Sitting on top of a rocket flying into space might sound like a dangerous idea, but there is a certain advantage to exactly this kind of configuration. By having the capsule placed on top of the rocket you are presented with the best option for escape, in the event of a failed launch vehicle, by adding a launch escape system (LES) on top of the capsule.
Basically the launch escape system is capable of pulling the space capsule to safe distance, followed by a nominal oceanic splashdown if the launch vehicle suffers a major malfunction such as detonation, course or angle-of-attack deviation.
The launch escape system must have certain requirements to ensure success, such as high acceleration, instant ignition and redundant separation systems related to the capsule. These requirements and systems have already begun testing at Copenhagen Suborbitals, and is continuously being studied and tried out to ensure that the best option for rescue is reliable.
With great inspiration from earlier launch escape systems by US space programs Mercury and Apollo, and the Russian Soyuz, the space capsule department of Copenhagen Suborbitals has come up with a final design, as presented below.
The engine of the launch escape system is solid propellant, providing easy storage and instant ignition without any of the handling and fueling problems related to cryogenic propellant. The solid propellant engine provides 85 kN of thrust for 2 seconds, accelerating the capsule to almost 15g, taking the astronaut to a safe distance almost instantly.
The aerodynamics of the capsule/LES has been thoroughly studied in wind tunnels to ensure nose-first stability throughout the entire trajectory, since the system is only passive stable. In order to verify these data, two 1/3 scale capsule/LES have been build to be flight-tested during the spring of 2014.
During the summer of 2011, a launch escape system test using the previous generation space capsule Tycho Deep Space 1 was conducted. All general systems such as ignition, separation systems and parachute deployment were tested – however, the aerodynamic stability of the capsule/LES configuration was not acceptable due to stability issues.