But that is the normal usage in the context of large engineering projects. A problem that is "easier" takes fewer resources to solve and hence is also "cheaper". Time, labor, capital, etc can all be reduced to a monetary value at this scale.
Due to the lack of existing SSTO launchers, designing a TSTO launcher is cheaper and easier.
You're implementing solved problems rather than solving some new problems.
Worse, you're trying to solve new problems that many people have already tried and failed to solve; the easy and cheap "just do X", "try Y", and "maybe Z will work out" solutions have all been found wanting,
which is why we're even considering the brain-meltingly complicated regenerating-shifting-multi-cycle SABRE engine in the first place.
Designing an upper stage from scratch is expensive, but the point is you don't need to design one from scratch for a minimum viable launcher.
Buy a STAR PAM, pay ULA to strengthen a Centaur for horizontal integration, etc.
Once you have money coming in you can invest in an optimised upper stage if needed, but as we've seen with Falcon 9 an 'optimum' upper stage is not strictly necessary.
Think about that for a moment and compare like for like. Skylon 15tonnes to LEO. F9 to LEO 22.8tonnes. F9 wins hands down.But Skylon comes back 100%. F9 US. 0 %. Skylon wins hands down. So, was F9 "easier" to design? As an expendable yes. But it turns out that designing in economic reusability (although SX claim physical recovery of the US is possible with a small enough payload) has proved impossible. And remember the TSTO design supposedly has more margin to begin with. The "easier" option is apparently "scrap the partial RLV and design a full RLV from the ground up that's 10x bigger." We'll see how that works. But TSTO, 3STO (or even 5STO, if you're talking about Pegasus with HAPS and including Stargazer) is what people know. Things change radically when you've got an engine that can provide >6x the Isp of the best viable propellant combination available and you've got people who have an aircraft background. And just a reminder. Skylon does it at the same payload fraction as an TSTO ELV, not the 1% (or less) of the commonly proposed VTOL SSTO.
Skylon may do.Asserting Skylon is easier because it has one stage, before it has ever flown, seems perhaps overoptimistic.
And it's not 6* the ISP over most of the delta-v range.
Unfortunately, it is looking likely that if BFR is not in fact much delayed, Skylon will be flying at best against a bugfixed V2 of BFR, not an initial version. BFR has enough systematic margin that enormous amounts can go wrong and exceed 15 tons to orbit.
The complicated funding environment in the UK at the moment may not help things along at all either..
Rolls-Royce and Boeing invest in UK space engineBy Jonathan Amos, April 12, 2018http://www.bbc.co.uk/news/science-environment-43732035[/i]The concept art looks different to anything I've seen before. Have I missed something?
>"We expect to leverage their revolutionary technology to support Boeing’s pursuit of hypersonic flight," Nordlund said in a statement.>
You missed the part where Skylon was sidetracked for more down to earth testbeds and concepts, including an air-launcher as depicted.One interesting quote from Boeinghttps://www.cnbc.com/2018/04/11/boeing-horizonx-ventures-joins-37-million-reaction-engines-investment.htmlQuote>"We expect to leverage their revolutionary technology to support Boeing’s pursuit of hypersonic flight," Nordlund said in a statement.>
Quote from: AnalogMan on 04/11/2018 11:54 pmRolls-Royce and Boeing invest in UK space engineBy Jonathan Amos, April 12, 2018http://www.bbc.co.uk/news/science-environment-43732035[/i]The concept art looks different to anything I've seen before. Have I missed something?
Rolls-Royce and Boeing invest in UK space engineBy Jonathan Amos, April 12, 2018http://www.bbc.co.uk/news/science-environment-43732035[/i]
Reaction Engines secures £26.5m investment from new industrial and financial investors– New strategic investments from Boeing and Rolls-Royce, additional investment from BAE Systems– Financial investments from Baillie Gifford Asset Management and Woodford Investment Management12 April 2018 – Reaction Engines Limited (‘Reaction Engines’) today announced that it has raised a further £26.5 million in a strategic fundraising by securing backing from some of the most influential names in aerospace and finance which will support its development of SABRE™ – a revolutionary new class of aerospace engine combining jet and rocket technologies.New strategic investors are Boeing HorizonX Ventures, the investment arm of Boeing, the world’s largest aerospace company and leading manufacturer of commercial jetliners and defence, space and security systems; and Rolls-Royce, a pre-eminent engineering company focused on world class power and propulsion systems whose experience and capability in building complex engine systems is well known.These new investors are in addition to BAE Systems, a global defence, aerospace and security company, which invested £20.6 million in Reaction Engines in 2015 and is providing further investment in this round, building on existing collaboration to provide expertise in engineering and programmes.Financial investments in Reaction Engines will also be made by Baillie Gifford Asset Management and Woodford Investment Management.The Company anticipates further investment interest in this funding round from existing shareholders and other financial institutions. All investments will take the form of a subscription for new shares, which is subject to the approval of existing shareholders.Mark Thomas, Chief Executive of Reaction Engines said:“This is a significant milestone for Reaction Engines and I am delighted to welcome our new strategic and financial shareholders. In addition to providing our largest round of private investment, these new partners bring invaluable expertise in both hypersonics and engine technologies with significant access to target markets. This is not only a vote of confidence in our technology but also underlines belief in our ability to develop a thriving commercial business which will provide strong financial returns for our shareholders.” Steve Nordlund, Vice President of Boeing HorizonX said:“We continue to connect capabilities around the globe with our investment in Reaction Engines, which is our first in a UK-based company. As Reaction Engines unlocks advanced propulsion that could change the future of air and space travel, we expect to leverage their revolutionary technology to support Boeing’s pursuit of hypersonic flight.”Paul Stein, Chief Technology Officer of Rolls-Royce said:“We are delighted to become a strategic investor in Reaction Engines Limited, an innovative UK company that is helping push the boundaries of aviation technology. We look forward to working with REL and assisting with the development of their technology, and we plan to incorporate this technology into our own future products.” Sam Gyimah, Minister of State for Universities, Science, Research and Innovation, said: “These investments are a real vote of confidence in Reaction Engines and its revolutionary SABRE engine, which has benefited from £60m in UK Government support. Boeing and Rolls-Royce will bring world-class expertise to the project ahead of its testing at Westcott, alongside the new National Space Propulsion Facility. “This is an exciting time as the UK’s commercial space industry goes from strength to strength, boosting the economy and creating high-skilled jobs across the country. Through our ambitious Industrial Strategy, we are working with the sector to pursue new opportunities, develop technologies and infrastructure, and enable small satellite launch and sub-orbital flight from UK spaceports for the first time.” The investments agreed to date take the total raised by Reaction Engines in the last three years to over £100 million, including British Government funding commitments, and will support key elements of the company’s SABRE development programme, which has the objective of commencing ground-based testing of a SABRE engine core in 2020.Reaction Engines has recently achieved a number of milestones for the development of SABRE, and is on track for the test of the engine core in 2020. It is currently constructing a new facility in Westcott, Buckinghamshire, UK for SABRE testing.The fundraising will also allow Reaction Engines to accelerate its commercialisation plans, with proprietary technology opportunities in motorsport, electric vehicle thermal management, waste heat recuperation, small satellite cooling and aero-engines.The Company has continued to grow its presence in the United States and recently secured a contract from the U.S. Defense Advanced Research Projects Agency (DARPA) to conduct high-temperature airflow testing of a Reaction Engines precooler heat exchanger. These tests will demonstrate the Company’s world-leading heat exchanger technology, contributing to a rapid leap forward in precooled propulsion, for both jet and combined cycle engines, as well as opening exciting possibilities for novel vehicle thermal management solutions.ENDS
You missed the part where Skylon was sidetracked for more down to earth testbeds and concepts, including a single engine testbed and an air-launcher.One interesting quote from BoeingCNBC....Quote>"We expect to leverage their revolutionary technology to support Boeing’s pursuit of hypersonic flight," Nordlund said in a statement.>
Our new partners bring invaluable expertise in both #hypersonics and engine technologies and will support key elements of the SABRE development programme. @RollsRoyce @Boeing @BoeingUK
https://twitter.com/ReactionEngines/status/984341611390947328?s=20QuoteOur new partners bring invaluable expertise in both #hypersonics and engine technologies and will support key elements of the SABRE development programme. @RollsRoyce @Boeing @BoeingUKNew tweet & new image I think.
We’re excited to continue pursuing and achieving our company goals, including our upcoming #HTX test later this year at our #TF2 test facility @reactionengUSA @SpaceportCO
Quote from: Star One on 04/12/2018 08:42 amhttps://twitter.com/ReactionEngines/status/984341611390947328?s=20QuoteOur new partners bring invaluable expertise in both #hypersonics and engine technologies and will support key elements of the SABRE development programme. @RollsRoyce @Boeing @BoeingUKNew tweet & new image I think.the image isn't new, it's a SABRE 3, and if Word Press is anything to go by it's been around since May 2016
I don’t know if any if either of these are new images, the one at the building site might be.https://twitter.com/ReactionEngines/status/984440584042622976?s=20QuoteWe’re excited to continue pursuing and achieving our company goals, including our upcoming #HTX test later this year at our #TF2 test facility @reactionengUSA @SpaceportCO
Mike Hood – Test Facility, Lead Engineer & Russ Payne – Chief Design Engineer – Reaction Engines – SABRE TF1 – Development of the SABRE Demonstrator Test FacilityThe Synergetic Air Breathing Rocket Engine (SABRE) is a class of combined cycle engines that have the potential to revolutionise aerospace propulsion. SABRE burns hydrogen fuel in air-breathing mode up to speeds in excess of Mach 5, then switches to a high-performance rocket mode that utilises on-board liquid oxygen. Novel light-weight compact heat exchangers allow efficient thermodynamic energy exchange between engine components via a helium loop, which results in an attractive combination of high thrust to weight and specific impulse in air-breathing mode.One of the unique features of SABRE is that much of its air-breathing operation can be tested on the ground. Testing an engine as unique as SABRE however, requires a custom-made facility. Conventional air propulsion facilities require large air feeds and conventional fuel systems; such a test facility can be fully enclosed if noise controls require it. This enclosed approach is not, however, compatible with hydrogen-fuelled systems. Conventional rocket test stands are designed to handle hydrogen fuels safely but lack the air inflow systems of a conventional air-breathing test facility and must be located remotely to accommodate the noise levels they generate during test.This presentation will look at the current development of the SABRE engine and the construction of its unique test facility SABRE TF1, at Westcott Venture Park.
https://www.bis-space.com/2018/01/14/20102/current-topics-in-rocket-propulsion-an-open-source-conferenceThis is tomorrow (Saturday) - any questions? I'm not technical so I may fail to ask them properly. Maybe someone better will be there? QuoteMike Hood – Test Facility, Lead Engineer & Russ Payne – Chief Design Engineer – Reaction Engines – SABRE TF1 – Development of the SABRE Demonstrator Test FacilityThe Synergetic Air Breathing Rocket Engine (SABRE) is a class of combined cycle engines that have the potential to revolutionise aerospace propulsion. SABRE burns hydrogen fuel in air-breathing mode up to speeds in excess of Mach 5, then switches to a high-performance rocket mode that utilises on-board liquid oxygen. Novel light-weight compact heat exchangers allow efficient thermodynamic energy exchange between engine components via a helium loop, which results in an attractive combination of high thrust to weight and specific impulse in air-breathing mode.One of the unique features of SABRE is that much of its air-breathing operation can be tested on the ground. Testing an engine as unique as SABRE however, requires a custom-made facility. Conventional air propulsion facilities require large air feeds and conventional fuel systems; such a test facility can be fully enclosed if noise controls require it. This enclosed approach is not, however, compatible with hydrogen-fuelled systems. Conventional rocket test stands are designed to handle hydrogen fuels safely but lack the air inflow systems of a conventional air-breathing test facility and must be located remotely to accommodate the noise levels they generate during test.This presentation will look at the current development of the SABRE engine and the construction of its unique test facility SABRE TF1, at Westcott Venture Park.
