DDE

Long as you don't need a fuel tank, the customers are happy. Only when braking. You can accelerate if the satellite provides the power, but, since thrust is miniscule and gets weaker as you move to higher orbits... not a good plan.

Now that is a really good question. It'd probably be overkill as an expendable stage... but it doesn't have to be expendable. I've heard of a solar-electric Russian tug design, but you can guess where that one went.

Efficiency pretty much equals stealth: the high power expenditure means a large thermal signature (which is something aerial anti-submarine platforms look for), and the nuclear reactor is a very noisy device - because of the turbines and the coolant pumps. The designs I've heard of that use natural coolant circulation can only manage to do so at low power levels - i.e. conventional silent running. Let me play peacekkeeper here. https://en.wikipedia.org/wiki/Electrodynamic_tether Quasi-reactionless propulsion.

Sabotage. Worth it, if the gloomy rumours of it being an offensive platform are true.

Seriously, you’d think the nation that had built the Voyagers (which fired their thrusters this year) could manage to come up with a few long-lasting hypergolic tugs. Although in context I do understand the issue. All of those late Soviet/Russian RBs began as supplemental upper stages for otherwise pretty anemic rockets. Fregat is an Earth escape stage, Volga is a refitted satellite propulsion bus, and Briz is the maneuvering upper stage of Naryad. As I said, the United States had hydrolox for all their dV needs and then some.

They should procure a Fregat then. *trollface*

So, any takers on what NROL-71 is? And don’t say “nice try, GRU”. Right now NASASpaceflight tips towards either a Block V KH-11 in a lower-inclination orbit, or a third stealthy, ASAT-hardened Misty. However, word in meatspace is that it’s got a really big emitter to go with the mirror - and that the scrubs are not accidental.

Didn’t stop all those other launches. Even those that went to Venus.

Which is especially important because Tesla operated in considerable secrecy - unsurprising, seeing as how both his employers and his competitors worked were ruthless buggers. For more modern myths, the equivalent explanation is “secret KGB lab”. Don’t forget that, before Rogozin was in the picture, somebody equipped the Yubileiny satellite with a Dean drive. The Japanese did test a catterpilar drive, and it was horrendously inefficient. And here I thought the thread would be about the combustion tap-off cycle...

The forces and the degree of violation of aerodynamics of the receiving plane (those are pretty huge doors) are a bit different. Getting into position can also be tough - skip to 1:00, watch the fly-by-wire work the tailplanes: The problem is that there’s a different, easier path: I’ve seen or heard of several patents for an airborne rearmament system. Once you have that going, there’s a lot less use for a proper aircraft carrier.

Isn’t that rather typical for US launchers thanks to the Centaur? As opposed to current Soviet launchers, all of which are effectively four-stage? And what’s the problem with slapping one of those Star solid-fuel kick stages onto the sat?

There may or may not be a gap in terms of costs (in time and money) between an expendable single stack, and three brand-new stacks (DoD insists on unused) that would hopefully amortize themselves over subsequent flights.

Insiders claims outright financial sabotage. The Proton, they say, is only this cheap because every imaginable expense has been shifted onto the Angara. This is coupled with Rogozin trying to evict the relevant rocket factory out of Moscow in favour of a site in Omsk, slated to produce Energia side boosters back in the day. The current Khrunichev site is optikized for a dozen Protons per year, and it stands on lucrative real estate that woild help pay off the company’s enormous debts @4472TJ You’ll actually hear plenty. And absolutely nothing concrete - deadlines on the order of decades. Jusging by what both Rogozin and, in person, Ryazanskyi preach, Russia sticks to the old government-only iterative LEO-Moon base-Mars paradigm. The most concrete you have is this nuclear-electric tug, for which Keldysh researches droplet radiators.

None of the achievements of Musk’s hired wrench-monkeys outright defies the realms of physical possibility. His propulsion guys come straight from Northrop Grumman.

You’re gonna need a bigger missile. Or perhaps you can launch a plane that launches a plane that launches a smallsat.