Previously they successfully caught the booster returning to the launch site from ~100 km about ~10 minutes from launch.
Here they caught the upper stage ,called starhip, which went to ~260 km orbit, deployed 50 tons of satellites and after 22 hours shed its orbital velocity and manuevered to be caught with centimeter precision. :)
Oh nice, it's great to see each milestone along the way.
I suppose the challenges with this step are that after starship did its job, we expect it to be worse-for-wear, and so maybe less able to stably land? (But it did it!)
It's more a difference of speed. A less known fact is that rockets and orbital mechanics is more about going fast than it is going high.
The booster has a max speed of mach 5 before it returns to the tower. The upper stage which landed had a max speed of mach 25 which has to be shed off somehow without breaking the ship!
It is very impressive that they can control the return trajectory accurately enough for a tower catch, and to coordinate the arms on the tower (which are very slow and heavy), to grab the rocket without damaging it.
But this was already convincingly demonstrated by catching the booster three times.
It is very hard to return the second stage from the orbit due to its vastly greater kinetic energy. Protecting the rocket from the heating during the reentry is something that has never been done until SpaceX started to practice with the Starship.
But they have already demonstrated this feat before, with pinpoint landings into the ocean.
The significance of today's event is mostly in demonstrating that they have such a high confidence in this system that they were able to satisfy the safety requirements for obtaining a licence to fly the Starship return trajectory over the populated landmass, crossing Mexican territory on the way to the tower. This is the cherry on the cake. Now all the pieces are in place, and once the remaining wrinkles in the system are ironed out, we can expect the flights to become routine, and eventually, the reuse of Starship to become routine as well.
The other, somewhat more modest, but still important milestone was that they kept the Starship in orbit for a whole day, and after that they still had the fuel for a deorbit and the landing burns. It did not all boil off.
Edit: Here is an interview with Lars Blackmore, the guy in charge of Entry, Descent, and Landing (EDL) for Starship, where he talks about flying the descent over land for the first time: https://youtu.be/POrMxoZbXVI?t=390
I recall the SpaceX chopsticks catch from about a year ago, which looked great.
This looks similar (heavy thing lands smoothly on a platform) but I gather it's very different from the comments?
Here they caught the upper stage ,called starhip, which went to ~260 km orbit, deployed 50 tons of satellites and after 22 hours shed its orbital velocity and manuevered to be caught with centimeter precision. :)
I suppose the challenges with this step are that after starship did its job, we expect it to be worse-for-wear, and so maybe less able to stably land? (But it did it!)
The booster has a max speed of mach 5 before it returns to the tower. The upper stage which landed had a max speed of mach 25 which has to be shed off somehow without breaking the ship!
But this was already convincingly demonstrated by catching the booster three times.
It is very hard to return the second stage from the orbit due to its vastly greater kinetic energy. Protecting the rocket from the heating during the reentry is something that has never been done until SpaceX started to practice with the Starship.
But they have already demonstrated this feat before, with pinpoint landings into the ocean.
The significance of today's event is mostly in demonstrating that they have such a high confidence in this system that they were able to satisfy the safety requirements for obtaining a licence to fly the Starship return trajectory over the populated landmass, crossing Mexican territory on the way to the tower. This is the cherry on the cake. Now all the pieces are in place, and once the remaining wrinkles in the system are ironed out, we can expect the flights to become routine, and eventually, the reuse of Starship to become routine as well.
The other, somewhat more modest, but still important milestone was that they kept the Starship in orbit for a whole day, and after that they still had the fuel for a deorbit and the landing burns. It did not all boil off.
Edit: Here is an interview with Lars Blackmore, the guy in charge of Entry, Descent, and Landing (EDL) for Starship, where he talks about flying the descent over land for the first time: https://youtu.be/POrMxoZbXVI?t=390