These aircraft ( E-150,Ye-151,Ye-152s ) were developed for a heavy interceptor to carry out automatic interceptions. The later versions were testbeds for the Foxbat engine.
the MiG bureau had developed a range of large fighter aircraft starting with the swept wing I-3 series (a.k.a. I-380, I-410 and I-420), followed by the I-7 and the I-75. The requirement for supersonic interception speed and the ability to carry heavy avionic systems dictated the size; in comparison the contemporary MiG-21F (similar in layout), weighed 4,819 kg (10,624 lb) and was 15.76m (51 ft 8-1/2in) long, compared with 12,345 kg (27,215 lb) and 18.14m (59 ft 6in) respectively, for the Ye-150.
The initial missile-armed version, designated Ye-150, flew for the first time on 8 July 1960, after extensive ground checks of systems and a delay in delivery of a flightworthy engine. Flight testing progressed slowly, hampered by the very short life of the R-15 engine (barely sufficient for pre-flight ground checks and a single flight), as well as problems with aileron buffeting, brake parachute failure, and the engine accessory gearbox disintegrating. Manufacturer's flight tests, over 42 flights, revealed very high rates of climb, impressive maximum speed (Mach 2.65 at 19,100 m (62,700 ft) using less than full throttle), and a phenomenal service ceiling of at least 21,000 m (69,000 ft).
Installation of weapons systems was not carried out on the Ye-150 and it was not authorised for production, but development continued with the Ye-151 and Ye-152.
Great subject-----another one that looks like it is ready to fly off the table.
"You watch the world exploding every single night Dancing in the sun a newborn in the light, Brothers and their fathers joining hands and make a chain The shadow of the Wicker Man is rising up again......" ------"The Wicker Man", by Iron Maiden