ESA Seeks Answers about Canceled IXV Launch

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LUXEMBOURG — The European Space Agency has created a board of inquiry to determine the cause of a last-minute decision by French authorities to cancel the launch of an experimental suborbital vehicle because of range-safety concerns.

The launch of the Intermediate Experimental Vehicle, IXV, in mid-November was scrapped in late October after the French space agency, CNES, and ESA determined that the flight trajectory of the Vega rocket carrying the IXV posed unacceptable risks to people in French Guiana.

Located on the northeast coast of South America, French Guiana is French national territory and home to Europe’s Guiana Space Center spaceport. France is in legal terms the “launching state” and has responsibility for safety issues.

The decision to cancel the launch pending studies of alternate flight paths came just weeks before the scheduled liftoff, and after the IXV recovery ship had been sent from Italy toward a Pacific Ocean destination for recovery of the vehicle after splashdown.

IXV program managers said the flight path had been known for years, but apparently the ESA IXV team and CNES had never done an in-depth assessment of whether it posed a risk, or never informed the CNES and ESA hierarchy that CNES had not approved the mission profile.

“The first goal of this board of inquiry is to find out where the communication breakdown happened so that we can prevent a recurrence,” said Roberto Battiston, president of the Italian Space Agency. Italy is leading the IXV development and had hoped for a launch before a meeting of ESA government ministers here Dec. 2.

ESA said Dec. 5 that the inquiry board should report its conclusions in February.

Whether a successful IXV mission would have affected the level of ESA ministers’ financial backing for an IXV follow-on is unclear. In any event, the Program for a Reusable In-Orbit Demonstrator for Europe (PRIDE), as expected, won only marginal backing at the ministerial conference.

Since the late-October launch cancellation issue, ESA and CNES officials have tentatively agreed to reschedule the IXV launch for mid-February after the IXV team came up with an alternative flight plan.

Under the new plan, Vega’s trajectory on liftoff will be modified by 3 degrees relative to north. The new path has been put into the CNES risk-assessment models and has been found to enable the launch to fall within the acceptable parameters of safety.

The modification will require the Vega rocket to perform a dogleg maneuver to return to the previous path and drop IXV at an altitude of 320 kilometers. No other changes will be needed for the mission, ESA said Dec. 5. The 2,000-kilogram, 5-meter-long IXV will then climb to 450 kilometers before descending and reentering the atmosphere over the Pacific Ocean.

The safety concerns centered on the fact that Vega will be flying over French Guiana with its unpressurized second and third stages, both solid-fueled.