Titan: Another special neighbor

This week’s mapping by Cassini of mountains on Titan brings back into focus another intriguing member of our solar system.

Cassini has found what is believed to be the highest mountain on Titan, a 10,948 peak near the equator.

Titan is bigger than Mercury and smaller than Mars. It is not a hospitable place. The surface temperature is about minus 280 degrees Fahrenheit and the air pressure is approximately 22 pounds per square inch compared with roughly 15 psi on earth. Titan’s gravity is slightly less than that of the Moon.

Yet NASA has described Titan as “ . . . one of the most Earth like worlds we have found to date.” The reasons lie in the unique combination of Titan’s composition, its distance from the Sun and its place in the orbit of Saturn.
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Einstein’s formula for a new propulsion system: Energy = Money x (Commitment from NASA)2

One of the biggest obstacles to space exploration is the lack of a propulsion system which will allow us to reach a destination in a meaningful period of time and return.

The New Horizons one way mission took ten years to get to Pluto. Planned missions to the moons of Jupiter and Saturn will take five to ten years to reach their objectives. A round trip to Mars could take three years depending on the length of time spent on the surface.

Testifying before the House Space Subcommittee on Thursday March 17 2016 NASA Administrator Charles Bolden had this answer when asked about the need for “game changing” propulsion:

“We are on a journey to Mars and most people believe that in the end nuclear thermal propulsion will probably be the most effective form of propulsion to get there.”

Unfortunately Mr. Bolden’s statement “most people believe” has not yet translated into a commitment by the Agency to develop nuclear thermal propulsion system within a specific period of time.

As a result, the Agency is stuck planning all of its missions, manned or robotic, using chemical propulsion to lift off from Earth and then gravity assisted boosts from planets to reach the exploration site.

Mission objectives, the number and size of instruments, scientific goals, and staffing requirements for the 2020’s and beyond are all constrained by the limits imposed by 1960’s propulsion capabilities.
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NASA hoping for a stellar look at the plumes of Enceladus

This week it was possible to observe the light of a star in the Orion constellation though the plumes of
Enceladus and NASA positioned Cassini to do that.

The star is Epsilon Orionis, the middle star in the belt of Orion. Such an alignment is called a stellar occultation. Usually “occultation” refers to an event where one object blocks and observer’s view of a second object.

In this case, the observer’s view isn’t blocked, its filtered through the water and gas of Enceladus’ plumes. Cassini has made four stellar and one solar occultations of the plumes over the last ten years.

From a distance of 535,000 miles from Enceladus NASA will use Cassini’s Ultraviolet Image Spectrograph (UVIS) to record the filtered starlight. The star itself is 2,000 light years from Enceladus.
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