Phoning home from the face of the Moon

Many of the maneuvers that open source Google Lunar X PRIZE contestant Team FREDNET‘s Moon-bound craft are to perform, if they succeed in sending one such into space, are too complicated for a computer to attempt unassisted by human control. Furthermore, the data collected by the spacecraft during its mission has to return in a timely manner to the Earth somehow.

Thus, Team FREDNET is looking at a number of options for establishing communication links with the team back on Earth to support the various stages of their mission. Most generously, the SETI Institute has offered all Google Lunar X PRIZE teams seven Earth days of free time on the institute’s Allen Telescope Array, located 290 miles northeast of San Francisco, California, for reception of data from the lunar surface.

Similarly, the Universal Space Network (USN) has offered the contestants a 50% discount on communication services (passes) for the spacecraft while in transit to the Moon and for 30 Earth days of operations on the lunar surface. The USN connects a total of 14 ground stations scattered over the surface of the Earth, making for good coverage any time of day for a lunar probe.

Apart from the services available to all contestants, Team FREDNET is also looking into communication options of their own. One such option is the venerable AMSAT organization, which has built and maintained amateur radio satellites for decades – much in the same civic spirit that is now driving Team FREDNET towards the Moon. AMSAT launched their first satellite, OSCAR, just a few years after the Soviet Union put the world’s first man-made satellite, Sputnik, into orbit.

Had Team FREDNET been able to meet the ITU‘s criteria for amateur radio communication, their spacecraft might have been able to depend solely on AMSAT’s satellites or ground station capabilities for radio links to the Earth. But, unfortunately, Team FREDNET can not satisfy ITU’s particular requirement for unencrypted communications – the Google Lunar X Prize rules specifically demand that teams transmit data from the Moon encrypted, in order to prevent unauthorized third-parties from intercepting and releasing data such as footage from the lunar surface prematurely.

Team FREDNET is still in contact with AMSAT, however, and are exploring other possibilities for collaboration:

Even though we can not use amateur radio frequencies for video downlink, due to restrictions on encryption, it is still an option for telecommand uplink and telemetry downlink,” said Alexandru Csete, leader of Team FREDNET’s Communication Systems group. “The question is what we can give back in return for using amateur radio frequencies?” Csete continues. “In my and many other’s opinion, we shouldn’t use amateur radio frequencies for this purpose just because it is a ‘cheap’ option. We must give something in return to the amateur radio community, for instance having a ham radio payload on board the lunar bus or lander. These are the areas we are currently investigating.”

The Jamesburg Earth Station in Cachagua Valley, California

The Jamesburg Earth Station in Cachagua Valley, California. (Source: http://www.jamesburgdish.org)

Another interesting offer has come forward from the Jamesburg Earth Station in Carmel Valley, California, a former COMSAT ground station that served for 40 years as the terrestrial link for geostationary INTELSAT satellites over the Pacific Ocean until it went out of service when AT&T replaced it’s capacity with fiber optic cables, and subsequently sold the station to a private investor.

Jamesburg was built by AT&T/COMSAT to handle telephone and television traffic between Asia, Micronesia, and North America, and already got a taste of the Moon when it enabled world-wide, live TV coverage distribution of the Apollo moon landings back in the early 1970’s.

With it’s very high gain antenna (approximately 60 dBi), Jamesburg affirmed its capabilities in lunar communications in 2007 when a group of radio amateurs revived the abandoned station for use in a “moon bouncing” experiment – transmitting a signal from Earth towards the Moon, letting it reflect (bounce) off the lunar surface, and picking it up back on Earth again.

According to Pat Barthelow, who leads the group of volunteers who currently manage the station for its owner, Jamesburg could be an option for any Google Lunar X Prize team, including Team FREDNET, if the interested team or teams can build a business offer or model to pay the costs involved.

With the Earth’s half a century use of satellite communications and radio astronomy, it is likely that there is many more ‘dishes’ out there that could support Team FREDNET in their quest to the Moon. We can only hope that the operators of these systems will also step forward and offer their assistance to Team FREDNET’s great initiative.

Advertisements

About this entry