probationary second string substitute apprentice relief blogger in training john hare
I had a thought on a concept that’s even weirder the most the ones that I have. I have long thought that the most useful product the moon has its’ energy of position. Finding a way to use that energy of position is the problem.
I have suggested inverse aero braking, which is lunar volatiles in an earth grazing trajectory smacking the heatshield of a suborbital vehicle to raise it orbital velocity.
A concept that seems popular is having rotovators in Earth orbit. The rotovators can pick up suborbital vehicles and accelerate them to escape velocity. They can also collect incoming payloads from the moon and other parts of the solar system and lower them to suborbital velocity. The momentum exchange could balance out lifting payload from earth and accepting payload from other parts of the solar system and the moon with a net zero use of propellant.
This is another concept entirely. If a volatile unit from the moon was placed in an earth grazing trajectory, and that unit smacked a volatile unit in a vehicle on a suborbital trajectory from the earth in the opposite direction, the impact velocity would be on the order of 14 km/s. If both of these volatile units were water, the impact velocity would impart an energy to these units that was on the order of nine times the energy released from a hydrogen oxygen rocket engine. If these two units of water were nine times the temperature obtained by normal hydrogen oxygen rocket engine, an Isp of 3 times the 450 seconds obtained by the normal rocket engine would be theoretically possible. Obviously this would not work exactly like that because the average velocity of the two units would be 7 km/s toward the rear of the craft before any propulsion was realized.
My question is, how much propulsion could be realized from this impact in this vast amount of energy released? It would seem that the craft could realize an Isp of 650 seconds of which half of that would be from lunar material. Therefore it seems possible that the vehicle could experience an effective Isp of 1300 seconds when it is traveling at 3 km/s toward the incoming stream of particles.
As the suborbital craft accelerates to orbital velocity, the impacts will become ever more energetic. By the time the vehicle reaches orbital velocity the impacts of the two volatile units will be over 19 km/s. This would release over 16 times the energy released by the standard hydrogen oxygen rocket engine per unit mass. With half of the mass supplied by lunar sources,Isp should be even higher than in the preceding example. Effective Isp would seem to be on the order of 1800.
The problem with this thought experiment, is that I do not have the tools to calculate what would really happen. I’m hoping someone that reads this has both the tools and interest to take a look at it and find out if there’s anything worth pursuing.
One of the issues would be what proportion of mass would be most efficient if this concept actually worked. Would it be better to have a small amount of lunar material releasing a lot of energy into a larger amount of earth material, or would it be better to have as much lunar material as possible with just enough earth material to generate the heat. Which kind of material would be best? Is it actually water, hydrogen, or just lunar regolith to to impart the energy.
Given all the super precise targeting available now, how likely is it that this could even be made to work if the energy worked out. The bullet hit bullet accuracy seems to already exist, but this would be machine-gun bullet hit bullet. How much tracking and control would have to be in the pellets coming from the moon, and how much in the ship that was aiming for them? How much space would need to be between the pellets to keep the ship on course? How would one mitigate the damage from a lunar pellet that missed? Is it even possible to mitigate the damage?
Assuming this could be made to work, and insane values of Isp were available from plain water, massive tonnage could be raised from the earth. Thousands of tons could be assembled in low Earth orbit for a Mars mission. Tens of thousands of tons could be assembled in low Earth orbit for solar power satellites. Then the same method could be used to raise those tens of thousands of tons to geostationary. The lunar economy could be self-supporting in just a few years if this technology worked.
If this technique is useful, then the outer solar system would be within quick reach. A ship following a pellet stream that had been placed by slower ship, could accelerate to velocity’s that would bring one to Jupiter in a few months. A probe to Pluto could possibly make the trip in two years or less. The Oort cloud could be explored by groups of fairly small probes within the working lifetime of a dedicated researcher.
The Space Show, hosted by David Livingston at www.TheSpaceShow.com, will have the following guests this week:
1. Monday, Juni 15, 2015, 2-3:30 PM PDT (21-22:30 GMT)
RANDA and ROD MILLIRON of Interorbital Systems.
Randa Milliron is the CEO and co-founder of Interorbital Systems (IOS), a private-sector rocket manufacturing and orbital space launch corporation based in Mojave, California. Randa holds a BA in Psychology and an MA in African Languages from Duquesne University. She is a do [...]
Second string substitute apprentice relief blogger in training john hare
The various antics of our elected officials in Washington tend to bring into question their motives and loyalties. The commercial crew cuts by the house that were cut even further by the senate seem to be a gambit to downselect to a single provider. Boeing being the likely selectee.
One problem with this is that commercial crew is heavily politicized. A down select to one will cause outcry from the other. So there will likely be some form of compromise unless the full senate increases the item toward the original request. If the commercial crew budget stays low however, and they try to split it up in some seemingly fair manner, Boeing will push the schedule out by years. If pushed out enough years, their participation will become visibly non viable. Somewhere around that point, Boeing could be encouraged to walk away from commercial crew as too much trouble. That would be more or less a voluntary downselect. If there is a functional downselect to SpaceX this way, seemingly by accident, the senate and house could in good conscious reduce item funding to $600M or so and brag about the savings even if it basically happened by accident and opposite intent.
Could be quite entertaining across the next several years.
Rosetta's lander Philae has woken up after seven months in hibernation on the surface of Comet 67P/Churyumov-Gerasimenko.
The signals were received at ESA's European Space Operations Centre in Darmstadt at 22:28 CEST on 13 June. More than 300 data packets have been analysed by the teams at the Lander Control Center at the German Aerospace Center (DLR).
"Philae is doing very well: It has an operating temperature of -35ºC and has 24 Watts available," explains DLR Philae Project Manager [...]
Second string substitute apprentice relief blogger john hare.
In my last post I described a new type of turbojet based on my cage jet of years ago. The engine I described has the capability of good thrust and good fuel economy which is ideal for launch assist platforms. Launch assist platforms want to have the capability of lifting very heavy loads off runway, and taking them to very high altitudes, and pitching up in a gamma maneuver that allows near vertical launch of the orbital vehicle. Sometimes they want to cruise to a particular launch location and cruise back to base.
In order to reduce upfront investment, most of us start by looking at existing aircraft that can be modified for our purposes. That is almost certainly the way to get started, but has the problem of limiting our capabilities to that of whatever carrier aircraft is selected. The problem with designing our own Launch Assist Platform Aircraft, is that it adds a tremendous amount of expense to a project is almost always funds limited. To date, the launch assist platform aircraft that have been designed have been designed by aircraft designers that are going for extremely capable aircraft, but don’t seem to have much input from the launch industry. The White Knight series of lifters exemplifies this.
I suggest what should be done is design the aircraft around the launch vehicle, instead of vice versa. We should also design around available finances, skill sets, and available ground facilities.
First thing is the launch vehicle payload required, which defines the rocket vehicle, and dictates the capabilities of the Launch Assist Platform Aircraft. It is necessary that we make an assumption about the maximum payload that this system will will want to place into orbit. For the purposes of this blog post, I am going to make the assumption that it is desired to place 25 tons in orbit as a maximum payload. While this is much less than the heavy lift vehicle’s several companies are considering along with NASA and the United States Congress, it is quite sufficient for almost any mission we see in the next decade, as long as we assume orbital tugs and propellant depots. By developing the launch assist platform now with its attendant launch vehicles, a revenue stream can be developed first, which can then be enhanced by the orbital tugs, and the propellant depots.
Designing the launch assist platform aircraft, is much like designing the foundation for a multi-story building. When designing a building you do not start with the foundation, you start with a roof. Then you design the top floor which also carries the loads of the roof, then the second from the top floor, all away down to the basement. Only after all that do you design the foundation of the whole building. In a similar manner we have to work backwards from the payload to the launch assist platform aircraft. If we assume a basic launch architecture of launch assist platform, and single stage from there to orbit, the mass ratio can be on the order of 12 with high-performance kerosene engines. The dry mass would be on the order of 4% each for payload and vehicle.
4% net for a payload of 25 tons gives a rocket vehicle of 625 tons. This becomes the desired payload of the launch assist platform aircraft. This is clearly beyond the capability of any existing aircraft including the White Knight 3. This is the technical requirement based on my assumptions.
Available finances dictate the actual capabilities we will end up with. Trying to design a conventional aircraft with the capability of 625 tons in external carrying capacity is not going to work. There’s not enough work for that vehicle to use on other projects which means that the launch assist platform aircraft must carry the entire burden of cost simply on launch revenue. Available finances are the funds that can be spent on the vehicle considering ROI, and not based on some percentage of a billionaire’s net worth, or how much money can be conned from the United States Congress. The 25 ton payloads, at the pricing that can be expected a decade from now when the system would hit its’ prime dictates how much money could be spent now if we assume that the system is flying at least daily. Since it could be competing against $500 a kilogram or less from other companies, the finances suggest a gross revenue of about 12 1/2 million dollars per flight. Subtract fixed and marginal costs from that number, and multiplied by the number of flights expected annually, and we get a number 10 years out that we can work backwards to find the amount of money available today. Since the LAP is only one component of a two unit system, it is only worth a percentage of the total. The rocket stage will get the lions share of the costs and investments leaving perhaps 2 million per flight available to service the debt on the LAP after its’ own fixed and marginal costs. Assuming a flight rate of 250 per year, and revenue available for debt interest is $500M per year. A high risk debt can be expected to have an effective interest rate on the order of 25%. So the vehicle debt at that price range and interest can be no more than $2B.
If we assume that the initial investment covered a development time of six years, and a further four years was spent ramping up business, and the interest on the development money was at 25%, then there would be something on the order of $200 million available to develop the launch assist platform. The only way this can possibly be done for that number is if the vehicle though very large is very very simple.
The second requirement is to design the launch assist platform around the available skill sets of the people available to the project. Since this is a blue sky concept, I am going to assume that reasonably competent but not brilliant designers are available, along with a workforce that is motivated and experienced at the construction method under consideration. This requires that the construction method under consideration be very simple.
The vehicle must also be designed around available facilities. This is fairly simple, runways and available hangers will limit the design. Runways have length, width, and weight limitations. Hangers have length and width limitations unless you build a fancy and very expensive new structure. Since the 625 ton upper stage will probably be matched by a 625 ton launch assist platform, the runway must have the capability of handling 1250 tons. Since this exceeds any aircraft ever built the weight must be distributed over wider areas that any aircraft landing gear has ever experienced before. 1250 metric tons is 2,750,000 pounds. 2,750,000 pounds can be accommodated by using a hovercraft undercarriage of the type that was experimented with 50 years ago. If we assume a very high wing loading, there will be something toward 30,000 ft.² of wing area. It will take a very low aspect ratio wing to fit in the available facilities. The aspect ratio will probably actually be around 1.5.
In the cartoon you can see the hammerhead shroud hanging over the front of the vehicle. The cage jets are inside of the wings. And instead of wheels underneath there are hovercraft skirts to spread the load across the whole runway.
The way I see it this launch assist platform will be a flying wing with a wingspan of about 200 feet and a length of about 200 feet with sweep to wingtips are still 100 feet long. The launch vehicle will ride on top of the wing centerline. The hammerhead shroud will protrude in front of the vehicle. There will be a huge cage jet mounted inside each wing. Each cage jet will mass about 40,000 pounds and have a thrust of 1,000,000 pounds. The airframe should be around 10% of takeoff mass and will be about 125 tons for airframe. With engines and airframe at 165 tons, and other required systems at 35 tons, there will be about 425 tons of fuel available to cruise and accelerate. Enough fuel will have been burned by the time of the gamma maneuver, that the vehicle can accelerate at a fairly high rate during the gamma maneuver on cage jets alone. The rockets on the launch vehicle can be lit before separation allowing rocket systems checkout during the maneuver. When the vehicle separate the launch assist platform will have a higher thrust to weight ratio than the rocket, which will allow it to accelerate away without worrying about rocket plume impingement.
Shortly before Mars' June 2015 conjunction, the Curiosity Rover celebrated 1000 sols on the red planet. After its August 5, 2012 landing, Curiosity's 1000th sol or martian day on the surface corresponded to planet Earth's calendar date May 31, 2015. Because the line-of-sight to Mars is close to the Sun near the conjunction, radio communications are affected and the six-wheeled, car-sized robotic rover cautiously remains parked at this spot for now.
The view looks back toward the stomping gro [...]
Three Expedition 43 crew members are readapting to Earth’s gravity after returning home Thursday morning. The trio still onboard the International Space Station is working advanced microgravity science, orbital maintenance and exercise to remain fit and counter the effects of living in space.
Expedition 44 started early Thursday morning after the Soyuz TMA-15M spacecraft undocked from the Rassvet module. NASA astronaut Terry Virts, ESA astronaut Samantha Cristoforetti and Russian cosmonaut [...]
This Planck image shows the complicated link between the magnetic field of our galaxy and its interstellar dust. In particular, the arrangement of the magnetic field is more uniform along the spiralling structure of the Milky Way. The small clouds …
Second string substitute relief blogger john hare.
Some years ago I did a few posts about an air turborocket with the bladeing based on the squirrel cage fan. October of 2008 if you’re interested. Some varieties of the squirrel cage fan have blade geometries that are simultaneously useful as compressors and radial inflow turbines. By using the blades as compressors on 75% of the cycle and as turbines on 25% of the cycle, 100% of the incoming air regeneratively cooled the blades so they could run a considerably hotter turbine inlet temperature than normal. The higher the allowable temperature, the higher the available performance. The other benefit of this blade geometry is that all moving components were on a single wheel, which allows for massive weight reduction compared to conventional turbine based engines.
The downside of the concept is that the cycle doesn’t close. Using the same blade for outflow compressor and inflow turbine means that the turbine inlet pressure must be considerably higher than the compressor will deliver. It was only as an air turborocket that the concept works as originally conceived. As an air turborocket though, thrust/weight ratios of 25 are quite attainable with specific impulses of nearly a thousand. By adding multiple wheels the specific impulses were somewhat closer to that of turbojets, though not turbofans. Adding extra wheels was still like adding epicycles to make the concept attractive.
The cagejet turborocket will always be a niche engine if it ever gets built. Thrust /weight will be far less than rockets, while fuel economy will be worse than turbojets and far worse than modern turbofans. Attractive for Launch Assist Platforms that want high acceleration for limited time in the atmosphere, but not for the long cruises some of these platforms want. Also attractive for some limited military applications.
It was called to my attention a few years back that perhaps I was too focused on reaction turbines when impulse turbines were useful in some applications. An impulse turbine can be a bit less fussy in the bladeing in exchange for considerably more critical nozzles to drive them. If I could use the impulse turbine concept, it might be possible to work a radial outflow turbine with the same blade that is a compressor on the rest of the cycle. If this can be done, the cycle might close an allow an engine that doesn’t require a rocket to drive the engine. The elimination of the oxidizer turns it into a very light turbojet with high thrust/weight.
A second thing pointed out to me was that the squirrel cage blades were speed limited by the mach number at the leading edge of the blade. This is the same problem of centrifugal compressors. The speed limit forces the inlet area down in relation to the wheel diameter. It also puts a limit on available compression ratio. A compression ratio of 2 is respectable for an air turborocket, and insufficient for a turbojet. By putting a fan in the inlet plane of the cage, it is possible to power prewhirl the incoming air so that the cage blades can run faster. Double the possible compression ratio faster. So I added a fan that prewhirls the incoming air, but also creates some compression in its’ own right. Compression ratio of 4 is now possible which is barely in turbojet country.
The third modification to the concept is the fuel handling. By using blades with fuel passages and film cooling holes that are also fuel injection holes, it is possible to get very fast mixing, while also using the fuel to regeneratively cool the blades as well as supply film cooling to them. With the blades being cooled by 100% of the air during 75% of the cycle, and simultaneously cooled by 100% of the fuel during 100% of the cycle, it is possible to run this turbojet at stochiometric mixtures without damaging the blades. This allows a high thrust/weight ratio from the turbojet even with a compression ratio of 4, and eliminates fuel hungry afterburners.
This side view shows the incoming air in light blue that goes through the compressor/turbine blades into the volute for pressure recovery. From the volute into the burner that is mostly not shown except for the section close to the turbine nozzles. After the burn the hot gas is through the turbine nozzles to the turbine blades. Into the thrust nozzle after driving the turbines to produce the thrust.
This is a side view of the engine. The air enters through the prewhirl fan on the left. It enters the compressor blades on 75% of the cage interior perimeter shown here on the bottom. Leaves the compressor blades into the volute shown on the very bottom. Hits the flameholders in the hot section. Burns and enters the turbine nozzles and turbine blades. Leaves the turbine blades into the thrust nozzle. Provides thrust.
By running the liquid fuel through blades as shown here, the blades are both regeneratively and film cooled by the entire fuel flow. The compressing air strips the fuel film from the blades and mixes with it in the volute even as it is doing pressure recovery. The air and fuel will be well mixed before the mixture hits the flame holders.
What results from all this is a true turbojet capable of a thrust/weight of 25 at sea level with a specific impulse of over 2,000. In cruise considerably more. The double regenerative blade cooling along with the fuel film cooling means that this engine could run stochiometric up to around Mach 5 without throttling down. It also means that the use of liquid oxygen for mass injection precooling would allow even higher thrust at any altitude or airspeed. Enough fuel could be used to burn all the oxygen for high thrust even at high altitudes.
An auxiliary rocket could be used in the burn chamber in air turborocket mode for extreme altitudes and to guard against flame outs if there is an inlet unstart.
This type engine could be used as an add on for a conventional air launch aircraft. Use the normal engines for cruise with the cagejets at take off and the gamma maneuver. Mach 0.9 in a near vertical climb at 50,000 feet would seem a good place to be compared to the drop and light of most air launch concepts. If the cagejets are wanted to cruise also, then they could be used as jets during cruise and turborockets when a lot of extra thrust is needed.
If it was desirable to modify this engine further for turbofan class fuel economy, a second smaller cage could be used to bring the total compression ratio to 16 for the burn in the second spool. Specific impulse to several thousand with the possibility of getting extreme thrust levels with the flick of the switch.
Braided, serpentine filaments of glowing gas suggest this nebula's popular name, The Medusa Nebula. Also known as Abell 21, this Medusa is an old planetary nebula some 1,500 light-years away along the southern border of the constellation Gemini. Like its mythological namesake, the nebula is associated with a dramatic transformation.
The planetary nebula phase represents a final stage in the evolution of low mass stars like the sun, as they transform themselves from red giants to hot white dw [...]
We’re about to head out on a two week road-trip/vacation–the longest vacation we’ve done as a family since I started Altius in 2010. Here’s our planned route map:
We’re talking about 3500 miles, not counting any driving around at our destinations and visiting 9 states1. We’ll be visiting Yellowstone, Tiff’s family in Oregon, the Redwoods, Silicon Valley, and my family in Utah.
Overview of our schedule:
Day 1: Leave Lafayette and drive up to Dubois, WY.
Days 2-3: Camp in Yellowstone.
Day 4: Break camp, catch church near Yellowstone, then head toward Eugene (via Montana and Spokane, WA).
Day 5: Arrive in Eugene, OR at Tiff’s dad’s place.
Days 6-9: Have fun near Eugene, including probably a trip out to the Oregon Coast.
Day 10: Drive down to the Redwoods in California, then from there down to San Francisco.
Day 11: Spend time in San Francisco with a friend’s family.
Day 12: Taking a one-day break from my vacation to visit some various groups in Silicon Valley for Altius, and then hanging out with the Traugotts2 in Livermore.
Day 13: Drive to my sister’s place in Eagle Mountain, Utah.
Day 14: Visit my family in Utah, including my parents, several of my siblings, my grandmother who is turning 95 later this monthclever one about logicians.'>3, and a physicist friend of mine.
Day 15: Drive home to Colorado.
Day 16: Hopefully be alive enough to go back in to the office…
It should be epic. And hopefully fun. But definitely epic. I’ll post pictures as I get to places with internet access.
NASA’s Hubble Space Telescope has detected a stratosphere, one of the primary layers of Earth’s atmosphere, on a massive and blazing-hot exoplanet known as WASP-33b.
The presence of a stratosphere can provide clues about the composition of a planet and how it formed. This atmospheric layer includes molecules that absorb ultraviolet and visible light, acting as a kind of “sunscreen” for the planet it surrounds. Until now, scientists were uncertain whether these molecules would be found [...]
They wouldn't float like balloons or give you the chance to talk in high, squeaky voices, but planets with helium skies may constitute an exotic planetary class in our Milky Way galaxy. Researchers using data from NASA's Spitzer Space Telescope propose that warm Neptune-size planets with clouds of helium may be strewn about the galaxy by the thousands.
"We don't have any planets like this in our own solar system," said Renyu Hu, NASA Hubble Fellow at the agency's Jet Propulsion Laboratory in [...]
Expedition 43 Commander Terry Virts of NASA, Samantha Cristoforetti of ESA and Anton Shkaplerov of Roscosmos landed their Soyuz TMA-15M spacecraft in Kazakhstan at 9:44 a.m. EDT. Russian recovery teams will help the crew exit the Soyuz vehicle and adjust to gravity after their stay in space.
The trio arrived at the International Space Station on Nov. 24, 2014, and spent more than six months conducting research and technology demonstrations. Virts, Cristoforetti and Shkaplerov spent 199 days a [...]
Before getting into my thoughts on potential options for the carrier plane itself, I wanted to mention a few nice-to-have options for the carrier plane itself. I don’t know that any of these is strictly required, but all potentially help:
For many reasons cryogenic propellants would be the best option for truly competitive air-launch. But both for boiloff reasons, and for providing cross-fed propellants during the gamma-maneuver, having some smaller propellant tanks on the aircraft itself could be useful. These tanks could be insulated more thoroughly than flight tanks, since the carrier plane is the least weight-sensitive part of the system.
One clever option that Doug Jones mentioned to me at Space Access if you have such tanks is to fly up to 30kft, vent the launch vehicle propellant tanks (one at a time)1, let the tank vent until it is at the now much lower ambient pressure, and then refill the tank till nearly full. Cryo propellants will boil at a colder temperature at altitude, and the heat absorbed by boiling off some of the propellants will chill the remaining propellant to this lower temperature, densifying it2, and significantly reducing the pressure needed in the tanks to suppress pump cavitation. Both of these can result in a non-trivial reduction in system mass, especially if your system is large enough that you’re not at minimum gage levels for your tank wall material.
Crossfeed Pumps and T-Zero Disconnects
A lot of ground launch vehicles have propellant, pressurant, and electrical umbilicals/quick disconnects that only separate right as the vehicle is taking off the pad. You might not want to cut it quite as close here (T-1 disconnects would be fine too), and you’ll definitely want features for retracting the hoses out of the air-stream after they’ve disconnected, but making these types of hoses and disconnects shouldn’t be that hard. In the case of crossfeed pumps, you only need a pump that can keep up with the flow-rate of the engines operating at whatever throttle level they’re running at during flight operations, and push against the backpressure from the main propellant tank pressurant, since you’re feeding in through the same fill ports the vehicle uses for ground filling. The power levels required would be low enough that an electric powered pump would make a lot of sense–easy to control the pump flow-rate/pressure to make sure you don’t over or underfill the tank. You’re probably talking about needing a pressure of 15psi or less, which means that compared to an electropump for a main propulsion system (like RocketLabs and Ventions are using), you’re probably only looking at 1-5% of the power needed for the cross-feed pumps. I see how cross-feed for dual strap-ons on a tri-core rocket stage like Delta-IV or Falcon Heavy might be hard, but this seems relatively straightforward by comparison.
Propellant Umbilical Reconnect Mechanisms
A slightly harder task would be designing the disconnects in a way that they could be in-flight reconnected. This might involve some level of robotic or mechanism hardware to make the reconnection, but could be handy in case of a last-second abort. Also, this same sort of hardware would likely be exactly what you’d want for refueling or detanking the upper stage at an orbital propellant depot.
Emergency Detanking Hardware
In addition to cross-feed/tank-up pumps, it might be good to have a way of detanking the propellants from the rocket in case of an aborted mission. This could possibly use some of the same hardware, but thought should be taken on how and where you route the dumping propellant, and how you sequence them, so you avoid building up hazardous concentrations of flammable materials near spark sources during an emergency propellant dumping operation.
In-air Propellant Transfer Hardware
I wasn’t thinking about this in my baseline Boomerang system, but having the ability to transfer propellants to the carrier aircraft in-flight might enable launch vehicle performance enhancements without requiring a bigger carrier aircraft. While kerosene transfer is routinely done by the military, LOX and cryogenic propellant transfer should also be technically feasible, but would require some demonstration3. I’d probably have prop transfer go into the holding tanks on the aircraft, and from there into the launch vehicle (that way you minimize the odds of damage to the vehicle, and reduce the dry mass impact on the launch vehicle itself).
Most aircraft mass limits are due to take off thrust and abort considerations. If you could launch with the rocket empty or mostly empty of at least one propellant type4, you could carry a much bigger rocket and payload at takeoff with the same carrier plane. This would allow growing to a larger system over time if desired without requiring a new carrier vehicle design. Depending on the range of the tanker aircraft, this might also give the carrier airplane more flexibility on how far it flew prior to launch operations.
Tow Cable Reattachment Hardware
At least some carrier plane options would use a glider-based carrier plane towed by a larger, more traditional aircraft. It might be challenging, but in the case of an abort with a glider based carrier aircraft having a mechanism similar to the in-air-fuel transfer mechanism that allows reconnecting a tow cable to the nose of the carrier aircraft might be valuable. It might even be useful for normal operations, where the towing aircraft could maneuver out of the way for launch, and then catch up with the glider and reconnect with it to tow it home to the launch site. If you’re particularly crazy/clever, you might even be able to find a way to combine this with in-air propellant transfer hardware to enable retanking the rocket in case of an abort, though I’m not sure what scenarios that capability would make sense.
Anyhow, as I said at the start of this blog post, most of these capabilities are nice-to-have, not have-to-have. Prioritywise, the top-up tanks and cross-feed pumps are the ones I think would be most worth looking into for a first generation Boomerang system.
Next up in Part IV: my thoughts on carrier plane options.
The following is a statement from NASA Administrator Charles Bolden on the Senate Appropriations subcommittee vote Wednesday on NASA’s Fiscal Year 2016 commercial crew budget:
"I am deeply disappointed that the Senate Appropriations subcommittee does not fully support NASA's plan to once again launch American astronauts from U.S. soil as soon as possible, and instead favors continuing to write checks to Russia.
“Remarkably, the Senate reduces funding for our Commercial Crew Program [...]
This colorful skyscape spans about three full moons (1.5 degrees) across nebula rich starfields along the plane of our Milky Way Galaxy in the royal northern constellation Cepheus. Near the edge of the region's massive molecular cloud some 2,400 light-years away, bright reddish emission region Sharpless (Sh) 155 lies at the upper left, also known as the Cave Nebula. About 10 light-years across the cosmic cave's bright rims of gas are ionized by ultraviolet light from hot young stars.
Dusty b [...]
Three Expedition 43 crew members are busy preparing for their homecoming during their last full day in space. Commander Terry Virts ceremoniously handed over control of the International Space Station this morning to veteran cosmonaut Gennady Padalka.
Virts and Flight Engineers Anton Shkaplerov and Samantha Cristoforetti will end their stay tomorrow at 6:20 a.m. EDT when they undock from the Rassvet module. The trio in their Soyuz TMA-15M spacecraft will parachute to a landing in Kazakhstan a [...]
Although the Universe may seem spacious most galaxies are clumped together in groups or clusters and a neighbour is never far away. But this galaxy, known as NGC 6503, has found itself in a lonely position, shown here at the edge of a strangely empty patch of space called the Local Void. This new NASA/ESA Hubble Space Telescope image shows a very rich set of colours, adding to the detail seen in previous images.
NGC 6503 is only some 18 million light-years away from us in the constellation of [...]
New images of dwarf planet Ceres, taken by NASA's Dawn spacecraft, show the cratered surface of this mysterious world in sharper detail than ever before. These are among the first snapshots from Dawn's second mapping orbit, which is 2,700 miles (4,400 kilometers) above Ceres.
The region with the brightest spots is in a crater about 55 miles (90 kilometers) across. The spots consist of many individual bright points of differing sizes, with a central cluster. So far, scientists have found no ob [...]