Comments on: Isar Aerospace’s first launch attempt fails seconds after lift-off

By: Jeff Wright

Jeff Wright — Fri, 04 Apr 2025 03:29:25 +0000

Astra’s power slide was comical at least.

This looked like something from a Bond movie.

By: pzatchok

pzatchok — Wed, 02 Apr 2025 20:49:29 +0000

It could be these guys photo bombing the launch.

mystery science theater 3000.

https://wallpapercave.com/wp/wp10287568.png

By: Dick Eagleson

Dick Eagleson — Tue, 01 Apr 2025 16:25:56 +0000

As first launch failures go I’d call it a creditable effort – better than Virgin Orbit, Astra or ABL, about the same as SpaceX, not as good as Firefly or Rocket Lab.

By: agimarc

agimarc — Tue, 01 Apr 2025 16:06:10 +0000

sippin_bourbon says:

“Ronaldus…

North pole penguins?”

Puffins fill the penguin niche in the Arctic, though they are smaller and can still fly a bit. Most likely people. Cheers –

By: Edward

Edward — Tue, 01 Apr 2025 03:33:50 +0000

Patrick Underwood,
I’m not getting the impression that anyone was criticizing the Isar engineers. Control is a difficult thing to do; it is just that several companies have made it look easy. Over the years, I have noted other test rockets also weave visibly during ascent.

My Automatic Control Systems class started out very challenging, as we had to learn how to overcome the damping problem and the sneaky ways in which it manifests itself. Analysis for stability was not my forte, because instead of damping out oscillations, like a swinging door does, a system can increase its instability until failure. Fortunately, all my lab work performed properly, and I fooled my professor into believing I knew what I was doing. Maybe I did know, but I sure did not think so. I stayed away from systems control and thermal engineering (which also showed signs of being more art than science).

This may be one of the reasons that the company had previously announced that no matter what happened, they would consider this launch a success. They were bound to learn something. Destined, maybe.

They made it off the pad in an upward direction, not the famous “side step” launch. Scott Manley estimates that they made it to 500 meters.
https://www.youtube.com/watch?v=eFyMAaeYdvs (17 minutes)

By: pzatchok

pzatchok — Mon, 31 Mar 2025 20:15:21 +0000

That one didn’t survive though.

By: pzatchok

pzatchok — Mon, 31 Mar 2025 20:12:39 +0000

If the crash zone is water I can see a reason to not blow up the rocket.

At lower altitudes it might be better to let if fall into the water so it might stay together and possibly not leak or explode.,

It could also leave more evidence intact for study.

By: Gary

Gary — Mon, 31 Mar 2025 18:17:54 +0000

Maybe puffins instead of penguins?

By: Marcus Z

Marcus Z — Mon, 31 Mar 2025 13:38:12 +0000

From https://x.com/ask_e_ladden/status/1906368554024194214

https://t.co/FO0V3hMoKK

By: Patrick Underwood

Patrick Underwood — Mon, 31 Mar 2025 02:29:37 +0000

Sigh. These people tried launching a rocket into orbit. What did y’all do today?

Yeah, me neither.

By: mkent

mkent — Mon, 31 Mar 2025 02:00:29 +0000

Isar is claiming success with “30 seconds” of sustained flight, but that didn’t happen. You can see the thrust-vector oscillations start at about T+14s just as the rocket plume emerged from its contrail.
From the outside it looked a lot like pilot-induced oscillation, so likely a guidance & control issue, but only telemetry will show for sure.

”It would be interesting to know the flight termination methodology.”

The flight termination methodology was to terminate thrust by shutting down the engines, which happened about T+25s or so.

By: David Eastman

David Eastman — Mon, 31 Mar 2025 01:54:49 +0000

I have no idea what kind, if any, of FTS is installed on that rocket. As has been said, per their regs, all that’s required is engine termination, which certainly happened, whether by command or not. But there is a certain logic in not deliberately detonating a rocket below a certain altitude, the debris field would have most likely been quite a bit wider and mostly over the launch facilities if they’d blown the rocket up when and where it failed. As is, it had enough horizontal velocity built up that the ground impact was, barely, far enough away from the facilities to avoid serious damage.

By: John

John — Mon, 31 Mar 2025 01:31:09 +0000

Yeah Ronaldus, the global warming killed the north pole penguins.

But I see the point that it should have kaboomed before reaching the ground or water. There could have been walruses or whales there! It would be interesting to know the flight termination methodology.

Post brought to you partially by sarcasm.

By: BillB

BillB — Sun, 30 Mar 2025 23:03:29 +0000

As to those oscillations, from knowledge, just having the wrong arithmetic operation on a minor factor in a control algorithm can cause that kind of problem.

By: sippin_bourbon

sippin_bourbon — Sun, 30 Mar 2025 22:21:41 +0000

Ronaldus…

North pole penguins?

By: Tom Donohue

Tom Donohue — Sun, 30 Mar 2025 21:22:31 +0000

The video from the drone camera shows the rocket plunging into the sea with no flight termination system activation to be seen. The ensuing explosion did remove all of the snow from the roof of at least one building visible on the left side of the video. IMHO, the rocket looked good with all engines burning. Once the oscillations began, they became too dynamic and any compensations from engine gimbling was just ineffective. I’m sure that some small detail will be identified as the culprit that kept this rocket from reaching orbit.

By: Thomas Wilson

Thomas Wilson — Sun, 30 Mar 2025 20:45:41 +0000

Space is hard . . .

By: Ronaldus Magnus

Ronaldus Magnus — Sun, 30 Mar 2025 20:00:25 +0000

At the bottom of the video, just to the left of center, are 3-4…people, penguins? Whoever they are, I’m glad the rocket did not fall on them!

By: Richard M

Richard M — Sun, 30 Mar 2025 19:09:08 +0000

From the video it appears the company above all needs to upgrade its flight termination system.

I wondered about this, too. There’s some discussion at the NSF forum that on a launcher this small, under local regs, the FTS merely disables the engines when the failure criteria are met, rather than detonating explosives. If true, then maybe there *was* an FTS success here. But I have yet to see anything from Isar clarifying this.

By: David Eastman

David Eastman — Sun, 30 Mar 2025 18:46:26 +0000

While you have to expect problems on any first launch, losing stability control that early in the flight is not promising. Failure modes that the older companies haven’t seen in decades is not a good start. Makes you wonder how much, if any, in the way of experienced engineers they have in the company, or if they’re starting from scratch with just book knowledge.

By: John

John — Sun, 30 Mar 2025 16:51:26 +0000

Here’s some drone footage.
https://x.com/KSpaceAcademy/status/1906341521097400526

We’re going to need a few years for an environmental impact study on the marine environment. Sarcasm?