Isar outlines what caused the failure on the first launch of its Spectrum rocket
Spectrum falling seconds after launch
According to officials of the German rocket startup Isar Aerospace, its Spectrum rocket failed during its first launch in March 2025 because of a loss of attitude control, which then caused the rocket to self-destruct.
Alexandre Dalloneau, vice president of mission and launch operations at Isar, said that the company had not properly characterized bending modes of the vehicle at liftoff. “The controllability has to be tuned in order to counter such behavior,” he said. That environment was not fully modeled and incorporated into the vehicle’s control system. “We were outside the environment that we expected, so that the controllability does not succeed.”
That loss of attitude control caused the vehicle to go outside the safety zone at the launch site. That, in turn, triggered the flight termination system on the rocket. He said the company has revised its modeling of vehicle modes at liftoff to correct the problem.
The company is now working towards a second launch from Norway’s Andoya spaceport, which it hopes to attempt either late this year or early next year. Afterward it hopes to launch eight-plus times a year, based on the demand it is presently seeing for its rocket.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Spectrum falling seconds after launch
According to officials of the German rocket startup Isar Aerospace, its Spectrum rocket failed during its first launch in March 2025 because of a loss of attitude control, which then caused the rocket to self-destruct.
Alexandre Dalloneau, vice president of mission and launch operations at Isar, said that the company had not properly characterized bending modes of the vehicle at liftoff. “The controllability has to be tuned in order to counter such behavior,” he said. That environment was not fully modeled and incorporated into the vehicle’s control system. “We were outside the environment that we expected, so that the controllability does not succeed.”
That loss of attitude control caused the vehicle to go outside the safety zone at the launch site. That, in turn, triggered the flight termination system on the rocket. He said the company has revised its modeling of vehicle modes at liftoff to correct the problem.
The company is now working towards a second launch from Norway’s Andoya spaceport, which it hopes to attempt either late this year or early next year. Afterward it hopes to launch eight-plus times a year, based on the demand it is presently seeing for its rocket.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Pitch loads, bending moments–all arguments against top-mount space planes not encased in fairing/shrouds, thus X-37 (and Dream Chaser) don’t launch “naked.”
Here, we see even simple cylinders can have problems.
Piggyback/side-mounts mean the core can blow up in your face, but it also allows wider payloads with connection points well away from engines. The LV stack is more squat, and the tops of all stages pointed–all engines as ground level.
Aerodynamicists and mass-efficiency gurus hate parallel staging /side mount payload combination, but it also means your workers are mostly at ground level.
The chopstick LUTs are such that you are asking workers to paint the Sistine Chapel atop a skyscraper scaffolding.
Such a set up will spook workers into “good-enough” thinking that Energia-Buran anglers never had.
In the same way Elon can dismiss the CFD wonks, you can dismiss folks who think all rockets should be pencils.