XCOR против Pratt&Whitney

[Salo]

http://www.spacenews.com/civil/110204-engine-costs-drive-atlas5-prices.html

Fri, 4 February, 2011
Rising Engine Costs, Uncertainty Drive Up Atlas 5 Prices for NASA[/size]
By Amy Svitak

WASHINGTON — Rising propulsion costs, demand uncertainty and an eroding industrial base are the drivers behind what NASA says is a significant price increase for the Atlas 5 rocket, which is used to launch the agency's most valuable scientific payloads, according to industry and NASA officials.

Industry officials said the winding down of the space shuttle program has led to higher prices for the RL 10 upper-stage engine, the second-most-expensive component on the Atlas 5, which is built by United Launch Alliance (ULA) of Denver, a Boeing-Lockheed Martin joint venture. The RL 10 is manufactured by Pratt & Whitney Rocketdyne of Canoga Park, Calif., which also builds the space shuttle's main engines.

"The RL 10 is one that's been impacted substantially by the fact that the space shuttle program is no longer active," said George Sowers, vice president of business development and advanced programs at ULA. "So Pratt Whitney has all this capacity sized to do a space shuttle program and an RL 10 program, and when the space shuttle program goes away then they have all this capacity and all this cost and the only place they can charge it is back against the RL 10 program."

The ULA-built Delta 4 rocket also uses a variant of the RL 10 as well as a Pratt & Whitney Rocketdyne-built main engine, but this vehicle currently is not used to launch NASA payloads.

Jim Maser, president of Pratt & Whitney Rocketdyne, said a number of factors, including lower production rates and changes in the way customers buy propulsion products and services, are driving up costs.

"Procurements over time have decreased in total volume and also the amount being procured per year [has decreased]," Maser said in a Feb. 3 interview, noting that RL 10s at one time were bought in quantities of 40 to 60 over multiple years at high annual production rates. Today, production rates have dropped from tens per year to three or four per year. "Combine that with another reduction in base, particularly on the NASA side, and that tends to challenge costs," he said.

Maser said NASA's space shuttle follow-on program, Constellation, was expected to supplant between 80 and 100 percent of Pratt & Whitney's work on the orbiter fleet, slated for retirement this year. But that changed when U.S. President Barack Obama proposed dismantling Constellation in favor of using privately developed rockets and spacecraft to transport astronauts to and from Earth orbit. Work is continuing on elements of Constellation, including the J-2X upper-stage engine that would be built by Pratt & Whitney Rocketdyne, but with NASA operating under a temporary funding measure and the budget outlook uncertain, the future direction of the human spaceflight program is murky at best.

"So we have to accommodate that at some level," Maser said. The question is how long do we have to accommodate it for? If we're expected to carry all the risk of that uncertainty it's very difficult for us to cover without losing money."

Pratt & Whitney Rocketdyne is facing the prospect of its business being "about half of what the shuttle business has been in the past," Maser said, adding that the company is taking steps to reduce its facilities by over half in the next few years.

Meanwhile, prices for the Russian-built RD-180, a liquid oxygen/kerosene engine that powers the Atlas 5's main stage, are also on the rise. The RD-180, the single most expensive Atlas 5 component, is built by NPO Energomash of Khimki, near Moscow.

"In general when you're looking at liquid propulsion, costs are going up and it's reflected in prices," Maser said.

But Sowers said the Russians are simply charging what the customer is willing to pay. "The Russians have learned over the years the wonders of capitalism, and have become really good at letting the market drive their prices up," he said.

Jim Norman, NASA assistant associate administrator for launch services, told the NASA Advisory Council's planetary science subcommittee Jan. 26 that fewer launches, lower production rates, smaller lot buys from suppliers and basic inflation are contributing to higher Atlas 5 costs.

"It is a big jump," Norman said, detailing projected cost increases over the next five years for launching planetary science missions under the new NASA Launch Services 2, or NLS 2, contracting vehicle. Under the previous NLS contract, in effect between 1999 and 2010, the cost to launch an Atlas 5 rocket was between $100 million and $125 million. Under NLS 2, which NASA signed with ULA and other rocket manufacturers in September, the Atlas 5 cost range grew to between $102 million and $334 million per mission.

Sowers emphasized that the upper end of the cost range is a cost cap that launch providers are not to exceed when estimating the cost of NASA missions. He said NASA insisted on locking in prices as far out as 2015 despite numerous uncertainties concerning overall demand.

"The majority of what NASA would perceive as cost increases is coming from the uncertainty in our business environment and the way they've set up the NLS 2 contract," he said. "Since they're holding our feet to the fire for these price caps, we're being very conservative and protecting our risk."

Sowers said that price cap will come down if ULA is successful in negotiating a bulk purchase of Atlas 5 and Delta 4 launches with the U.S. Defense Department over a five-year period beginning in October 2012.

"We're working with the Air Force on what we're calling a multiyear buy and this will help eliminate a lot of the uncertainty we're talking about and help us bring our prices back into the realm of what our historical prices have been," Sowers said, adding that the company has urged NASA to consider the potential cost-cap reduction when budgeting for future missions. He said specific mission proposals include a "downward adjustment clause" that would lower cost estimates if the Air Force bulk-buy deal comes to pass.

But Norman cautioned there are risk factors that could drive Atlas 5 prices even higher than the upper range of the NLS 2 prices. The Air Force and National Reconnaissance Office are trying to come to terms on their relative contributions to the so-called Evolved Expendable Launch Vehicle Launch Capabilities contract that covers personnel and other overhead costs that are not factored into the prices of individual Atlas 5 and Delta 4 launches, he said. A failure to reach agreement, Norman said, could raise NASA's Atlas 5 costs by as much as $140 million per mission as ULA's overhead costs are swept into individual launch contracts.

Sowers characterized that risk as unlikely. "We've had discussions with NASA about how to budget, and that's really their call," he said. "We think that's a very low likelihood and it would be foolish to budget for that. But that's up to them."

Norman said another challenge affecting the NLS 2 contract is Atlas 5 performance, which has diminished since the first NLS 1 agreement was put in place.

"There have been some performance losses being offered for the Atlas 5 in particular as part of the NLS 2 vs. NLS 1," Norman said, adding that ULA has made structural changes that added weight to the rocket. "We've lost about 400 to 500 kilograms of performance in terms of what is being offered."

Norman said his team would work with mission planners to address the performance shortfall, most likely by incorporating strap-on solid-rocket boosters to enhance capability.

Sowers attributed the decrease in performance to ULA's effort to account for future performance risk.

"All we really did was took our history of performance and put risk into our future performance," he said. "They're annoyed at us for doing that. But any time you negotiate a new contract, we're trying to make sure we're not putting our company at risk in the future."

[Salo]

http://www.spacenews.com/launch/110322-ula-xcor-engine-project.html

Tue, 22 March, 2011
ULA and XCOR Join Forces on Upper Stage Engine Project[/size]
By Amy Svitak

    WASHINGTON — Commercial spaceflight startup XCOR Aerospace and United Launch Alliance (ULA) plan to develop a low-cost liquid oxygen/liquid hydrogen engine that could one day replace the RL 10 that currently powers the upper stage of ULA's Atlas 5 and Delta 4 rockets, the companies announced March 22.

    George Sowers, ULA vice president of business development and advanced programs, noted that the cost of the RL 10, built by Pratt & Whitney Rocketdyne of Canoga Park, Calif., has soared in recent years due to demand uncertainty and an eroding industrial base as NASA's space shuttle program heads toward retirement this year.

    "It gives us options for a next-generation upper-stage engine," Sowers said in a March 21 interview, adding, "This isn't the only option we're looking at. Certainly we're looking at options for the next generation of RL 10s as well."

    Sowers said the XCOR-built engine would generate 25,000 to 30,000 pounds of thrust.

    "The overall performance targets we're aiming for are very similar to an RL 10 in terms of thrust and efficiency," Sowers said. "So we're not really looking to change the basic upper-stage design. What we're looking for would be an engine that we could drop into existing stages."

    Sowers said the new engine could be operational within five to 10 years.

    "We don't have a specific target time; it's really as the risks are retired we make decisions and pass various decision gates," he said.

    Jeff Greason, chief executive of Mojave, Calif.-based XCOR, declined to specify development costs for the new engine, but said he expects it to be competitive in the market.

    "We have been forced because of our company's history to innovate in ways to develop engines that are cheaper to produce," he said. "I have no intention of showing my number but I am looking to supply this engine, should everything proceed as we hope, at a very, very substantially lower price ... than other engines on the market today."

    Greason said XCOR has been working with Denver-based ULA for the past couple of years to demonstrate an engine nozzle weighing hundreds of pounds less than the large upper-stage engine nozzles in use today.

    The new upper-stage engine would be based in part on the liquid oxygen and kerosene-fueled 5K18 engine XCOR is developing for its planned Lynx suborbital vehicle, which is designed to carry tourists along with research payloads. Greason said recent testing proved the ability of the 5K18's cryogenic piston-pump technology to pump liquid hydrogen.

    Greason said XCOR and ULA have yet to nail down a formal test regime for the nozzle and other engine components, but said the development program would be based on performance milestones to ensure a cost-effective approach.

    "I have no idea how many tests we'll do, but it'll be a very big number," he said. "That's the way we do everything: Test a little, tweak it, test a little, tweak it."

    Greason said recent hot-fire tests of the nozzle validate XCOR's design, materials and manufacturing processes.

     "If you've got to build a rocket plane that flies four times a day very efficiently and for very low cost, you have to do things in a very different way with engine technologies and thrusters and things like that," Greason said. "So it's got the attention of folks like George. We've knocked off a couple of risk reduction items and got to the point where we can move the technology ahead."

    Although XCOR has tested a number of engines on suborbital flights the company has yet to fly anything in the vacuum of space, a challenge Greason said XCOR is eager to tackle.

     "We're not scared of it, the characteristics are understood," he said. "Really the far more interesting challenge is not the going-to-space part of it; it's developing a highly cost effective liquid engine technology."

    Sowers said ULA, a Boeing-Lockheed Martin joint venture, finds XCOR an attractive partner because of the agility and innovation a small company can bring to development projects.

    "In terms of development cost, one reason we like working with XCOR is they can make rapid progress quickly with a small team," he said. "We're hopeful we can dramatically reduce development costs with this kind of approach."

http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/awx/2011/03/22/awx_03_22_2011_p0-299850.xml&headline=ULA,%20XCOR%20to%20Develop%20Upper-Stage%20Engine

ULA, XCOR to Develop Upper-Stage Engine[/size]

Mar 22, 2011
 
By Frank Morring, Jr. morring@aviationweek.com
WASHINGTON

United Launch Alliance (ULA) and XCOR Aerospace are planning a joint effort to develop a low-cost upper-stage engine in the same class as the venerable RL-10, using technology XCOR is developing for its planned Lynx suborbital spaceplane.

The two companies have been testing actively cooled aluminum nozzles XCOR is developing for its liquid oxygen/kerosene 5K18 engine for the Lynx, a reusable two-seat piloted vehicle the company plans to use for commercial research and tourist flights.

XCOR also has demonstrated a piston-driven cryogenic pump with liquid hydrogen fuel that will be applied to the new engine development, adding robustness and fuel-handling improvements over traditional turbopumps.

"Conceived as a lower-cost, risk-managed program compared to traditional engine development efforts, the multi-year project's main objective is to produce a flight-ready LOX/LH2 upper-stage engine in the 25,000 to 30,000 lb.-thrust class that costs significantly less to produce and is easier to operate and integrate than competing engine technologies," the companies say in a joint announcement released today. "If successful, the effort will lead to significantly lower-cost and more capable commercial and U.S. government space flights delivered by ULA."

ULA flies the Atlas V and Delta IV Evolved Expendable Launch Vehicles (EELV) for U.S. government customers. Both use RL-10 upper-stage engines and both are expected to rise in cost after the space shuttle's retirement takes away a considerable portion of the U.S. rocket-engine business's customer base.

"ULA understands that we have to offer competitive prices to our government and commercial customers along with the outstanding and unmatched reliability they expect from us," says George Sowers, ULA vice president of business development and advanced programs. "By working with XCOR, we see the potential to develop engines that offer the performance and reliability our customers need at a more affordable price."

Tests with XCOR's kerosene-fueled Lynx engine demonstrated that the company's nozzle technology can withstand repeated exposure to high-temperature rocket plumes without discernible degradation, the companies say. The milestone-driven follow-on program will scale up the nozzle design to an EELV-sized, upper-stage engine that could replace the RL-10 in some applications.

Most of the work will be done at XCOR's facilities in Mojave, Calif., according to Jeff Greason, XCOR CEO. While details are proprietary, Greason said Monday that the new lightweight nozzle is "regeneratively cooled by passages that are made inexpensively in the walls." Kerosene was used in the hot-fire testing that led to the agreement with ULA, and the larger engine development will apply the manufacturing approach to nozzle walls that use liquid hydrogen as a coolant, Greason says.

Sowers said Monday that the pace of the development will depend on the level of investment as milestones are met in the build-a-little, test-a-little approach favored by XCOR. Under the low-cost development approach, it would be 5-10 years before flight engines are available, depending on how the work goes.

"What we're looking at are options for [a] next-generation, upper-stage engine," Sowers says. "Certainly the RL-10 has been a workhorse for us over the years, and right now all of our national security depends on it. It's been a great engine, very reliable. But we're incredibly intrigued with the technology that XCOR is bringing to the party, and we want to explore it to the fullest."

[Salo]

http://xcor.com/press-releases/2011/11-03-22_XCOR_and_ULA_demonstrate_rocket_engine_nozzle.html

XCOR and ULA Demonstrate Revolutionary Rocket Engine Nozzle Technology;
Also Sign Contract for Liquid Hydrogen Engine Development[/size]


XCOR test fires its Lynx 5K18 engine with lightweight aluminum nozzle; United Launch Alliance (ULA) and XCOR
to apply the nozzle and XCOR's liquid hydrogen (LH2) pump technology to new LH2 engine development.
 (Photo Credit: Mike Massee / XCOR)

March 22, 2011, Centennial, CO, and Mojave, CA, USA: United Launch Alliance (ULA) and XCOR Aerospace announced today their successful hot-fire demonstrations of a lighter-weight, lower-cost approach to liquid-fueled rocket-engine vacuum nozzles. The new nozzle technology, which uses aluminum alloys and innovative manufacturing techniques, is projected to be less costly and save hundreds of pounds of mass compared to nozzles in use today in typical large upper-stage rocket engine systems.

Under a 2010 joint risk-reduction program by XCOR and ULA, ULA facilitated an accelerated demonstration of the nozzle technology, which was developed in XCOR's Lynx reusable, suborbital-vehicle technology program. ULA sought to determine the nozzle technology's applicability to future expendable launch vehicle programs. Earlier in the same risk-reduction program, XCOR demonstrated the ability to pump liquid hydrogen (LH2) using cryogenic piston-pump technology it developed for the Lynx suborbital vehicle.

Based on the results of these successful technology demonstrations, ULA today announced a larger follow-on program with XCOR to develop a liquid oxygen (LOX)/LH2 engine.

Conceived as a lower-cost, risk-managed program compared to traditional engine development efforts, the multi-year project's main objective is to produce a flight-ready LOX/LH2 upper-stage engine in the 25,000 to 30,000 lbf thrust class that costs significantly less to produce and is easier to operate and integrate than competing engine technologies. If successful, the effort will lead to significantly lower-cost and more-capable commercial and US government space flights delivered by ULA.

"ULA understands that we have to offer competitive prices to our government and commercial customers along with the outstanding and unmatched reliability they expect from us," said Dr. George Sowers, vice president of business development and advanced programs at ULA. "By working with XCOR, we see the potential to develop engines that offer the performance and reliability our customers need at a more affordable price."

The companies structured their LOX/LH2 engine development program with multiple "go / no-go" decision points and performance milestones to ensure a cost-effective and risk-managed approach to this challenging effort. As demonstrated during prior ULA and XCOR joint engagements, XCOR's small-company environment facilitates rapid turnaround for build and test cycles that drive innovative learning, while ULA's small company project management approach ensures their needs are met but does not stifle the creative process or saddle XCOR with excessive paperwork burdens typical of large government contracts. In addition, ULA is helping to bolster the Tier 2 and Tier 3 aerospace-industrial supply chain in the United States, which is critical to ensuring the United States aerospace sector remains competitive in the global marketplace.

"This announcement validates XCOR's business mantra of 'stay focused on propulsion, Lynx and the customer' and ULA is a great customer," said Andrew Nelson, Chief Operating Officer at XCOR. "And when you have innovative, safe, low-cost and fully reusable technologies that fly multiple times a day, those technologies will find other buyers, such as ULA. Whether it is non-toxic thrusters, fully reusable main-engine propulsion, cryogenic flight-weight piston pumps, or non-flammable cryogenically compatible composite tanks and structures – the future looks bright for XCOR."

The demonstrations announced today are from integrated engine/nozzle test firings with XCOR's Lynx 5K18 LOX/kerosene engine. The engine/nozzle combination demonstrates the ability of the aluminum nozzle to withstand the high temperatures of rocket-engine exhaust over numerous tests, with no discernable degradation of the material properties of the alloys.  The tests validated the design, materials and manufacturing processes used in the nozzle, and laid a foundation for scaling the design to EELV-sized engines. The results also demonstrate the reusability of the engine and nozzle combination which is essential for low-cost, daily suborbital flights by the Lynx and other vehicles.

"We are honored to work with the great team of individuals at ULA, a Tier 1 aerospace supplier," said Jeff Greason, XCOR CEO. "The critical engine technology we're developing for ULA may one day launch satellites, capsules and space stations for government and commercial customers. Customers such as the US Air Force, NASA, the National Reconnaissance Office, Boeing and Bigelow Aerospace all stand to benefit from this partnership. For a rocket engineer, there is nothing more exciting than firing a new engine for the first time. We can't wait for the day when we first fire the new hydrogen engine for ULA."

# # # # #

United Launch Alliance - 50-50 joint venture owned by Lockheed Martin and The Boeing Company—is the nation's rocket company, bringing together two of the launch industry's most experienced and successful teams – Atlas and Delta. ULA provides reliable, cost-efficient space launch services for the Department of Defense, NASA, the National Reconnaissance Office and other commercial organizations. ULA program management, engineering, test and mission support functions are headquartered in Denver, Colo. Manufacturing, assembly and integration operations are located at Decatur, Ala. and Harlingen, Tex. Launch operations are located at Cape Canaveral Air Force Station, Florida, and Vandenberg Air Force Base, Calif. For more information on the ULA joint venture, visit the ULA website at www.ulalaunch.com.

XCOR Aerospace is located in Mojave, California. The company is in the business of developing and producing safe, reliable and reusable rocket powered vehicles, propulsion systems, advanced non-flammable composites and other enabling technologies. XCOR is currently working with aerospace prime contractors and government customers on major propulsion systems, and concurrently building the Lynx, a piloted, two-seat, fully reusable, liquid rocket-powered vehicle that takes off and lands horizontally. The Lynx production models (designated Lynx Mark II) are designed to be robust, multi-commercial mission vehicles capable of flying to 100+ km in altitude up to four times per day and are being offered on a wet lease basis. (www.xcor.com)

[hecata]

Это они же сделали КС из алюминия лазерным спеканием, или нет?

[Salo]

http://thesop.org/story/science/2009/04/13/rocket-fuel-piston-pump-hot-ticket-to-space.php

Rocket Fuel Piston Pump Hot Ticket To Space[/size]   

Liquid fuel rockets are simple in concept.  You light the propellants, which blast out one end and provide the thrust you need.  In practice, however, liquid fuel engines are quite a bit more complex, and one of the keys to successful and safe space flight is how you get liquid oxygen and fuel into the engine. XCOR solves the problem with proprietary and highly unique piston pumps.

Most of the complications arise from getting the fuel to the rocket engine, " says XCOR`s chief engineer Dan DeLong.  How you solve that problem determines how well your rocket propulsion system will work. "

The simplest systems use pressurized tanks to force the propellants into the engine, but these tanks have to be heavy and strong enough to withstand hundreds of pounds of pressure per square inch.

This weight can be prohibitive in a vehicle intended to fly to space, because even lightweight tanks account for 85-90 percent of the weight of a typical rocket-powered launcher.  To enable engineers to use lightweight tanks, rocket propulsion systems use pumps instead of pressurization.

Knowing this, the XCOR team began developing proprietary pumps early in its program. Using internal funds, we started development of a super-cold cryogenic piston pump and filed IP claims on our work.  Later we won a DARPA contract to further this initial development. We then extended the original design by developing a piston pump for fuels at room temperatures and demonstrated it successfully, further extending our IP portfolio.  The developed fuel piston pump was later incorporated into the second generation rocket-powered test bed aircraft and successfully run hundreds of times and flown 40 times in flight without any noticeable wear or tear.

The test bed vehicle was powered by a 1,500 lbf thrust kerosene-liquid oxygen engine that had pump-fed kerosene and pressure-fed LOX.  The use of a piston pump was a departure from usual rocket engineering.  If not using pressure fed systems, most designs use turbine pumps (much different from piston pumps), but XCOR selected a piston pump because they are more flexible and can be scaled up or re-engineered to pump either cryogenic materials or typical fuels, such as kerosene, alcohol or methane.

XCOR will now use pumps to supply liquid oxygen as well as the kerosene to the Lynx`s four engines.  As a result, the team has been working hard on an updated cryogenic piston pump based on our previous works. Mike Valant is the lead engineer on this project.

We are currently testing the cryogenic pump using liquid nitrogen instead of liquid oxygen, " he explains.  The liquid nitrogen is actually a little colder than the liquid oxygen and has roughly the same fluid properties.  Because liquid nitrogen is inert (you can use it as a fire extinguishing agent), we can do our tests much more conveniently. Using liquid nitrogen also allows us to build and to test pumps without having to make every single wetted pump component oxygen-compatible, so the tests and test articles are much more cost-effective. "

  Liquid oxygen is not poisonous, but you have to be careful with it, because it makes it awfully easy to start a fire, " says XCOR`s safety officer Randall Clague.  For example, if you spill LOX on asphalt, it can cause the asphalt to become highly reactive and potentially burst into flame. "
Valant has been supervising a series of tests of the new cryogenic piston pump to check its reliability, pumping capacity and speed.  He says the results give him confidence that the pumps will have more than enough capacity and reliability to supply the Lynx rocket engines with all of the propellants they need to carry the two-seat craft to the edge of space.

These tests are providing us a lot of information, and teaching us what adjustments we need to make to improve pump performance, " Valant says.  These pump tests may not be as exciting to watch as the engine hot fires, but they are just as important. "

[Salo]

Это они же сделали КС из алюминия лазерным спеканием, или нет?

Пока пишут о сопле из алюминиевого сплава.

[frigate]

25,000 to 30,000 lbf thrust - это 11.340 - 13.608 тс тяги  :idea:

[Salo]

Итак озвучены две фичи: сопло из алюминиевого сплава, которое позволяет сэкономить около 50 кг массы двигателя, и поршневые криогенные насосы.

[Петр Зайцев]

Всем кто разумеет по-англицки, читать постинг Гоффа про люминиевые РД:
http://selenianboondocks.com/2011/03/xcorula-aluminum-rocket-nozzle-announcement/

Aluminum has a ton of advantages especially for cryogenic engines (ie Methane or LH2 fueled ones), but even for non-cryo ones as well. A quick list includes:

    * Low density and high strength-to-weight allows you to get a very lightweight engine without having to push margins or analysis anywhere near as far as with more traditional materials.
    * Low-cost and easy availability of many alloys with good mechanical and thermal properties. Once you've tried to source a high-strength copper alloy for a medium-ish sized rocket engine you'll know why this matters.
    * Easy, quick, and cheap to machine, even if you want to do tricksy things with the cooling groove geometries.
    * There are a ton of manufacturing process options that are semi-unique to aluminum that give you a lot of tools for optimization of the design without excessive costs. Some of these knobs allow you to optimize either for maximum heat flux into the coolant (for expander cycle engines) or minimum heat flux into the coolant while still keeping the wall cool.
    * High thermoconductivity (about 50-60% of pure copper's thermal conductivity) allows you to keep walls cooler–which is kind of necessary with it's low softening temperature.
    * If you can keep it cool enough for long-duration operations (which you usually can for low-moderate pressure engines), thermal stresses can be much lower making it easier to make engines that can stand hundreds or even thousands of cycles

The list definitely goes on from there (like making feasible an alternative engine cycle that I was supposed to have blogged about months ago), but that gives you an idea.

В комментариях:

The copper ones tend to be heavier, but they obviously have good thermal conductivity, so that helps. The stainless or superalloy ones tend to have very low thermalconductivities (going off the top of my head, I think most are in the 17-25W/m*K range, compared to 160-200W/m*K for most aluminums and 300-350W/m*K for most typical rocket-grade coppers). What that means is that for the same thickness of wall, the stainless or inconel tubes are going to have 8-12x the temperature rise of an aluminum wall...

Another part of the equation is that aluminum works best either when you have a really cold coolant, or when the chamber pressures are modest, or both. There are some recent tricks that I think might allow extension for both chambers and nozzles all the way into the Merlin engine chamber pressure range (a bit north of 1ksi, and with LOX/Kero–Kero's not that great of a coolant), but they're relatively newer. Most rocket engines in the past have tried to push the chamber pressure a lot higher, which when combined with 60s/70s era materials and processes meant that Aluminum only worked for a small subset of engines.

. . .

The big issue is that you have to work aggressively to keep the wall cool, which can involve coatings, tricksyness on the coolant side geometry, thinning the walls, and other things, many of which hadn't originally been thought of (or even possible) when rocket engine development was already stagnating in the late 60s/early 70s.

Далее по тексту ТРДэшники объясняют про охлаждаемые лопатки и пр.

[Salo]

http://www.xcor.com/products/index.html

Piston Pumps[/size]

For the past five years, XCOR has been developing a low-cost and easy to manufacture fuel pump for rocket propellant use.

One benefit of a piston-style design is that the pump is capable of pumping more fuel at a higher operational speed. Using this innovative pump design, drive gas to operate the pumps could be delivered by any of the three classical methods: staged combustion, gas generator, or expander. However, we chose a fourth, which is a proprietary thermodynamic cycle that is most similar to the expander.  XCOR has patented this cycle, which has the advantage of not lowering the engine specific impulse as a gas generator would.


XCOR 3-Cylinder Rocket Propellant Piston Pump

Availability of pump-fed engines in the one thousand to ten thousand pound thrust range will reveal new applications.  This is the size range typically used by solid rocket motors for satellite orbital insertion.  If an engine is also capable of multiple restarts, the insertion stage could also do the job of orbital maneuvering.  Thus, a separate orbital maneuvering stage could be eliminated.

Piston pumps will offer increased performance for hybrid rocket motors as well.  The oxidizer, whether liquid oxygen, nitrous oxide, or other, can be stored in lightweight propellant tanks for stage performance gains.  In addition to reducing the weight of hybrid propulsion, this technology will also allow innovative packaging of hybrid engines in volume-constrained applications such as air-launched boosters because the tanks need not be configured for high pressure storage.

Another advantage of positive displacement pumps compared with turbomachinery, is the ability to start and stop rapidly.  This "on-demand" operation is applicable to both free-piston and crankshaft configurations.  Examples of this application include divert thrusters for missile defense vehicles and attitude control thrusters.

http://www.xcor.com/products/pumps/index.html

XCOR Rocket Propellant Piston Pumps[/size]

Fuel and oxidizer pumps are the primary components of many rocket engines. In 2002, XCOR demonstrated its first breadboard prototype for a reciprocating piston pump. The development took fewer than four weeks from initial design to demonstration of pumping pressures and flow rate appropriate to XCOR's 400 lbf XR-4A3 EZ-Rocket engines.

The first pump XCOR built was the result of a design study on upper stage engines that demonstrated pump-fed engines had substantial benefits. We realized, however, that affordable flight-weight pumps, which combined the flow rate, pressure, and closed thermodynamic cycle required for XCOR's engines did not exist.  So we developed a suitable piston pump--the breadboard piston pump--and thermodynamic cycle concept , and applied for a DARPA Small Business Technology Transfer (STTR) contract to test it.


Breadboard Free Piston Pump

We were awarded this DARPA STTR Phase I contract to test the breadboard motor and pump assembly, and used the data to calibrate customized analytical models of the pump behavior. We also completed initial design work for a 2,000 lbf thrust rocket engine piston pump, identified the key technology requirements for future work, and carried out design work on both crankshaft and free-piston configurations.

A bridge contract from DARPA and matching private investment enabled us to continue to focus on the free piston assembly.  At this time we recommended the final design configuration of a free piston machine to be developed during Phase II. While working on this bridge task, a new check valve approach was developed that provided considerable pump speed improvements. As a result, we incorporated the new valve into the pump design.

In 2003, XCOR received a DARPA STTR Phase II contract to design, build, and test a small, lightweight, and responsive liquid oxygen (LOX) pump with integrated (pump and motor) assembly. At the same time, we also produced a fuel pump and motor assembly that demonstrated flight-type flow rates and pressures.

Both motor and pump sections were designed as piston machines, instead of the more traditional turbo-centrifugal hardware.


Intermediate Phase II Fuel Pump

The Phase II LOX piston pump was designed and tested to handle repeated stop-start cycles in the propulsion system. We also qualified custom-designed cryogenic seals for the pump piston and rod, and built a check valve test apparatus. In conjunction with our academic partner, we measured check valve performance, purchased and qualified the reciprocating seals for LOX, and built and tested a sleeve-valve actuated drive motor.

XCOR also contributed its own resources to concurrently develop the fuel pump, which allowed us to accelerate LOX pump development by learning lessons about the integrated pump/motor assembly. Both pumps were designed to be used with our 1,800 lbf, XR-4K5 LOX/kerosene engine.

A Phase II contract extension allowed us to conduct preliminary design of an integrated two stage, air-launched concept using this piston pump along with our engine and composite LOX tank technology.  This included substantial preliminary design work on LOX/methane engines and initial coupon tests of XCOR's LOX tank materials.


The Single Cylinder Crankshaft Pump: Precursor to the Three Cylinder

After the DARPA contracts were completed, we devoted internal resources to developing a more robust pump configuration, one designed for reliability and long life in commercial applications. This work culminated in the single cylinder crankshaft pump. During the early test program, this pump accumulated over four hours of run time.

That convinced us the crankshaft design was fundamentally sound and led to the design, build, and test of the three cylinder pump (photo above), which, after accumulating over five hours of run time in the test program, was integrated into the 1,500 lb thrust XR-4K14 engine and flown on the Rocket Racer.

This is a single acting motor and pump. The components are all rated to run at 6,000 rpm, but the 4K14 engine does not come near to reaching that potential. Instead the pump speed is less than 900 rpm.  Therefore, this pump can be turned faster to supply propellants to a much larger rocket engine.

These latest piston pumps are powered with engine heat, which, when used with XCOR's patent pending thermodynamic cycle, can achieve an Isp as high as the staged combustion cycle, which is the most efficient cycle for LOX/hydrocarbon engines and used on the best engines now.


3 Cylinder Pump Providing Fuel to the XR-4K14 1,500 lb-thrust LOX/kerosene engine in flight configuration.

 XCOR's proprietary piston pumps can pump like  turbopumps but are able to stop and start quickly.  They are also less expensive. A benefit of a piston-style design is that the pump is capable of pumping more fuel at a higher operational speed. Using this innovative pump design, drive gas to operate the pumps can be delivered by any of the three classical methods: staged combustion, gas generator, or expander. We have chosen a fourth, however, which is a proprietary thermodynamic cycle that is most similar to the expander. XCOR has patented this cycle, which has the advantage of not lowering the engine specific impulse, as a gas generator would.

While our pumps are designed for LOX and kerosene propellants, they can be easily adapted to pump any other commonly used propellants.

[Петр Зайцев]

Все эти поршни - это пустое в контексте данной дискуссии. Экскор их разрабатывал для того, чтобы создать безотказный двигатель, который можно заправлять черт знает каким топливом из грязных баков, и который при этом держит огромный ресурс в секундах и в запусках с полным цыклом разогрева и охлаждения. Все это конечно замечательно и важно для Линкса, но не имеет никакого отношения к двигателям верхних ступеней, в которых заинтересован ULA. Там главное - это удельный импульс, ну и удельная тяга. Сейчас еще стала важна цена, но только если характеристики не хуже, чем у RL-10. Вот тут-то и выползает хитрое использование алюминия. А поршневые насосы тут не при чем, даже если Экскор умудрится привинтить такое чудо на искомый двигатель.

[Salo]

http://www.flightglobal.com/articles/2011/03/30/354901/xcor-ula-team-up-for-upper-stage-booster.html

DATE:30/03/11
SOURCE:Flight International
Xcor, ULA team up for upper-stage booster[/size]
By Stephen Trimble

Commercial spaceflight start-up Xcor Aerospace has teamed with the United Launch Alliance (ULA) to develop a low-cost challenger to the 52-year-old Pratt & Whitney Rocketdyne RL10 engine.

The agreement between Xcor and the ULA, a Boeing-Lockheed Martin joint venture marketed as "the nation's rocket company", quickly follows a set of successful demonstrations of Xcor's aluminium alloy nozzle technology.

Demonstrations have shown that Xcor's major innovations, including the aluminium materials and a piston-based pump for cryogenic fuels, could form a feasible alternative to existing booster technology.

When combined with a liquid oxygen/liquid hydrogen engine, the new engine will produce 25,000-30,000lb thrust (110-135kN), allowing the new venture to compete for upper-stage positions on evolved expendable launch vehicle (EELV)-class rockets.

"By working with Xcor, we see the potential to develop engines that offer the performance and reliability our customers need at a more affordable price," says George Sowers, the ULA's vice-president of business development and advanced programmes.

The new partnership is aimed at challenging the dominance of the RL10, which since its introduction in 1959 has powered a wide range of space missions, including NASA's Viking and Voyager, and more recently the Lockheed Atlas V and Boeing Delta IVs that formed the basis for the EELV programme.

ULA and Xcor's announcement emphasises a cautious approach will be taken with the introduction of all-new materials, such as the aluminium nozzle, and engine design to compete with the proven reliability of the RL10.

A series of "go/no-go" decision points built into the development programme is intended to manage the risk of what even the partners describe as a "challenging effort".

The partnership also boosts Xcor's plans to leverage the aluminium nozzle for the 5K18 liquid oxygen/kerosene engine powering its Lynx suborbital spaceplane.

"The critical engine technology we're developing for ULA may one day launch satellites, capsules and space stations for government and commercial customers," says Xcor chief executive Jeff Greason. "Customers such as the US Air Force, NASA, the National Reconnaissance Office, Boeing and Bigelow Aerospace all stand to benefit from this partnership."

Separately, Mojave-based Xcor has sold at least six Lynx suborbital flights to the independent, non-profit Southwest Research Institute of San Antonio, Texas, which has also bought two flights aboard Virgin Galactic's suborbital SpaceShipTwo, also being developed in Mojave, and will use the flights to carry scientists and experiments beyond the atmosphere.

The 9m (30ft)-long Lynx is being developed to take off and land from a normal runway up to four times a day, carrying a pilot, passenger and payloads of up to 650kg (1,430lb) in either the pressurised cabin or exposed to the vacuum of space or thin air of the upper atmosphere, with a maximum altitude of 330,000ft.

Xcor had planned to test fly its Mark 1 Lynx prototype in 2010, but now expects to fly in 2012, with first flight of the commercial version, Mark II, to follow some nine to 18 months later.

Lynx promises aircraft-like operations from any licensed spaceport with a 2,400m runway, suitable abort options, 2h turnaround and 40 flights between preventive maintenance actions. Lynx operates under visual flight rules, and initially it will only fly during days of good visibility.

SpaceShipTwo carries two pilots and, with its much larger cabin, up to six researchers who could conduct out-of-seat microgravity experiments.

Virgin Galactic is also taking a vastly different technical route. SpaceShipTwo will be carried to 50,000ft by a specially designed four-engined, twin-fuselage "mothership", WhiteKnightTwo, before being released to make its rocket-powered ascent to as high as 316,000ft. Virgin, which in 2004 won the Ansari X Prize for the first private manned spaceflight, says its test programme will run through most of 2011 before commercial operations begin.
Additional reporting by Dan Thisdell in London


 © Pratt & Whitney Rocketdyne
Pratt & Whitney Rocketdyne RL10 engine

[Salo]

Rocketdyne Worries About Retaining Workforce[/size]
Apr 22, 2011
 
By Guy Norris, Michael Mecham
West Palm Beach, Fla., West Palm Beach, Fla.

Pratt & Whitney Rocketdyne needs answers fast from NASA on the agency's direction in space exploration as it continues to consolidate facilities and staff in the wake of the Constellation and space shuttle terminations.

"We're really concerned about this lack of a decision," says PWR President Jim Maser, speaking to Aviation Week here at its rocket test headquarters recently. Earlier, he testified to Congress on the potentially damaging impact of the slow transition from Constellation to the planned follow-on Space Launch System (SLS).

"I don't know if it did any good, but at least being asked to testify shows we may be gaining a bit of traction," he says of his appearance before the House Science Committee's subcommittee on space and aeronautics (AW&ST April 4, p. 31). Maser testified in his capacity as chairman of the American Institute of Aeronautics and Astronautics' Corporate Membership Committee.

For PWR, some firm direction is better than none at all as it continues to rationalize its production workforce. "The shuttle ends in June, and J-2X [an engine originally in development for the now-canceled Ares launch vehicle under the Constellation program], is in a flat or declining budget," says Maser. "We believe it's got to be worked out by the fourth quarter this year. If things don't change, we know we will have to reduce numbers this summer. But what we'd like to do is speed up. I don't want guarantees, I just want to know what NASA plans to do."

In terms of workforce, "we're down year-over-year by 15%, and this year it's still up in the air. The last thing we want is to be under-staffed as we try to execute work we have on contract, or as we try to capture new work."

"From a fixed infrastructure standpoint, across Rocketdyne we have a two-to-one ratio in excess capacity in terms of footage, and we have a plan to [reduce that] by half over the next three years. That's a non-trivial activity," says Maser. He notes that the reduction process began in 2008 with Pratt's initial acquisition of the rocket engine manufacturer. Following the closure of the company's solid rocket facility in San Jose, Calif., PWR is consolidating work at its two Canoga Park sites near Los Angeles. The Canoga Avenue site—where the space shuttle main engines were built—will be closed. All its work is being transferred to the nearby, and more modern, DeSoto plant, which currently has responsibility for missile defense and related attitude control propulsion system work.

The company is also re-organizing its activities in Florida and Mississippi. The site here will be used for the assembly and test of all "small" engines up to 50,000 lb. thrust. All larger engine test and development work will be focused at its Stennis Space Center in Mississippi.

The first J-2X engine is being assembled at Stennis now and will be tested in May. Despite the scrapping of Ares, Maser believes the J-2X development continues to be worthwhile.

"Constellation would really be a waste of money if the heavy-lift architecture doesn't use any of that, and I'd argue that this is unlikely. Even if we don't use any of it, [J-2X] has maintained the critical skills we need to maintain the baseline."

PWR also is poised to complete development of the RS68A, the most powerful hydrogen-fueled engine made, and recently delivered the third flight-test engine for integration into a Delta IV launch vehicle.

"We're just wrapping up -68A and held a design certification review in California with United Launch Alliance (ULA) and the National Reconnaissance Office (NRO) on March 31," says Maser. "We've built and tested the first three flight engines, we've delivered two." Earlier in March, PWR completed a series of hardware acceptance reviews following tests on the first of three RS-68As that were then shipped to ULA's integration facility in Decatur, Ala., for installation into the first stage of the Delta IV. The third, and final engine, 30005, was cleared for delivery after its acceptance review following hot-fire testing at Stennis.

"We're nownegotiating the next lot buy of the engine to provide them through 2017. This will include a final batch of three more -68s as well as -68As. All we have to do is get back to steady-state production. We've been in a period of instability in terms of flow through our factories and test stand at Stennis," comments Maser.

The RS-68A is a liquid-hydrogen/liquid-oxygen booster engine designed to provide 705,000 lb. of liftoff thrust, or 42,000 lb. more than the basic RS-68. Although the NRO does not comment on specific missions, there is speculation that the engine could make its debut on NRO L-36, thought to be due for launch in 2012.

PWR continues work with Polaris on the Bantam low-cost, dual-use booster/launch abort system for Boeing's CST100 spacecraft. Four of the variable-thrust engines would be used for orbital maneuvering. But should a launch abort be required, the Bantam engines could go from cold to full 50,000-lb.-thrust power in 80 milliseconds and sustain that output for 3 sec. in order to separate the crew capsule safely from the launcher.

The company also is developing an RL-10C upper-stage engine that converts RL-10Bs used for the Delta IV to an RL10A configuration for the Atlas V. The development includes a smooth-walled combustion chamber that abandons the use of cooling tubes that climbed the walls of the chamber.

[Salo]

Вот немного о жидкостной САС CST-100:

PWR continues work with Polaris on the Bantam low-cost, dual-use booster/launch abort system for Boeing's CST100 spacecraft. Four of the variable-thrust engines would be used for orbital maneuvering. But should a launch abort be required, the Bantam engines could go from cold to full 50,000-lb.-thrust power in 80 milliseconds and sustain that output for 3 sec. in order to separate the crew capsule safely from the launcher.

[Salo]

[Salo]

http://www.hobbyspace.com/nucleus/index.php?itemid=37041

SA'12: Friday Morning pt.1
Mark Street, XCOR Aerospace

- background of XCOR
- Video of LOX/Methane engine firing
- Engines are long lasting. After 1000 firings no sign of wear.
- Safety mechanism to prevent hard starts
- Rocket valves, custom valve maker
- Non-burnite composite LOX compatible tanks.
- Piston pumps - lower power/wt than turbine but work over wider range and a lot cheaper
- X-Racer
-- Could repeatedly turn engine off and back on within seconds
-- 8 minute refueling
- Lynx
-- Custom airframe
-- Mach 4
-- 100 km

- Activity for the past year:
-- Reaction control system for Lynx
--- Lots of testing of 40lb thrust engine
- Low mass valve project
- Lynx engine testing
-- Video
-- Engine is essentially ready
- Work with ULA on a low cost LOX/LH2 engine
-- XCOR focused on pumps
-- Built special stand for pump tests
-- Installed LH2 storage tank
- Testing piston pump for cryo fluids.

- Lynx has been main focus
-- 10500 pounds at takeoff
-- Mark I version - 60km altitude, Mach 2
-- Latest airframe model. Just a few days old. Looks somewhat different than older images.
-- Lots of wind tunnel testing
--- Fantastic amount of info in a short time.
--- Recent tweaking to deal with Yaw/Roll
--- Cool video of shock waves around model as it is turned
--- Most recent tunnel test at end of March. Appears that tweaks have solved the final problems.
--- Should soon be ready to make airframe.
-- Describes major components of Lynx from nose to tail
-- Status of component construction
-- Fueselage delivered
-- Sneak peak of shop floor
-- Build fueslage, tanks, engines on top of trailer, which can be pulled to test stand.
-- No schedule but goal is to fly by end of the year.

Q&A:
- Segmented window saves cost over single piece
- Mark I LOX tank will be aluminum.
- Pump fed LOX and Kerosene
- More fuel and LOX volume in Mk. II but most improvement will be in lower wt.
- Same mold line
- Incremental test plan for expansion of flight envelope
- Pumps will be driven by He expansion
- He is recycled
- Both pilot and passenger will wear pressure suits.
- L/D better than shuttle but not a great glider
- Brakes sized to handle returns on aborted flights.
- Will build and sell engines but want to sell multiple engines, not just one
- Landing gear a mix of in-house and outside components
===

Frank Zegler, United Launch Alliance
- Focus on upper stage
- Independent power, attitude contorl, pressurization & vent systems
- Lot of high performance systems
- People not allowed near He tanks at peak pressures
- Very expensive to integrate spacecraft
- Brittle point-designs with limited growth capability
- Much technology such as hypergolic thrusters not shared with other industry
- Expense comes from lots of people involved.
- In-space vehicle systems architecture diagram
- Lots of work over past 20 years on composites, valves, etc.
- However, only improved by few percent
- Low-rate
- Goals:
-- slash costs by designing in best possible system reliability
-- Stay within broad industry standards
-- Simple commercial designs and materials
-- Amplify performance and mission capability
-- Support all likely future transport architectures

-IVF (Integrated Vehicle Fluids) Basic Concept
-- Use only hydrogen and oxygen on board
--- Pressurization & vent
--- Attitude control & vehicle settling
--- Power
-- Use waste gas wherever possible
-- Small H2/O2 burning engine to provide power to all vehicle functions
-- Leverage tech in other industries
- Compares diagram of engine and plumbing for current Centaur and one that is IVF transformed
- Use 300 volt power like a hybrid car
- Shows small H2/O2 thruster that they have been testing
- In 1965 H2/O2 single cylinder engine ran for 500 hours.
- ICE projects
- Inline test engine for burning H2/O2
-- Regeneratively cooled
- 2-stage cryopumps generation 1 design
-- Learning from XCOR

- Optimize for overall vehicle design, not individual systems
- Store energy in one place - the main vehicle tanks
- Most energy handled as heat, not electricity
- Most mass savings come from reducing residuals/losses
- Micro-g for settling greatly reduces boil-offsimplifies systems, handling of heat, etc.
- Use bit of waste H2/O2 for micro acceleration.
- Big reduction in stage mass.
- 300 V really helps a lot with, e.g. valves.

- IVF shows a path forward to new levels of cost, reliability & capability
- Benefits existing vehicles but is a powerful design tool for next-gen vehicles, especially crewed vehicles.
-- Long operational flight duration systems, light & modular
-- Extremely high peak power output dovetails with cruise solar power
-- Components valuable for depots, active cooling systems, in situ propellant synthesis
-- Removable, simple, and repairable in-situ with common tools
- Components made of common materials, everyday processes
- Works with methane & other propellants

Q&A:
- Get off roller coaster of spending huge amounts of money to lower cost of, say, a titanium hydrazine tank only to see its cost go back up as the price of titanium rises.
- Helps upper stage of launch vehicles but especially good for in-space vehicles.
- Can reduce LH tank wall thickness down to 12 thousandths from 20.[/size]

[Salo]

http://www.parabolicarc.com/2012/04/13/space-access-12-xcor-aerospace-update/#more-37261

Space Access 12: XCOR Aerospace Update[/size]
Posted by Doug Messier
on April 13, 2012, at 10:40 am


XCOR test fires its Lynx 5K18 engine with lightweight aluminum nozzle; United Launch Alliance (ULA) and XCOR to apply the nozzle and XCOR

[Salo]

http://www.parabolicarc.com/2013/09/23/50085/

XCOR Reaches Milestone on Liquid Hydrogen Engine
Posted by Doug Messier
on September 23, 2013, at 10:24 am in News   

XCOR piston pump (Credit: XCOR)

September 23rd, 2013, Mojave, California and Centennial, Colorado (XCOR/ULA PR) – XCOR Aerospace and United Launch Alliance announced significant progress today in the XCOR/ULA liquid hydrogen (LH2) engine development program.

"We are happy to announce that we have successfully operated our liquid hydrogen pump at full design flow rate and pressure conditions," said XCOR Chief Executive Officer Jeff Greason. "This milestone builds on our earlier success with liquid oxygen and kerosene pumps, which have powered many of our hotfires. Achieving this goal allows us to proceed with integrated testing of our liquid hydrogen demonstrator engine, fed by our liquid hydrogen and liquid oxygen piston pumps. The ultimate goal is a far more cost-effective upper-stage engine for ULA and their customers."

Conceived as a lower-cost, risk-managed program, the XCOR LH2 engine program is intended to produce a flight-ready cryogenic upper-stage engine in the 25,000 lbf thrust class with growth potential up to 50,000 lbf thrust or more. When complete, it should cost significantly less to produce and be easier to operate than competing rocket engine technologies.

However, it isn't just about thrust class. "Factors such as the extreme low temperature and small molecule size of liquid hydrogen present new technical challenges compared to liquid oxygen or kerosene," said Greason. "Demonstrating our ability to safely pump this fluid at high flow rates and pressures, with relatively low mass is a significant engineering milestone that will deliver yet another line of innovation and business to XCOR."

"XCOR's and ULA's investment in this program should result in much lower cost and more capable commercial and government launch capabilities," said XCOR Chief Operating Officer Andrew Nelson. "By drawing from several hundred years of human experience in the development of piston machinery, XCOR seeks to dramatically increase reliability, reusability and long term manufacturability of rocket propellant pumps. The decrease in manufacturing and maintenance costs of XCOR's rocket propellant pumps is at least an order of magnitude in volume production when compared to traditional rocket turbo machinery."

With the completion of the flow rate and pressure tests, Nelson added, "We are proud to say that our collaboration with ULA has borne significant results.   This is a new application of time-tested principles that tangibly demonstrates we can produce an upper-stage cryogenic engine with similar or better performance than today's state of the art, with long life, reusability and reliability at significantly less cost. And it is only taking place at XCOR."

(Editor's Note: The piston pump is described in more detail on XCOR's blog today.)

"Today's milestone is further validation of the effort that we began with XCOR several years ago, leveraging more than a century of automotive industry insights to develop a truly new concept in engine design," noted George Sowers, ULA's Vice President of Human Launch Services. "These technology demonstrations have paved the way for ULA's support of the liquid hydrogen engine program. We are beginning to see substantial results from ULA's continued investment of time and resources in the ULA/XCOR hydrogen engine program and look forward to the next phase of development in this groundbreaking endeavor."

About XCOR Aerospace: XCOR Aerospace is based in Mojave, California. It is currently starting the process to create a new Research and Development Center in Midland, Texas and an operational and manufacturing site at the Kennedy Space Center in Florida. XCOR builds safe, reliable and reusable rocket-powered vehicles, propulsion systems, advanced non-flammable composites and rocket piston pumps. XCOR works with aerospace prime contractors and government customers on major propulsion systems, while also building Lynx. Lynx is a piloted, two-seat, fully reusable liquid rocket-powered vehicle that takes-off and lands horizontally. The Lynx family of vehicles serves three primary missions depending on their specific type including: research & scientific missions, private spaceflight, and micro satellite launch (only on the Lynx Mark III). Lynx production models (designated Lynx Mark II) are designed to be robust, multi-mission (research / scientific or private spaceflight) commercial vehicles capable of flying to 100+ km in altitude up to four times per day. Lynx vehicles are available to customers in the free world on a wet lease basis to start their own manned space flight program. (www.xcor.com).

United Launch Alliance: ULA is a 50-50 joint venture owned by Lockheed Martin and The Boeing Company, and is the nation's rocket company, bringing together two of the launch industry's most experienced and successful teams – Atlas and Delta. ULA provides reliable, cost-efficient space launch services for the Department of Defense, NASA, the National Reconnaissance Office and other commercial organizations. ULA program management, engineering, test, and mission support functions are headquartered in Denver, Colo. Manufacturing, assembly and integration operations are located at Decatur, Ala., and Harlingen, Texas. Launch operations are located at Cape Canaveral AFS, Fla., and Vandenberg AFB, Calif. For more information on ULA, visit the ULA Web site at www.ulalaunch.com, or call the ULA Launch Hotline at 1-877-ULA-4321 (852-4321). Join the conversation at www.facebook.com/ulalaunch and twitter.com/ulalaunch .

[Петр Зайцев]

Может я и поторопился с суждениями. По крайней мере Гризон надеется задействовать этот свой ПНА в реальном двигателе.

Кстати Гоф запостил на NSF, что когда он работал у Мастена, ULA настолько хотели набрать часы на альтернативном двигателе, что они предлагали предоставить Центавр на переделку бесплатно, чтобы гонять его на привязи с альтернативным двигателелм по типу Xoie. Жаль двигателя не было тогда. Его, правда, и сейчас нет - только ПНА. XCOR еще с камерой много возни предстоит.

[avmich]

У XCOR прицел скорее на безотказность, неважно с какими топливами, можно и водород - с ним они давненько возятся. Не знаю как УИ - хотя у RL-10 вроде бы давление не такое большое, поршневому вполне по силам - но вот по части стоимости их предложения наверняка интересны.