Carnival of Space week 61 is up at Mangsbatpage
This site contributed the article on hypersonic technology of the Blackswift and other hypersonic programs
Centauri Dreams look at the NanoSail-D: Solar Sail Deployment Plan
Colony worlds look at solar steam to power martian cities
21st century waves looks at 10 reasons why China is good for space
Check out the Carnival for a lot more.
Showing posts with label propulsion. Show all posts
Showing posts with label propulsion. Show all posts
July 02, 2008
Carnival of Space Week 61
July 01, 2008
Hypersonic Falcon HTV-3X
Falcon HTV-3X
The Blackswift Hypersonic program may not get fully funded for the $750 million that it needs, but the program has
a lot of interesting technology and innovations for greater efficiency. This technology and innovations are discussed below.
Making a scramjet rocket would be a better program to fund for space access. A scramjet rocket would be simpler and cheaper than a space plane and would not need to have the weight of wings and other gear.
From the designers of Skylon, there is a fairly practical spaceplane design. It is called the Mach 5 A2 commercial Concorde replacement.
The MHD bypass to slow the supersonic air so that a turbine can function while the scramjet goes up to Mach 7
However, there is a lot of interesting technology in the Blackswift program. Constant volume combustion, more efficient than Brayton cycle Humphrey cycle propulsion (like a pulse-detonation engine).
The goal is to achieve a flying Mach 6 demonstrator by 2013.
It would use regular fuel instead of hydrogen, which would be more practical but have relatively lower performance.
June 13, 2008
Carnival of Space Week 58
Carnival of Space 58 is up at UniverseToday
This site contributed an article on the top ten near term developments for vastly increased capabilities in space
Centauri Dreams talks about a light tower for propelling solar sails
Bad Astronomy talks about a quantum mechanics test at the space station
Colony Worlds indicates that future colonists should grow bamboo
Hobbyspace reports that the 2008 Lunar Lander Challenge will take place at Holloman Air Force Base in Alamogordo, New Mexico, October 24-25, 2008. This year's competition will be webcast online; the public can follow the action at the X PRIZE Foundation website www.xprize.org.
Check out the carnival of Space 58 at UniverseToday for a lot more
June 09, 2008
Lorentz Force propulsion Successful test
Since the recent trial [with explosive arcing problems] , Peck and his colleagues at the University of Michigan and State University of New York, Binghamton, have successfully tested (but not yet published) their propulsion system, which could speed satellites along at more than four and a half miles a second. More recent tests of solder-less satellites at the University of Michigan have been successful, said Peck.
Peck and his colleagues argue this new kind of mini device could make satellite missions more affordable and feasible.
The propellant-less satellite idea works a lot like a TV. A 'gun' at the back of the TV shoots out negatively charged electrons. As they speed towards the viewer, a magnet changes their direction. On a planetary scale, the electron would be the satellite zooming around the magnet, in this case the Earth. As the satellite zooms around the spinning Earth it would experience a force (known as the Lorentz force) pushing it at an angle perpendicular to its direction. The satellite would steal a tiny bit of the Earth's energy to propel it forward.
Other designs using the same principle, including the Electro Dynamic Tether, have been successfully used in orbit. One difference between the EDT and the new system is that the tether has to be aligned in a specific direction, where the new satellites wouldn't need to be.
FURTHER READING
Using Lorentz force propulsion could be used to refuel Orion nuclear rockets.
June 04, 2008
Propellantless propulsion experiment explodes, SpaceX falcon 9 does not
Lorentz actuated propulsion would require no propellant. However, recent experiments simulating orbit conditions resulted in explosions.
The team tested the ability of various objects to hold a charge in a vacuum while being bombarded with plasma, as would be the case in orbit. To generate the charge on the test object, they attached it to a sample of radioactive Americium-24, an alpha-particle emitter, and applied a voltage. The electric field carries away the positively charged alpha particles leaving the object highly charged. Microscopic arcing was observed at voltages as low as -300 V. This arcing caused solder to explode off of the object.
Experimental Study of a Lorentz Actuated Orbit, preprint paper
The arcing that occurs at low voltages is a serious problem but can essentially be eliminated if the wires and solder are well insulated. The object can easily be charged in plasma only if it is insulated in such a way that it is not in direct contact with the plasma. The only problem then is the net zero charge that is observed by the magnetic field. The plasma itself, created in the lab, is not exactly identical to that of outer space or the upper atmosphere. Even though the electron temperature closely relates to those regions, the electron density is four orders of magnitude higher and may cause different results than one would obtain in a lower electron density environment. Experimental research on a Lorentz Actuated Orbit is still ongoing with the hope that one day we will be able to establish an experimental basis for sizing a propellantless propulsion system.
SpaceX Conducts First Five Engine Firing of Falcon 9 Rocket
Space Exploration Technologies Corp. (SpaceX) conducted the first five-engine firing of its Falcon 9 medium to heavy lift rocket at its Texas Test Facility outside McGregor on Thursday, May 29. At full power the engines generated almost half a million pounds of force, and consumed 1,750 lbs of fuel and liquid oxygen per second. This five engine test again sets the record as the most powerful test yet on the towering 235-foot tall test stand.
The first Falcon 9, contracted to launch a US government payload, will arrive at the SpaceX launch site at Cape Canaveral by the end of 2008, according to vice-president for propulsion Tom Mueller.
The maiden flight is expected late in the first quarter of 2009, some six months later than originally planned. The next flight of SpaceX's smaller Falcon 1 rocket is scheduled for late June or July of 2008.
Last month, SpaceX secured a NASA launch services contract that could be worth up to $1 billion and last from June 2010 to the end of 2012.
May 01, 2008
The Carnival of Space - the anniversary edition
The one year anniversary edition of the Carnival of space is up at Why Home School ? As this is the anniversary edition it is the largest ever with the most articles.
I provided my article updating the progress of the vasimr plasma rocket and comparing the solar electric sail to a dandelion seed on the solar wind.
Centauri Dreams talks about Nick Bostrom's article about the Big Filter theory of the Fermi Paradox
Colony Worlds talks about conquering the kuiper belt
Loads of astronomy and the theme of space television with mentions of Star Trek, Space 1999, Battlestar Galactica, My Favorite Martian, Lost in Space, Babylon 5 and 2001 a Space Odyssey.
April 28, 2008
Vasimr 200KW almost flight ready in 2008 and the solar electric sail like a Dandelion seed
I will look at two near term space systems the Vasimr and the solar electric sail. Both could provide a significant increase in the performance of various space missions. Both have their advantages and would be welcome improvements in the capabilities of space systems. Vasimr can go up to higher power levels that are limited by the Vasimr system and the power system. The Solar electric sail uses no propellant while the Vasimr is ten times or more efficient than current chemical systems. Both could be in space flight tests in the next year or three.
The 200 kilowatt VX200 Vasimr system is almost ready for flight tests and the type of missions impacts it would have are discussed. The solar electric sail system which I reviewed last week is discussed again. Comparison is made to dandelion seeds and how the multiple parachute configuration could be used to combine the propulsion of several solar electric sails to move larger objects.
The 200 kilowatt Vasimr plasma engine is expected to reach NASA's technology readiness level 6 in 2008 An initial test firing of the full engine
prototype has been postponed until the 2nd quarter of 2008 in order to give Scientific Magnetics of Culham, UK. the needed time to complete its certification of the superconducting subsystem.
A 12 MW Vasimr system could send a ship to Mars in less than 120 days one way. A 200 MW Vasimr could go to Mars in 39 days.
1-2MW Vasimr lunar cargo vehicle could transfer up to 39% of the mass from low earth orbit to the moon.
The 6 page study of a Vasimr powered lunar cargo vehicle. Five of the 200 kilowatt Vasimr engines could make up a 1 MW plasma powered vehicle.
March 17, Alliant Techsystems (NYSE: ATK) [$4.1 billion company] and the Ad Astra Rocket Company of Houston, Texas signed and executed a Technology
Development Alliance to explore future in-space propulsion systems for lunar and planetary missions.
VASIMR versus the Solar electric Sail
A VASIMR system can get up to 300 kilometers/second and faster while the solar electric sail goes 100 kilometers/second. Both systems could be improved beyond those performance levels. The variable specific impulse magnetoplasma rocket (VASIMR) uses radio waves and magnetic fields to accelerate a propellant. Current VASIMR designs should be capable of producing specific impulses ranging from 10,000-300,000 m/s (1,000-30,000 seconds) - the low end of this range is comparable to some ion thruster designs. 
I was noticing how much like a dandelion seed the solar electric sail system would be. The solar electric sail would be blown by the solar wind.
I also believe that the solar electric sail could have multiple sails attached to one vehicle like a multiple parachute system.
Technology Readiness levels [6-9]
6. System/subsystem model or prototype demonstration in a relevant environment: Representative model or prototype system, which is well beyond the breadboard tested for TRL 5, is tested in a relevant environment. Represents a major step up in a technology's demonstrated readiness. Examples include testing a prototype in a high fidelity laboratory environment or in simulated operational environment.
7. System prototype demonstration in an operational environment Prototype near or at planned operational system. Examples include testing the prototype in a test bed aircraft.
8. Actual system completed and 'flight qualified' through test and demonstration.
9. Actual system 'flight proven' through successful mission operations.
They are expecting to get to a flight test in 2010.
April 24, 2008
Carnival of Space Week 51
Carnival of Space Week 51 is up at astroengine.
I contributed my article on the Finnish solar wind riding electric sail, which is nearing readiness for flight testing
Centauri Dreams talks more about the electric solar space sail.
Colony Worlds talks about the need for ants for space colonies. Bees could have problems with the different or lack of magnetic fields. Ants might be needed to take the place of Bees for pollination.
Ethan Siegel ponders what it would take to destroy the Universe. Using a particle accelerator with a radius that would span 10**14 kilometres (or from Earth to the nearest star system) might be able to do it)
Go to astroengines for a lot more.
April 16, 2008
Solar Wind Electric Sail Propulsion planning test mission
A simplified picture of the electric sail. An actual system would have 50 to 100 or more 20 kilometer wires. 100 kg spaceships could be accelerated to final speeds of 40-100 km/second. The electric sail is an extremely promising new propulsion technique which is nearly ready to be tested. If electron heating turns out to be successful performance may be increased even more. Costs for solar system missions will go down and new capabilities and performance will be possible.
The electric solar wind sail developed at the Finnish Meteorological Institute two years ago has moved rapidly from invention towards implementation. The main parts of the device are long metallic tethers and a solar-powered electron gun which keeps the tethers positively charged. The solar wind exerts a small but continuous thrust on the tethers and the spacecraft.
"We haven't encountered major problems in any of the technical fields thus far. This has already enabled us to start planning the first test mission,” says Dr. Pekka Janhunen. An important subgoal was reached when the Electronics Research Laboratory of the University of Helsinki managed to develop a method for constructing a multiline micrometeoroid-resistant tether out of very thin metal wires using ultrasonic welding. The newly developed technique allows the bonding together of thin metal wires in any geometry; thus, the method might also have spinoff applications outside the electric sail.
The electric sail could enable faster and cheaper solar system exploration. It might also enable economic utilisation of asteroid resources for, e.g. producing rocket fuel in orbit.
Deploying the wiresAn ideal (i.e. fully reflecting) solar sail receives a radiation pressure force of 9μN/m2 at 1AU distance from the Sun. Let us calculate how thin a solar sail should be, to reach the same specific acceleration as an electric sail wire plus electron gun subsystems. Using an 82 km/s final speed, one obtains that the solar sail should have an areal density of 1.1 g/m**2, which translates to 200 nm thickness if the material is aluminium and 50% of the mass is assumed to go to support structures. This is 5–10 times thinner than present technology.
The electric sail resembles the solar sail in that it provides small but inexhaustible thrust which is directed outward from the Sun, with a modest control of the thrust direction allowed (probably by a few tens of degrees). Some possible missions:
1. Missions going outward in the solar system and aiming for >50 km/s final speed, such as missions going out of the heliosphere and fast and cheap flyby missions of any target in the outer solar system. 2-4 years to Pluto instead of 10 years with chemical rockets and gravity slingshots.
2. By inclining the sail to some angle it can also be used to spiral inward in the solar system to study e.g. Mercury and Sun. Also a nonzero inclination with respect to the ecliptic plane is possible to achieve which may be beneficial for observing the Sun. Also the return trip back to Earth from the inner solar system is possible, as is cruising back and forth in the inner solar system and visiting multiple targets such as asteroids.
3. the electric sail could be used to implement a solar wind monitoring spacecraft which is placed permanently between Earth and Sun at somewhere else than the Lagrange point, thus providing a space weather service with more than one hour of warning time. Propulsion and data taking phases probably must be interleaved because ion measurements are not possible when the platform is charged to high positive voltage, although the plasma density and dynamic pressure of the solar wind can probably be sensed by an electron detector and accelerometer even when the electric sail voltage is turned on.
4. Once accelerated to a high outward speed an electric sailing spacecraft cannot by itself stop to orbit a remote target because the radial component of the thrust is always positive. For stopping under those circumstances one has to use aerocapture or some other traditional technique. Although the electric sail does not provide a marked speed benefit for such missions, being propellantless it might still provide cost saving; this remains to be studied. In interstellar space the plasma flow is rather slow. Thus the electric sail cannot be used for acceleration, but it can instead be used for braking the spacecraft.
5. It might also provide cheap transportation of raw materials such as water mined from asteroids and used for in-situ fuel making at high Earth orbit.
March 18, 2008
Supercompressed silicon and hydrogen superconducts at room temperature
A new superconducting material fabricated by a Canadian-German team has been fabricated out of a silicon-hydrogen compound [after supercompression, 96-120GPa] and does not require cooling. They had to keep the material under pressure (100GPa) in order to get it to superconduct.
CORRECTION: The press release talked about not using refrigerant and EEtimes said room temperature superconductor. They believe that the new silane / hydrogen compounds could reach room temperature superconducting levels. The temperature at which superconductivity occurs exhibits some interesting behavior. It hangs around 5-10K for most of the pressure range (50-200GPa), but in a small range between 100-125GPa, it increases quite sharply. Although the researchers only have five data points in the range and never observed a critical temperature higher than 20K, the shape of the curve indicates that, for some small range of pressures, a very high critical temperature might be achieved. So they still have to investigate the critical pressure range and possibly other compounds and still get them to work after pressure is removed. The other unpressurized material which could be superconducting at 185K are closer to being possible improved application, but they need some more independent confirmations.
So there is still work to do to make this more practical. Figure out a way to quench the metal such that it stays and metal and superconducting when pressure is removed or figure out a better but similar material. There is also the early word on the non-pressurized advances to -87C. This is at the cusp of a decent lab freezer, that easily go down to -86C. A lot of improvement and activity in the area of superconducting material seems to be happening now.
ANOTHER UPDATE
Fullerenes could theoretically be loaded with hydrogen (or other gases like silane) into the range of the correct pressure. The problem is still being able to do it and what the actual peak critical temperature is at optimal pressure The best route is probably to learn more about superconductors from these materials and then figure out a better compound that does not require these extreme efforts.
UPDATE: 3 page pdf on the methods used for the experiment.
We have used diamond anvil cell equipped with beveled diamonds and gasket made of cubic BN powder mixed with epoxy. Commercial silane of 99.99% purity (Air Liquide) was loaded trough capillaries into a small cavity surrounding diamonds where it was condensed at ≈112-150 K. All the system was carefully checked with a helium leak detector to be ensured the absolute tightness − a necessary precaution because silane is a pyrophoric substance.
Decomposition can indeed occur when silane was loaded at P<50 GPa and warmed to room temperature. In this case we clearly observed Si at the X-ray diffraction patterns, and the H2 vibron in Raman spectra even not from transparent but metallic sample at higher pressures. Thus, we avoided decomposition by loading silane and performing further measurements at low temperatures below 120-150 K. We warmed the sample up to 300 K only at pressures above 100 GPa. X-ray diffraction measurements proved that no Si phase appeared in this case. It is important that with our sensitive Raman setup we observed no hydrogen vibrons either in the sample or in the surrounding transparent cBN gasket.
This follows the recent news of higher critical temperature superconductors that are made under normal pressure at up to 185K or -87C.
"If you put hydrogen compounds under enough pressure, you can get superconductivity," said professor John Tse of the University of Saskatchewan. "These new superconductors can be operated at higher temperatures, perhaps without a refrigerant."
He performed the theoretical work with doctoral candidate Yansun Yao. The experimental confirmation was performed by researcher Mikhail Eremets at the Max Plank Institute in Germany.
The new family of superconductors are based on a hydrogen compound called "silane," which is the silicon analog of methane--combining a single silicon atom with four hydrogen atoms to form a molecular hydride. (Methane is a single carbon atom with four hydrogens).
Researchers have speculated for years that hydrogen under enough pressure would superconduct at room temperature, but have been unable to achieve the necessary conditions (hydrogen is the most difficult element to compress). The Canadian and German researchers attributed their success to adding hydrogen to a compound with silicon that reduced the amount of compression needed to achieve superconductivity.
In an article published today in the prestigious journal Science, the team has produced the first experimental proof that superconductivity can occur in hydrogen compounds known as molecular hydrides.
In related research, Tse’s team is using the Canadian Light Source synchrotron to study high pressure structures of other hydrides systems on potential superconductivity and making use of them to store hydrogen for fuel cells.
WHAT WOULD COMMERCIALLY USABLE ROOM TEMPERATURE SUPERCONDUCTORS MEAN ?
BBC News talked about that anticipated but delayed vision from the hoped for results from the 1987 "warmer" superconducting breakthroughs.
Levitating high-speed trains, super-efficient power generators and ultra-powerful supercomputers would become commonplace thanks to a new breed of materials known as high temperature superconductors (HTSC).
Those difficult to manipulate superconductors have been on track to make smaller and more efficient motors with commercial impact in 2010 South Korea was making significant advances with 1300hp superconducting generators.
They were also being tested in 36.5 MW motors for navy ships.
Here was a more recent list of predictions of what "warm" superconductors that we had before the most recent two announcements could provide. 100Tbps routers, faster communications, faster computers, better sensors and more. Room temperature versions would make all of these things cheaper, more widespread and more powerful.
If the new room temperature superconductors have or can be made to have a very high current density relative to their weight, then there is the possibility of a ground launched magnetic sail or high performance magnetic sails for space propulsion.
31 page pdf of the 1999 Zubrin study for Nasa on magnetic sails
Getting up to 100 billion to 1 trillion or more amperes per cubic meter is the current density for high performing magnetic sails.
D.G. Andrews and R.M. Zubrin, "Magnetic Sails and Interstellar Travel." Journal of the British Interplanetary Society, 1990. The first paper published, concerned primarily with the cost savings to other propulsion systems from the use of the magsail as an interstellar brake.
R.M. Zubrin and D.G. Andrews, "Magnetic Sails and Interplanetary Travel." Journal of Spacecraft and Rockets, April 1991. The technical description and very thorough analysis of the magsail for interplanetary travel. Excellent.
R.M. Zubrin, "The Magnetic Sail." Analog Science Fiction & Fact, May 1992. A version of the above paper edited for a non-technical audience. Useful for general concepts, inadequate for a full understanding.
FURTHER READING
Superconductivity in Hydrogen Dominant Materials: Silane [journal Science abstract]
M. I. Eremets,1* I. A. Trojan,1 S. A. Medvedev,1 J. S. Tse,2 Y. Yao2
The metallization of hydrogen directly would require pressure in excess of 400 gigapascals (GPa), out of the reach of present experimental techniques. The dense group IVa hydrides attract considerable attention because hydrogen in these compounds is chemically precompressed and a metallic state is expected to be achievable at experimentally accessible pressures. We report the transformation of insulating molecular silane to a metal at 50 GPa, becoming superconducting at a transition temperature of Tc = 17 kelvin at 96 and 120 GPa. The metallic phase has a hexagonal close-packed structure with a high density of atomic hydrogen, creating a three-dimensional conducting network. These experimental findings support the idea of modeling metallic hydrogen with hydrogen-rich alloy.
1 Max Planck Institute für Chemie, Postfach 3060, 55020 Mainz, Germany.
2 Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, S7N 5E2, Canada.
On leave from A. V. Shubnikov Institute of Crystallography, Russian Academy of Sciences, 117333, Leninskii Avenue 59, Moscow, Russia.
February 07, 2008
Carnival of Space Week 40
Carnival of Space #40 is up at orbiting frog
I contributed my article on SpaceX's progress on the Falcon 9 rocket
Hobby space updates the activites of Bigelow Aerospace who are making an inflatable space hotel
Centauri Dreams lives up to its siet name with a talk about the Longshot space mission. It was a plan to develop technologies over 20-30 years for a 100 year mission to reach the alpha centauri solar system.Longshot was conceived as being built with modular components on the ground and then launched to low-Earth orbit for assembly at the space station presumed to be operational there. The enabling technologies included a “pulsed fusion micro-explosion drive” (I’m quoting from the Project Longshot report) with a specific impulse of 1 million seconds, along with a long-life fission reactor with 300 kilowatts power output.
The Longshot pdf report is here
Hypersonic vehicles designs and progress
From the designers of Skylon, a fairly practical spaceplane designs, comes the Mach 5 A2 commercial Concorde replacement. The A2 and the Scimitar engine are more affordable and longer lasting versions of the Skylon spaceplane and Sabre engine.
Analysis of the Development, Production and Operating costs suggests that the average ticket price would be comparable to an existing Business class ticket. The A2 vehicle could capture all of the current business and first class traffic due to the greatly reduced journey time of 4.6 hours compared to the current 22 hours.
Unlike Concorde the A2 vehicle has exceptional range (approx 20,000 km both subsonic and supersonic) and is therefore able to service a large number of routes whilst simultaneously avoiding supersonic overflight of populated areas. Its good subsonic performance enables it to service conventional subsonic overland routes thereby increasing its sales potential to airlines.
To achieve the range requirement liquid hydrogen fuel is mandatory since the specific calorific energy of hydrocarbon fuels is too low. Reaction Engines have conceived the Scimitar precooled engine concept which exploits the unique thermodynamic properties of liquid hydrogen. 
The Scimitar Engine is a derivative of the Sabre spaceplane engine intended for SSTO launcher application. Consequently most of the Scimitar engine technology is similar to Sabre but designed for much longer life. Both engines are designed around existing gas turbine, rocket and subsonic ramjet technology. However the incorporation of lightweight heat exchangers in the main thermodynamic cycles of these engines is a new feature to aerospace propulsion.
The A2 is larger than an Airbus A380 super jumbo jet.
FURTHER READING
More pictures of the A2
The Reaction Engines site who have designed the Skylon space plane and the A2 commercial transport (The A2 is also referred to as the Lapcat project, Long-Term Advanced Propulsion Concepts and Technologies project)
Skylon Images
The key to the Skylon and A2 planes are precooled engines as explained in this 9 page pdf.The issues relevant to propulsion design for Single Stage To Orbit (SSTO) vehicles are considered. In particular two airbreathing engine concepts involving precooling are compared; SABRE (Synergetic Air-Breathing and Rocket Engine) as designed for the Skylon SSTO launch vehicle, and a LACE (Liquid Air Cycle Engine) considered in the 1960’s by the Americans for an early generation spaceplane. It is shown that through entropy minimisation the SABRE has made substantial gains in performance over the traditional LACE precooled engine concept, and has shown itself as the basis of a viable means of realising a SSTO vehicle. Further, it is demonstrated that the precooler is a major source of thermodynamic irreversibility within the engine cycle and that further reduction in entropy can be realised by increasing the heat transfer coefficient on the air side of the precooler. If this were to be achieved, it would improve the payload mass delivered to orbit by the Skylon launch vehicle by between 5 and 10%.
The US hypersonic program is also looking to use fuel to cool the engine of its hypersonic planes.Successful recent ground tests of jet-fueled, ramjet/scramjet demonstrator engines by Pratt & Whitney Rocketdyne and Aerojet represent important progress toward flight-testing of three separate hypersonic-vehicle programs.
Using JP-7 jet fuel, PWR ran the combustor successfully at a variety of Mach numbers from Mach 2.5 to Mach 6.0, demonstrating "desired operability and performance" at each speed, the company said.
FaCET aims to develop a hypersonic test vehicle -- which could fly in 2012 -- that would take off and land by itself, use an advanced turbojet to get up to a speed of at least Mach 4 and then use a liquid hydrogen-powered scramjet to get to Mach 10 and beyond. Jet fuel can't be used as a scramjet fuel at speeds as high as Mach 10.
The US should be flight testing an unmanned mach 10 aircraft in 2008
NASA hypersonics expert Dr Isaiah Blankson believes that MHD energy-conversion in the intakes can take 30-40% of the energy, letting a turbine engine run at up to Mach 7. One engine able to take the plane all the way to Mach 7 and have a lot of extra power for things like military lasers or railgun launchers.The advantage of this proposal is that it seems like a simpler design than some other proposals for scramjets Scramjets promise to be better than rockets by not needing the 75% of the weight which is oxidizer, but designs need to simpler and not replace the oxidizer with a heavier and more expensive aircraft.
Reportedly, Blankson says extracting 30 to 40 per cent of the inflow energy would cut its speed by 50 to 75 per cent. That sounds counterintuitive, as kinetic energy is proportional to the square of velocity, but presumably a man with his background knows what he's on about. Potentially, a Mach 7 flow would slow to Mach 3 downstream of the MHD, and then a Blackbird type setup could handle it.
January 23, 2008
Virgin Galactic revealed and compared to shifting NASA plans
The biggest twist is that the WhiteKnightTwo plane has spread out and sprouted another passenger cabin on its 140-foot-long wing. The two cabins and four Pratt & Whitney jet engines straddle a central mount for the rocket plane, which will be carried to an altitude of 50,000 feet and dropped. Then SpaceShipTwo will light up its hybrid rocket engine for the final push to the edge of outer space.
UPDATE:
Scaled Composites plans to build 40-50 launch aircraft. At least 15 will be used for space tourism, with the rest used for satellites and other payloads.
Virgin Galactic says it thinks it could launch small satellites in the range of 50-100kg into low-Earth orbit using an unmanned rocket hung from White Knight Two for less than $2.5m.
They have spent $70m already and will spend another $130 million. Virgin Galactic expects to break even in 2014. Reducing the price of a trip into space to attract more customers is also part of the plan, as is exploiting every possible form of additional income, such as selling media rights.
Live coverage from Wired of the event
I think a related news is that on Feb 12-13 there will be "leaders of the space community" who will look at forming an alternative to the Lunar Vision for Space Exploration centered around manned asteroid landings. If alternative-vision planners have their way, the mission could instead be flown to an asteroid in about 2025 as opposed to the original and uncertain 2020 target for a lunar landing. The contrast between NASA plans and Virgin galactic will be discussed below.
Artistic representation of Scaled Composites spaceshiptwo in space. Eight seater craft, seating 2 pilots and 6 passengers, which will be used by Virgin Galactic passengers.
White Knight 2
The new White Knight 2 mothership, says Whitehorn will have four jet engines and is a significant departure from the first White Knight.
The mothership is 70 percent complete and will be the largest all-carbon-composite airplane in the world. Test flights are expected to begin this summer.
More on the shifting Nasa plans:
The asteroid visit and Lagrangian mission concepts would use much of the same CEV Ares I and Ares V heavy-lift booster infrastructure, but in ways that would be much faster stepping-stones to Mars than developing a manned lunar base. Asteroid and Lagrangian point missions would each last several weeks or months. Both the libration points and asteroids would be about 1 million mi. from Earth, requiring operations more like much longer trips to Mars at least 40-100 million mi. away.
Robotic options for all mission elements also will be reviewed, and one working group will be devoted to better defining manned versus robotic tradeoffs.
White Knight 2 model
Contrast of Nasa plans with Virgin Galactic.
Nasa plans if they are successful do not achieve the main program milestones until 2025 or 2020. Virgin Galactic could start flying passengers in late 2009.
Virgin Galactic could expand the number of people (passengers) who get to fly by 10 to 1000 times versus the NASA plans. Seats on spaceshiptwo cost $200,000. Virgin Galactic says more than 200 individuals have booked, and another 85,000 have registered an interest to fly. Tens of millions of dollars in deposits have already been taken. If set prices drop to $100,000 each then 85,000 people would generate $8.5 billion in revenue. This could make spaceshipthree (an orbital system) fully fundable from Virgin Galactic operational profits.
Virgin Galactic appears to be offering a path forward to safer (100 times or more safer) and cheaper travel into space for a lot more people. NASA plans are for multi-billion new hardware (which does not have interesting new capabilities beyond what is currently available) and on the ground jobs for the current bureaucracy and plans for a few elite astronauts to go on short term missions.
Virgin Galactic has systems that leverage and build upon the best of what has gone before. NASA plans restart development every few years and costs are constantly escalating.
NASA plans are centered around justifying building the CEV Ares I and Ares V heavy-lift booster infrastructure. Before that it was around justifying building the International Space station. Before that it was around justifying the Hubble Space telescope and the Space shuttle. The hardware should be about supporting the missions and finding ways to increase safety and lower costs and expand capability.
NASA should look at shorter development cycles. What can NASA deliver in 4 years that can reduce costs and add new capability ?
Low orbit fuel space stations would fit that short development timeline and provide useful value for later missions both by NASA and private industry.
Missions for better propulsion (better ion drive, Vasimr, laser array launches etc...). Fuel efficient electric engines for LEO to moon, langrange points, asteroids etc...
Development of space mining and resource utilization. Generating oxygen from regolith etc...
December 20, 2007
Carnival of Space 34
The Carnival of Space 34 is up at Rainer Gerhards space launch blog.
I provided my updated look at the status of scramjets
Colony Worlds considers gravity suits for offworld children
A Babe in the Universe reports on the Gravity Recovery and Interior Laboratory mission to study the moon
There is a lot of speculation about gamma rays and 3C321 (a galaxy blasting another galaxy with fatal radiation).
Centauri Dreams analyzes gamma rays and civilization
December 18, 2007
Cuttlefish bones template for new superconductors with almost 100 times higher current density
UK chemists have used cuttlefish bones to template the growth of new superconductors that have almost 100 times higher current density. The weight of 1 cm**3 of superconducting cuttlebone replica is 0.06 g, compared to 6.38 g in the case of an equivalent sized monolith of pure Y123. With an overall decrease in mass of two orders in magnitude, these materials could well find application in areas where weight is of critical importance, such as space-based and mobile device technologies. It is envisaged too, that our method could apply equally well in the synthesis of light and porous giant magnetoresistive, piezoelectric and ferromagnetic materials.
Cuttlefish
Cuttlefish bone templated superconductor
A very high critical current density using light weight material can enable far better magsails. These lightweight and high critical density superconductors could even enable ground launched magsails. They need to find a good way to reinforce the structural strength (perhaps carbon nanotubes) that do not reduce the critical current too far and they need to produce the superconductors in high volume and a reasonable cost and preferably in the form of wires. Note: they have proved that an ordered, macroporous morphology provides a greatly improved critical current density. Therefore, any other means of creating ordered macroporous morphologies (such as three dimensional nanostructuring) can be used as well and could allow for a better tuning of the critical current and structural strength properties.
The critical current density of the cuttlebone templated Y123 was measured at 1.6 MAcm−2 at 10 K and 1 T field. This is almost two orders of magnitude higher than that observed in a commercially available Y123 powder (Aldrich 99.9% — average particle size 5 µm), for which SQUID magnetometry revealed a Tc of 92 K and a critical current density of 0.02 MAcm−2 at 10 K and 1 T field.
Chart of current density and magnetic field strength
In terms of mechanical strength, the cuttlebone-templated superconductors are self-supporting but very weak (<1.5 kPa). After calcination (with 10% silver nitrate), the monoliths were noticeably more structurally stable. Compressive strength testing confirmed this, with monoliths capable of withstanding a compressive strength of 27.95 kPa, a figure comparable with certain roofing materials used in the construction industry. EDXA revealed the presence of silver in the material, and PXRD showed more pronounced peaks due to Y123 than in the undoped sample, confirmation that the silver is promoting a more pronounced crystalline structure. SEM images show that the silver doped replicas retain the cuttlebone morphology exceedingly well, even to the extent that the fine structure of the S-shaped pillars are reproduced in detail. TEM revealed that the crystallite size was now 3 µm ± 0.2 µm, larger than seen in the undoped samples. This increase in crystallite size has ramifications for the electronic behaviour of these materials, as an increase in crystallite size can often lead to a decrease in critical temperature and current. SQUID magnetometry confirms this, with a pronounced decrease in both Tc (to 73 K) and Jc (to 0.16 MA cm−2) of the silver doped samples. It is apparent therefore, that a balance must be struck between an improvement in compressive strength and the electronic performance of the superconducting monolith.
Simon Hall at the University of Bristol and colleagues soaked the cuttlefish bone - cuttlebone - in a solution of the precursors of the yttrium barium copper oxide superconductor Y123 and then heated the sample to over 900 °C to form the superconductor. Cuttlebone has an open structure, consisting of calcium carbonate layers connected by pillars. This allows the sample to be oxidised efficiently when heated, so unlike other synthesis methods flowing oxygen is not needed to produce high quality Y123.
The researchers found that the complex porous structure of the cuttlebone was retained, giving a lightweight superconducting material. They also discovered that the critical current density of their material was almost two orders of magnitude higher than that of the commercially available Y123 powder.
FURTHER READING
Magsail analysis for a game using real equations.
Enhancing magsail launches using light weight high volume magnets and a big lightweight tower.
December 05, 2007
Carnival of space week 32
Carnival of space 32 is up at robot guy
My entry was on my favorite proposed launch systems
Bad Astronomy talks about using Mass as a verb
Colony worlds talks about energy in space from space solar and helium 3
Space files mentions that the Planetary Society has raised $250,000 for a second space sail
Centauri Dreams talks about young stars and old planets
Note: My wife and I just had our second child. So posts are light this week.
November 30, 2007
A review my favorite space launch and propulsion systems
Accelerating future had reviewed systems for getting into space in 2006
I had covered the EM drive but is definitely one of the long shots with a lot of unknowns in the science (ie. I seriously doubt that it will work).
My preferences are for:
Bussard IEC fusion earth to orbit spaceship. Credit: Tom Ligon and EMC2fusion
Fusion propulsion if Bussard IEC fusion or Trialpha energy colliding beam fusion or laser fusion or Z pinch fusion work. The fusion systems would have a superior version for getting from ground to orbit. However, as we have experienced fusion technology could disappoint and take longer than we would like to develop.
Laser launch concept
Laser mirror concept for station keeping. For laser mirror propulsion, there would be an array of large (100+ kw solid state) lasers firing at one of the mirrors and the other non-moving mirror would be on the moon or the earth.
Mirror Laser array launches Solid state high power lasers are progressing far faster in power and efficiency than many people realize. I think convergence of technology could make this happen far quicker than many would expect. It would bring the cost of launches down to about the cost of electricity (even better with mirror systems)
I would really like it if people would become rational and allow nuclear rocket launches. The liberty ship is one that could luanch 1000 tons at a go and would not release radiation into the atmosphere I think nuclear rocket systems would be safer than chemical and space planes because there is so much safety margin to play with.
Project Orion definitely made sense. It would be cheaper than the space elevator. The launch cost for the largest Orions was 5 cents per pound (11 cent/kg) to Earth orbit in 1958 dollars. In 2005 dollars, the cost would be 32 cents/lb or 70 cents.
Minimag Orion and other external nuclear pulse propulsion systems One thing to note is the pussy footing around with sub-critical explosions is stupid if we have technology for achieving 10+% of the speed of light and have 20+GW laser arrays. 10 kiloton TNT equivalent bombs would be like hand grenades.
What seems like a cheap system for bringing the cost of gravity hardened systems and cargo into space for less than 25% of current costs is ram accelerators (big guns)
A nuclear powered vasimr might look more like this nuclear electric vehicle. Replace the MPD thrusters with vasimr engines, replace the Brayton units with advanced thermoelectric devices. 
Image of a vasimr rocket
Nuclear powered Vasimr for getting around from orbit to other places
My issues with the space elevator is that it will take longer than I would like to make it happen. It brings the goal of bringing the cost of getting to space to approach the cost of the electricity to lift mass to the right height. The mirror laser array system seems like something that could come together faster than the space elevator. I also prefer a longer space pier over the space elevator. However, I still support the space elevator project because other approaches might have development delays as well. Capturing mind share and imagination are useful things for making something happen.
I am also concerned about the performance of the recent contest climbers when they could not climb because of wind. The actual climbers will have to go through high winds at higher altitudes. I do not think this is a show stopper but a possible show delayer.
J Storr Hall's space pier seems like a better approach than the space elevator. One design would lift 10-ton payloads up a 100 km elevator and then accelerating it to 8