Why the demand for heavier satellite launchers nowadays?

Way back in the 1960s the United States developed a huge rocket, the Saturn V, to support manned lunar landings; the Soviet Union tried to develop the N1 rocket which failed. But both were cancelled after the end of the “space race”. A resurgence of the Cold War in the 1980s led to the Shuttle and the Soviet Union’s Energia rocket; but the former afaik never launched its maximum design payload and Energia was cancelled when the Soviet Union disbanded.

For decades the status quo was to mostly launch modest payloads on small or medium rockets. But in recent years the demand for heavier payload capacity has increased, leading to more robust launchers such as the Ariane 5, the Delta IV, and heavier launch systems now in development or being considered. My question is, why is the demand there now for multiton payloads? Adjusted for inflation, the cost of kilos to orbit hasn’t gone down significantly, so why are users willing to pay the freight?

I’m kind of thinking that the Saturn V was the Great Eastern of rockets: over-anticipating a demand that would only appear decades later.

There is only so much room in geostationary orbit. IIRC, they went from 5 to3 to 2 degres between satellites. Too close together, and a dish will pick up crosstalk from an adjacent satellite and so the two can’t use the same frequency band.

So the next step is to have much more powerful and versatile satellites parked overhead. Theyc an cover more range of the spectrum and with more power, you can use handheld units rather than needing a dish to hear the satellite. Instead of broadcasting to the whole visible earth, you have multiple transmitters which are aimed (like spotlights) to reach only a specific small area but with greater power.

Plus, in the future I imagine the development will include more commercial versions of the space station; also, some of the recent space probles (like Cassini to Saturn) are the size of a small bus.

Not a bad analogy, but it was built for one monomaniacal purpose and then abandoned once that was achieved; besides national loss of interest and will, the engineering was far more fragile and less sustainable than the heavy lifters that were developed later.

Really, everything through SkyLab was rushed, ill-conceived tech and planning with almost zero thought of sustainability and a future for the US in space. The Saturn V was a fabulous beast, but like all myths it couldn’t last long.


The space shuttle was first conceived in 1969.

At least for the US, the Shuttles carried most of the things in the same payload mass category as the Delta IV Heavy and the Ariane 5.

If not in the late 1950s, with the X plane projects.

I phrased that clumsily. In addition to its civilian missions, the Shuttle was conceived of as supporting robust DoD/Air Force requirements to the extent that a Shuttle Blue program was anticipated operating out of Vandenberg AFB. Energia/Buran was built expressly to match the (supposed) US capability.

The demand for EELV-class launch vehicles (in the US) is almost exclusiely driven by National Reconnaissance Office, National Oceanic and Atmospheric Administration, and the Department of Defense, launching the NROL reconnaissance, GOES weather surveillance, and and GPS/Global SATCOM/DSCS navigation and communication satellites, respectively, all going to Medium Earth Orbit or Geostationary/Geosynchronous Earth Orbit, with a smattering of interplanetary spacecraft and commercial telecommunications satellites.

Back in the late 'Nineties it was assumed that there would be a market for low cost light/medium lift vehicles to support smaller telecommunications birds in LEO to MEO (e.g. Iridium), but neither the market for cheap satellite telecom nor the low cost reliable launchers really emerged, hence the retirement of the Boeing Delta II vehicle and the relatively few number of Lockheed Martin Athena and OSC Pegasus and Taurus launches. The failure of companies like Rotary Rocket, Kistler, and AMROC to develop genuinely commerical low cost launch services meant that the cost to orbit never dropped to a point that it was cheap enough to maintain large constellations of satellites necessary for operations from LEO. DoD launches for sub-EELV payloads have largely used the Minotaur family of Minuteman- and Peacekeeper-based launch vehicles.

That doesn’t mean that there is no demand for light and medium launch vehicles, however. There are plenty of vehicles available at a variety of lift classes from Russia, China, and Japan which are very competitive in terms of payload to orbit cost and which carry more commerical tonnage than the EELV vehicles. Many telecommunications and commerical surveillance satellites are launched on these systems, albeit with varying degrees of reliabilility. SpaceX offers the Falcon 9 and (soon) the Falcon Heavy, which are both EELV class heavy lift vehicles, but they carry substantially more mass than any single commerical payload requires, apparently driven not by commerical need but the founder’s desire for interplanetary exploration. The Orbital Antares rocket is a Delta II class launch vehicle which promises to fill the middle ground of light/medium lift vehicles, but the low rate of production and questions about future availability of the NK-33/-43 based engines make it questionable as a contender.

Much of the cost in launching stuff to orbit isn’t in building the rocket structures, flight software, and propulsion system itself, but in all of the processing, integration, and launch/range activities. In other words, the cost isn’t in the parts; it’s the labor. And since the labor is in roughly the same order of magnitude for a small vehicle with N stages as it is for a large vehicle with N stages, it makes more sense from a conventional standpoint for launch providers to focus on heavy lift capability. However, there are a number of ways that the processing/integration/range costs can be reduced by simplifying the vehicle design, accepting lower performance in exchange for greater robustness and reduced cost, and automating a lot of the acceptance and integration testing. This means redefining the processes which have been successful in the past but retaining all of the basic features that made them so successful, instead of just waving the “COTS” banner and blindly relying on the design to compensate for poor build quality, counterfeit components, and lack of qualification and characterization testing.

The Saturn V, as noted, wasn’t built to be a commerically viable vehicle and there is no conceivable demand which would require it for a profitable enterprise. It was a point solution to a problem of sending people to the Moon, and as a result it was neither cheap enough to be adapted for commercial use nor sufficiently expandable to provide the basis of a post-Apollo exploration vehicle. The Space Transporation System (“Shuttle”) on the other hand, was a broad solution to an array of capabilities that nobody was really asking for, and fundamentally was a transportation system to a space infrastructure that nobody built until the 2000s. Although it was expected to carry commerical payloads (and the government decision to shut down all other expendable space launch programs meant it was the only US launcher expected to be available) it was never cost-competitive with even the most expensive expendable launchers, and the often years-long schedule slips made it untenable even before the government decided to no longer accept commerical payloads. It mainly served as an object lesson to people who assumed reusability would translate into reduced costs (though whether a launcher that had to be largely rebuilt after every launch counts as “reusable” versus refurbishable is more than a semantic discussion).

There is plenty of demand for smaller orbital launchers; the question is getting them down to a cost point that makes them competitive with foreign launchers while still reliable enough to be useful and safe to launch from US ranges.