IXV paves the way for PRIDE and more

An artist's impression of ESA's IXV lifting body attached to its upper sage booster during its first sub-orbital flight
An artist’s impression of ESA’s IXV lifting body attached to its upper sage booster during its first sub-orbital flight

On Wednesday, February 11th, the European Space Agency (ESA) launched a Vega rocket from their Guiana Space Centre in French Guiana, South America. The rocket has been Europe’s launch system for lightweight payloads since 2012, and in this capacity it has generally been used to lift Earth observation mission payloads into polar orbits, where they can see as much of the Earth’s surface as the planet rotates beneath them.

The February 11th mission was different, however. This was launched due west, out over the Atlantic and directly towards Africa. And, rather than carrying a satellite, the rocket carried a new, experimental spaceplane, very unglamorously called IXV,  for Intermediate eXperimental Vehicle.

Dubbed a “mini-shuttle” by some in the media, IXV is more correctly a lifting body design. That is, it has no wings of any description. Instead, it uses its own aerodynamic shape to generate lift and stability during re-entry into the Earth’s atmosphere. This particular principle of flight isn’t new. Lifting body designs have been used for a number of experimental purposes over the years, including in the 1960s and 1970s as NASA investigated potential designs for a reusable space vehicle (although the evolving mission requirements for the space shuttle meant that a lifting body design was eventually rejected in favour of a delta wing configuration).

The IXV mission
The IXV mission

In popular culture, and for those old enough to remember, footage of the crash and disintegration of a lifting body piloted by Bruce Peterson, was used in the opening titles of the TV series The Six Million Dollar Man. Unlike the fictional Steve Austin, however, Peterson survived his crash without the aid of bionics, although he did lose his sight in one eye … courtesy of an infection which occurred while he was in hospital after the crash. More recently, the use of a lifting body approach has been been demonstrated by Sierra Nevada’s Dream Chaser vehicle, which had been intended to fly crews to and from the International Space Station.

Europe’s IXV is an uncrewed vehicle, weighing just under 2 tonnes. It’s primary objective is to research the re-entry and flight characteristics of such a vehicle shape and to test the re-entry shielding technologies that ESA are developing. All of this is with a view to developing a new generation of reusable space vehicles that could be employed for both crewed and uncrewed missions. The first of these is likely to be PRIDE – the Programme for Reusable In-orbit Demonstrator in Europe – a genuine spaceplane using a combination lifting body / winged design.

ESA's PRIDE aims to demonstrate the use of a reusable spaceplane in satellite launch operations
ESA’s PRIDE aims to demonstrate the use of a reusable spaceplane in satellite launch operations

PRIDE is designed to be launched atop a rocket and, once in orbit, deploy satellite payloads prior to returning to Earth for a conventional runway landing, refurbishment and reuse. In this, it would be somewhat similar to the US Air Force’s uncrewed and classified X-37B spaceplane, which is capable of long duration orbital flights, notching-up some 1,367 days in space in just 3 missions between 2010 and 2014. However, unlike the X-37 programme, which is believed to be both an advanced technologies test vehicle and potentially capable of undertaking reconnaissance activities when in orbit, PRIDE would be a purely civilian operation.

Another potential use for the technologies seen in IXV is in providing the means to operate reusable boosters as a part of Europe’s next generation of launch vehicles, which would be capable of flying themselves back to a safe landing after use. Lifting body technologies and the re-entry systems used on IXV might also be used in missions to returns samples from Mars and the asteroids to Earth, and spaceplane technologies in general might one day form a part of ESA’s strategy for ferrying crews to / from orbital space facilities in the future.

The technologies being tested by IXV may one day be used in reusable boosters forming a part of ESA's next generation of launchers
The technologies being tested by IXV may one day be used in reusable boosters forming a part of ESA’s next generation of launchers

IXV’s maiden flight was relatively short – just under 2 hours in duration – and sub-orbital in nature. Boosted to an altitude of around 450 kilometres (281 miles), the vehicle cruised over Africa prior to initiating re-entry through the Earth’s atmosphere at a speed of some 7.5 kilometres per second (just under 16,800 miles per hour), using its shape to generate lift and stability, and two tail-mounted “paddles” for steering. Once through the heat of re-entry and slowed to hypersonic speeds, a special parachute deployed to slow the vehicle to subsonic speeds. This allowed the main parachute system could be deployed, which brought the car-sized vehicle to a relatively “soft” splashdown at just 7 metres a second (12.5 mph), so it could be recovered by the vessel Nos Aries.

The entire mission, from launch to splashdown, occurred almost precisely on schedule. Only a slight delay prior to lift-off causing the schedule to be adjusted. Ironically, recovery of the vehicle following splashdown took almost as along as the mission itself, and an overcast sky in the recovery zone presented images being captured of the vehicle’s descent by parachute.

Nevertheless, the mission was a great success. Now begins a long trawl through the data gathered by some 300 instruments and sensors spread throughout and over the little spaceplane.

All images and video, courtesy of the European Space Agency