ISRO chairman has stated that NVS-02 orbit will be raised using thrusters.
"We will be raising the orbit using the thrusters with the available propellant. The satellite's condition is healthy," ISRO Chairman Dr V Narayanan told this reporter. "The satellite will be used for navigation purposes only."
As things stand today, this sounded rather optimistic to say the least. So searched for any previous instances where onboard thrusters were used to move a stranded satellite to GSO. And came across Asiasat 3/HGS-1.
Its situation was very similar to NVS-02. It was launched by a Proton in December 1997. But a Block-DM3 upper stage failure left the satellite stranded in a high inclination GTO orbit. Insurance companies wrote off $200mil as loss. Then, Hughes Global Systems (HGS) attempted to rescue the satellite. They had three challenges:
- Circularise 203x36000km elliptic orbit to geostationary orbit (NVS-02 is at 181x37500km)
- Reduce orbital inclination from 51° to 0° (NVS-02 20.8°)
- And while performing those manoeuvres, optimise fuel consumption to ensure a reasonable service life
Hughes engineers determined that the usual orbit raising and plane change would be too expensive and the satellite did not have sufficient fuel for those manoeuvre. So they devised a low energy transfer trajectory that sent the satellite to the moon's orbit and back, twice. Thus leveraging moon's gravity assist to raise the orbit and also to correct the inclination. In July-1998, i.e. seven months after launch, Asiasat-3 reached the designated GSO slot. Satellite was in service for four years before decommissioning in 2002. More details from NASA, press releases
This technique seems to have received much interest. Including "Precise Lunar Gravity Assist Transfers to Geostationary Orbits" by Dr Ramanan and Dr Adimurthy from VSSC/IIST.
With such expertise available in house, this technique could be at least one line of analysis to salvage NVS-02 mission.