cubinator

Starship tank volume is approximately a cylinder 9 m diameter and 30 m tall. That volume is 1908 m^3. LH2 density is 71 kg/m^3, so 135 tons of hydrogen would fit in the tanks. Let's now use the trusty rocket equation: m0 is 85 tons + fuel mass, mf is just 85 tons. If you could just fill a Starship's fuel tanks with hydrogen and slap a NTR with Isp of 1000 on the bottom, you'd get... 9348 m/s Improved NTR designs might reach Isp of 1500 (14022 m/s) or 2000 (18696 m/s). Burning all that would get you to Mars in 2.5 months or less, though stopping once you get there would be a bigger challenge.

Starship seems to have the potential to be the STS we really needed.

It looked to be travelling at constant speed, which means it was powered T = mg during descent.

And today we have the time travel mod to play...

Interesting.

Low lunar orbit would require more stationkeeping fuel than low Earth orbit, wouldn't it?

First powered aerodynamic flight, you get the idea.

Simulations aren't perfect. So many equations, especially in aerospace engineering, have pieces that aren't actually mathematically derived. Jet engines have a "manufacturer's constant" that goes in an exponent to calculate thrust. All kinds of numbers are decided on by real-world testing because there's no way to derive them mathematically. Even when you plug it all into a simulation, you have to check and compare with real world data to make sure the simulation is predicting things correctly, not in some alternate universe where drag or flow works slightly differently. So simulation will never totally match a real system when making something as complicated as a rocket.

Jeff Who can pony up whatever "advance payment" he needs, there's no reason for that to be NASA's responsibility.

This is an absolutely towering lunar lander. A worthy successor to the Lunar Excursion Module, especially considering the 50 year lull.

Confirmed Starship lunar lander!

It's like a cross between a conventional nozzle and an aerospike in all the worst ways.

not only that, on the NASA event page it seems to imply that only two astronauts will land on the first mission. Can you imagine having an entire Starship to share with just one other person?

They cleaned it up real nice!

They've got to get the price competing with parabolic airplane rides.

It's disabled on the official one.

"brief hold"

So how long until this thing is flying daily? Pretty exciting that they are getting ready to carry people!

Maybe you could use a binary black hole to accelerate a particle beam.

I don't know, but you'd definitely come back with less hair.

Well, clearly there's some way to fuse pretty much all the elements.

The most I'd want is a whole-universe scale slider - the ability to make the planets 10x bigger, 10x further away, and to give my rockets sqrt(10) as much delta-V.

Yeah, I thought about that, but I think the luminosity figure takes that into account, since it basically says "here's how much power per unit area is coming out" no matter if you're in a diffuse cloud of hot gas or in contact with a hot stove pan. If you were to use the figure for that larger area, you'd be including a bunch of photons that actually weren't going to contact your body.

Assuming your surface area is 1.7 m^2, your mass is 62 kg, your albedo is 0.4, and your specific heat is 3600 J kg-1 °K-1: The sun's luminosity is 3.828×1026 J m-2 s-1 over its entire area. Dividing out so we get only the luminosity from the area of a human, the power you are exposed to is 1.07e8 W. So, assuming this power is being emitted from all points and in all directions around the edge of the photosphere, Energy = Power * albedo * time In 1 microsecond you will absorb 42.7 J. Q = mcΔT Your change in temperature is .0002 degrees. In 1 millisecond you will absorb 42743 J. Your change in temperature will be .192 degrees. Conclusion: An average person will not be killed by heat when visiting the edge of the Sun's photosphere for 1 microsecond. For 1 millisecond, the Sun would warm you to the core by .192 degrees Kelvin on average, which may not seem like much but your temperature would probably be much hotter near the surface, as you have to absorb all that heat through your skin. People with dark skin, dark hair, or darker spots on their skin might be burned visiting the Sun, even for short times on the microsecond scale. Other factors could hurt or kill you besides heat, like ionizing radiation.

In-flight Wi-Fi so you can scroll memes at 5G AND 5 gees.