Frequently asked questions on IXV

What does IXV stand for?

Intermediate eXperimental Vehicle. The mission is intended as an intermediate step, after the ARD (Atmospheric Reentry Demonstrator) capsule flight in 1998, on the path to developing advanced European autonomous space transportation systems with a reentry capability.

When did the mission start?

IXV was initially defined in 2002 to harmonise several different Agency and national experimental vehicle conceptual proposals. Industrial activities started in 2005. The mission is now part of ESA’s IXV and PRIDE Program Office, tasked with implementing the IXV mission through completion and defining potential IXV follow-on missions, including PRIDE.

What is the purpose of IXV?

The mission tested under representative flight conditions the performance of critical systems and technologies aspects that enable autonomous controlled reentry for return missions from low Earth orbit.

What critical systems and technologies will be involved?

System Level. This was the first time in the world that a lifting body is flown in flight conditions representative of a low Earth orbit return mission. Past missions have flight tested either winged bodies, which are highly controllable but also very complex and costly, or capsules, which are difficult to control but offer less complexity and lower cost. Lifting bodies – spacecraft with no wings that gain lift through the action of aerodynamic forces on their body – maximize the advantages of winged bodies and capsules while minimizing their disadvantages.

Aerothermodynamics. Hypersonic aerothermodynamics phenomena, generated by the dissociation of O2-N2 molecules at high velocities and temperatures, induce changes in aerodynamic behavior that are poorly understood. A more precise understanding of such phenomena is of the utmost importance in validating design tools and processes, reducing vehicle design margins necessary today to cope with engineering uncertainties, and optimizing vehicle payloads capabilities.

Guidance, Navigation and Control (GNC).  IXV was the first European spacecraft to control flight through a combination of thrusters and flaps, relying on improved guidance algorithms and enhanced navigation obtained through the coupling of inertial measurements and satellite navigation.

Thermal Protection and Hot Structures.  The mission was the first in Europe to test a wide variety of new materials and concepts under flight conditions representative of a low Earth orbit return mission. Materials and concepts investigated included different types of ceramics matrix composites, used on nose, shingles, hinges and flaps, and ablatives such as cork and silicon based materials, used on the vehicle leeward surfaces.

Could any of these new technologies be reused in the commercial arena?

Several technologies developed for IXV could be reused not only in other space applications but outside the space arena as well. Examples include ultra-lightweight honeycomb carbon fiber reinforced polymers, high performance avionics components and advanced ceramic braking systems. 

What uses will autonomous controlled reentry serve?

Such a capability is essential for developing a wide range of space transportation applications, including space planes, reusable launchers stages, planetary probes and sample return, cargo and crew transport vehicles. Mastery of reentry technology could also be useful in innovative future missions for Earth observation, microgravity experimentation, high-altitude atmospheric research and servicing and disposing of future generation satellites.

What does the vehicle look like?

The vehicle has a lifting body shape (it is capable of producing lift without wings) and was equipped with outer thermal protection and hot structures and an advanced inner composite structure that divided the vehicle into four bays. The first bay (from front to rear) houses the avionics, including power, data handling, telemetry and communication systems; the second, the four stage supersonic parachute system; the third, the propulsion and propulsion control systems; and the fourth, the propellant tank, thrusters, flaps actuators and antennas. The vehicle is enveloped by more than 300 measurement sensors for inflight experimentation, including conventional sensors and an advanced infrared camera.

THE IXV MISSION

How big is IXV?

The vehicle is 5 meters long, 1.5 meters high, and 2.2 meters width - about the size of an automobile - and weighs almost 2 tons, including fuel.

How and when will the vehicle be launched and recovered?

The vehicle was injected into a suborbital path by a Vega rocket from the European Spaceport in French Guiana on 11 February, 2015 and was recovered in the Pacific Ocean. The launch had initially been set for 18 November but had to be postponed because of the need for additional trajectory analysis.

Why was a Vega launcher chosen for IXV, and was it already qualified  for such a mission?

Vega is Europe’s preferred launch vehicle for light payloads and was determined to be the most efficient and cost-effective European solution for launching the IXV. Moreover, its flexibile multimission design was found to be ideal for the specific requirements of the mission, and its 2-tonne lift capability is more than sufficient for the IXV’s suborbital trajectory.

Was the mission insured?

The IXV was not insured in case of launcher failure.

Where will mission operations be managed?

IXV was controlled by the Mission Control Centre in Turin, Italy. Part of the Advanced Logistics Technology Engineering Centre (ALTEC), this facility was in charge of coordinating the activities of the entire ground segment, including the fixed ground station in Libreville (Gabon) and Malindi (Kenya) and the transportable naval station in the Pacific Ocean on the recovery ship, and ensured end-to-end control of the mission, from lift-off to splash-down, in cooperation with the Launch Control Centre in Kourou, French Guiana.

What are the success criteria for the mission?

IXV was a success as flight data was successfully recovered by ground stations and the vehicle.

How did the mission function?

IXV separated from Vega at an altitude of 320 km and climbed to a height of about 450 km, performing a series of in-orbit operations, including propulsion system priming, actuator initiation and telemetry acquisition, to prepare for reentry. It then began its return mission, impacting the atmosphere under conditions fully representative of a low Earth orbit return mission and performing a set of dedicated manoeuvres as it passes through the reentry corridor, declining from hypersonic speed at Mach 25 down to supersonic speed at Mach 1.4. During the reentry phase, telemetry communications underwent a black-out due to ionization of the surrounding air. As soon as the vehicle reached supersonic speed, the multi-stage parachute was deployed to brake the descent and floatation balloons were inflated. It splashed down in the Pacific and recovery operations were initiated to secure the mission for post-flight analysis.

How was IXV recovered?

The vehicle was recovered by divers from the Italian vessel Nos Aries. The vessel set sail from Genoa on 6 October to reach the splash-down site before launch. A dress rehearsal was performed three days before liftoff. The day of the mission, weather balloons were released to verify that wind conditions along the descent path were adequate to permit launch.

During the descent, Nos Aries was located on a circle within 25 km of the nominal landing area. Readings from sensors and radio beacons on the IXV will enable the vessel to pinpoint the exact splash-down spot.

BACKGROUND

What was the total cost of the mission?

Design and development of the IXV flight vehicle, ground support equipment, and ground segment (mission control update, naval antenna, telemetry kits, communications network), along with qualification and mission operations cost around 150 million euros. This includes expenses related to the recovery ship but excludes the cost of the VEGA rocket.

How does this compare with the original envelope?

There was no cost overrun for the IXV mission.

Who are the IXV mission contractors?

The Prime Contractor for IXV flight segment and ground segment is Thales Alenia Space Italia, supported by about 40 other European companies, universities and research institutes.

Which ESA Member States are participating in the mission and how?

The IXV mission was primarily supported by seven member states, with Italy providing the largest share of funding. France, Switzerland, Spain, Belgium, Ireland and Portugal also have significant roles in the mission.

What kind of results will be presented?

Mission scientists and engineers will collate and analyze inflight measurement data from the 300 or so sensors and the advanced infrared camera in the IXV’s flight experimentation package. Key data will include flight aerothermodynamic characteristics and the performance of guidance, navigation and control systems, vehicle thermal protection and hot structures and materials.

RELATED MISSIONS

What were the IXV predecessor missions?

The Atmospheric Reentry Demonstrator (ARD) capsule, which made a successful flight in 1998, was Europe’s first step towards an advanced operational reentry capability.

The IXV lifting body configuration was down-selected after a comparison of the industrial tradeoff offered by various ESA and national proposals. It built mainly on experience from ESA’s Atmoshperic Reentry Experimental Vehicle (AREV) and CNES’s PRE-X reusable atmospheric reentry concepts.

What will be the next step after IXV?

Several potential IXV follow-on mission scenarios are currently under discussion.

In parallel, ESA studied PRIDE, an initiative aimed at defining a prototype for an operational reentry vehicle that would serve as an orbital platform to test in orbit technologies for multiple applications not only for future European Space Transportation, such as future reusable launchers stages, but also for Earth Observation, Robotic Exploration, Microgravity Experimentation, and Clean Space needs. PRIDE (Programme for Reusable In-orbit Demonstrator for Europe) was approved at the ESA Ministerial Council in Naples, Italy.

What kind of mission is PRIDE?

PRIDE spaceplane will be similar to but smaller and cheaper than the US’s X-37B but, unlike the X-37B, would be managed under civil auspices. It would be launched by Europe’s Vega light rocket, orbit robotically, operate in orbit, and land automatically on ground in a runway.

The mission will focus on system and technology performance verification under all flight conditions - hypersonic, supersonic, transonic and subsonic – and it is expected to cost around 200 million euros.

What sort of applications are envisioned for PRIDE?

The first PRIDE principle is to implement applications-driven mission requirements, starting from space application needs and priorities in terms of technology in-orbit experimentation and demonstration shared among the PRIDE participating States. Therefore, ESA and national end-users will be involved in the mission and payloads trade-off and down-selection process, and in the finalization of the mission requirements. Applications will target, without being limited to:

• Exploration technologies experimentation and demonstration, in cooperation with ESA/SRE and/or ESA/HSO and national organizations;
• Orbital infrastructures servicing experimentation and demonstration, in cooperation with ESA/TEC and national organizations;
• Earth observation experimentation and demonstration, in cooperation with ESA/EOP and national organizations;
• Earth science experimentation and demonstration, in cooperation with ESA/SRE and national organizations;

Micro-gravity experimentation and demonstration, in cooperation with ESA/HSO and national organizations.