Among the 28 satellites to be launched by ISRO ’s PSLV, would be a satellite AISAT, which was designed and fabricated by Exseed Space, a company which has base in Hyderabad and Mumbai.
Exseed Space, the private satellite manufacturer, built the satellite christened AISAT, in a record time of six days for AMSAT INDIA an organization for the Indian amateur radio satellite programme. This experimental radio payload is an Automatic Packet Reporting System (APRS) – also called a digipeater that can be used for real time digital communication globally.
The importance of PSLV launch would be the initiative to check the space debris, an increasing problem engaging the attention of space scientists all over. Whenever a rocket carrying satellites is launched, the three stage rockets would jettison and return to earth, while the final stage one would typically become space debris, orbiting earth for a long time till it eventually burns out on re-entry.
To check this space debris problem, ISRO came up with an innovative solution. The fourth stage rocket could itself be used as an orbiting platform with payloads attached directly to it.
So, while all satellites have solar panels, power sources and antenna of their own. AISAT, in a world-first, has none of the above systems.
It uses a shared source of power provided from solar panels on the fourth stage platform and an antenna system provided on the platform by ISRO. This approach makes the payload smaller, lighter and much less expensive to develop a payload. As a result of this simplification, AISAT was built from start to finish in a record time of six working days by Exseed Space.
Typically, over half the mass and half the volume of a satellite is taken up by the solar panels and antenna systems and this innovation of using the rocket’s solar panels and antenna brought down the satellite build cost dramatically.
This experimental radio payload on the fourth stage platform is APRS, an amateur radio based system for real time digital communications using a 1200 baud data rate. APRS data are typically transmitted on a single frequency and repeated locally by area relay stations for widespread dissemination on earth. In addition, all such data are typically sourced into the APRS Internet System via amateur radio satellite gateway stations located all over the world and distributed globally for ubiquitous and immediate access. APRS digipeater payloads in space, like the one to be launched on April 1, work like terrestrial APRS digipeaters, but with a much larger global footprint.
The frequency used by this payload will be 145.825 MHz in line with other Amateur Radio 1200 bps APRS satellites and the path is via AISAT and also via ARISS (Amateur Radio on International Space Station). The APRS payload will be powered on at 12:29 IST or 06:59 UTC on April 1, 2019 approximately over 70N Lon and 65E Lat (around Sweden, Norway, Denmark, Finland, Poland, Moscow).
AMSAT INDIA and Exseed Space welcomed the amateur radio fraternity around these countries to report the first signals and to make full use of the payload. Radio Hams worldwide were also requested to use the payload actively and for satellite gateways to feed APRS traffic.
The payload was realized in record time – just six working days – by the Exseed Space team headed by Ashhar Farhan, VU2ESE in Hyderabad.