sevenperforce

Wait, how did I miss that? Okay, back to the drawing board then.

....and yep, a 9-Terrier solution will work! Of course there's nothing under there but a probe core, but oh well. I think an 8-Terrier orbital solution (VTO, KSC) is possible, but it would be razor-thin.

I've got an 11-Terrier traditional rocket that reaches orbit with plenty of margin from the KSC. Trying to get a 9-Terrier solution to work.

I am 100% confident that an Eve SSTO, even if possible, would have such razor-thin margins that anything extra would tank it. So, no, you can't make it from Kerbin to Eve and back without staging. Not to say that you can't reuse everything. You can. But it has to stage or dock or refuel at some point.

**cracks knuckles**

The skirt is not the problem. The problem is that violinists are used to a certain amount of weight pulling their bow toward the center of the earth. Without that, they'd have to re-learn the amount of force to use to play. It would have to be their second or third flight to even have a chance of completing a concerto. The bluest Danube. Looks just like my Crew Dragon clone tests in KSP. Which means KSP's engine is halfway decent.

I guess they'd have to dock sideways, since tail-to-tail docking has no egress/ingress options.

Mach 2.85 is not even hypersonic. You need a ramjet or rocket to get to hypersonic speeds, and you need a scramjet to stay there. Presumably this would be powered by a bypass turboramjet.

If we have the BFR operational, I think it makes sense to test the basic "land on another world, get out, walk around, get back in, and come home" sooner rather than later.

I don't know of any other off-the-shelf engine that could do the job. The problem is regression. Simpler and cheaper to pair a COTS turbofan with COTS SRBs if you want to get the exact same payload to the exact same altitude and speed. Which begs, why not put the SRBs on the payload? Which means you're flying a Pegasus, which means you can use an existing manned jet carrier plane, which takes us right back to current tech. And Pegasus can barely compete with SpaceX in price-per-launch, despite delivering 1/10th the payload to LEO.

Ditto. That's not a reason not to send ships to Mars. I think SpaceX should send an unmanned BFS to Mars as soon as they possibly can. But I sure was hell would like to see ECLSS tested on the moon first. Funny. When I just had a wife and two boys, I thought I'd be okay with a one-way ticket to Mars, assuming that my boys were grown and my wife was going with me. Now that I have a daughter? Screw that.

https://www.space.com/40918-air-launched-rocket-ravn-aevum.html Pretty straightforward concept. Carrier vehicle takes off autonomously from an ordinary runway under jet turbine power, climbs to high altitude, and releases the two-stage expendable rocket at just under Mach 3. The carrier vehicle returns to the landing site; the first stage boosts suborbital and the cryogenic third stage does the rest. I'm guessing the first stage is solid. They make a big deal about "three-hour turnaround time" but that seems like a great deal of hokum. I wonder what powerplant they'll be using on the carrier vehicle.

I know Chris is an STS guy, but good grief, I'd sure as hell rather ride a Falcon or BFR to Mars than strap into the Shuttle. We need to think of going to Mars like we did during Mercury and Apollo, not in terms of Skylab and riding Soyuz to the ISS.

I did a fully-reusable Falcon 5 clone that landed propulsively with solids, for a challenge.... unfortunately the images have died, for some reason, but I think I might still have them somewhere.

The way to do propulsive landings with solid rockets is to use oversized pop-out grid fins as airbrakes, low-drag legs with shock absorbers, and a weak central landing rocket with just enough thrust to lower terminal velocity to something that the legs can handle (TWR < 1). Calculate terminal velocity with your grid fins out and use that to determine time from apogee to impact. Then you pop your grid fins at apogee and have your legs and your solid motor timed to activate about 10 seconds before would-be impact. The additional drag from the legs, plus the solid motor's thrust, will slow the rocket enough for the legs to absorb the remaining velocity. The landing motor will continue to burn after touchdown but thrust is low enough that it won't take off again. The only problem is torching whatever you end up landing on.

The outer gravitational field of a body is equal to that of a point mass if-and-only-if the body is spherically symmetric. So it could be a hollow shell, or a gigantic water droplet of uniform density, or a matryoshka doll planet of nested shells, or a differentiated sphere like most planets; as long as there is spherical symmetry, it works. Furthermore, the deviation from a point-mass field is only relative to the deviation from spherical symmetry. Earth is almost a perfect sphere, and so its outer gravitational field is almost exactly that of a point mass. Venus and the Sun deviate even less. Saturn deviates much more. A highly oblate body like Pluto's moon Nix deviates grossly from the point-mass field shape.

Almost, but you don't have the law quite right. Per the shell theorem, arguably Newton's most vital contribution to classical mechanics, the gravitational field outside a solid body is identical to the gravitational field of a point mass, if the solid body is spherically symmetric. This means that we don't have to calculate different gravitational fields for the core and the mantle and the crust; Earth's gravitational field is equivalent to that of a point mass inasmuch as Earth is spherically symmetric. However, the Earth is not spherically symmetric; it bulges around the middle. Thus, the mass is distributed in such a way that the resultant gravitational field deviates from that of a point mass. In orbit, this effect is negligible, but at the very surface, it's measurable enough to cause that 350-joule deviation.

The 351 J error is probably attributable to the oblate spheroid.

You got it.

Yes to labels or yes to the layout? The background will be solid white and the outlines will all be solid so you should be able to drop it on another background easily enough.

Well, let's see. New Shepard is 16 meters. Falcon 1 was 23 meters. I could actually have a Falcon 9 over on one side by itself, and arrange the other four rockets staggered next to it. Everything would have the same resolution and the rockets would be properly vertical but the wallpaper would be portrait rather than landscape. Would you want labels or no?

Yeah, any methane they produce on-world and cart off-world is a net decrease.

Sure, I could do that. What would the theme be? Currently-or-soon-to-be-operating private launch vehicles? All-kerolox launch vehicles that cluster similar engines in the first stage as are used in the second stage? The Block 5 would tower over the other two. Electron is 17 meters, New Line 1 is 20 meters, and F9 is a whopping 70 meters. If you're looking for a side-by-side comparison, putting up Electron, NL1, Falcon 1, and perhaps New Shepard could be more interesting. I might even be able to do twice the scale if I used only the smaller ones. Also, if you do happen to download or use the images, consider https://gofundme.com/buy-a-guy-a-beer/ because how else am I going to manage?

Sort of a "Journey to the Center of the Mars" notion.

For those who like European rockets.... Full resolution over here: