What Does It TakeTo Build A Resusable Launcher

SpaceX pranged another booster recently.

This seems to be a recurring theme with their hardware.  I think that the big problem is that their approach to that barge is too energetic and the barge is too small.  Still SpaceX is making progress and getting payloads up even if they don’t recover the booster.  Perhaps another approach would be to get rid of the barge altogether and bring the booster into a water landing. What needs to happen is the Falcon 9 needs to come to a hover on it’s engines and then slowly maneuver on the engines to a stop.

The old  Delta Clipper could do this, but the DC-X couldn’t reach orbit. Of course the DC-X was proof of concept test bed that was supposed to pave the way for the vehicles that would follow.


In many ways, space travel has actually regressed seemingly.  I know that that is not the case and that the fact is that the space shuttle was the wrong vehicle for too many jobs and too big for a first reusable vehicle. The fact is that shuttle operations soaked up a lot of money that could have been used to design successor vehicles.  And the bureaucrats at NASA were able to keep competing space vehicles off the pad for the most part, as long as the shuttle was operational.  Which is how we got to the current situation with the Russians providing access to the ISS and a fleet of mid 1950’s designed rockets used to launch most US payloads.

The good part of this is that the vacuum created by the shutdown of the shuttle program finally allowed private space vehicles to emerge.  And it looks like Space X and the others are   taking the lead.


That said, there is something significant about the development of this capability relevant to the future use and development of cislunar space. With the Falcon 9 first stage recovery, SpaceX developed the capability to safely soft-land a throttleable, cryogenic engine system—a key technical development needed for the creation of a permanent space-based transportation system. Although there are differences between landing the Falcon 9 stage and a lunar soft-lander, if one can be done, so can the other. All lunar landers to date, both robotic and manned, have used storable propellants (usually hydrazine and nitrogen tetroxide) and then, after a single use, were discarded. To return to the Moon permanently, we must develop reusable propulsion systems that use the propellants that we are able to manufacture on the Moon (cryogenic liquid oxygen and liquid hydrogen and/or liquid methane).

A comparable technical project toward achieving these ends was completed two decades ago—the Department of Defense Delta Clipper (DC-X) project. This effort was part of the research program by the Strategic Defense Initiative Organization, whose efforts required developing reliable and routine access to space. The Delta Clipper used LOX-hydrogen rocket engines that could be throttled between 30 and 100 percent of their rated thrust. This particular vehicle was designed not to achieve orbit, but to prototype the various systems and technologies needed to build a single-stage-to-orbit (SSTO) launch vehicle in the future.

The DC-X launched vertically like any rocket—it was able to maneuver in attitude during flight, then re-orient to nose-first attitude for reentry, and soft-land vertically at launch site. The vehicle successfully flew eight times under the remote control of a human pilot. Astronaut Pete Conrad, who had previously conducted the first precision soft-landing on the Moon during the Apollo 12 mission in 1969, was one of the DC-X remote control pilots. The DC-X was a one-third-scale version of an actual SSTO. It only flew to an altitude of a couple thousand feet, but it certified the systems that would be needed later for a full-size DC-Y launch vehicle.

The idea of a SSTO launch system is as old as spaceflight itself and has been proposed in many guises over the years. Always it has been assumed that the development of such a vehicle would make space access routine and cheap. But in fact, flight through Earth’s atmosphere on both ends of a mission imposes significant stress on vehicle systems and thus, difficulties (read: costs) during preparation for reuse. The greatest value to be realized from a reusable cryogenic space vehicle would come from developing a version that is permanently based in space, one that is not subjected to the extreme thermal environments of Earth orbital re-entry.

Four years ago, Tony Lavoie and I developed an architecture whose aim was to establish a resource-processing outpost on the Moon. In order to maximize efficiency and minimize cost, we imagined a lunar soft-lander designed to 1) use the propellant that we planned to make on the Moon from lunar polar water; and 2) be permanently space-based, traveling only between low lunar orbit and the surface, and reusable for multiple trips (it was for this reason that we based our orbital node in low lunar orbit (100 km), where lunar single-stage-to-orbit is possible). This hypothetical lander would be able to throttle its engines for terminal descent, and be of modular construction for between-flight servicing and engine change-out on the Moon.

Read more: http://www.airspacemag.com/daily-planet/reusable-launch-vehicles-and-lunar-return-180957849/#b3UZWsivK2VzP0oP.99
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Getting more or less permanent moon tug operating is certainly ambitious.  If for other than all the infrastructure required, on the moon.  The thing is, though, that once you have something like that set up, you are literally halfway to anywhere.  Getting the hardware on the moon to make this work is going to require a family of new vehicles we don’t have.  Fortunately  we’ve had a long time to work on those new vehicles.



Also, unlike the old cold war days the various space agencies can draw in each other for design skills, resources and planning.  Which means that those old plans sitting in somebody’s drawer can taken out, evaluated and updated to create new vehicles to take advantage of the new materials that the last forty year or so have come up with.

There’s also work being done to create engines that don’t require the super performance of H2 and all the problems that H2  creates.  methane has a higher boiling point and is heavier and doesn’t have the nasty habit of leaking through  leaks that don’t exist. On a lot of levels involving handling and turnaround methane has a lot going for it.


The Russians are also going to methane, which for the Russians is a big leap to a fully cryogenic stage, something they’ve had trouble with in the past.  But they can draw on decades of cooperative experience in cryogenics from NASA and that will make a difference for them.


It looks like the race to develop the technologies to finally break the launchers form the disintegrating totem poles is on.  It can’t happen too soon.