December 25, 2015

SpaceX’s Reusable Rockets Will Make Space Cheaper — But How Much? (Source: The Verge)
It costs $60 million to make the Falcon 9, and $200,000 to fuel it, according to SpaceX CEO Elon Musk. Reusing rockets could substantially lower these costs, he says; theoretically, a rocket would only need to be refueled to launch multiple times again. But SpaceX needs to be certain that its returned rockets are capable of flying again.

The Falcon 9 experiences major temperature changes during its flights, as well as intense pressures and vibrations from the winds in the atmosphere. These all produce wear-and-tear on the vehicle's hardware — meaning the rocket might need repairs and updates before it can launch again. Refurbishing a rocket engine is often expensive. And if those repairs take too long, SpaceX can’t launch its vehicles as frequently.

Really, a lot hinges on the design. If the Falcon 9 isn’t damaged much during launch and descent, repairs may not be expensive or time-consuming. Last year, SpaceX said it was confident that it could land its rockets and re-fly them "with no required refurbishment." Now engineers must find out if that design holds up to reality. If it does, a reusable vehicle makes sense. (12/24)

For Air Force Space Planners, Diversity is its Own Deterrent (Source: Space News)
The U.S. Air Force’s traditional approach to replacing space systems just doesn’t cut it anymore, says Winston Beauchamp, the Air Force deputy undersecretary for space.

“The way we have acquired space systems for the past several decades was on the basis of something called ‘functional availability,’ which is a metric designed to estimate how long a space system will last so we can plan to inject its replacement right at the point of failure,” Beauchamp said. “That is an approach that might make sense in a benign environment but as you just laid out, that’s not the environment we find outselves in anymore.” (12/24)

Proton Launches Commercial Satellite (Source: ILS)
On 25 December 2015, a Proton-M  launch vehicle carrying a Russian communications satellite Express-AMU1 lifted off from Baikonur at 00:31 Moscow Time. This was the eighth and final space launch in 2015 using the heavy-lift Russian-made Proton. The launch and flight of the launch vehicle proceeded nominally. (12/25)

Martian Gullies: Caused by Exploding Dry Ice? (Source: Sky & Telescope)
Planetary scientists are taking a close look at whether enigmatic gullies seen on many steep Martian slopes might not be caused by liquid water but instead by episodic coatings of frozen carbon dioxide. Even though there's evidence for occasional trickles of salt-infused water on the surface, the changes captured by HiRISE are too extensive to be the work of running water. (12/24)

All the Year’s Kickbutt Science From Space (Source: WIRED)
This was a badass year for space. When I learned about the solar system in elementary school, I thought of the planets as solid, immutable objects. They were far away, relatively unknowable, but I was comfortable—happy, even—with what I did know about them. The one with the rings, the one with the spot, the really tiny cold one. That was enough.

This year’s planetary research, though, has reminded me that exploration of the solar system (and beyond) is just beginning. When the New Horizons probe finally reached Pluto in July, after nearly a decade of travel through space, scientists essentially discovered a new world. And the images of its remarkably diverse icy surface, trickling in at just one to four kilobits a second, woke a new generation up to the possibilities of astronomical outreach. Click here. (12/24)