SRIHARIKOTA, (Andhra Pradesh), July 18: In its maiden voyage, India's first homegrown private orbital rocket, Vikram-1 Test Flight-1 on Saturday successfully placed multiple technology demonstration payloads and postcards, including from Prime Minister Narendra Modi into a low earth orbit, with the PM calling the mission as a "defining moment" in the country's space journey.Follow the Daily Excelsior channel on WhatsApp  Dubbed 'Mission Aagaman' (arrival), it marks the entry of India's private space sector into the orbital launch market, spearheaded by Hyderabad-based Skyroot Aerospace.Advertisement The mission was a "grand success," the company said.Click here to watch videoThe four-stage, seven-storey-tall Vikram-1 rocket lifted…