Sorry, original blog on the issue of MIRV testing by stealth inadvertently deleted. This augmented replacement blog on the same topic.
The PSLV-C 20 launched February 25 carried a payload of seven satellites, which were injected into their separate precise orbits using the embedded System-on-Chip (SOC). The SOC, it may be recalled, was used on Agni-5 for guidance and terminal accuracy. The SOC on C-20 is the testing of MIRV capacity by stealth. And while India has had this capability to disperse payloads from PSLV — MIRV tech in situ since 2004-05, this is the first near military application of it. Hopefully, GOI will greensignal a proper MIRV-ed Agni-5 test soon. The only problem with the MIRVed military payloads will be that such miniaturisation of nuclear and thermonuclear weapons as has been obtained to fit the nose cone geometries of Agni missiles cannot be reliable, unless the level of miniaturisation achieved in the 1998 tests is deemed adequate. Because that’s the level at which the weapons designs have got frozen, and absent further testing, will be a liability. To iterate, assuming warheads miniaturised to a certain extent were actually tested in 1998, then that’s all the level of miniaturisation the country will have to be content with. No testing means that the 20 KT weapon has been sufficiently miniaturised to fit several of these in the nose cones of Agni IRBMs. The bigger, older, problem remains however: The fizzled S-1 means the thermonuclear weapon too is suspect. Marry the suspect miniaturised warhead with the suspect thermonuclear warheads and we get a suspect hydrogen deterrent assuming again there’s such a thing. In the event, the 20 KT fission warhead seems the standard weapon for all delivery sytems. So, why pretend to having fusion weapons in the 125-175 KT scale in the arsenal? After all, there’s only so much traction missile accuracy will get India against equally accurate Chinese missiles carrying the 1.1-3-3 megaton standard issue warhead on its IRBMS.