New Delhi: ISRO is dispatching its first interplanetary mission to Venus with the purpose of studying the thick and toxic atmosphere, the shrouded subsurface,
and even the subsurface. ISRO had previously revealed that 19 payloads are packed on the mission. Staff scientist at the Space Applications Centre Sriram Saran Bhiravarasu revealed additional details of two instruments on board the mission, the S-Band Synthetic Aperture Radar for Venus mission (VSAR) and the Venus Advanced Radar for Topside Ionosphere and Subsurface Sounding (VARTISS), at the Venus Exploration Analysis Group (VEXAG) conference 2025 in New York organised by the Lunar and Planetary Institute.
The SAR instrument on board the Shukrayaan mission will allow for one-to-one comparisons with the SAR instrument on the Magellan probe by NASA that investigated the volcanic and tectonic features on Venus between 1990 and 1994. The ESA’s EnVision and NASA’s VERITAS missions are headed to Venus in 2031 and 2032, but ISRO will get there before then. The instrument will investigate the volcanic activity on Venus, as well as surface changes due to various geological processes. “We will be studying the resurfacing history by studying the impact craters in detail, regarding their modification or partially filled status,” Sriram said.
The Subsurface Sounder
The VARTISS instrument has two modes, one to probe the sounder, and another to probe the subsurface. The electronics is the same for both the modes, with a different antenna for each. The subsurface sounder itself has a low penetration and high penetration mode. Very little is known about the remote interior of Venus. The high penetration mode can reach a depth of up to one kilometre, and this instrument could be the first to provide a clear picture of the Venusian subsurface. The instrument can be used to identify active volcanic regions and hotspots, as well as ancient impact craters buried over time. The Shukrayaan mission to Venus is slotted for launch no sooner than the first quarter of 2028.
