In keeping with this week’s space theme, three other noteworthy events:
Today NASA’s Messenger probe orbiting Mercury finally ran out of propellant and, as planned, crashed into the planet surface, ending its historic 11 year mission.

Last image of Mercury received from the Messenger space probe
The spacecraft traveled more than six and a half years before it was inserted into orbit around Mercury on March 18, 2011. The prime mission was to orbit the planet and collect data for one Earth year. The spacecraft’s healthy instruments, remaining fuel, and new questions raised by early findings resulted in two approved operations extensions, allowing the mission to continue for almost four years and resulting in more scientific firsts.
One key science finding in 2012 provided compelling support for the hypothesis that Mercury harbors abundant frozen water and other volatile materials in its permanently shadowed polar craters.
Data indicated the ice in Mercury’s polar regions, if spread over an area the size of Washington, would be more than two miles thick. For the first time, scientists began seeing clearly a chapter in the story of how the inner planets, including Earth, acquired water and some of the chemical building blocks for life.
A dark layer covering most of the water ice deposits supports the theory that organic compounds, as well as water, were delivered from the outer solar system to the inner planets and may have led to prebiotic chemical synthesis and, thusly, life on Earth.
On Wednesday, Jeff Bezo’s Blue Origin had a successful test launch of the New Sheppard reusable vertical takeoff & landing spacecraft. After a brief suborbital mission, the capsule parachuted safely back to earth.
From Reuters’ coverage:
Blue Origin is among a handful of companies developing privately owned spaceships to fly experiments, satellites and passengers into space. Like Virgin Galactic, a U.S. offshoot of Richard Branson’s London-based Virgin Group, and privately owned XCOR Aerospace, Blue Origin is eyeing suborbital spaceflights, which reach altitudes of about 62 miles (100 km), as a stepping stone to orbital flight.
[Meanwhile] Boeing and privately owned Space Exploration Technologies, or SpaceX, both of which have financial support from NASA, are skipping suborbital flight and building space taxis to ferry crews to and from the International Space Station, which flies about 250 miles (418 km) above Earth.
Lest we take space exploration for granted, here’s an example of just how difficult it actually is: On Tuesday a Progress resupply mission to the International Space Station had a communication/propulsion failure of some sort. The vehicle is not responding to propulsion commands, and appears to be spinning out of control, though it is transmitting video. It will likely renter the atmosphere sometime in the next two weeks with the unfortunate loss of 6000 pounds of food, fuel and other supplies.