I noticed the news barely covered it, and I thought at the time it might be to avoid casting doubt on the human-crewed launch.
https://www.dallasnews.com/business/technology/2020/05/29/wa...
Can't wait to see this work, though, it really will be a step change for space exploration.
There's probably a cost/benefit calculation here, too: SN15 has been said to be bringing significant design improvements over the current design they're flying, and SN10 is of the older design. SN11 is probably ready or very close to ready for "high-bay" stacking... SN10 was waiting in the high-bay along with the first booster (BN1)leaving really no room for anything else to go in there. SN12, also of the same older design is being pro-actively scrapped right now and SN13, SN14 are also not going to happen so they get to SN15 faster. They have a test article at the launch site (SN7.2) to test a different construction material (3mm think stainless steel vs. the current 4mm). All that said and done... I'm sure they want to get SN10 in the air and would be disappointed by losing it... but they already have their sights fixed on the future it doesn't completely represent.
Suicide burns are probably a very bad idea when they have crews and passengers anyway. I assume they'll fire up the landing engines sooner and leave enough time for the vacuum engines to fire as backups if needed.
The engines with vacuum optimized nozzles are not suited for landing. They can not be gimbaled and are very over-expanded as well. I would not be surprised if the engines with vacuum nozzles destroyed themselves if they were fired at sea-level.
At least this time 1 of the engines was functioning correctly all the way to the explosion. This is an improvement over SN8 where all the engines failed to re-lit properly.
SN8 was really close. Only a couple more seconds before the engine ate itself would do. :)
SN8: https://youtu.be/ap-BkkrRg-o?t=6884
SN9: https://youtu.be/_zZ7fIkpBgs?t=704
With SN8, you can clearly see two engines lighting and burning properly until just before it (crash) lands.
With SN9, you can clearly see one engine lighting and burning properly, but the second engine did not light cleanly and did not stay lit.
A so called “engine-rich” burn resulted, which is why there’s a flash of green flame.
Total thrust was much lower than spec, hence the hard landing even though both engines ignited.
Both of the failed landing have looked like propellant flow problems rather than true engine problems but even so I'd love the chance to get it "right" by getting it "wrong" in that the wrong engines fired up but it didn't hit the ground too hard.
> Three Raptor engines, including SN49. SN9 has had one cryogenic proof test and six static fires. SpaceX attempted to fly SN9 on 28 and 29 of January 2021, but failed to receive permission from the FAA. During landing, one of the engines failed to ignite successfully, causing another hard landing that destroyed SN9.
https://en.wikipedia.org/wiki/SpaceX_Starship?oldformat=true...
This test was slightly shorter than the previous one (6 minutes, 26 seconds vs 6 minutes, 42 seconds) Next launch is expected within February.
Just because it looks cool is not a reason to do it.
I'm pretty certain that 'looks cool' has nothing to do with it.
SN10 had to be moved away from the assembly point because SN11, SN12, etc are close behind. They needed the space.
Why wasn't SN10 further away? SpaceX is moving fast, and moving these building-sized craft around is slow.
SpaceX has a many years of experience in landing rockets. Perhaps more directly, they have a lot of experience in failing to land rockets. To that end, they've use a kind of 'fail safe' methodology, where for most of the approach, the vehicle's trajectory is toward a safe, low-value spot.
For example, during the booster return of the CRS-16 mission in 2018, there was a problem, so the booster automatically didn't translate back toward its nominal landing pad. https://www.youtube.com/watch?v=LFdep0qCmYA In that case, the problem ended up not being severe enough to cause a crash.
They expect to lose many rockets along the way. They only put 3 raptor engines in there because that's the expensive part.
This is in contrast to the SLS where they spend 5 years and billions of dollars designing and building one rocket that's make of break, with the second rocket launching people.
Understatement of the day.
What's kind of odd is how the video has a weird 80s-90s era sci fi feel. All these years I've thought those special effects were terrible.
Also the center of rotation can be controlled to be inside the passenger section. Add some seats that can automatically tilt 90 degrees and the forces might be barely noticable.
Starship (the 2nd stage) will always do that flip & land on legs, as it also needs to do it on Mars.
Second stage has always been about that flip, be it on the Moon, Mars or Earth
Anyone guess whats going on?
IMO Everyday Astronaut has the best video of the landing (https://youtu.be/l4-PwxnJimg?t=16263) - this is similar to what SpaceX had with SN8
SN9 knew the ground was where it was, but had an engine mishap preventing power to match control, so I’m debating with myself whether it was CFIT or UFIT. Maybe a superposition of both?
This change in perception from the public, is the most critical change to fundamentally accelerate the progress of space exploration.
