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Starship's Third Flight Test [video]

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Re: Starship's Third Flight Test [video]

#251

The test is essentially a success at this point. Starship can take payload to orbit and open/close the payload doors. The remaining things are icing on the cake. They can refine re-usability while flying payloads.

I'm not sure the payload doors successfully opened and closed. Anyone have more details?

I heard the announcement about the door opening and saw - what I assume to be - live images from the inside which showed the door first opened, then closed so it seems that test worked.

Re: Starship's Third Flight Test [video]

#252

So FAA cleared SpaceX and then within a few days they completed their launch pretty successfully by all accounts. So does that mean SpaceX could have launched a while back with no issues and were just waiting on the FAA? Did the FAA literally just slow down progress? Not a good look on the FAA, they should just let SpaceX do what it does at the speed they want. If they cannot add any value to this engagement, the lea…

It's a bit of a complex interplay. If the FAA were finishing their investigations very quickly, SpaceX could be more aggressive with their testing. But on the other hand, as SpaceX gets a better read on how long the FAA might take, they time their readiness to when the FAA will be done.

For example, here they waited ~1 week between Starship being ready and done with a wet-dress rehearsal. If they knew that the FAA would be finishing earlier, they'd try to get through the WDR earlier. But since there's plenty of other development and testing to do on the ground, they just do that in the meantime.

The FAA delays were more of an issue around IFT-1 because they really couldn't proceed on much without knowing how all the big systems they built would perform, they would've been working blind (and considering how the launch infrastructure needed further strengthening, doing too much more without that data would've probably been a waste of money). That isn't really the case now, while they wait on the FAA they can focus on the payload bays, refining the control systems, building the second launch tower etc.

Re: Starship's Third Flight Test [video]

#254
post #123

Earlier quoted context omitted.

Not quite: the apogee burn they had planned didn't happen (no word as to why yet), so the ship didn't technically demonstrate the capability reach orbit. It came back down in the Indian ocean on its original suborbital trajectory, essentially like an ICBM.

[flagged]

Please don't replace the text of comments like this once they have replies. It's unfair to the users who responded because now their comments lack the necessary context to be understood.

We're all wrong sometimes and it would be fine to add an "Edit:" after the original text followed by an explanation or retraction or whatever you want.

Re: Starship's Third Flight Test [video]

#255

Earlier quoted context omitted.

I wouldn’t classify the re-entry survival problem as icing. But otherwise, I agree with you.

If their cost per kg to orbit, with total loss of both Booster and Starship, is substantially lower than any of their competitors - then it is success, and recovery is just icing on their profit margins. Er, cake. (And would be very cool marketing and PR, obviously. Not that SpaceX has much need for either of those.)

No quite; even if 1st and 2nd stages deliver cargo to orbit cheaper than competition, you still has to make sure there is enough demand to pay back the cost of Starship creation. That demand may require not just being cheaper, but to being substantially cheaper than competition, to enable additional uses.

What SpaceX is doing with Starlink reminds of the situation with early versions of Windows, when, as Bill Gates described, the industry wasn't keen to produce applications for it. So Microsoft started writing Word and Excel in house. Similarly, SpaceX created Starlink which needs lots of launches, and which couldn't exist with previous level of launch prices, but is able to make profits if the prices are as low as SpaceX can provide.

Re: Starship's Third Flight Test [video]

#256

FR24 shows a Dassault Falcon 900EX doing circles around the expected Starship re-entry location (Perth to Perth flight plan): https://www.flightradar24.com/MXJ/345b8f09

Interesting that there was a flight sent to be in the splashdown area. My guess would have been there's not much engineering/scientific benefit to getting in the neighborhood of the splashdown. Maybe some footage could be gotten just for curiosity but at this early stage of re-entry testing of such a new and different vehicle I suspect the odds of being close enough to acquire decent air-to-air visuals would be pretty low.

Maybe the flight was an attempt to get close enough for a stored telemetry downlink post-rentry blackout but pre-splashdown?

Re: Starship's Third Flight Test [video]

#257

Earlier quoted context omitted.

Starship is huge and heavy and made of steel, it will not burn up on reentry, if it falls on a populated area it will kill people. They will not be allowed orbital trajectories until they demonstrate they can control the deorbit burn.

An empty Starship has a very low ballistic coefficient, it will be torn apart by the atmosphere if not carefully controlled. Add to that the FTS and there is no real danger to population on the ground.

Of course it will not maintain its shape, but the pieces that land will be large.

It's made of 4mm thick steel sheets, and the FAA disagrees with you.

Re: Starship's Third Flight Test [video]

#258

The test is essentially a success at this point. Starship can take payload to orbit and open/close the payload doors. The remaining things are icing on the cake. They can refine re-usability while flying payloads.

Here's a fun thought, how many Starship launches would it take to put the equivalent mass of the ISS up in the same orbit?

Re: Starship's Third Flight Test [video]

#259
post #258

The test is essentially a success at this point. Starship can take payload to orbit and open/close the payload doors. The remaining things are icing on the cake. They can refine re-usability while flying payloads.

Here's a fun thought, how many Starship launches would it take to put the equivalent mass of the ISS up in the same orbit?

The ISS weighs ~420 metric tons. That is 2-3 expendable launches or 3-4 reusable ones.

Re: Starship's Third Flight Test [video]

#260

Earlier quoted context omitted.

It's at 26000 km/h which sufficient for orbital velocity. It looks like it's in an elliptical orbit. I guess we'll see soon if they need to do a de-orbit burn, or if the orbit just intersects the atmosphere and they use atmospheric braking?

I did the math. So, the minimal orbit at 180 km, the one that grazes the earth's surface at its perigee, is about 7.75 km/s or 27,900 kph. The other commenters are right: it was never technically orbital. edit: (let* ((μ 398600.0) ;; km^3/s^2 (r 6371.0) ;; km (peri (+ r 0.0)) (apo (+ r 180.0)) (a (* 0.5 (+ peri apo)))) (sqrt (* μ (- (/ 2.0 apo) (/ 1.0 a))))) ;; 7.745844595118488

But it would have been if they executed the burn in at a slightly different angle.
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