PCSat2 Installed on ISS During Space Walk:

The PCSat2 http://web.usna.navy.mil/~bruninga/pcsat2.html Amateur Radio package has been installed on the exterior of the International Space Station (ISS) as Materials International Space Station Experiment 5 (MISSE5).

Astronaut Soichi Noguchi, KD5TVP, unfolded the suitcase-like Passive Experiment Container (PEC) holding PCSat2 and other experiments mounted atop the ISS P6 truss structure August 3 during a space walk with Astronaut Steve Robinson. Noguchi deployed the "tape measure" antennas by pulling up a couple of Mylar strips that allowed the antennas to pop out. PCSat2 is not yet available to users.

Built by US Naval Academy students under the guidance of APRS guru Bob Bruninga, WB4APR, PCSat2 will operate in cooperation with the Amateur Radio on the International Space Station (ARISS) program http://www.rac.ca/ariss. It will provide a 10-meter PSK31 multi-user transponder, an FM voice repeater for possible use with ISS crew members and an AX.25 packet system for use as a UI digipeater and for telemetry, command, control.

Bruninga says the PSK31 transponder will not be turned on for general use until ground controllers have a better understanding of its thermal and power load. But it was enabled on August 5 over the US for a test, and the FM downlink (435.275 MHz) displayed the signal of a station transmitting on 29.402 MHz.

The NA1SS/RS0ISS ARISS equipment was powered down during the PCSat2 installation, but it was back up August 4, when STS-114 crew member Andy Thomas, KD5CHF/VK5MIR, made some terrestrial contacts while the ISS and Discovery were passing over his native Australia.

Bruninga says PCSat2 may be ready for use within a few days, but he asks that stations not attempt to use the system until it's been checked out and an announcement made. In the meantime, Bruninga has invited well-equipped ground stations to help capture early telemetry on the alternate downlink of 437.975 MHz. By week's end, some Earth stations were already reporting telemetry from PCSat2. Telemetry is at 1200 and 9600 baud. E-mail telemetry files to pc2@grc.nasa.gov. Bruninga says the UHF downlink is only 1 W and will require a gain antenna to copy.

Bruninga also has asked 1200 baud IGates or SATgates to monitor 437.975 MHz and feed the global APRS system live telemetry page http://www.pcsat2.info/PCSat2Web/RealTime.jsp.

PCSat2's primary downlink frequency is 435.275 MHz; the packet digipeater up and downlink frequency is 145.825 MHz. More information is on the USNA Web site http://www.ew.usna.edu/~bruninga/pec/pc2ops.html.

Source:

The ARRL Letter Vol. 24, No. 30 August 5, 2005

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