A couple of new posts on other sites that might be of interest to the readers of this blog.
Over at Air & Space, I discuss the new science results from the Chang’E-3 Yutu rover investigations. Comment here, if you are so inclined.
Also, Glenn Smith and I have an op-ed at Space News on the likely cost of a human Mars mission. Comments here are welcome.
Nice to hear results from Yutu’s roving.
It should serve as an example of what more we can learn from the Moon.
If only…..
For the Mars mission, I have some thoughts.
The ship need not be based on ISS, but perhaps more like Skylab; a single, large structure.
Perhaps the Skylab 2 concept can serve as well.
Also, the TSS need not be expendable.
Boeing outlined a plan for a Mars craft that has a lifetime of 11 years, IIRC.
It doesn’t not return to LEO, but to L2.
Also, IIRC, an NTR Mars vehicle has been outlined that would be reusable, use lunar resources, and use biomodel NTRs.
Such a concept seems more likely to come to pass AFTER Cislunar Next is accomplished, obviously.
“Similarly configured small missions could explore the polar regions of the Moon (where we expect to find water ice),-”
NewSpace proponents commonly libel the SLS as the “rocket to nowhere” while their favorite conveyance, marketed by SpaceX, is actually the inferior lift vehicle. The SLS can deliver worthwhile payloads across cislunar space into lunar orbit. These payloads, in my view, are the building blocks of the next space age. Upper stage wet workshops and semi-expendable robot landers can be used to provide a true space station, shielded from space radiation generated by the worst possible solar events. The robots can land on ice deposits and take off with a load of harvested water, then transfer the water to workshops in lunar orbit- repeatedly. When this scenario is considered, it is the ISS that is a “space station to nowhere.” By adding a propulsion system to these fully shielded lunar space stations they become spaceships- quite unlike the ISS. Chemical propulsion is essentially useless for pushing massively shielded crew compartments Beyond Earth Orbit. Since lighting off nuclear devices is not appropriate inside the Earth’s magnetosphere, the Moon is the place to do it- along with acquiring the prerequisite shielding.
“-U.S. and Russian systems on ISS demonstrate rates of hardware failures that would be unsustainable on a Mars mission. Finally, to underscore the difficulty and danger, there would be no possibility of crew rescue during a human mission to Mars.”
Missions Beyond Earth Orbit will require a rescue ship either in company or in transit close to the mission spaceship. What is being described as a “TSS” is more properly defined as a spaceship capable of providing Earth gravity and radiation levels on multi-year missions. As in the days of sailing ships, small fleets are needed for expeditions: single spaceships are completely inappropriate. But like most Mars scenarios, the cost makes such multi-ship expeditions problematic. Interestingly, accepting the requirement for a fleet of spaceships brings the “horizon goal” of Mars itself into question. Nuclear propelled spaceships make icy bodies like Ceres and the moons of the gas giants far more desirable destinations. The steps to multiple simultaneous human crewed missions to the gas giants are not hard to imagine. Shielded space stations can transit from lunar orbit to GEO and replace the satellite junkyard and capture the majority of revenues generated by the 100 billion dollar a year telecom market. Once a GEO infrastructure is established the lunar orbit assembly of workshops can continue with spaceships able to carry the nuclear deterrent. By moving the deterrent into deep space the cost of replacing the submarine, ICBM, and bomber fleets are avoided. These spaceships can also defend the Earth from the threat of impacts by comets and asteroids. A more connected, peaceful, and safe Earth- and human missions to dozens of moons- is just the beginning.
The ice on the Moon is the key enabling resource that should be the central focus of the entire Human Space Flight community.
The NAUTILUS-X was estimated at $3.7 billion in 2011 … http://phys.org/news/2011-02-nasa-nautilus-x-reusable-deep-spacecraft.html http://en.wikipedia.org/wiki/Nautilus-X
The SLS is a boondoggle and isn’t even sked for a first flight until 2018. Block I of the SLS will lift 70 MT.
The first iteration of the Falcon Heavy should lift off later this year and can lift 53 MT.
SpaceX has alreddy begun work on the XX. This should hav a lift of 140 MT. Anymore slips of the sked of the SLS and the XX could beat it to the pad.
However, having an a few nautilus-x craft could render moot the need for HLV. Indeed many argue that a HLV isn’t needed for the Moon and maybe not even needed for Mars. That it would be more economical to lift a string of smaller rockets.
The Nautilus concept is basically a cislunar-Libration point vehicle. It is inadequate as a Mars spacecraft. It may find employment as a transit node somewhere in cislunar space.
Falcon Heavy and XX are vaporware. I’ll believe them when I see them.
The nautilus-x is designd to go for a two-year mission. If that is only the length of while the crew is onboard for the flights to and fro (and not counting their ground time), then that would cover a Mars mission.
But even if it is only for near-moon space and moon flights, then it is still a good frame to build upon. We could learn a lot from it.
We’ll soon know about the Falcon Heavy. It is suppose to hav a test flight before the year is out. They do hav customers for it next year so I’m gessing they’ll get it done.
As for the XX, we’ll know if they build and test the whole raptor engin. They hav a ways and while to go with it but given the drawn-out SLS sked, I don’t think they need to be in a hurry. But, unlike NASA, Musk has a goal.
“But, unlike NASA, Musk has a goal.”
Mars is about the crummiest place imaginable to try and colonize. Reusing rocket stages defies the rocket equation and was rejected half a century ago. 27 little kerosene burning engines is a cluster of bad ideas. Good luck with all of that.
The flexible path insured NASA would have no goal. The next administration will hopefully fix that fundamental mistake and the Moon will become the place to go. Every other space faring nation on Earth is going to the Moon. When the U.S. policy changes this will bypass the dead end of LEO and retire the ISS early. Goodbye NewSpace. Whether SpaceX can survive as a satellite launch company without the massive free NASA support and ISS tax dollars they receive remains to be seen. I doubt it.
The Nautilus-X is a design concept, not a design. It is a valid and interesting one, but there have been numerous others over the years (actually decades).
Dr. Spudis’s editorial produced a lengthy list of technology developments required to make long term habitation modules possible. The Nautilus-X and other design concepts would all benefit from these developments, but none of them simply by their existence helps to produce those advancements. Thus they do nothing to change the editorials cost estimates.
The Falcon Heavy discussion has pretty much been had, except to note that a pro Falcon Heavy supporter above (Nelson Bridwell, March 13, 2015 at 8:22 pm) now says he expects the first launch in 2016. That is in keeping with the SpaceX “tradition” that the first Falcon Heavy launch is (like tomorrow in the old song – “always a day away”) always a year away. If it ever does launch look for (in another SpaceX “tradition) its cost to triple.
So you think that Space X knows a lot more about building a super heavy lift vehicle than Boeing and ATK??? Interesting!
The Falcon heavy will only be able to deploy about half the payload as the SLS and has a substantially smaller fairing diameter for carrying payloads into orbit.
A liquid methane fueled Space X super heavy would be more dangerous than liquid hydrogen. And methane combustion would also enhance global warming.
Habitats derived from the SLS propellant tanks would be substantially larger and lighter that any other concepts our there– including Bigelow’s inflatable concepts.
Marcel
I suspect the funky falcon faux heavy and Bigelow’s inflatable tents are the basic components NewSpace is hoping to build their LEO tourist empire with. That and using those “escape” systems on the two taxi’s to keep the tents in orbit. This scenario is denied by the various parties so I could be wrong. But since 4000 cheap and nasty satellites and hyperloop transportation seem to be going forward, who is to say what is unlikely anymore? 80,000 colonists on Mars by 2040 also. And Lockheed Martin says they almost have fusion reactors ready. And space elevators are on the way to.
There’s a sucker born every minute.
I would not get attached to the Falcon Heavy. It was originally scheduled to fly in 2012, then 2013 and then 2014. Now in 2015.
Even if it actually (eventually) flies, do not get attached to currently quoted prices:
– The price of an F9 was originally said to be $27M in 2010.
– By 2012, the cost was $54M.
– It is now around $80M-$90M.
– Except for the CRS contract, of course, where they are charging the government (that subsidized the F9 development) $133M.
Even sticking to their “commercial” prices that is a tripling of original quotes when the transactions became real.
“The SLS is a boondoggle-”
NewSpace proponents are very unhappy about the SLS. That is crystal clear. What is less clear to the public is the reason for this unhappiness.
NewSpace is essentially an Ayn-Rand-in-Space libertarian fantasy that considers state-run programs and the space agency to be the root of all evil. The Howard Roark/John Galt/Tony Stark hero of NewSpace, him-who-need-not-be-named, is the rallying point for this cult. Any public funds not going to the company that embodies the object of their worship are in the NewSpace view a criminal waste.
What is really disturbing to these groupies is the prospect of that great evil- a state run exploration program- actually getting back on track with a real space program. The “entrepreneur” and the company they idolize does not have the technology- and cannot justify begging for the tax dollars- to efficiently leave Earth orbit behind. Going back to the Moon bypasses Low Earth Orbit and dumps the NewSpace manifesto in the trashcan. Where it belongs. LEO is a dead end.
The two-faced double agents in NASA that support the NewSpace agenda are doing their best to keep any logical plan for a real space program from even being discussed.
1.5 trillion for some bootprints on Mars is pretty staggering. However, there are two issues that make this figure less daunting in regards to Human Space Flight Beyond Earth and Lunar Orbit (HSF-BELO). Both are associated with the nuclear energy that no one seems able to admit will be required for interplanetary travel. The first issue is the nuclear deterrent is in need of replacement soon and that has a 1 trillion dollar price tag. Unfortunately, the technology to maintain deterrence, at least on Earth, is lacking due to advances in submarine detection and more accurate missiles. Moving the deterrent off the planet into deep space is highly desirable because it removes the hair-trigger-minutes-to-launch situation in place that is rapidly deteriorating. The second issue is planetary protection. Spaceships assembled from SLS wet workshops in lunar orbit utilizing lunar-water-as-cosmic-ray-shielding can restore deterrence and provide impact interdiction (as well as provide a new telecom GEO infrastructure thus solving the looming space debris problem).
As Marcia Smith points out in an op-ed, “NASA has a mandate from the White House Office of Science and Technology Policy (OSTP) to take the lead in performing an “options analysis and assessment of the technologies that may be applicable to [near Earth orbit] mitigation/deflection (along with preliminary research and development activities concerning such technologies and activities…)”. That quote is from OSTP’s 2010 response to Congress on U.S. government roles and missions regarding threats from asteroids (and comets).”
http://aviationweek.com/ideaxchange/let-s-fix-asteroid-redirect-mission
http://www.cbo.gov/sites/default/files/cbofiles/attachments/12-19-2013-NuclearForces.pdf
http://cns.miis.edu/opapers/pdfs/140107_trillion_dollar_nuclear_triad.pdf
Paul:
A somewhat general question:
In addition to traces of H2O and He3, the Moon contains significant quantities of silicon, oxygen, iron, aluminum, and magnesium. If we wanted to use these materials to manufacture useful components of a lunar outpost, what do you think would be the most practical way to accomplish this? Solar thermal production of glasses? Solar thermal melting and electrical separation of metals? Are these processes that we could prototype in the laboratory in advance of actual space missions?
Thanks,
Nelson
Nelson,
Much work has been done on using the non-volatile elements of the Moon for a variety of purposes. You can start with fairly low-tech approaches (such as piling up loose regolith to make blast berms to protect outpost pieces from flying dust) and gradually transition to making ceramics (fusing soil with solar thermal) and aggregates (construction materials). Eventually, metals may be extracted from the soil, but this is a fairly energy intensive activity. The water is extracted first because it is easiest and the most useful — other substances receive attention as the need for off-planet commodities grow.
“Eventually, metals may be extracted from the soil, but this is a fairly energy intensive activity.”
Paul,
(1) For the record, does that mean (in your opinion) that this would be the point where nuclear energy would be required?
(2) If yes, what is the current estimate of fissionable material available on the moon?
I realize that is a long range question, but it never hurts to look ahead.
Truthfully, unless you’re at one of the poles and maybe even then, nuclear energy is going to be needed for anything bigger than a small outpost.
Thorium can be noted in reactors (see http://indiatoday.intoday.in/story/worlds-first-thorium-based-nuclear-reactor-barc/1/343569.html ) and the Moon has a fulsumness of thorium.
By the time we get there, molten salt reactors will likely be the reactor of choice which is even better for thorium.
It’s all a question of scale — how much and what products are needed when. Metals can be extracted via a number of reduction processes (I have a soft spot for fluorine reduction — see this paper) but because the metal-oxygen bonds are strong, a lot of energy is required to break them. As long as we can add solar arrays to the polar peaks, we can stay non-nuclear. If we go to the equator or mid-latitudes, a reactor will likely be needed.
Fuel for the reactor is the least massive element so it is likely that nuclear fuel will be imported from Earth, at least for the foreseeable future. Respectable thorium deposits occur on the western near side, so we may eventually be free from even this requirement.
Thanks.
I was, as I said, thinking “long range” and that is the answer I was hoping to here.
“Fuel for the reactor is the least massive element so it is likely that nuclear fuel will be imported from Earth, at least for the foreseeable future.”
A few pounds of plutonium held in a gloved palm represent several supertankers of chemical energy. The Orion LAS and appropriate survivable packaging allow for the safest transport of fissionable material to the Moon.
“As long as we can add solar arrays to the polar peaks, we can stay non-nuclear.”
I would add to my other comment concerning plutonium that I more than agree with Dr. Spudis that solar energy is all that is required. The Moon also seems perfect for wireless energy transmission as beaming energy over long distances would be less difficult than on Earth.
http://spectrum.ieee.org/green-tech/solar/how-japan-plans-to-build-an-orbital-solar-farm
My advocacy of transporting fissionable material to the Moon has more to the with Nuclear Pulse Propulsion than for use in reactors.
“It’s all a question of scale — how much and what products are needed when.”
Scale is the primary obstacle in Nuclear Pulse Propulsion. Building pulse units small enough and getting a plate or sail device large enough to be efficient outside the magnetosphere are the problems to be solved. Fortunately, large sums have gone into fusion weapon research devoted to making H-bombs as small as possible.
The two options for a pulse propulsion “engine” are a giant parachute-like sail or a big dumb plate. The parachute, or “Medusa” concept, would require very small bombs and would probably not be very durable. It might serve as an interim but the multi-thousand ton monolithic metal plate is where extremely high Isp numbers in the tens of thousands are found because larger bombs can be used. I like to think of them as flying saucers made real.
Fabricating such massive plates on the Moon would open up the solar system to human exploration. Such extremely high velocities would be possible that round trip journeys to the gas giants might take only a few years. There is certainly no shortage of plutonium. Welcome to the 21st century.
Nelson,
Since you have asked specifically about solar thermal production of lunar glasses, I provide you with this link to an article by yours truly:
http://www.portaltotheuniverse.org/blogs/posts/view/357925/
Regards,
G. W. (Glenn) Smith
P.S. Yes, I am apparently one of two Glenn Smith’s involved with this blog — and I humbly yield place of precedence to the other, O. Glenn Smith, since he is Dr. Spudis’ collaborator!
Recently I wondering if commercial lunar base could established at low cost.
Now this commercial lunar base isn’t [or doesn’t start out] as manned base.
And instead calling it a base, one could call it a landing zone or perhaps the beginning of a spaceport.
So I am starting with a premise of doing something with lunar dust [mitigate dust problem]. And I am assuming if cleared an area of top 3 inches of the fine and loose top regolith that this could be an improvement.
So one starts out just collecting the top layer of regolith and piling in craters. That one finishes with say 1/2 football field of land zone which does not have the surface dust in areas and leaving the compacted surface the way it is.
A later goal would be to have a paved area to land spacecraft but idea is to start with what one could be analogous to a dirt runway.. And not aiming having no dust kick up from a landing or take off, but rather to reduce it, so that vehicles could land fairly close to each other [within say 50 meters without damaging them].
In addition to removing dust, one might have landing zone in a depression [small crater cleared of dust] or have berms and/or natural terrain so as limit damage to other spacecraft.
In terms profitable the main aspect is not spend a lot of money and to acquire real estate.
And this improved real estate is place that spacecraft can land safely and precisely.
So what making is a base camp which others could land and they leave to go somewhere else or
do something in your particular chunk a real estate.
So this locate one picks does not need minable water within 1 km [or more distance], but rather instead what it needs a location which allows communication to Earth and a location with good amount of solar energy.
So, one lands spacecraft which can communicate to Earth and it deploys a few small [toyish] vehicles which recon and collect the top dust and sorts rocks and dust and piles them separately. And make trails of dust removed and establishes somewhat flat and larger areas that spacecraft could land.
So rake, scrape, and/or sweep off the top surface. Put fist size rocks or smaller in one location and the dust/sand in other piles. And the bigger rocks leave in place.
Idea is to use this sorted regolith later, but utilizing it in near term is not a short term objective.
So even relatively small area is going to have hundred of tons of dust to move and what is first landed could be limited to handling say less than 100 tons. First landing is exploratory and a focus in making landing site for next spacecraft which might move say 500 tons or more.
And things like the third landing might focus on returning a lunar samples, paving a landing site, developing solar farms for a lot of electrical energy, and/or whatever.
But the first landed spacecraft needs to pay for it’s itself and thereby allowing one to get to the second and third and etc landings.
So one doing something roughly of the scale of Google X prize or something about 100 million or less. And second one might have cost of say 200 million- as it will have more capability.
So first mission is experimental but also has primary mission to clear a landing site [for next mission] which somewhat close to first mission [within 100 meters] . And second mission’s focus will be clearing more area and allowing landing to be as close as is practical- probably don’t want land nearer than as say 30 feet- just in terms general safety.
So purpose is have less dust related to rocket landing and less dust for vehicles which can use the built trails. And purpose also to establish a chunk of real estate which may eventually get to manned landing and be base which can be useful for additional lunar exploration and mining.
A good location would be peak of “ethereal light” close to South pole of the rim of Shackleton Crater.
So question is, would removing the dust of first 3″ be useful to allow landing which are close other things or do actually need to have the area paved?
Second I am assuming that if have beacons at lunar surface and know precisely where going to land, that quite precise landing are possible and perhaps one could land with less fuel margins.
I think that lunar dust isn’t nearly the problem that it has been made out. It is true that it is highly abrasive and coatings of it can greatly aggravate thermal control issues, but since the days of Apollo, we have found that its control and mitigation is not nearly the problem that it had been thought to be. For one thing, the dust is quasi-magnetic and much of it can be removed with magnetic fields.
Paving the regolith is relatively easy using microwave sintering. This could be done early in lunar return by a teleoperated rover.
I tend to think of the regolith dust as an asset rather than a liability because it could eliminate the significant energy that otherwise could be required to blast and break up large rocks prior to an extraction process. All that work has already been done for us by previous meteor impacts. In fact, I suspect that the most favorable location for metal/ceramic extraction processes might be places that have the loosest, deepest layers of regolith so that minimum transport of feedstock would be required.
If we assume that NASA’s human spaceflight related budget is going to be close to its current $8 billion a year budget then NASA should have about $160 billion to spend on human space travel over the next 20 years.
$8 billion a year should be plenty of funding for NASA to return permanently to the Moon during the 2020s and then to Mars in the 2030s. But it’s clearly not enough if NASA’s still running an expensive $3 billion a year LEO program (the ISS). So the ISS needs to be either terminated in the near future or NASA’s annual human spaceflight related budget needs to be raised by approximately $3 billion.
The DHS (Deep Space Hab), reusable OTV (Orbital Transfer Vehicles), regolith shielded habitats, and even artificial gravity habitats could all be cheaply derived from the SLS propellant tank technology. The Skylab II DHS concept, for instance, suggest that an ISS outfitted SLS propellant tank for a 500 day crewed mission could be deployed at a Lagrange point with a single SLS launch.
A reusable single staged LOX/LH2 extraterrestrial landing vehicle for cargo and crew missions to the Moon, the moons of Mars, and even to the Martian surface (utilizing HIAD or ADEPT technologies) should cost less than $12 billion to develop. That would be less than $1.7 billion per year over a seven year development period.
The most dangerous and expensive way to travel to Mars and back to cis-lunar space is to travel between LEO to Low Mars Orbit using aerobraking.
The safest and the cheapest way to travel between the Earth and Mars is to travel between one of the Earth-Moon Lagrange points to High Mars Orbit using propellant depots at both ends with propellant derived from lunar water resources and eventually Deimos water resources.
Marcel
“-the cheapest way to travel between the Earth and Mars-”
I am a follower of Gerard K. O’Neill and as such I believe the Moon is the first place to go and exploiting lunar resources to power civilization on planet Earth- and eventually acquire new lebensraum in space- is the prize.
The two central concepts of O’Neill’s vision were Solar Power Satellites built with lunar resources and the conclusion there are no bodies in the solar system suitable for colonization leaving artificial hollow moons constructed from lunar resources as the answer.
These concepts are completely contrary to the popular culture hype spread by NewSpace advocates over the last several years. A vast state-run public works project using super-heavy lift vehicles to return to the Moon is the NewSpace nightmare. So….I have to speak out when words like “cheapest” and dead end goals like LEO space stations and missions to Mars are discussed.
I want to explore Titan and the subsurface oceans of the gas giant moons as much as the next space advocate but first things first. And Mars……not even a good destination.
Mars is a gimmick; mistakenly popularized as “just close enough” to get to on the cheap.
There is no cheap.
The SpaceX Falcon XX was vaporware back in 2010 when it was announced by SpaceX engineer (now FORMER SpaceX engineer) Tom Markusek. Musk denouced it as merely a bunch of ideas for discussion. Instead, he promised to announce an HLV design last year, at which point it would have been powerpoint vaporware, but not even that happened because not even Musk is exactly sure what his BFR is.
The Falcon Heavy, an HLV/2, appears to be real hardware that is currently being manufactured. I expect that the launch may happen sometime in 2016…
http://www.nasaspaceflight.com/2015/02/falcon-heavy-production-39a-hif-rises/
I would love for NASA to conduct a Lunar Manufacturing Centennial Challenge where you place your lander/robot in a large vacuum chamber with sunlight and lots of lunar regolith simulant. Your challenge would be to manufacture parts of your initial hardware, where the winner produces the largest mass fraction of his robot in a set period of time. (As part of the challenge, you would demonstrate that the robot would still continue to function for some time with these replacement parts installed.)
If a variety of metals and ceramics can be extracted from regolith then I would think that you could manufacture >90% of the robot (and support infrastructure) mass (structures, wheels, electric motors…), just importing electronic components such as computers, communications, and photovoltaics.
Speaking as a non-expert, I would think that if you wanted to expand a facility that generates electric power and manufactures robots, you could just stay in one place and use the local regolith as the feed-stock.
Also, I am wondering what would be the best way to expand electric power output. Would it be best to make simple reflective solar concentrators and static thermoelectric power generators, or try to manufacture some type of photovoltaics.
This is a technology that could be pioneered and continuously refined here before implementation on the lunar surface.
Speaking as a former field soldier/operator/mechanic and aircraft technician/aircrewman, it is my considered if not expert opinion that any type of industry on the Moon will first require very large production floors on the scale of sports arenas. I have been on tours of different factories/shipyards while attending technical schools. The need for these very large underground or partially underground with overhead radiation shield facilities is that everything normally associated with widely dispersed terrestrial manufacturing will have to be concentrated in a few locations. Having done a little research and seen first hand some excavation sites the way for this to happen on the Moon is probably going to be either building on natural impact craters or using explosives or a combination of both. I was not real impressed with the tunneling project I followed while living in Seattle. The machine is still broke as far as I know.
Manufacturing things like solar panels and refining and fabricating metal alloy components takes human technicians- hundreds of them. No way around it. All this 3-D printing talk is fine if you have high quality stock- but creating that stock and making larger items takes a factory. The best first project in my view that can be undertaken is in orbit using robot landers to harvest and bring water up to wet workshops.
Bill: I tend to agree with you that people underestimate the massive infrastructure that is required in order to manufacture certain components such as semiconductors. That is why we should focus first on lunar manufacturing of low-tech, high mass components such as structural members, wire, motors, Stirling engines, … 19th century technology.
As far as people, because the Moon is only about one light-second away, I think that we will want to remotely operate as much as we can from the Earth. About the only absolute necessity for basing people on the Moon would be for service operations (like Hubble repairs) that require fine-motor-skills. And if we can do surgery with robots, I suspect that we should be able to eventually perform most service operations remotely, too.
We will want people up on the Moon at some point, but I think that we should first concentrate on remotely creating a substantial infrastructure.
My take on SLS vs SpaceX: SLS is what NASA needs now. It is not the cheapest option, but because NASA is not required by stockholders to make the largest possible profit, cost is a secondary consideration.
If SpaceX can provide a lower cost launch option for NASA in the future, such as an expendable Falcon Heavy in the near future, or a reusable HLV in the distant future, that will be all the better.
In either case, NASA comes out a winner. The only thing that NASA really needs is a realistic, consistent exploration roadmap that is not the pawn of political upmanship and armchair generals.
Five years ago SpaceX was a company with very little to show for itself other than lots of wild promises. Their initial attempts at reusability were embarrassing failures
However, that is no longer the case. They have matured rapidly and are becoming a credible, significant provider of launch services. The rest of the industry has taken notice and has begun to imitate them, down to ULA’s efforts to build suspense by refusing to reveal any details of it’s NGLS until an April announcement.
Time will tell, but bickering about SLS vs SpaceX is probably not the most productive use of our energies.