Your assertion is that RQ-170 can do what X47-B can do with upgraded software. Prove it.
And? Why different engines?
I feel like I am arguing with a FOOL here.
What is autonomy?
Autonomy is commonly defined as the ability to make decisions without human intervention. To that end, the goal of autonomy is to teach machines to be "smart" and act more like humans.
X47-B raises the bar in this regard in comparison to other drones such as RQ-170 and RQ-4.
I have already provided you reasonable hint which you FAILED to grasp:
According to Kellenberger, "the capacity to discriminate" in warfare is a requirement of international humanitarian law. In the case of advanced drones, that capacity will "depend entirely on the quality and variety of sensors and programming" employed as opposed to individuals, Kellenberger says. The ICRC is addressing the issue as it relates to the Geneva Conventions. Drones now account for 7,500 aircraft in the military and one-third of all military aircraft today, the L.A. Times reported Thursday. Drone platforms represent potential cost and combat benefits. There is currently no plan to allow the X-47B to autonomously make decisions about killing enemy combatants. But that may change. In the Air Force's report (PDF), the Air Force states that "authorizing a machine to make lethal combat decisions is contingent upon political and military leaders resolving legal and ethical questions."
X47-B have greater variety of onboard sensors in comparison to RQ-170 and RQ-4 drones, as pointed out by me earlier:
Your silly argument is that these sensors have nothing to do with autonomous capabilities. Do you work in Northman? Do you know that how these technologies are being put to use?
Now what is a Robot?
Robots are physical agents that perform tasks by manipulating the physical world. They are equipped with sensors to perceive their environment and effectors to assert physical forces on it.
And you assume that F-22 designers do not know this?
To apply the complex system of paints and coatings necessary to meet the F-22's stringent radar cross section (RCS) requirements takes not only state-of-the-art equipment and hands-on technicians, but also a wide-ranging support system. A new type of paint, or topcoat, increases the F-22 Raptor's stealthiness by reducing its vulnerability to infrared threats. To meet F-22 requirements, Boeing developed the topcoat to protect the aircraft against a broad range of wavelengths. The new paint replaces conventional topcoats, performing all the required environmentally protective functions while also reducing the aircraft's vulnerability to detection.