Beyond LEO

guest blogger john hare

There is a fairly constant murmur that commercial space will not go beyond LEO and more mumbling that there must be a specific destination with a specific timeline.

The second mumbling assumes that there is some top down command structure that will make one thing happen regardless of obstacles or opportunities along the way. Goals for the short term are often good, but not so much for the uncertain future. It is roughly the difference between getting married or staying single. When you get married, it better be the right one, and all the other options better be off the table. A single goal and time frame assumes that no other goal is worthwhile, and that nothing will ever change the relative values.

The murmur about commercial not going beyond LEO is often from people that haven’t considered the implications of CATS. For this post, I suggest that CATS is $1K per kilogram to LEO and work out a few costs that apparently haven’t been considered openly enough. I also suggest that RLVs are giving launch on demand in order to hit that price point.

Say someone wants to send a small commercial robot probe to a NEO. Current state of the art might be a one ton spacecraft with a mass ratio of three to go from LEO to the object. At $10K per kilogram for launch costs, $30M. The way it is currently done, perhaps $50M for the vehicle itself and another few million for operations. So $85-90M for one data set. From program start to launch could easily be from three to five years, plus looking for funding and operating the vehicle almost as an afterthought. It would be easy to burn a decade on the program, and well over $100M considering the time value of money.

With CATS and launch on demand, other methods become attractive. If it is allowed to triple the mass of the probe and use less efficient engines, a three ton vehicle with nine tones of propellant becomes 12 tons IMLEO instead of 3 currently, though launch costs drop from $30M with a long lead time to $12M whenever you get ready to go. With relaxed mass constraints developing the probe becomes a construction project rather than research and development. Shield modern electronics with mass rather than use expensive antiques that are space rated. It seems possible that the three ton probe could drop to $1,000.00 per kilogram in construction costs, for a total of $3M in hardware costs. Lead time could drop to a few months with relaxed hardware mass restrictions. Engineers could spec a 7mm bolt from COTS suppliers rather than spend the time and money to determine that a 6.26mm bolt gives the exact safety margin required.

If CATS makes it possible to send a NEO probe within three months of decision for a total cost of  $15M, that is a time frame and cost that fits into a quarterly stockholders report. Pick your favorite reason to go, and it is quite possible that there is a millionaire out there that will agree with you. Minerals, volatiles, SPS materials, or just to see what is there become affordable to many thousands of interested people. At that price point, hundreds of probes per decade would certainly fly.

Many many people will point out that a three ton probe is way too much craft for early prospecting. Some people will certainly agree that 10 kg of fairly sophisticated instruments could be quite capable and not even be all that expensive if they didn’t have to support a decade program and could avoid a lot of that helpful oversight. 10 kg of instruments in a 40 kg vehicle with an IMLEO of 200 kg including propellant would drop the launch costs to $200k. Instruments and hardware by the right people might double that total cost. With a total of $400k per flight, commercial and private players would launch them by the thousands. I think it would be safe to suggest that known NEOs, the moon, Mars, Venus, Mercury, and most of the asteroid belt would be explored for a fraction of today’s government exploration budgets.

There are some that would try to do probes with a 1 kg cube sat, While I’m skeptical, CATS would make it possible for them to prove me wrong for around $10k.

I personally am more interested in the effects on human spaceflight. With $1,000.00kg for launch costs, a person’s direct mass cost to LEO would be around $100k. A reasonable overhead for life support and supplies would bring it to perhaps $500k for a several week visit. A true CATS launch on demand would let people go during a month vacation. Bigalow would have to get busy building stations and hotels to accommodate the customers that could and would  go at that price point.  There is a laundry list of experiments that companies and governments would do if their orbital workers could do a three month LEO  tour for under a million. An EVA worker cost would drop to a couple of thousand dollars an hour under these conditions.

What about beyond LEO? A five ton vehicle could certainly shuttle from LEO to LLO and back with four people. Flying the same vehicle repeatedly with four people and supplies would require about twelve tons of propellant and provisions per trip. Twelve tons of supplies is about $12M in launch costs and about $6,346.50 for the actual supplies. Circumnavigating the moon for under $4M per person including launch costs and LEO accommodations is considerably less than anything currently planned and should be proportionately more attractive to customers.

If the vehicle has entered LLO, then a modest craft can single stage from there to the surface and back. Propellant costs would bring the whole adventure to about $8M per person for the round trip from Earth’s surface to a moon base and back. Additional time on the surface is simply a matter of supplies. At $10k per kilogram on the Lunar surface, a person could stretch their stay by about three weeks per million dollars. It is a fairly safe bet that many people will go, and some of them will go for profit as they look for something they think valuable to some market. Anyone that can create more than 5 kg per day in resources from the local materials can stretch their stay almost indefinitely.

For some, it’s Mars or nothing. There is no reason they can’t get to Mars while everybody else exploits the nothing they disdain. Think of a ship of a thousand tons for their comfortable journey to Mars that takes ten thousand man hours of EVA to assemble and needs three thousand tons of propellant for the trip. What would that cost? At $1K per kg for the ship mass, $1B for construction. $4B for launch cost. $20M for EVA labor costs. Total costs for a thousand ton ship on Mars trajectory, $5.02B plus tax, tag, and title.

Quit yammering about commercial stopping in LEO. If commercial creates CATS, the rest follows.

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I do construction for a living and aerospace as an occasional hobby. I am an inventor and a bit of an entrepreneur. I've been self employed since the 1980s and working in concrete since the 1970s. When I grow up, I want to work with rockets and spacecraft. I did a stupid rocket trick a few decades back and decided not to try another hot fire without adult supervision. Haven't located much of that as we are all big kids when working with our passions.

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28 Responses to Beyond LEO

  1. Martijn Meijering says:

    We cannot stress this enough: CATS is all we need.

  2. Roga says:

    Unfortunately, CATS is not terribly useful until at least $1000/kg, and probably closer to $100/kg if you’re talking about today’s payloads. There is absolutely horrid demand elasticity for space launch… payloads cost too damn much. The only way out of the revenue trap is to make the payload markets change so that payloads are not the overwhelming cost.

    We saw costs hit the $2000-3000/kg level in the early aughts, and they bounced right back up once the supply glut was used up and ITAR was strengthened. John is hinting at the way out, though. We have to make the payload market solve for cheaper and more standardized, or we’re sunk. But that will take some time, and some adventurous investors and companies. Last time, in the Roton days, we could not keep the cost low enough for long enough for the payload business plans to close. Hopefully next time will be different. You not only have to lower the price, but be prepared to keep it low for the decade+ it will take for new customers to emerge with more elastic payloads.

  3. K. D. says:

    Did you ever define CATS? I don’t see the acronym expanded in your article, nor did I find it searching the rest of the Selenium Boondocks recent posts.

    Since some non-astronomy, non-space-science noobs are reading this, it would help if you updated the post with a link to a glossary, or expanded a few acronyms on first use.

    I thoroughly enjoyed the main idea of the post, and thank you Mr. Hare, for writing it.

  4. Martijn Meijering says:

    Wouldn’t $1000/kg be enough for substantial elasticity in the space tourism segment, assuming NASA’s commercial crew plans come to fruition?


    So lets commerical create CATS. 🙂 I am all for it. But guess what? Commercial will not develop unless there is a market. It is the old chicken and egg problem, but you also do not want govt. creating a HLV. At least the Direct Team wants to simulate CATS by creating a fuel depot and the we shall see how much commerical firms want CATS.

  6. john hare says:

    The egg came first.

  7. Pete says:

    There already are small low cost nano satellites, but the cheap on demand launch vehicles are not there. If the launch vehicles were there, the small satellite market would I expect grow very quickly and grow to include orbital assembly systems including depots. The market is already there, in an embryonic form, but it needs the help of a chicken to grow.

    Whether NASA tries for a HLV or not is fairly irrelevant. Actually, NASA HSF is pretty irrelevant, the market that matters is private. If someone did give NASA CATS, they would pile on requirements until it was no longer CATS – best avoid that market. NASA money may be very seductive, but it leads one away from the commercial market (dangerous).

    I suspect one does need to get below $1000/kg, but I think that would be a good starting point, as long as it was not a dead end design and could evolve lower with ongoing incremental improvement and higher flight rates.

  8. Pete says:

    The BA-330 is approximately 330m^3, 23 ton and $100m. This equates to ~$4000/kg, which is not low enough to really justify cheap access to space. Even so the going rate on a space home would now seem to be in the few tens of millions range per person, excluding up keep. (To be fair, ISS is closer to $250,000/kg including launching and operation – Bigelow is a big improvement over this).

    A ten to hundredfold plus cost reduction seems possible over the BA-330, with low cost design and mass production, habitats might only need cost a few tens of dollars per kilogram (plus launch costs). This is sufficient to make space settlement possible on a large scale and extra terrestrial resources would have difficulty competing with this anytime soon.

    Sizable “extra terrestrial” resources that are often overlooked include skimming of the Earth’s atmosphere for O2 and N2, mining of high value space junk and of course mass accumulation from earth derived consumerables (food that goes up does not need to come back…).

    Another near term prospect is perhaps a ~1:25 LH2/LOX rocket transport between the moon and LEO using terrestrial and lunar LH2/LOX at each end. Transporting regolith to LEO where processing and manufacturing systems could start being developed would be interesting. Developing such an industry will be a very big job requiring many start ups – perhaps best done closer to home than on site on the moon.

  9. john hare says:

    I don’t think the embryo needs a chicken, just a small supply of food and protection from the predators. We need to let the eggs hatch and watch to see which ones can make it. We may end up with ducks or geese and specifying a chicken might be counterproductive at this time. Trying to push a single design is often like trying to help the chick out of it’s shell, counterproductive. We will see if a Lynx can win against a Dragon.

  10. Pete says:

    Just to check, is the egg and the chicken the market and the launch vehicles respectively? Or vice versa? 🙂

  11. The BA-330 is approximately 330m^3, 23 ton and $100m.

    Got a reference for that? What are they launching 23t on?

  12. john hare says:

    At this time both the market and launch vehicles are eggs of possibly different species. There are no chickens and there won’t be if the eggs aren’t properly cared for. When the various eggs hatch and the hatchlings grow, then possibly they can interbreed to make a viable adult.

    The HLV fetish is an attempt to turn ostriches into laying hens, from people that know that three eggs for one omelet is clearly wasteful.

  13. A_M_Swallow says:

    BEO spacecraft – Bigelow Sundancer with propulsion module.
    The Sundancer masses 8,619 kg. The propulsion module will need propellant tanks sufficiently large to fly between LEO spacestation and EML-1 spacestation, a delta-V of 3.77 km/s.
    A cockpit to drive the spacecraft and seats, to prevent the 6 people from damaging themselves whilst accelerating, will also be needed. There will be additional mass due to people, air, food, water, clothing and scientific instruments. I am assuming that there will be a propellant depot at EML1 to supply the return fuel.

  14. Pete says:

    The BA-330 is approximately 330m^3, 23 ton and $100m.

    Got a reference for that? What are they launching 23t on?

    Just Wikipedia, though it seems about right. The Bigelow site also suggests it can handle up to 6 people long term. There was a fairly detailed paper written on the original Transhab design which I have not read in a few years.

  15. A_M_Swallow says:

    CATS – Think carefully before you name your launcher program after a musical composed by Andrew Lloyd Webber, you are going to get a lot of pussy jokes. It will also be hard to find articles when searching.

  16. Pete says:

    Forgot to add, Falcon 9 heavy has a stated 32t to LEO capability. Presumably capable of lifting the BA-330, among others. Though these heavy lift vehicles do not make sense to me – if assembled from smaller payloads these habitats could provide a high flight rate market for CATS vehicles. Bigelow seems to be on the side of heavy lift.

  17. A_M_Swallow says:

    The existing Atlas V and Delta IV can lift 23 metric tons to LEO.

  18. Martijn Meijering says:

    This equates to ~$4000/kg, which is not low enough to really justify cheap access to space.

    Cheap access to space is not needed for launching the habs, but it could be needed to make their exploitation profitable.

  19. Martijn Meijering says:

    And it would almost certainly be sufficient.

  20. Pete says:

    This equates to ~$4000/kg, which is not low enough to really justify cheap access to space.

    Cheap access to space is not needed for launching the habs, but it could be needed to make their exploitation profitable.

    That is the equivalent of something like $300k/m^2. It should be much less than a tenth of this to become seriously competitive with Earth based accommodation and this is low hanging development fruit. A little development work here could pay huge dividends – there is no need to be cramped in space.

    Bigelow is at a similar price point to SpaceX, while they are both substantial improvements, neither is in the cheap access to space regime.

    There is currently no inflatable orbital assembly habitat system being developed that is a match for the new space RLVs being developed by XCOR, Masten, Armadillo, etc. If there was, these vehicles would get developed much faster and space would happen much sooner. Anyone have a spare ten million to make this happen? Unfortunately this is not as sexy as developing rocket vehicles so does not get the attention it deserves – being the market/payload this is every bit as important as developing the rocket vehicle. It is the new space egg to go with the new space chicken.

  21. A_M_Swallow says:

    Providing the cost of the hobs continues to drop than affordable spacestations will appear in the end.

    If the inspace propulsion also drops in price then spaceships will also become viable.

  22. Ed Minchau says:

    KD: CATS stands for Cheap Access To Space. This is not to be confused with COTS (Commercial Off-The-Shelf) or COTS (Commercial Orbital Transportation Services) , although all three could mean the same thing in certain cases.

    Boy, we sure do love us some acronyms in this business.

  23. Paul says:

    K. D. (#4) said:
    Since some non-astronomy, non-space-science noobs are reading this, it would help if you updated the post with a link to a glossary, or expanded a few acronyms on first use.

    I’ve noticed the “About” page allows normal public comments. So since the blog is quiet lately, would the regular commenters like to add a poor-man’s glossary there? In the form, “Acronym: Expansion, Definition, Example Article.” 4Eg:

    CATS: Cheap Access To Space, very low cost space flight. See, Beyond Leo

    COTS: Either Commercial, Off-The-Shelf hardware or NASA’s Commercial Orbital Transportation Services program.

    NEO/IMLEO/RLV/SSTO/TSTO/Biamese… Etc etc.

    That sort of thing. That way, we n00bs can just click on the “About” tab when we forget or don’t know something. (Which is a lot. God it took me ages to figure out my first “Biamese” reference.)

  24. Eric Collins says:

    A couple of years ago, I posted some thoughts on my blog about how to expand upon habitable volume in space once we have a foothold established. Here is the link ( Basically, one should be looking at how to assemble an airtight volume on-orbit from bulk material (e.g. Bigelow habitat material). Once you have the capability to assemble these structures on orbit, there is really no limit to the size of the habitats that can be constructed.

  25. Pete says:

    Yes it does not appear to be too difficult to construct inflatable habitats from few hundred kilogram payloads using quite basic orbital assembly. Perhaps start by erecting a very large impact protection tent. Large hangers would also seem possible, which allow yet larger and more complicated assemblies to be put together inside. There are simple ways of making resealable seams (large air locks) and there are also ways of doing it from coiled up carbon fiber sheet, if something more rigid is desired. Lots of options.

  26. Pete, oh, I thought you were talking about Boeing’s capsule, never mind, I must have been distracted or something when I wrote that. 🙂

  27. A_M_Swallow says:

    SpaceX has announced that the heat shield on a Dragon will allow it to reenter from lunar orbit.

    That will also permit a Dragon to return from a spacestation at EML1.

    Since designing, testing and certifying a life support system is a major and expensive task the quickest way of producing a manned lunar lander may be to add engines and legs to a Sundancer (or rival).
    Delta-V EML1 to lunar surface is 2.52 km/s one way.
    Mass of Sundancer is 8,618.4 kg + people + consumables + engines (say about 10 mT) + propellant.


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