September 1, 2011 by Dan Swinhoe
The space race has taken an interesting turn in the last few years. India and China hope to put men on the moon, NASA wants men on Mars and companies interested in making space a commercial hotspot have been gathering steam.
The latest news in the Aerospace world is the glowing report given to a British Spaceplane concept by the European Space Agency. The plane, Skylon, has been developed by UK based company Reactions Engines Ltd and according to the report could represent “a major breakthrough in propulsion worldwide.”
The report was commissioned by UK Space Agency (UKSA) and conducted by the ESA after an extensive look at many areas of the Skylon concept, including the details of the new Sabre engines and the finances of the business. Ask the Experts spoke to Natalie Allred of Reactions Engines to find out a bit more about the project.
“We are very grateful to ESA for committing hundreds of hours of effort to the review of the Skylon project, at the request of the UK Space Agency. We have taken into consideration all of the observations and conclusions drawn by UKSA, which have been invaluable to our final design exercise and our planning process.
“The ESA is very keen to see the first fully working model of the engine that is so different from the rest of the field. And would be an enormous step forward for the Skylon project as a whole. Phase III of the development programme will commence later this year and will concentrate on developing the complete engine including a flying test bed for the intake and nacelle and a ground test bed for an engine demonstrator.”
How Skylon Works
The concept as a whole sees Skylon as an unpiloted reusable Space plane, one that takes off and lands on a horizontal runway in the same way a regular plane does. This method of space flight is called single stage to orbit (SSTO) and has great potential to be cheaper, easier (once some of the technical problems have been solved) and more environmentally friendly. It has potential to take satellites up to into the atmosphere, parts (or people) to space stations but above all it’s versatile and up to the buyer what they use it for.
Natalie explained that “Skylon is an alternative to all current space launch systems. It has a similar launch capability to the Shuttle but does not have the crew and other in orbit services offered by the Shuttle.”
Sabre Engines and LAPCAT
Obviously all the technology involved with Space is top notch, everything has to be perfect otherwise nothing ever gets off the ground (or more importantly never comes back). But Skylon’s Sabre engines are especially clever. It’s a combination of both jet and rocket engines, the jet part is for take off and switches to the rocket part for higher speeds and orbit. With these combined engines comes their own problems.The engine uses oxygen from the air, which at high speeds will be incredibly hot and need to be cooled, which causes the moisture to freeze. By using a clever anti-frost system the Sabre engines are both lighter, more fuel efficient and more powerful.
“Producing pre-cooler heat exchangers with a mass that makes the vehicle work and can control the frost formation is the one fundamental new technology needed to make Skylon work. As with any advanced aerospace project, there will be other technical challenges, but they are all in areas where solutions have been found before.”
The technology is ahead of pretty much everyone else out there. And everyone at REL is confident in Skylon’s potential in itself and beating any rivals. Natalie tells us: “The engine and the airframe go together so any vehicle using SABRE is likely to be very close to SKYLON. Any other spaceplane using the SABRE approach would have to alter size to differentiate itself from SKYLON. We think that we have the optimum vehicle for the near and middle term space launch markets. In the long term if the space launch market grows enough, there may be an economic argument for specialist vehicles of different sizes.”
The commercial space industry is still growing in all sorts of directions and it’s hard to predict what exactly the future holds, but ESA was very happy with the economic predictions for when Skylon is up and running. But REL aren’t going to tell people what they should be doing with their space planes. “The economics of Skylon are based on selling vehicles to operators. It is the customer operators who will decide what services they offer, we are not going to proscribe what business plans they pursue.” Natalie continues; “To maximize the market for Skylon we have made sure it can cover not only the existing launch market requirements, but also new ones such as public access (a more accurate term than space tourism), building large systems such as solar power satellites and supporting new initiatives such as human flight to the Moon and Mars. We have ensured that anything that has been reasonably projected as a realistic future space application can be supported by Skylon. Skylon will open up many possibilities for future markets, but whether these applications are actually realised depends upon what operators offer and what the operatorsʼ customers are willing to buy.”
Right now Skylon and its engines represent everything that REL are working on but there’s potential for different ideas in the future. “We have considered using SABRE technology in terrestrial point to point hypersonic passenger travel in the EU/ESA LAPCAT technology study programme.” The LAPCAT programme wants to cut the long haul flights, such as London to Sydney, from 24 hours to three or four and keep the cost at around the current cost of the same trip on business class.
While the LAPCAT programme sounds like a great idea and a perfect application for the Sabre engines, REL’s focus right now is getting the idea out of the concept and testing stage and into proper production. “The first flying vehicles in 2016 will be full size and include engines. The first production standard vehicles will fly in 2018 and after a 2 year test programme SKYLONs will go into commercial service in 2020.”
Skylon itself already has quite a history behind it. “It has taken nearly 30 years with political, financial and technical problems to resolve.” Natalie says. Skylon started life in the early 80s as Hotol, an early version developed with British Aerospace and Rolls Royce, and even managed to secure £2 Million from the government. Funding was stopped however and so REL was formed with the intention to continue work on Hotol, which over time changed into Skylon.
But most importantly…what about the costs?
Obviously projects with this sort of ambition require funding and the estimate cost to fully realise the project could be up to £7.5 Billion. But the MD of REL, Alan Bond, told the BBC they wouldn’t be looking to the Government for any support, and they only want their help on changing legislation. Would they really refuse Cameron’s money if he offered? “It would depend upon what the money was for and its purpose. We foresee totally commercial space access and would not want to compromise this leading to World Trade Organisation issues in the future. We need legislation to clarify some of the commercial rules for space launches such as the insurance requirements. We also need new legislation to enable Skylon to be certified under modified versions of the aviation rules.”
REL are one of the leading companies in the UK in what it does, but what about the UK as a whole in space industries? “This is a very complex question not one amenable to a simple answer. The UK has a large overall space industry if ‘downstream’ (i.e. applications) activity is included but a very weak “upstream” industry (that supplies spacecraft and launchers). The Space IGT report in 2010 proposed that the UK should target getting 10% of the total global space industry by 2030 (£40 billion per annum from £400 billion). To achieve this, it will be necessary to introduce the new applications which SKYLON will enable and also to use the UKʼs large aircraft industry as a basis to expand its small upstream industry.”