AMSAT-NAAMSAT News Service

March 4, 2001

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Phase 3D/AO-40 Update

The month of March begins with good news about AMSAT-OSCAR 40.

The ARRL is reporting the following in the current ARRL Letter:

The sun began triggering AO-40's sun sensor as the satellite emerged from Earth's shadow on orbit 147. The news has boosted ground controllers' optimism that they might be able to regain control over the satellite's spin rate and attitude sooner than had been predicted.

AMSAT-DL's Peter Guelzow, DB2OS, said this past week that as soon as the sensor unit delivers good sensor data, controllers will be able to reduce AO-40's spin and make it easier to adjust attitude. "This also will lead to an improvement in reception of the S-Band telemetry," he said.

For the past few weeks, AO-40 has remained in a semi-hibernation state, because the satellite's high angle has prevented the sensor from seeing sunlight. Controllers had planned to work around the sensor issue by using a software routine.

Once ground controllers can get accurate AO-40 attitude data, they should be able to correctly aim AO-40's high-gain antennas for optimal reception on Earth. Ground controllers have been relying on telemetry from AO-40's S-band downlink -- but they are holding out hope that at least some of the satellite's other transmitters will still function.

The next major step will be to bring AO-40 into an orientation where ground controllers can fire the onboard arcjet thruster -- using only gaseous ammonia and no electrical power. The test firing will allow checking out the guidance electronics and the arcjet valves.

Guelzow said plans call for optimizing the current orbit with a live arcjet firing. He said that several independent analyses -- including one done by the French space agency, CNES -- confirm that the current orbit will be stable for many years, longer than the spacecraft's anticipated lifetime.
(end)

The AMSAT-DL web site is reporting the following:

Determination of AO-40's actual attitude is under progress. The YACE camera and IHU-2 have been turned on by ground controllers in order to receive additional attitude information when AO-40 is close to Earth (at perigee). The first highly compressed images showing parts of the Earth's surface have already been downloaded as this edition of ANS is broadcast.

AO-40's orbital parameters (number 44) are as follows:

Satellite: 		AO-40
Catalog number: 	26609
Epoch time:      	01060.32118714
Inclination:        	5.5180 deg
RA of node:       	218.3353 deg
Eccentricity:    	0.8134782
Arg of perigee:   	228.5693 deg
Mean anomaly:      	26.7905 deg
Mean motion:    	1.26955381 rev/day
Decay rate:        	9.0e-08 rev/day^2
Epoch rev:             	153
Checksum:		280

When last listed, AO-40 ALON/ALAT was 226/-7.

Moe Wheatley, AE4JY, has released Version 1.0 of AO40Rcv. More information is available at http://www.qsl.net/ae4jy/ao40rcv.htm

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

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

AMSAT-NA Board of Directors Meeting

The Board of Directors of AMSAT-NA met February 24-25, 2001 in Orlando, Florida to consider a number of items, specifically the format and nature of the next AMSAT satellite project(s).

During the meeting it was recognized that it will be some time before a full evaluation of AO-40 will be completed and that all of the designed functions of that satellite may not be available. It was also recognized that it takes several years from initial concept to launch for any new satellite project, and that the year 2001 is the right time to start the planning and design process for the next series of satellites.

Present during these discussions were several members of the AMSAT-NA project committee, who made proposals to the Directors for their consideration. These proposals were made based on two guiding principles:

  1. the input from AMSAT membership about the type of spacecraft, frequencies and operating requirements, and
  2. the desire of the AMSAT technical membership to keep advancing the state-of-the-art and providing new solutions for improving satellite communications.

Accordingly, the Board of Directors approved the following three projects.

First, a new satellite to be placed into a geostationary transfer orbit. The proposed satellite project would feature communications at 2 meters, 70 centimeters, 1.2, 2.4, and 5.4 GHz, with actual uplink/downlink frequencies to be determined. The satellite would weigh a maximum of 100 kg in mass and would have a power consumption of about 100 watts. Stabilization would be provided by spinning the spacecraft.

Second, the Directors approved the idea of designing, building and testing a new Internal Housekeeping Unit (IHU) for use in future AMSAT satellites. The existing design, although very stable, uses components which are very hard to find. A new unit design would use improved techniques and more readily available components.

Third, the Board approved design, construction and demonstration of a new mode using digital modulation techniques. This would improve communications under very poor conditions or, alternatively, permit the use of lower power and/or simple antennas.

It is anticipated that both the second and third projects would be ready to be a part of the main satellite project, with both a digital modulation system along with traditional SSB/CW modulation techniques.

The Board of Directors also approved (in principle) a draft report from the AMSAT strategy committee, with a full report to follow at a later date. Finally, discussion took place on a proposed new development program which will be initiated during 2001 and aimed toward the involvement of AMSAT corporate sponsors.

Stay tuned to ANS for more information on these exciting projects!

[ANS thanks AMSAT-NA President Robin Haighton, VE3FRH, for this information]

A New Crew for Space Station Alpha

The ARRL is reporting that it's almost time for a crew change aboard ISS Alpha, and two hams are among the new crew members. Relieving the current ISS crew will be the Expedition 2 crew of Commander Yuri Usachev, UA9AD/R3MIR, and astronauts Susan Helms, KC7NHZ, and Jim Voss.

The new crew is scheduled to head to the station on March 8th aboard space shuttle Discovery.

The current Space Station Alpha Commander, astronaut William Shepherd, KD5GSL, recently completed another successful school contact, this time with the Polynesian Voyaging Society. Five high school students from Hawaii and one from American Samoa got a chance to talk with Shepard aboard Alpha. The six-minute contact took place March 1st as part of the Amateur Radio on the International Space
Station program.

[ANS thanks the ARRL and ARISS 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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