Based on the information present in the given passage, you need to write a correct answer to the given question. A correct answer is one that correctly and completely answers the question. Do not write answers that address the question partially or incorrectly. The correct answer must be contained in the given paragraph.
Q: Paragraph- Sent 1: Alien Planet starts out with an interstellar spacecraft named Von Braun , leaving Earth's orbit .
Sent 2: Traveling at 20 % the speed of light , it reaches Darwin IV in 42 years .
Sent 3: Upon reaching orbit , it deploys the Darwin Reconnaissance Orbiter , Which looks for potential landing sites for the probes .
Sent 4: The first probe , Balboa , explodes along with its lifting body transport during entry , because one of its wings failed to unfold .
Sent 5: Two backup probes , Leonardo da Vinci and Isaac Newton , successfully land on the planet , and learn much about its bizarre indigenous lifeforms , including an apparently sapient species .
Sent 6: The robotic probes sent out to research on Darwin IV are called Horus Probes .
Sent 7: Each Horus probe consists of an { { convert } } long inflatable , hydrogen-filled balloon , Which is covered with solar receptors , a computer ` brain ' , a ` head ' covered with sensors , and several smaller robots that can be sent to places too dangerous for the probes themselves .
Sent 8: The probes have a limited degree of artificial intelligence , very similar to the ` processing power ' of a 4-year-old .
Sent 9: All the real thinking is done by a supercomputer in the orbiting Von Braun .
Sent 10: The probes are programmed with different personalities ; Ike is more cautious , while Leo is the risk-taker .
Sent 11: The two probes are also equipped with a holographic message that will be projected to any sentient life found on Darwin .
Sent 12: After the two probes inflate their gas-bags , they encounter a voracious Arrowtongue and watch it pursue a Gyrosprinter . 
Question: Of all the features with Which the probes are equipped, Which is primarily for communication with alien life forms?.
A: 
The holographic projector.