What engine is this???

The picture is a little blurry, but looks like a 912UL 80 hp. 

The aircraft was an unmanned drone developed by a company for NASA for high altitude research.  Below is the description of that engine:

"Perseus B is powered by a Rotax 914 horizontally opposed four-cylinder piston engine mounted in the midfuselage area. An Aurora-developed three-stage, fourturbine turbocharger provides sea-level air pressure to the engine up to 60,000 feet. A two-blade, variable-pitch propeller mounted at the rear of the fuselage is linked to the engine by a driveshaft."

As a note, not mentioned, it also had a special ignition due to the fact that a normal one will not fire at those altitudes.  In addition it used a special intake system and ran LOx, liquid oxygen, to supply enough at such altitude.  There are some good articles from the time.  Just research Perseus B by Aurora.  

Cheers

Very interesting RW. First of all, how would you possibly know this!!   Intuitively, it would not seem that there would be enough exhaust energy to spin four turbochargers.  It looks like they wring every bit of kinetic energy out of the exhaust.  

Hi Jeff...simple answer, I am old and remember that project as it was so very unusual in the first place.  There was a competition put out for high altitude drones to attempt to replace manned aircraft.  (think hurricane hunters for example) The primary benefit from the programs turned out to be the bases for a lot of the current high altitude drones we see today.  While piston engines are far less money they did and still do act as a good test bed for sensors and instrumentation development.  Today for endurance and high altitude the go to expensive drones like the Global Hawk.  

You can find all the data and history on the NASA website.  Check out: 

NASA's Small High-. Altitude Science Aircraft (SHASA) program, which later evolved into the ERAST

The engine picture shown is I believe the test model that was run in a high altitude ground based chamber for the project, before the test flights. 

Cheers

Oddly enough, just last week, a Rotax engineer in Austria showed us the same engine but a different photograph and mentioned that it was  80,000 feet.