SpaceX has done an excellent job of decreasing the cost of sending payloads to space and looks set to continue to lower costs. I’m wondering what might be the future implications of that.
How expensive did it use to be? How cheap can SpaceX do it now? How cheap might it get?
What new industries or activities might grow or be created?
I guess most people think of taking joyrides to the moon as their idea what cheap spaceflight might mean. While that’s possible I personally think it will mainly manifest in the growth of satellites. I don’t want to limit the discussion to the implications of satellites but I am particularly curious about that. What could open up or become widespread if satellites are much cheaper to send into space?
IMHO, the biggest impediment to relatively cheap space flight is the inefficiency of current power sources. We need to be able to send up a ship and have 100% of it (sans used fuel) return intact. We can’t do that now. Another drawback with current power sources is the lack of speed that they can produce. A trip to Mars right now would take hundreds of days. That means it takes a lot of supplies for the crew.
If you drove to the store in a Cadillac and returned months later with just the driver’s seat, dashboard and steering wheel, you’d go broke pretty quickly. Essentially, that’s what space travel is like right now.
This 2016 article mentions the cost for various current methods to lift a pound of payload into orbit:
Space Shuttle (when it was operating): ~$10,000 per pound (launches were expensive in the absolute, but carried a lot of payload)
Cygnus (Orbital Science): $43,180 per pound
SpaceX: $27,000 per pound currently, though they claim that the Falcon 9 will lower that to $9,100 per pound.
This 2008 NASA article referenced the $10,000 per pound number for the shuttle, and stated:
That said, ten years into their 25-year timeframe for “hundreds of dollars per pound,” I have no idea if it’s still a realistic goal, much less the “tens of dollars per pound” by 2048.
When I was working on laser propulsion, the claim was that it would produce extremely low cost-to-orbits, because you are, in essence, leaving the engine on the ground and sending up only reaction mass and payload. Of course, there’s a huge amount of development and large setup costs, but once that was done, the marginal cost was supposed to be outrageously low. This 1989 paper claims $20-$200 per kilo:
Of course, nobody seems to be doing much with it now. Even Leik Myrabo isn’t highly visible these days, and he’d gotten as far as sending up foot-long Apollo lightcraft out at White Sands. This article about his work is almost a decade old
An orbital space elevator (“beanstalk”, “skyhook”, et cetera) would have to extend out to geostationary orbit (and with an anchor that extends somewhat beyond there to maintain tension) by definition. Unfortunately, the specific strength required for a cable reaching an altitude of 35,786 km is well beyond any real-world material we can produce in any useable length, notwithstanding the difficulties in constructing and operating such a megastructure that remain to be resolved.
It is difficult to credibly anticipate what new industries might arise from inexpensive access for large payloads to orbital space (nor does such capability imply that all of the other difficulties in space operations and particularly human habitation are easily resolved) but one of the advantages from a scientific standpoint is that it would be much easier and cheaper to launch exploration missions, particularly to the outer planets, as well as constructing necessary infrastructure to support development of space industries and facilitate communications. Being able to launch large payloads essentially on demand would reduce mission times for a Jupiter or Saturn mission from a couple of decades to just a few years, allowing planetary scientists to work on more than one or two big missions in a career, and allowing astronomers to launch a plethora of progressively more advanced satellites as the technology develops rather than relying on a single satellite for decades with intermittant servicing.
That should have been “space observatories”. As for how they would be more advanced, using multi-aperature optics, higher resolution Wolter-type X-ray telescopes, and of course very long baseline laser interferometers that would permit detection of gravity signals with too long of a wavelength for terrestrial observatories and with less errant noise. It is also possible to have a solar orbiting satellite oriented to a particular visual field for weeks or months without interruption at any point in the sky not occluded by the Sun, allowing detection of much weaker images and with an effective aperature of kilometers instead of being structurally limited to about 10 m.
Aren’t Skyhooks different then space elevators. IIRC a skyhook is a rotating orbital ‘cable’ that dips into the atmosphere, idea is to ‘hook’ a ship then have it ride around to the high elevation and be released into orbit.
Excellent point. I asked a similar question at another site in regards to a moon landing today using more advanced technology. Here’s how it was put to me. During the Apollo era, to get one pound into lunar orbit and return it back to Earth(no landing. Apollo 8 for example) would take about 400 lbs of fuel. Now to land one pound on the moon and safely return it to Earth(pretty well just the 2 astronauts) it jumps up to a 9000/1 ratio. Of course, this doesn’t take into account the moon rock and core samples or the 3rd astronaut left in orbit. It sure makes it clear why robotic exploration is the better path to go. It was also explained to me that even with today’s technology, there wouldn’t be much change in that 9000/1 ratio.
I should mention this 9000/1 ratio was for an Apollo mission. I’m sure it would be reduced a fair bit for something like what the Russians planned with a lone occupant lunar module and minimal/none lunar experiments planned.
Isn’t a long commute to Mars determined by orbital mechanics?
I thought that propellant costs were only a small part of thecosts. I thought it mainly had to do with extensive testing done through many hours of high-skill human labor.
Yes, the propellant is relatively cheap but it’s the amount required and the weight of it to lift anything out of Earth’s gravity well that’s the problem. For an Apollo-style mission to the moon, an additional stage was needed for the TLI burn plus the moon landing hardware so even more propellant required for those and more propellant needed to get that into LEO. The 1st stage of the Saturn V when empty weighed 287,000 lbs. When fully loaded, 5,040,000 lbs. Designing the separate tanks for the RP-1 and LOX so that they can support that kind of weight, withstand Max Q plus be as light as possible is not a simple task and a huge contribution to the extensive testing involved. Of course the weight of fuel for the next 2 stages where significantly less but when it was all said and done, it took nearly 6 million lbs of fuel/LOX from launch to end of the TLI burn. For the rest of the mission, the CM/SM & LM only used about 60,000 lbs of propellant. Now, this was for a mission that at most, lasted only about 12 days.
Now imagine what all would be involved for a manned mission to Mars that could last months or even years. All sorts of things that would ensure crew survival as best as possible plus the requirements for successfully exploring a new world plus returning samples. They would have to trim weight as much as possible so all kinds of proposals and testing of new processes plus extensive testing for reliability which for the Apollo program was a 99.99992% requirement. Here’s an example in regards to the Orion capsule. They are using a different welding process called friction stir welding for the metal fabrication. Check out some youtube videos on it. Its main advantage is that they can use thinner material than the other welding processes because there’s much less heat distortion. Because of this, they saved about 800 lbs of material weight on just the capsule alone. However, there were numerous delays and rework due to the complexities of using this new system plus all the extensive testing to make sure the welds quality met their high standards.
The sky is the limit…if we can simply solve the minor (:p) issue of launch cost to orbit. While I agree SpaceX and several others have done a great job, we really need a breakthrough…something like metallic hydrogen (if it can even be made…if it even actually exists as is postulated) or some other exotic material with much higher specific impulse than the current chemical fuels and/or something like large scale industrial production of multi-kilometer long strands of graphene or some other high strength material. The nice thing is that there are tons of researchers looking into this stuff…but the down side is that none of them might pay off down the road. Certainly most of this isn’t really feasible today (or even possible in some cases).
I think once we do get (cheaply) into orbit then things like already in development nuclear rockets (or that mythical metallic hydrogen…or even more exotic and probably even more improbable to make on large scales anti-matter, the holy grail of specific impulse material) can get us around pretty good in the inner solar system to the NEO asteroids and the like to really jump start the space industry. There are already companies testing construction methods in space, even a company planning to build (theoretically) a space port and others that have tested small scale 3D printing technology in space, and companies planning to send out probes to start looking at the possibility of space mining (one company plans a probe next year, IIRC)…but it all really hinges on figuring out reduced launch costs. It kind of sucks that we live on such a big planet when it comes to space exploration. Of course, the other side of that coin is that having that magnetic field kind of comes in handy…
Anyway, suppose we have a viable space elevator or single stage to orbit and bring shipping a stuff to space @2-3 figures/lb.
Could we build a 0g smelting furnace? Create mass quantities of some alloy of Iridium/Osmium combined with Aluminum/Magnesium, something the in Earth’s gravity would diffract the very light and very heavy elements?