AMSAT-NA AMSAT News Service

September 15, 2002

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PCsat Will See Improved Eclipse Cycles

At present, NO-44 or PCsat, is working fine in the sun. When it comes out of eclipse, it takes about 10 minutes before it is strong enough to support digipeating. Right now in the northern hemisphere, its passes are occurring at night and early morning, so only the last 2 of the 7 passes a day are usable. The first pass is happening after 11 PM when the satellite has been in the dark for over 10 minutes and the batteries are just about out of power again.

But since these passes move earlier by 30 minutes a day, by the third week of September, PCsat will be usable again in the early evening and earlier and earlier over the next month. PCsat will enter full sun again in late September and be fully usable around the clock.

One aspect of satellite power systems, especially the ones that have power systems that can only operate in sun, is that as we on the surface of the earth rotate through a 24-hour day, the LEO satellites in 100-minute orbits essentially experience a 100-minute day. This translates into every HOUR of "your time" equals about 4 minutes of satellite time.

Thus, when you see a pass 3 hours after YOUR sunrise, this means the satellite (on this pass) has been in the sun 3*4 or 12 minutes. For PCsat, this is enough to charge its batteries to have enough PEAK current to handle a 2-watt packet burst. Similarly, 3 hours after sunset, PCsat has been running for about 12 minutes on battery power alone.

[ANS thanks Bob Bruninga WB4APR for the above information.]

AO-40 Update

Current ALON/ALAT ~ 45/7

ALAT is purposefully being moved up slightly in preparation for the larger increase in ALAT after 9/18.

The eclipse MB off period has been shifted from MA 60 to MA 110.

N  QST AMSAT AO-40  S2 Downlink   @=RUDAK OFF      2002-09-11
         MA      020   060   110   OFF@  216   240   020
         ---------7-----4-----1-----3-----5-----0-----7
         MB       |  *  |     |  *  |     |  *  |  *  |
         RUDAK    |     |     |     |  *  |     |     |
         V-Rx     |     |     |     |  *  |     |  *  |
         U-Rx     |  *  |  *  |  *  |     |  *  |     |
         Passband |     |     |  UL |     |  UL |     |

We have passed the longest eclipse duration and the eclipses will be rapidly decreasing in length over the next eight days.

Testing of the IHU-2 continues. Pauses and skipped telemetry blocks may be observed. IHU-2 has been left on longer for photos. If it occasionally crashes on side effect users may observe is that AO-40 is transmitting a steady bpsk carrier with no data. Sometimes it outputs gibberish.

As the IHU-1 should be functioning nominally, this is of no consequence to normal function and should be a quick fix as soon as a command station gets access and turns off or re-loads the IHU-2.

We are working to determine why the IHU-2 crashes and will be leaving it on quite a bit with variations in its software to turn caches on or off, wash the memory, etc., so this will probably happen multiple times in the future.

[ANS thanks Stacey Mills, W4SM for the above information.]

Space Station Over Seattle

Michael KC7QYR writes to let us know what is happening in the Pacific NW, specifically the "Greater Seattle Metropolitan Area" with regard to the ISS.

About three weeks ago a couple of us were discussing the ISS, and possible contact with same, on a local repeater. As the conversation progressed a few more people came into the discussion. Well, this went on for several evenings with further discussion and sighting reports. Each night the impromptu net grew as more and more hams joined in. The conversations began to progress from the visible sightings stage to tracking software, where to get it and the keps needed to keep current, and discussion of the old days of contacting Mir.

Now the conversations were getting interesting. Questions and answers flew every night, covering such things as AMSAT, NASA, ARISS, and the URLs where information could be found on the Internet. We were diligently listening to each pass that gave the slightest chance of a contact. And when possible some of us would meet on the repeater before and after each pass to cuss or discuss how good it was etc. Then in the evening every body would show up (again on the repeater) to report our findings and opinions to those that were unable to listen earlier.

Our group now stands at a dozen plus - old and new hams working toward a common goal. Interest has grown to include satellites in general with the emphasis still on the elusive ISS contact. People are scurrying around blowing the years old dust from their long forgotten TNC with renewed interest in packet radio. When in a conversation on a repeater or a QSO on HF, we find ourselves suddenly saying 73 and QSY to 145.800 FM. For some, that are at their place of employment, all work ceases upon the approach of a pass. This seems to have become an addiction with us although obsession may be more descriptive.

This loosely knit group has made three voice contacts with Valery. Two packet messages have been left on the PBBS, one of which has received a reply from the crew. ISS pass schedules are e-mailed to about 10 people every couple days. Many unproto packet QSOs have been made and confirmed, including NY state. Interest has been generated and initial contacts have been made with a local school to apply for a school contact through ARISS. At least two hams are collecting information needed to build a soundcard-to-radio interface and downloading software needed for packet and SSTV when it becomes available.

[ANS thanks Michael KC7QYR for the above information.]

The Better To Hear You With

A slight bit of discussion has taken place on the AMSAT-BB list in regards to what it may take to "hear" something from Mars once P5A is operational. Here is a report on what NASA is doing to make sure they are ready when six spacecraft besiege Mars in early 2004. The Parkes telescope in Canberra, Australia will come on-line to help NASA catch as much data from them as possible. The three tracking stations of NASA's Deep Space Network - near Canberra, Madrid in Spain and Goldstone in California, will be working flat out to monitor the Mars craft and several others.

NASA's Mars Global Surveyor and Mars Odyssey probes are already orbiting the planet. Six more missions will arrive in 2003-04. NASA's two robotic Mars Exploration Rovers will be looking for evidence of liquid water and analysing rocks and soil. Nozomi, Japan's first Mars probe, will be studying the upper atmosphere. And Europe's Mars Express will map surface and subsurface structures. It will drop a British lander, Beagle 2, which will search for signs of water and life.

The 64-meter Parkes telescope has tracked NASA spacecraft from the 1960s through to the 1990s. Its most prominent role was supporting the 1969 Apollo 11 Moon landing. Now NASA is spending $54 million to prepare the Deep Space Network for the coming "traffic jam".

NASA will provide payment to cover Parkes' tracking time, to build a sensitive new signal receiver, and to upgrade the telescope's surface. Some of the wire mesh panels in the outer part of the dish will be replaced with more even ones of perforated aluminum sheet, to enlarge the smooth part of dish's surface. This will make the dish more sensitive to signals at 8.4 GHz, the frequency at which the spacecraft will broadcast. The surface upgrade and the new receiver will double the amount of signal power the telescope can collect at this frequency.

[ANS thanks SpaceDaily for the above information.]

The Better To See You With

NASA announced on September 10 plans to build a next-generation successor to the Hubble Space Telescope in honor of James E. Webb, NASA's second administrator and the man who led NASA in the early days of the fledgling aerospace agency.

"It is fitting that Hubble's successor be named in honor of James Webb. Thanks to his efforts, we got our first glimpses at the dramatic landscapes of outer space," said NASA Administrator Sean O'Keefe. "He took our nation on its first voyages of exploration, turning our imagination into reality."

The James Webb Space Telescope is scheduled for launch in 2010 aboard an expendable launch vehicle. Unlike Hubble, space shuttle astronauts will not service the James Webb Space Telescope because it will be too far away. It will take about three months for the spacecraft to reach its destination, an orbit 940,000 miles or 1.5 million kilometers in space, called the second Lagrange point or L2, where the spacecraft is balanced between the gravity of the Sun and the Earth.

The James Webb Space Telescope will be able to look deeper into the universe than Hubble because of the increased light-collecting power of its larger mirror and the extraordinary sensitivity of its instruments to infrared light. Webb's primary mirror will be at least 20 feet in diameter, providing much more light gathering capability than Hubble's eight-foot primary mirror.

More information on James Webb Space Telescope is available on the Internet at http://www.ngst.nasa.gov

[ANS thanks NASA and SpaceDaily for the above information.]

New Pictures of ISS Ham Radio Operations at NASA Website

NASA released several images about amateur radio operations aboard ISS. Shown are Valery Korzun and Sergei Treschev are in the functional cargo block (FCB). The cosmonauts are using the WINPACK program running on the portable computer with the white patch from A.S.I. Agenzia Spaziale Italiana, for packet operations. The other computer is running a tracking program.

http://spaceflight.nasa.gov/gallery/images/station/crew-5/html/iss005e11300.html
http://spaceflight.nasa.gov/gallery/images/station/crew-5/html/iss005e11311.html
http://spaceflight.nasa.gov/gallery/images/station/crew-5/html/iss005e11317.html
http://spaceflight.nasa.gov/gallery/images/station/crew-5/html/iss005e11318.html

[ANS thanks NASA and Claudio IK1SLD for the above information.]

ANS in Brief

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Please send any amateur satellite news or reports to the ANS Editors at ans-editor@amsat.org

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This week's AMSAT News Service bulletins were edited by AMSAT  News Service Senior Editor JoAnne Maenpaa, WB9JEJ, wb9jej@amsat.org

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