The Skylon spaceplane is designed to provide cheap, reliable transport into low earth orbit. It is intended to replace the inadequate launcher systems used today with a practical transport system which will permit a rapid expansion in the volume of traffic into space. Current launchers (expendable multistage rockets) are expensive (approx. $150m per flight), unreliable (approx 5% loss rate) and limited to a low launch rate.

To overcome these failings Skylon has the following characteristics:

Reusability
Reduced cost per flight by amortising vehicle production cost over several flights. Preliminary calculations indicate that 200 reuses is close to the economic optimum for a first generation spaceplane without incurring performance penalties to achieve a longer fatigue life.

Single Stage (SSTO)
Multistage vehicles are more costly to develop and have greatly increased operational costs compared with single stage vehicles. This is due to the Quality Assurance operations necessary to safely mate and fuel two vehicles, particularly if one of the vehicles is piloted.

Unpiloted
By employing onboard computers to handle flight control the need for a pilot is eliminated and the size of the mission control centre is reduced. Dispensing with the pilot reduces the vehicle development cost due to the relaxation of required safety standards during the development programme and also increases the payload fraction due to saving the pilot cabin mass and life support system etc. Although Skylon is unpiloted it would be capable of carrying passengers by fitting a dedicated module (containg seating and life support systems) into the payload bay.

Abort Capability
The vehicle is capable of flying to and safely landing at strategically placed abort sites with up to half its engines shut down in a similar manner to aircraft. All flight critical systems would feature redundant channels to contain single point failures.

User Friendly Operations
Simple ground handling (e.g. tractor towing the vehicle around the spaceport on its own undercarriage) and automated checkout procedures. Minimal maintenance in between flights achieved by robust TPS and reliable engines. Simple payload integration achieved through maximum use of containerised payloads dispensing with the requirement for "clean room" facilities and allowing for simple interfacing with other forms of terrestrial transport.

Reentry Crossrange
The low reentry wing loading results in a hypersonic L/D that is sufficient to pull substantial crossrange. This increases the number of opportunities that the vehicle can reurn to the launch site from an highly inclined orbit thus improving the operational flexibility of the system.

Environmental ImpactSkylon employs environmentally friendly propellants ( hydrogen and oxygen) and being a single stage vehicle will not add to the orbital debris problem.