Space and Science BS Thread

I believe that this is more for cargo insertion to LEO, not humans. Also, I think they plan on having smaller rocket motors to ignite once the projectile reaches apogee so it can continue out of atmo.

I read a fiction series where they did something similar, but it was scramjet based and the "cannon barrel" was 2 kilometers long, straight up a mountain. The whole barrel was filled with the fuel mixture, so the scramjet ignition never went out due to too much wind. Basically, it shot the cargo pods into space in a hybrid of the 2 ideas.



I feel like that explanation was just about as clear as mud. Sorry.

 

Space debris from a 2007 Chinese ASAT test nearing the ISS later this week..

https://www.newsweek.com/chinese-sp...-space-station-russian-scientists-iss-1647883

 

Interesting read but nothing earth shattering.
https://twitter.com/lori_garver/status/1458494442948677638?s=

 

SLS - vehicle for crew transport (Orion Capsule)
Gateway - assembled onsite, likely from multiple FH launches.
HLS - Starship based, fueled by multiple starship launches.

 

Weather remains at 70%

Crew is strapped down - harch closing coming up.

 

It can’t possibly accommodate humans, they’d be jelly well before launch. I doubt most satellites could handle those G-forces either unless the sling has a huge radius. Hypersonic in a circle? That’s what made some type of linear acceleration preferred in those SF stories.

 

Just for shits and grins I looked up the force on a rotating body and found:

W = weight(lbs)
V = velocity(ft/sec)
g = gravity(32ft/sec^2)
R = radius to center of mass(ft)

let’s try a 100 lb satellite with an exit velocity of Mach 3(3372 ft/sec) using a sling with a 100 ft radius.
The 100’s cancel out along with units other than lbs leaving a ratio of (11,370,384/32)lbs or 355,324.5 lbs.

Conclusion: I don’t know what they think they can use it for but it won’t be anything other than pancakes when it arrives.

 

Fwiw escape velocity is closer to Mach 33 than Mach 3 and that doesn’t even account for reaching orbital velocity.

 

https://twitter.com/spacex/status/1458616785876381700?s=21

https://twitter.com/astro_anth/status/1458622147459526656?s=21

https://twitter.com/SpaceX/status/1458787128486219781?s=20

 

Close, but final launch system will be much larger than the test system. From the article:

So the final launch system will use a ~500' diameter slingshot with a ~250' arm. That might change your math a bit.

 

Another day at the rocket ranch

 

SOOO fricken unfair.

 

New Glenn mockup headed towards 36 today...

 

I'm surprised they don't have the grass draped in plastic and a clean room tunnel over the whole road.

 

Not nearly enough. Try it. Run some numbers that include a rocket motor with enough fuel(and that mass) to accelerate to orbital velocity from even Mach 1(1124 ft/sec) and it just gets worse. Orbital velocity is measured in tens of thousands of ft/sec(ISS 17,239 mph or more than 25,000 ft/sec).
To reduce the force on that 100 lb slug to 500 lbs prior to exit the velocity would have to drop to Mach 1 using a device a mile in diameter(2500 ft radius) but they specified not just supersonic but hypersonic which is why I chose Mach 3 for the example. Adding a rocket motor and fuel would proportionately increase the size of the launcher(a 1000 lb total mass would add another zero to the radius) and I’m no rocket engineer but I’m guessing it would take more than that to accelerate to Leo.
It could work at the projected size I suppose but only for payloads that can survive not several g’s but rather several hundred g’s or thousands at the projected size. It’s the radial acceleration that kills the idea since that’s what squares the velocity in the force equation. A linear acceleration doesn’t do that.
The only way I see of making it work for anything as fragile as a satellite is to build it flat on the ground like a miles in diameter cyclotron possibly with a hyper loop tunnel before transitioning to vertical or whatever launch angle is required maintaining or even increasing the radius for the final segment.
Let’s try it again assuming:

a 10,000 lb rocket including fuel (basically a second stage)
Mach 5 launch velocity (5620 ft/sec)
100,000 ft(~19 miles) radius launcher

F = 10,000(5620)^2/ 32(100,000)
= ~98,000 lbs or roughly 10 g’s

At that size it seems it would be better to just go linear instead then the length need only be as long as necessary to accelerate to the launch velocity at 5 g acceleration.
V = AT so T = Mach 5/5G or 5620/160 or 35 seconds
X = 1/2AT^2 or 1/2 x 160 x (35)^2 = 98,000 ft ramp.

I pulled weight and launch speed out of a hat but not a totally random hat

 

Thanks! Cool to see anything inside KSC

 

Wait for it…

https://twitter.com/wxrjm/status/1458639619810111492?s=21

 

That was awesome. I love this thread. Thank you!

 

Thanks. I might be missing something but it sure seems like going hypersonic in a circle is just an expensive way to turn things into paste.