Putin vows to perfect mystery rocket after blast

Interesting news report from the BBC. Thank you

wonder how much fuel trump has given him

Basically the Russians are working on a nuclear powered pulse jet fitted onto a cruise missile that could hypothetically remain airborne for years and provide a second-strike capability. This technology has been worked on since the 60's and was abandoned due to the risks and challenges this propulsion method has.
I think it is a smokescreen, like nearly everything Russia says publicly is.
Russia has been announcing all sorts of gee-whiz weapons systems in the past few years - Armata tanks, Su-57s, a Nimitz-sized aircraft carrier (!) {yeah, right. Their existing carrier has a permanently escorting tugboat to tow it to port whenever it's engines break down}, hypersonic missiles, and this thing.
My theory is that the Russians are pulling the same thing on us as we did on them in the 80's with SDI (Star Wars anti-missile system), announce all of these weapons systems hoping we will try and develop our own programs at great expense in order to counter capabilities that don't exist.
The Russian's real capabilities are not in high tech platforms. They are in MILDEC, cyber warfare, espionage, and Special Warfare. They are quite good - I would argue better than us - at those things. But they recognize that platforms and firepower is what gets money in the US Defense industry, and they are prompting more spending in the wrong place.
Very, very smart on their part, if true.