Search This Blog

Thursday, January 9, 2014

New Mission Concepts for SLS With Use of Large Upper Stage

By Leonidas Papadopoulos

Boeing recently released a proposal for a new upper stage for the SLS Block I configuration, that would enable the launch of even heavier payloads to deep-space destinations. Image Credit: NASA

David Strumfels:  I have been down on the SLS, because I thought companies like SpaceX were getting closer to heavy/manned launchers sooner and probably cheaper.  A rocket like the close to testing Falcon Heavy will not have the capabilities of the SLS, but two might and still save over the SLS (in $$;  logistics in multiple coordinated launches will make it more complicated, erasing the savings); furthermore, SpaceX can make the existing Falcon Heavy and increase their capacities considerably (as they have been doing with their Falcon series in general) on a modest budget and time scale.

This article makes me wobble on my stance, however.  (It certainly makes me pant).  Now that missions are being proposed for it, I start to see the advantages of having this kind of ultra-heavy lift capacity, and the plans increasing this capacity strengthen those advantages.  Once it's ready, probably the Falcon series will probably never catch up; and I doubt the company has serious plans to do so.  Now.  So, I'm starting to become a rooter.  Or many it's just "rocket-envy."

New Mission Concepts for SLS With Use of Large Upper Stage

 
Boeing recently released a proposal for a new upper stage for the SLS Block I configuration that would enable the launch of even heavier payloads to deep-space destinations. Image Credit: NASA

Boeing recently released a set of proposals for new missions beyond low-Earth orbit for NASA’s Space Launch System, or SLS, utilising a newly designed Upper Stage.

The SLS is NASA’s next generation heavy-lift launch vehicle (HLV), which is on schedule to make its inaugural unmanned test flight in 2017. It will be used for launching the Orion Multi-Purpose Crew Vehicle, or MPCV, the space agency’s next manned spacecraft currently under construction, to deep-space destinations such as the Moon and Mars—a capability that had been lost with the cancellation of the Apollo lunar missions more than 40 years ago.

An artist rendering of the various configurations of NASA's Space Launch System. Image Caption/Credit: NASA
An artist rendering of the various configurations of NASA’s Space Launch System. Image Caption/Credit: NASA

Although the first two launches of the SLS in 2017 and 2021 respectively are designed to be test flights of the initial Block I configuration capable of delivering 70 metric tons to low-Earth orbit (LEO), NASA is designing the heavy launch system to be evolvable, with the final Block II configuration having a payload capacity of 130 metric tons to LEO—rivaling the capability of the Saturn V rocket that sent humans to the Moon during the 1960s and ’70s.

As reported at the NASA Spaceflight.com website, Boeing, which is the prime contractor for designing and building the SLS’s core and upper stages, recently presented its proposal for a new Large Upper Stage, or LUS, for use on the SLS, which would enable new missions to low-Earth orbit and beyond.

The currently designed upper stage for the Block I version of SLS is an Interim Cryogenic Propulsion Stage (ICPS), also known as the Delta Cryogenic Second Stage, or DCSS. This is the same upper stage used on the Delta IV rocket, and it employs a single RL-10B2 engine developed by Pratt & Whitney. Although the ICPS would boost a 70-metric-ton payload to LEO in the SLS Block I version, Boeing’s proposal for the LUS would significantly advance this capability to more than 90 metric tons, allowing for even more ambitious deep-space missions. “A new 8.4m Large Upper Stage (LUS), as a follow on to the interim Cryogenic Propulsion Stage (ICPS), can provide significant increases in SLS payload injection capability,” notes the company in its presentation.
An alternate concept of placing a human outpost to the Earth-Moon L2 point with the SLS is Skylab II, proposed by a team of engineers working with the Advanced Concepts Office at NASA's Marshall Space Flight Center. Image Credit: NASA
An alternate concept of placing a human outpost to the Earth-Moon L2 point with the SLS is Skylab II, proposed by a team of engineers working with the Advanced Concepts Office at NASA’s Marshall Space Flight Center. Image Credit: NASA
“Someone reminded me that, up until the last two modules were put up on the ISS (via Shuttle), Skylab had more crew volume,” says Jim Crocker, Vice President and General Manager, Civil Space, Lockheed Martin Space Systems Co. “Skylab was done with one Saturn V. Sometimes it requires re-thinking of what you’re doing.”

These new mission concepts studied by Boeing fall into four main categories: LEO destinations, cislunar and lunar missions, Mars and Outer Solar System destinations.

One of the payloads that could take advantage of the SLS’s LEO payload capability, according to the Boeing study, is Bigelow Aerospace’s proposed BA 2100 inflatable habitat. Bigelow Aerospace is best known for its innovative and ambitious work on designing and launching inflatable modules in orbit, based on NASA’s TransHab technology. The private company has already launched two experimental modules in low-Earth orbit, Genesis I and II in 2006 and 2007 respectively. It is already planning to send a Bigelow Expandable Activity Module, or BEAM, on the International Space Station in 2015 and plans to develop  the first privately built space station called Bigelow Commercial Space Station, constructed from several BA 330 modules that are currently under development.

The large Bigelow BA 2100 module, could fit inside the 8.4m payload fairing of the proposed LUS upper stage. Image Credit: NASASpaceFlight.com
The large Bigelow BA 2100 module could fit inside the 8.4m payload fairing of the proposed LUS upper stage. Image Credit: NASASpaceFlight.com

Yet the company revealed even more ambitious plans in the 2010 International Symposium for Private and Commercial Spaceflight held in Las Cruces, N.M., with the unveiling of the BA 2100, or Olympus module concept. As the number on its name implies, BA 2100 would feature a living area of 2,100 cubic meters of volume, completely dwarfing the smaller BA 330. This enormous habitat would have a calculated mass of 70 to 100 metric tons, making the SLS the only heavy-lift vehicle capable of placing it into orbit. That fact was acknowledged by Bigelow Aerospace Vice President Jay Ingham as well. “If a super-heavy-lift launch vehicle ever did exist, probably in the range of around 100 metric tons, would require an 8-meter fairing to launch the BA-2100,” Ingham discussed during the Symposium.

“SLS allows delivery of the BA-2100 via direct insertion to a low earth orbit and is the only launch vehicle capable of delivering a payload this large to LEO,” notes Boeing in its LUS concept presentation. Besides being used as a space hotel complex or space science research laboratory in low-Earth orbit, the BA 2100 could also be used as a large self-sufficient crew habitat for long interplanetary missions to Mars or anywhere else in the Solar System.

The main purpose of the SLS is to enable beyond-Earth orbit human space exploration. In 2011 Boeing proposed a design for a cislunar Exploration Gateway Platform, located in the L1 or L2 Lagrangian points of the Earth-Moon system. This mission concept envisioned the use of existing left-over hardware from the ISS program for the construction of a cislunar manned outpost that would enable regular access to cislunar space and the lunar surface itself. Many within the space agency view this concept as the next logical step beyond low-Earth orbit for human exploration, serving as a testing ground for long-duration missions prior to a human trip to Mars. “Building a translunar outpost is an important first step in retrieving an asteroid, returning to the moon or venturing to Mars.
Using the SLS/LUS would allow the Exploration Platform to be constructed and crewed in only two launches, as opposed to the four missions required using SLS/ICPS (interim Cryogenic Propulsion Stage), thus saving cost and significantly shortening the time required to start accruing the benefits of a crewed Exploration Platform in translunar space,” notes the new Boeing study.
Boeing's proposal for an Exploration Gateway Platform, at a Lagrandgian point in the Earth-Moon system. Image Credit: Boeing/NASA
Boeing’s proposal for an Exploration Gateway Platform, at a Lagrangian point in the Earth-Moon system. Image Credit: Boeing/NASA
A mockup of the proposed Bigelow BA 2100 inflatable module. With a projected payload mass between 70 to 100 metric tones, the only launch vehicle existing or under development that could place it to orbit, is the SLS. Image Credit: Bigelow Aerospace
A mockup of the proposed Bigelow BA 2100 inflatable module. With a projected payload mass between 70 to 100 metric tons, the only launch vehicle existing or under development that could place it to orbit is the SLS. Image Credit: Bigelow Aerospace

Besides human space exploration, the LUS could greatly advance robotic exploration as well, with its ability to directly send large interplanetary spacecraft to their destinations to the outer Solar System, mitigating the need for multiple gravity-assist manuevers that greatly prolong the mission duration to many years or decades.

The Interim Cryogenic Propulsion Stage currently designed for the SLS Block I version uses a 5m payload fairing that is capable of sending approximately 3 metric tons of payload to Jupiter, 1.8 tons to Saturn, and just 0.13 tons to Uranus. The proposed LUS upper stage, featuring an 8.4m payload fairing, would be capable of sending three to four times more massive payloads to these destinations.
Depending on the LUS variant being used (having a single, dual, or 4-engine configuration), the new upper stage could directly send a payload of approximately 8.5 metric tons to Jupiter, 6 tons to Saturn, and 2 tons to Uranus. This payload capability would enable new and exciting missions to Europa, Titan, Enceladus, and Uranus that just aren’t possible with existing launch vehicles today.
“The SLS provides a critical heavy-lift launch capability enabling diverse deep space missions,” states the Boeing report. “The added payload to destination that can be provided by a new Large Upper Stage, would be an enhancement for future science, astronomy, and Human spaceflight missions.”
The 4-engine configuration of Boeing's proposed Large Upper Stage for the SLS. Image Credit: NASASpaceFlight.com
The 4-engine configuration of Boeing’s proposed Large Upper Stage for the SLS. Image Credit: NASASpaceFlight.com

The new SLS/LUS lift capability would enable a Europa orbiter or lander to reach the Jovian moon in approximately three years after launch, and a similar mission could reach Titan in four. “Imagine the science return with SLS, where we can get there within a few years, and how that can accelerate scientific discovery,” says Crocker. “We don’t know what we’re going to find in science, but we do know that if you find it sooner, you get a much higher science return for your investment.”

A dedicated Uranus orbiter has also been the longing of the planetary science community. A Uranus orbiter is listed as the third highest priority Flagship mission after Mars and Europa in the 2013-2022 U.S. Planetary Science Decadal Survey. Dr. Mark Hofstadter, a planetary scientist at NASA’s Jet Propulsion Laboratory, stressed that point during a presentation at the January 2013 meeting of the Outer Planets Assessment Group, in Atlanta, Ga. “The Group is concerned that no action was taken on its findings last year regarding a Uranus mission study,” notes Hofstadter in the presentation, “and again urges that NASA initiate such a study responsive to Decadal Survey science goals for the ice giants.”
The 8m primary mirror version of the proposed ATLAST space telescope. Image Credit: NASA, MSFC Advanced Concepts Office
The 8m primary mirror version of the proposed ATLAST space telescope. Image Credit: NASA, MSFC Advanced Concepts Office

Planetary exploration wouldn’t be the only field in space science that could benefit from the use of the SLS/LUS concept. The new upper stage would also be able to lift the proposed Advanced Technology Large Aperture Space Telescope, or ATLAST, that is under consideration by NASA. ATLAST is a next generation space telescope, featuring a monolithic 8m primary mirror, four times bigger than the one on the Hubble Space Telescope. An alternative design also calls for a 16m segmented primary mirror, which could also fit inside the bigger LUS payload fairing. According to the Space Telescope Science Institute’s project website, “ATLAST will have an angular resolution that is 5 – 10 times better than the James Webb Space Telescope and a sensitivity limit that is up to 2000 times better than the Hubble Space Telescope … It is envisioned as a flagship mission of the 2025 – 2035 period, designed to address one of the most compelling questions of our time. Is there life else where in our Galaxy? It will accomplish this by detecting ‘biosignatures’ (such as molecular oxygen, ozone, water, and methane) in the spectra of terrestrial exoplanets.”

Maybe the most important aspect of the LUS design is its cost-saving approach to the SLS’s development. If chosen by NASA, the LUS would be constructed at the agency’s Vertical Weld Center at Michoud Assembly Facility in New Orleans, where Boeing already will be constructing the SLS’s Core Stage, without the need for extra welding or other machining equipment, thus helping to further bring the SLS’s development costs down.
Video Credit: NASA/Marshall Space Flight Center

Since its inception in 2011, the SLS has been heavily criticised by many within the space community for its perceived lack of missions. During her recent appearance on a radio talk show, former NASA Deputy Administrator Lori Garver heavily criticised SLS as being a rocket to nowhere.“Where is it going to go?” she asked during the show. Although Boeing’s LUS upper stage concept hasn’t been yet approved by NASA, it nevertheless largely invalidates Garver’s criticism by showcasing that the space agency’s newest heavy-lift vehicle could be used for all shorts of exciting and ambitious human and robotic missions throughout the Solar System.

Wednesday, January 8, 2014

Evolution of Confusion -- Daniell Dennet

http://www.youtube.com/watch?v=5Bwe7TIv4LY&feature=player_detailpage


















Daniel Dennet on The Evolution of Confusion


Could Other Animals Have (their version of) Gods Too? Hitch Got Me Thinking

 
 
 
 
 
 
 
 
 
 
 
 
 
At first sight this seems the usual delightfully charming Hitchens saying the kind of things he was and is so famous and fondly remembered for.  Only on second or third sight did I realize that, at least this time, the great man was in error.  Completely in error.
 
For one thing, it is an unforgiveable insult to chimpanzees all over the world; worse, to the entire -- sans H. sapiens -- animal kingdom on this planet.  If creating gods really is maladaptive, irrational, and just plain foolish, then we humans must be at the bottom of the evolutionary cesspool, hardly near the top.  Yet Hitchens unfortunately implies exactly the opposite, as though creating supernatural beings somehow "reduces" our evolutionary pedestal down to the level of our clownish closest cousin.  By half a chromosome, but that's a lot.
 
But then I re-wondered about it.  How do we know that chimps haven't made, somewhere in their history, things akin to our gods?  They certainly aren't capable of science, nowhere near to our level at least; so why shouldn't they believe in the supernatural?  Lack of science is certainly most the reason almost all of our ancestors believed in gods and other supernatural phenomenon.
 
On the other hand, are chimps capable of belief, which involves some pretty sophisticated cognition skills?  I don't know if (or how) there have been studies of this, or even conclusions drawn, but I will say this:  don't bet your life's fortune that the answer is negative.  So many animals, including the other apes, have been shown over the last 20-40 years to possess much more sophisticated behaviors and cognition skills than we'd ever suspected.  New discoveries seem to happen almost daily.  (Hence the animal rights movement.)
 
"Half a chromosome away from being chimpanzee" is probably at least a bad analogy; that little bit of DNA might not make as much difference as we suppose.  It is certainly nothing to be either proud or ashamed of, and quite possibly has nothing to do with believing in gods or not.
 
Still -- it sounds so Hitch.  So on the money.


Dark matter 'wind' may be warped by the sun

18:00 08 January 2014 by Katia Moskvitch
Source:  http://www.newscientist.com/article/dn24830-dark-matter-wind-may-be-warped-by-the-sun.html#.Us2x850o6L9

 














Dark-matter hunters may need to check their calendars. The sun's gravity could change the time when dark matter signals are detected on Earth, which could help sharpen the search for the elusive substance.
 
Invisible dark matter is thought to make up most of the matter in the universe. Physicists hope to detect it in the form of weakly interacting massive particles (WIMPs) when they collide with ordinary matter in underground detectors.
 
Some have argued that the rate of such interactions should vary with the seasons, as Earth's orbit brings it ploughing through the cloud of dark matter suffusing the galaxy. When the planet heads into this "WIMP wind", around 1 June, we should see more dark matter strikes; in December, when Earth is moving downwind, we should see fewer.
 
Previously, two experiments, including the DAMA detector at Gran Sasso, Italy, and the CoGeNT detector in Soudan, Minnesota, reported observing just this sort of seasonal signal. But these claims have attracted scepticism because more-sensitive detectors have come up empty.

Warp factor

Now, Benjamin Safdi of Princeton University and his colleagues note something that all experiments have neglected: the sun. As WIMPs stream through the solar system, the sun's gravity bends their trajectories, focusing the streaming particles on a particular location in Earth's orbit. This effect can shift the date of the maximum number of collisions by anything from a few days up to several months, depending on the WIMPs' mass and speed. "This force warps the dark matter 'wind' in a way that had not previously been noticed," Safdi says.


The fact that the date of maximum WIMP collisions should change depending on their energy could lend future searches a sharper scalpel to scrape true dark matter signals away from background noise, he adds.
 
"Our result gives dark matter direct-detection experiments an excellent way of distinguishing real interactions with the galactic dark matter halo from background," Safdi says. "It is hard to imagine a background source which could mimic this energy-dependent modulation."

Punchline coming

The work does not explain DAMA's possible dark-matter signal, but re-analysing the data using the new approach could help support or refute their results, Safdi says.
 
"There is already a slight trend in the data consistent with our prediction for the gravitational focusing effect – that is, the date of the maximum moves further away from June 1 at lower energies," says team member Samuel Lee, also of Princeton. "One punchline of our study is that accounting for the gravitational focusing effect can perhaps rule out or confirm the dark-matter interpretation of the DAMA annual modulation."
 
Richard Gaitskell of Brown University in Providence, Rhode Island, who works on a direct-detection experiment in South Dakota called LUX, says that the new work could be important for helping design future experimental set-ups. "These researchers have clearly demonstrated just how potentially interesting data from a direct-detection experiment can be," he says.
 
Journal reference: Physical Review Letters, DOI:10.1103/PhysRevLett.112.011301


 

Hawking & Mlodinow: No 'theory of everything'

Thursday, September 30, 2010
 














In a Scientific American essay based on their new book A Grand Design, Stephen Hawking and Leonard Mlodinow are now claiming physicists may never find a theory of everything. Instead, they propose a "family of interconnected theories" might emerge, with each describing a certain reality under specific conditions.
Most of the history of physics has been dominated by a realist approach. Scientists simply accepted that their observations could give direct information about an objective reality. In classical physics, such a view was easily defensible, but the emergence of quantum mechanics has shaken even the staunchest realist.

In a quantum world, particles don't have definite locations or even definite velocities until they've been observed. This is a far cry from Newton's world, and Hawking/Mlodinow argue that - in light of quantum mechanics - it doesn't matter what is actually real and what isn't, all that matters is what we experience as reality.

As an example, they talk about Neo from The Matrix. Even though Neo's world was virtual, as long as he didn't know it there was no reason for him to challenge the physical laws of that world. Similarly, they use the example of a goldfish in a curved bowl. The fish would experience a curvature of light as its reality and while it wouldn't be accurate to someone outside the bowl, to the fish it would be.

Scientific American: The Elusive Theory of Everything
"In our view, there is no picture or theory-independent concept of reality. Instead we adopt a view that we call model - dependent realism: the idea that a physical theory or world is a model (generally of a mathematical nature) and a set of rules that connect the elements of the model to observations. According to model - dependent realism, it is pointless to ask whether a model is real, only whether it agrees with observation. If two models agree with observation, neither model can be considered more real than the other. A person can use whichever model is more convenient in the situation under consideration."

This view is a staunch reversal for Hawking, who 30 years ago argued that not only would physicists find a theory of everything, but that it would happen by the year 2000. In his first speech as Lucasian Chair at Cambridge titled "Is the end in sight for theoretical physics?," Hawking argued that the unification of quantum mechanics and general relativity into one theory was inevitable and that the coming age of computers would render physicists obsolete, if not physics itself.

Of course, Hawking has become rather well known for jumping way out on a limb with his public remarks and for decades he embraced supergravity as having the potential to solve theoretical physicist's ills, even hosting a major conference on it in 1982. However, but Hawking has never harbored allegiances to theories that describe a physical reality.

So, while two well-known physicists coming out against a theory of everything is compelling, it really shouldn't seem like anything new for Hawking.

"I take the positivist view point that a physical theory is just a mathematical model and that it is meaningless to ask whether it corresponds to reality. All that one can ask is that its predictions should be in agreement with observation."

Stephen hawking, The Nature of Space and Time (1996)

Organic mega flow battery promises breakthrough for renewable energy

59 minutes ago in Phys.org 

Organic mega flow battery promises breakthrough for renewable energy       
Large-scale storage of renewable energy for use when the sun isn't shining and the wind isn't blowing. Energy from solar panels is shown stored in green and blue chemicals in Harvard flow battery storage tanks, powering this green city at …

A team of Harvard scientists and engineers has demonstrated a new type of battery that could fundamentally transform the way electricity is stored on the grid, making power from renewable energy sources such as wind and solar far more economical and reliable.
The novel battery technology is reported in a paper published in Nature on January 9. Under the OPEN 2012 program, the Harvard team received funding from the U.S. Department of Energy's Advanced Research Projects Agency–Energy (ARPA-E) to develop the innovative grid-scale battery and plans to work with ARPA-E to catalyze further technological and market breakthroughs over the next several years.

The paper reports a metal-free that relies on the electrochemistry of naturally abundant, inexpensive, small organic (carbon-based) molecules called quinones, which are similar to molecules that store energy in plants and animals.

The mismatch between the availability of intermittent wind or sunshine and the variability of demand is the biggest obstacle to getting a large fraction of our electricity from renewable sources. A cost-effective means of storing large amounts of electrical energy could solve this problem.

The battery was designed, built, and tested in the laboratory of Michael J. Aziz, Gene and Tracy Sykes Professor of Materials and Energy Technologies at the Harvard School of Engineering and Applied Sciences (SEAS). Roy G. Gordon, Thomas Dudley Cabot Professor of Chemistry and Professor of Materials Science, led the work on the synthesis and chemical screening of molecules. Alán Aspuru-Guzik, Professor of Chemistry and Chemical Biology, used his pioneering high-throughput molecular screening methods to calculate the properties of more than 10,000 quinone molecules in search of the best candidates for the battery.

Flow batteries store energy in chemical fluids contained in external tanks—as with fuel cells—instead of within the battery container itself. The two main components—the electrochemical conversion hardware through which the fluids are flowed (which sets the peak power capacity), and the chemical storage tanks (which set the energy capacity)—may be independently sized. Thus the amount of energy that can be stored is limited only by the size of the tanks. The design permits larger amounts of energy to be stored at lower cost than with traditional batteries.


Read more at: http://phys.org/news/2014-01-mega-battery-breakthrough-renewable-energy.html#jCp
 


‘Habitable zones’ around stars ten times wider than we thought – study

Published time: January 08, 2014 14:31 by RT
 

A new paper published in the journal, Planetary and Space Science, describes how living organisms have just as much chance of surviving in areas below their uninhabitable planets’ surfaces.
This includes planets a staggering distance away from their stars, as well as even those that were recently discovered to be drifting in space by themselves, with no apparent host star. It is all about temperature.

The previous commonly accepted assertion was that the ‘Goldilocks’ zone was a requirement. It is the zone both far away and near to its star to provide the kind of climate capable of sustaining life, because it supports water which is neither boiling hot nor frozen.

Now a team of researchers from Aberdeen and St. Andrews universities has an updated view of things. PhD student Sean McMahon, author of the paper, says “that theory fails to take into account life that can exist beneath a planet's surface. As you get deeper …the temperature increases, and once you get down to a temperature where liquid water can exist – life can exist there too.”

To prove this, the scientists devised a computer model to cleverly approximate temperatures below the surfaces of planets by inputting the distance to their respective stars and crossing that with the planet’s size.

Using that model they discovered that the radius around a star, capable of supporting life, increased three-fold if new data on depth at which life can exist below the surface of a given planet were taken into account.

"The deepest known life on Earth is 5.3 km below the surface, but there may well be life even 10 km deep in places on Earth that haven't yet been drilled,” McMahon said.
What adds to the excitement is that the model allows for potentially expanding the habitable zone even more. If indeed we do find life 10km below the Earth’s surface, the math tells us that Earth-like planets could support life as far as 14 times the distance previously considered to be the Goldilocks zone.
To put this into perspective – our current habitable zone is considered to reach out as far as Mars. But new measurements that account for life existing under rocky surfaces take that radius as far as Jupiter and Saturn.

For example, the recently discovered Gliese 581 d could be a candidate. Sure, it is about 20 trillion kilometers away, but its cold surface could well hide life a couple of kilometers below the surface, scientists assume.

Scientists are excited at the subsurface theory on sustaining life. We can now widen our search for life, they hope, adding that the new findings are so radical that the fact of life on Earth (which itself is very different from the thousands of planets we know about) could itself be anomalous because life receives much more protection inside a warm, mineral-rich rock than risking survival on its inhospitable surface.

A land without a people for a people without a land

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/A_l...