate, improving the Sun angle and repositioning AO-40's antennas, all further tests can be done.

Command stations G3RUH and W4SM have completed a long-term prediction of AO-40's new orbit. Even after last year's accident and the resulting decrease of perigee - AO-40's orbit will be fairly stable through this period.

ALON/ALAT is currently 248/-7, as last listed on the AMSAT-DL web page.

The AO-40 element set (number 30) is as follows:

Satellite:		AO-40
Catalog number: 	26609
Epoch time:		01027.28372779
Inclination:		5.8370 degrees
RA of node:		227.6036 degrees
Eccentricity:		0.8132970
Arg of perigee:		212.6216 degrees
Mean anomaly:		48.4646 degrees
Mean motion:		1.26933309 rev/day
Decay rate:		-7.0e-07 rev/day^2
Epoch rev:		111
Checksum:		274

Stay tuned to AMSAT News Service, the official source of AO-40 news and information.

[ANS thanks AMSAT-DL and AMSAT-NA for this information]

SunSat Operations Cease

AMSAT OSCAR 35, known the world over as SunSat, has ceased operation. Johann, ZR1CBC, first broke the unfortunate news on the AMSAT-NA bulletin board:

"Our last contact with SunSat was on January 19, 2001 at 15:22:37 UTC. Unfortunately, little hope remains after two weeks of recovery attempts. My thanks to all who shared in our fun, your feedback and continual encouragement made most of it happen. I hope to talk to you on AMSAT Oscar 40 soon."

73, ZR1CBC

Houston, Texas AMSAT Area Coordinator Bruce Paige, KK5DO, recorded the very first operational pass of SunSat over the North America - see http://www.amsatnet.com/so35.ram

The SunSat team released the following statement, dated February 1, 2001:

We regret to announce that the last communication with SunSat from our ground station at the Electronic Systems Laboratory at Stellenbosch University took place recently. We are certain, after having performed several tests since the last contact, that an irreversible, physical failure has occurred on the satellite. It is therefore unlikely that we will have any further contact with SunSat, apart from the occasional visual sighting by telescope!

The SunSat team reported that SO-35 was recently exposed to continuous sunlight for a period of five months due to orbital parameters. The orbit was determined by the requirements of the Danish Orsted satellite, on which the SunSat platform was based. SunSat was a secondary (and free) payload attached to the Orsted spaceframe.

When the satellite became exposed to the full sun period, the SunSat command team continuously re-oriented the satellite in an attempt to alleviate high operating temperatures and battery overcharging. The ground team realized that battery capacity was a problem and efforts to recondition the battery cells seemed to help at first, however, the satellite then suddenly failed.

Interestingly, the ground team does not believe battery failure was the cause of the shutdown. The team believes the failure resulted from multiple internal problems or a possible collision with an external object resulting in major physical damage. The SunSat web site did not contain any information as to if the Orsted platform also suffered an operational failure.

The SunSat team was (nevertheless) very satisfied with SunSat's achievements in orbit during the period of nearly 2 years since launch. Built by graduate students at Stellenbosch, SO-35 was launched on February 23, 1999, from Vandenberg Air Force Base in California aboard a Delta II rocket.

When it was operational the SunSat package included 1200 and 9600 baud digital store-and-forward capability, a voice 'parrot' repeater system and Mode B/J operation with two VHF and two UHF transmit-receive systems.

ANS would like to congratulate the SunSat team for their outstanding achievements with SO-35 and thanks all the amateur radio operators that were associated with the satellite.

[ANS thanks the SunSat command team and the ARRL for this information]

Best Fist Winners Announced

Amateur radio operators worldwide participated in AMSAT-NA's 29th annual Straight Key Night on OSCAR, held last January 1, 2001. In keeping with the friendly tradition of this event, participants were encouraged to nominate someone he or she worked for 'Best Fist'.

AMSAT-NA Executive Vice President Ray Soifer, W2RS, recently announced the Best Fist winners as:

Congratulations to these fine operators from ANS!

SKN is totally informal, the whole idea is just have fun operating Morse code with a straight hand key via any amateur radio satellite (including the moon, "OSCAR Zero").

The 30th SKN event is scheduled for the start of year 2002!

[ANS thanks AMSAT-NA Executive Vice President Ray Soifer, W2RS, for this information]

ANS in Brief

ANS news in brief this week includes the following:

Weekly Satellite Report

Link to the weekly report on satellite ...

All Satellites
ISS . Mir . RS-12 . RS-13 . RS-15 . AO-10 . UO-11 . UO-14 . AO-16 . DO-17 . WO-18 . LO-19 . FO-20 . UO-22 . KO-23 . KO-25 . IO-26 . AO-27 . FO-29 . TO-31 . GO-32 . SO-33 . PO-34 . SO-35 . UO-36 . AO-40 . SO-41 . SO-42


Please send any amateur satellite news or reports to the ANS Editors at ans-editor@amsat.org, or to ANS Editor Dan James, NN0DJ, at nn0dj@amsat.org.

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This week's AMSAT News Service bulletins were edited by AMSAT  News Service editor Dan James, NN0DJ.

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