Amateur Radio call for assistance for UNITEC-1 Venus-bound satellite

On May 17 Japan's Space Agency JAXA plans to launch its Planet-C Venus Climate Orbiter 'AKATSUKI' mission to Venus.

Also aboard will be UNITEC-1, a 15 kg, 35cm cubed nano-satellite developed by twenty two universities and colleges of UNISEC (University Space Engineering Consortium).

UNITEC-1 be inserted into a Venus encounter trajectory and will become the world first university satellite which goes beyond Lunar orbit.

The main mission of UNITEC-1 is to perform technological experiments of on-board computers and test long-range, inter-planetary communication
using amateur radio frequencies:

Downlink Frequency: 5840.000MHz, band width 20MHz
Transmission Power: 4.8W/antenna, 9.6W total
Antenna: 2 Microstrip patch antennas
Modulation: AFSK/FM 1200bps during LEO flight
CW 1bps during Interplanetary flight

Due to development time and funding limitations UNITEC-1 does not have an attitude control system resulting in a tumbling motion in the inter-planetary trajectory. It will be impossible to maintain full-time earth pointing of the 5840 MHz patch antennas. Consequently, the 1 bps CW signal will detectable intermittently.

Tracking of the satellite should also be done using the same weak downlink signal. UNISEC cordially invites world-wide AMSAT and other amateur RF engineers to support the interplanetary team by receiving the very weak RF signal, decoding it and enabling tracking during the long journey to Venus.

In the future they hope to develop a world wide ground station network using the internet to relay your received
and decoded signals directly to the UNITEC-1 Mission Operation Center in Japan so that the real-time signal analysis can be performed.

In addition to the telemetry content of the beacon the direction of incoming RF signal and the amount of Doppler Shift will also be sent to the Operation Center to continually estimate the satellite trajectory (position and velocity). This trajectory data will be available to all of the world amateur ground stations fine tune their C-band antenna tracking.

As the Earth rotates, only the ground stations pointing toward UNITEC's direction can receive the signal. This challenge can be overcome by creating a global network of interplanetary-capable amateur radio earth stations.

Full information about this exciting mission and amateur radio challenge can be found on-line at: http://www.unisec.jp/unitec-1/en/top.html

Naomi Kurahara
UNITEC-1 project team

ANS