AMSAT-NAAMSAT News Service

April 15, 2001

Latest Bulletins
Last Week's Bulletins
2001 Bulletins
These Bulletins in plain text format
Subscribe to bulletins by e-mail
Submit your News for ANS


Phase 3D/AO-40 Update

April continues with recovery efforts concerning AO-40. The satellite appears to be healthy and reports indicate that very good telemetry has been received recently.

AMSAT-DL is reporting that the S-band beacon on AO-40 may not be transmitting continuously during each orbit. The AO-40 team received a report from Gunter, DF4PV, that he was suddenly losing the signal from the S-2 beacon transmitter. DF4PV reported the signal disappeared during a period where the satellite apparently entered an eclipse.

AMSAT-DL responded that the onboard IHU is running a software task to watch for critical situations, such as battery voltage. The IHU will turn the S-beacon off if the battery voltage drops to 26 volts This was the case recently due to a bad sun angle and a solar eclipse. The IHU automatically turned the beacon back on as these conditions ended.

This may continue for the next few orbits as well.

As predicted, AO-40 lost solar lock at the end of orbit 201 and the satellite was then officially in a hibernation state. The magnetorque system is off and will not be used until the satellite is in solar lock again. Although the SEU (sensor electronic unit) is not phase locked on the Sun, the Earth sensor continues to scan our planet.

Four pictures were recently taken during orbit 207. At the time the satellite's view was the Gulf of Mexico. In addition, the IHU-2 clock was checked and found to be correct. The spin rate was at 2.047 rpm.

In looking at the downloaded pictures, it appears the spacecraft spins about 14 degrees during camera exposure (picture distortion was minimal). The Earth's edge can be seen in three of the received images and the angular distance from the bore-sight indicates an attitude of ALON 128 - ALAT 14. This estimate agrees with the Earth sensor.

The AO-40 command team concludes that the camera and much of the IHU-2 unit is working correctly. The Earth sensor and camera mountings appear unchanged, and -- most importantly -- the team now has a firm idea on the attitude direction of the spacecraft.

73,
Peter DB2OS
for the AO-40 command team

[ANS thanks AMSAT-DL for this information]

ISS Packet System Active

The ARISS team reported to ANS that the packet system onboard Alpha has been activated. The have been several minor problems.

ARISS team members have been debugging issues with the packet module over the past few months. The team is fairly certain that the TNC's RAM battery backup died shortly after the equipment was commissioned. ARISS been waiting for the Expedition crews to connect a laptop to the packet module to check out the system and re-install the packet parameters, including a callsign. To date, this has not happened due to the high workload the crews have been faced with. The bottom line is it appears that the packet system is alive and working well (and able to support APRS) but is operating without the parameters installed prior to flight.

The ARISS team suggests those operators who are using the ISS packet system review the packet information found on the ARISS web site at http://ariss.gsfc.nasa.gov/

The page has great pictures and written descriptions of the amateur radio equipment on-board ISS.

The most common question the team has received recently is why can't we change the NOCALL to the ISS callsign? The ARISS group would love to do this. However, as stated above, the battery in the TNC has died and all the parameters, including the callsign, were then erased from the TNC RAM.

The ARISS team plan is to install the callsign when the current crew has the time to connect a computer to the packet equipment and run a program to correct the default settings. Both the Expedition-1 and Expedition-2 crews have not had the time to accomplish this task.

Also asked was what happened to the Cosmonautics Day voice operations?

The only place the team heard that voice operations occurred during the Cosmonautics Day event was in Russia. The crew had the times of the contacts on their daily timeline but must have been too busy to reach for the radio. The ARISS team will continue to ask the crew to do random voice contacts whenever possible.

The ARISS team is asking amateur radio satellite operators to be patient. The ARISS volunteers worked very hard to bring the initial hardware to fruition. From an operations standpoint, it will take a while before things start to settle out on ISS.

[ANS thanks the ARISS team for this information]

School Contacts Completed

Astronauts onboard ISS Alpha completed three school contacts recently.

The Vicksburg High School in Vicksburg, Mississippi enjoyed a contact with astronaut Susan Helms, KC7NHZ. Susan answered 18 questions during a horizon-to-horizon pass telebridged through the Sacred Hearts Academy station in Honolulu.

Youngsters at the Woodford County Middle School in Versailles, Kentucky, also talked with the International Space Station recently, this time with astronaut Jim Voss, using the station's NA1SS callsign. Voss' first outing on amateur radio from space was telebridged via a southern hemisphere pass under the direction of Tony Hutchison, VK5ZAI, in Australia.

A successful contact was also completed between the Admiral Moorer Middle School and the ISS crew. The contact originated from the NASA Goddard Ground Station, NN1SS, located in  Greenbelt, Maryland. The contact took place on April 16th.

[ANS thanks the ARISS team and the ARRL 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 . 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.

Return to top


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

AMSAT Top