Thread: Space Things
View Single Post
Old 11-22-2023, 04:35 PM   #557
Irace86.2.0
Senior Member
 
Irace86.2.0's Avatar
 
Join Date: Mar 2017
Drives: Q5 + BRZ + M796
Location: Santa Rosa, CA
Posts: 7,884
Thanks: 5,668
Thanked 5,810 Times in 3,300 Posts
Mentioned: 70 Post(s)
Tagged: 0 Thread(s)
I was watching this landing, and the whole time I am thinking about how a parachute system using thrusters for guidance along with an extremely strong, tall, series of nets from maybe four Eiffel Tower-sized points may be enough to catch a rocket that would probably be smaller and weigh less not having to carry as many rockets and fuel.

Follow me here: the Starship is 5000 tons, but most of that weight is tied up in the propellant (90%). Seems like catching 500 tons would be fairly easy with a series of nets and parachutes to reduce the speed. Rockets could deploy in its descent until all fuel was used along with parachutes to reduce the speed to sub 50 mph. Nets would catch the rocket from there.

https://www.youtube.com/shorts/3tdn5zwqUR0





As you can see in this landing simulation, they are using wings to slow the rocket from 68 m/s or 152 mph from about 500 ft above ground to landing. The Eiffel Tower is 1000 ft tall and weighs 10,000 tons. The Empire State Building is 1250 ft tall and weighs 365,000 tons, so we can engineer four super heavy and strong towers that are steel or steel and concrete or anything in between. Four structures of the weight of the Eiffel Tower would weigh 40,000 tons, and they would be catching something weighing 400 tons or 1% of the weight. This is like a 200 pound man catching a 2 pound rock using a baseball glove, where the rock is slowed by parachutes and rockets from 152 mph to something reasonable like maybe sub 50 mph. I parachute will slow a person to 5-20 mph, so I see no reason why parachutes with a giant series of nets couldn't stop a 500 ton or less load. After, use a crane to upright and suspend the rocket and slowly lower the nets to put it on the ground.

It is true that by the time it is landing, it already has lost most of its propellant, so it only weighs a fraction of what it started with and needs only a fraction of the propellant to stop, but still, seems like they could avoid that.

__________________
My Build | K24 Turbo Swap | *K24T BRZ SOLD*
Irace86.2.0 is offline   Reply With Quote