Podcaster: Dr. Al Grauer
Title: Travelers in the Night Digest: Eps. Eps. 413 & 414: Fission Rocket & Enormous Visitor
Organization: Travelers in The Night
Link : Travelers in the Night ; @Nmcanopus
Description: Today’s 2 topics:
- NASA is looking at alternative means of rocket propulsion. Back in the 1950s NASA’s project Orion was a study to investigate propelling a rocket by a series of atomic bomb explosions behind the vehicle.
- 2017 UX5! When Carson Fuls first spotted this enormous 1,200 foot diameter space rock it was more than 30 million miles away traveling in our direction at 10.7 mi/s.
Bio: Dr. Al Grauer is currently an observing member of the Catalina Sky Survey Team at the University of Arizona. This group has discovered nearly half of the Earth approaching objects known to exist. He received a PhD in Physics in 1971 and has been an observational Astronomer for 43 years. He retired as a University Professor after 39 years of interacting with students. He has conducted research projects using telescopes in Arizona, Chile, Australia, Hawaii, Louisiana, and Georgia with funding from NSF and NASA.
He is noted as Co-discoverer of comet P/2010 TO20 Linear-Grauer, Discoverer of comet C/2009 U5 Grauer and has asteroid 18871 Grauer named for him.
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Transcript:
413 – Fission Rocket
To get an idea of the energy involved in a rocket launch, the NASA Saturn V, moon rocket, fully fueled on the launch pad contained the chemical energy of 2,000 pounds of TNT. This old technology could carry us to Mars and back on missions that would last years. To cut the mission time, the risks, and the mass of supplies required for such a prolonged space mission NASA is looking at alternative means of rocket propulsion. Back in the 1950s NASA’s project Orion was a study to investigate propelling a rocket by a series of atomic bomb explosions behind the vehicle. Now a safer and more gentle way of propelling a space craft with nuclear fission is being studied as the result of a NASA grant to BWX Technologies. The concept is to heat liquid hydrogen using a high temperature fission reactor furnace which would expel the gas at a high velocity producing the rocket’s thrust. The process would be about twice as efficient in terms of thrust per pound of fuel when compared to burning a hydrogen and oxygen mixture. Since it is unacceptable to release trace amounts of radioactivity in the rocket’s exhaust, engineers are investigating a technique developed by NASA in which the hydrogen exhaust is burned with oxygen to produce water which can be caught and decontaminated. Don’t expect to buy a round trip ticket on a high speed fission powered rocket any time soon. However, in the long run nuclear technology could revolutionize the exploration and colonization of our solar system.
414 – Enormous Visitor
Without additional data, the true nature of the rapidly northward moving point of light my Catalina Sky Survey teammate Carson Fuls had just discovered would have remained a mystery. Fortunately, this new object was tracked by telescopes in both Arizona and New Mexico. These data were used to calculate it’s orbit around the Sun, estimate it’s size, and give it the name 2017 UX5. When Carson first spotted this enormous 1,200 foot diameter space rock it was more than 30 million miles away traveling in our direction at 10.7 mi/s. It’s orbit and that of the Earth’s nearly intersect and at the closest point they are about two and one half times the Moon’s distance from us apart. An asteroid the size of 2017 UX5 impacts the Earth every 76,000 years or so. According to the impact calculator developed at Purdue University and the Imperial College of London if 2017 UK5 is made of porous rock and came in at an angle of 45 degrees, it would start to break into pieces at an altitude of 41 miles and upon reaching the surface would create a crater 2.2 miles in diameter and 5/8 of a mile deep in sedimentary rock. The results 20 miles away from impact would be that of a 6.4 Richter Scale magnitude Earth quake followed by 176 mph air wind blast which would blow down 90% of the trees and collapse wood frame buildings. Fortunately asteroid hunters have not discovered any object like Carson’s discovery with our number on it.
For Travelers in the Night this is Dr. Al Grauer.
End of podcast:
365 Days of Astronomy
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