DARPA has announced the second phase of its ambitious XS-1 program. The agency is seeking to make access to space more regular and affordable by employing an entirely re-usable high-speed, sub-orbital automated spaceplane as the first stage of its launch vehicle.

Upon reaching a designated height, an expendable upper stage would separate from the space plane, and insert a payload into low-Earth orbit (LEO). The spaceplane would then autonomously land and be serviced for the next launch.

Phase 1 of the program saw DARPA award contracts to three companies, each of which was paired with a launch service provider. The teams were tasked with analyzing the feasibility of the project, and designing their own versions of the launcher.

"During Phase 1 of the XS-1 program, the space industry has evolved rapidly and we intend to take advantage of multiple impressive technological and commercial advances," states Jess Sponable, program manager for the XS-1. "We intend to leverage those advances along with our Phase 1 progress to break the cycle of escalating DoD space system launch costs, catalyze lower-cost satellite architectures, and prove that routine and responsive access to space can be achieved at costs an order of magnitude lower than with today's systems."

Phase 2 will integrate state-of-the-art technologies in combination with the advances made in Phase 1 of the program to design and fabricate a functioning launcher roughly the size of a conventional business jet. Whereas multiple contracts were offered in the first stage of the program, DARPA only envisions awarding a single commitment in Phase 2.

The second stage of the initiative will have four primary technical goals.

• Fly 10 times in a 10-day period (not including weather, range and emergency delays) to demonstrate aircraft-like access to space and eliminate concerns about the cost-effectiveness and reliability of reusable launch.
• Achieve flight velocity sufficiently high to enable use of a small (and therefore low-cost) expendable upper stage.
• Launch a 900 to 1,500-lb (408 to 680-kg) representative payload to demonstrate an immediate responsive launch capability able to support both DoD and commercial missions. The same XS-1 vehicle could eventually also launch future 3,000+-lb (1,361-kg) payloads by using a larger expendable upper stage.
• Reduce the cost of access to space for 3,000+-lb payloads, with a goal of approximately $5 million per flight for the operational system, which would include a reusable booster and expendable upper stage(s).

We can't control when the wind blows and when the sun shines, so finding efficient ways to store energy from alternative sources remains an urgent research problem. Now, a group of researchers led by Professor Ted Sargent at the University of Toronto's Faculty of Applied Science & Engineering may have a solution inspired by nature.

I received a lot of emails regarding this topic today so I thought I would repeat a post I did responding to Simon and hopes it puts this a little more in perspective

If the numbers stack up this is proberbly one of the biggest breakthroughs I have seen to date

I received a lot of emails regarding this topic today so I thought I would repeat a post I did responding to Simon and hope it puts this a little more in perspective

I think this is a work in progress and it is only part of the equation, solving the bottle necks or hurdles one by one. In this case quote: " the scientists focused on a step where oxygen atoms pair up to form a gas that bubbles away, which has been a bottleneck in the process"

I never expected it to be overunity as they need to work out the hydrogen side, however the biggest barrier seems to be overcome. I also am excited how they are using so many disciplines of science and developing completely new genres of material science. This really is a collaborative effort of skill sets and international collaberation.

In a previous article we published they mentioned they are at 100% at this part of the equation, now the other half has to be attended to.

This step, from my perspective, after 12 years of researching in the area is the first real major breakthrough that has provided the tools, science and direction to tackle the other hurdles and bottlenecks.

There will never be a single bullet which has often been claimed in the past, but a series of solutions for a very complex equation.

The team has designed the most efficient catalyst for storing energy in chemical form, by splitting water into hydrogen and oxygen, just like plants do during photosynthesis. Oxygen is released harmlessly into the atmosphere, and hydrogen, as H2, can be converted back into energy using hydrogen fuel cells.

"Today on a solar farm or a wind farm, storage is typically provided with batteries. But batteries are expensive, and can typically only store a fixed amount of energy," says Sargent. "That's why discovering a more efficient and highly scalable means of storing energy generated by renewables is one of the grand challenges in this field."

This new catalyst facilitates the oxygen-evolution portion of the chemical reaction, making the conversion from H2O into O2 and H2 more energy-efficient than ever before. The intrinsic efficiency of the new catalyst material is over three times more efficient than the best state-of-the-art catalyst.

The new catalyst is made of abundant and low-cost metals tungsten, iron and cobalt, which are much less expensive than state-of-the-art catalysts based on precious metals. It showed no signs of degradation over more than 500 hours of continuous activity, unlike other efficient but short-lived catalysts. Their work was published today in the leading journalScience.

"With the aid of theoretical predictions, we became convinced that including tungsten could lead to a better oxygen-evolving catalyst. Unfortunately, prior work did not show how to mix tungsten homogeneously with the active metals such as iron and cobalt," says Dr. Bo Zhang, one of the study's lead authors. "We invented a new way to distribute the catalyst homogenously in a gel, and as a result built a device that works incredibly efficiently and robustly."