Back to the Future on the Moon

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There have been no humans on the surface of the moon since the Apollo program ended in 1972.  Now, in addition to NASA, space agencies in India, China, Russia, Japan and Europe and developing plans to land humans on the moon. (NASA/Robin Lee)

What does NASA’s drive to return to the moon have to do with worlds of exoplanets and astrobiology that are generally discussed here?  The answer is actually quite a lot.

Not so much about the science, although current NASA plans would certainly make possible some very interesting science regarding humans living in deep space, as well as some ways to study the moon, Earth and our sun.

But it seems especially important now to look at what NASA and others have in mind regarding our moon because the current administration has made a top priority of returning landers and humans to there, prospecting for resources on the moon and ultimately setting up a human colony on the moon.

This has been laid out in executive directives and now is being translated into funding for NASA (and commercial) missions and projects.

There are at least two significant NASA projects specific to the moon initiative now planned, developed and in some cases funded.  They are the placement of a small space station that would orbit the moon, and simultaneously a series of robotic moon landings — to be conducted by commercial ventures but carrying NASA and other instruments from international and other commercial partners.

The goal is to start small and gradually increase the size of the landers until they are large enough to carry astronauts.

And the same growth line holds for the overall moon mission.  The often-stated goal is to establish a colony on the moon that will be a signal expansion of the reach of humanity and possibly a significant step towards sending humans further into space.

A major shift in NASA focus is under way and, most likely in the years ahead, a shift in NASA funding.

Given the potential size and importance of the moon initiative — and its potential consequences for NASA space science — it seems valuable to both learn more about it.

 

Cislunar space is, generally speaking, the area region between the Earth and the moon. Always changing because of the movements of the two objects.

Development work is now under way for what is considered to be the key near-term and moon-specific project.  It used to be called the the Deep Space Gateway as part of the Obama administration proposal for an asteroid retrieval mission, but now it’s the Lunar Orbital Platform-Gateway (LOP-G.)

If built, the four-person space station would serve as a quasi-permanent outpost orbiting the moon that advocates say would enhance exploration and later commercial exploitation of the moon.  It would provide a training area and safe haven for astronauts, could become a center for moon, Earth and solar science, and could continue and expand the international cooperation nurtured on the International Space Station (ISS) project for several decades.

In its Gateway Memorandum, published last month, NASA and the administration also made clear that the station would have, as a central goal, geopolitical importance.

As stated in the memorandum, “the next step in human spaceflight is the establishment of U.S. preeminence in cislunar space through the operations and the deployment of a U.S.-led lunar orbital platform,  “Gateway.”  (“Cislunar space” is the region lying  between the Earth and the moon.)

The administration requested $500 million for planning the LOP-G project in fiscal 2019.  The first component to be built and hopefully launched into cislunar space under the plan is the “power and propulsion element.”

 

An artist version of a completed Gateway spaceport with the Orion capsule approaching. (NASA)

Five companies have put together proposals for the “PPE,” and NASA officials have said they are ready to move ahead with procurement.

During a March meeting of the NASA Advisory Council’s human exploration and operations committee, Michele Gates, director of the Power and Propulsion Element at NASA Headquarters, said the agency will be ready to move ahead with procurement of the module when the five industry proposals are completed.

Some of those companies had been involved in studies for the cancelled Asteroid Redirect Mission and Gates said, “Our strategy is to leverage all of the work that’s been done, including on the Asteroid Redirect Mission.”

Five different companies have contracts to design possible space station habitation modules as well.

So the plan has some momentum.  If all moves ahead as described, NASA will launch the components of the Gateway in the early to mid 2020s.  More than a dozen international agencies have voiced interest in joining the project, including European, Japanese, Canadian and other ISS partners.

As part of that outreach, an informal partnership agreement has already been signed with Roscosmos, the Russian space agency, with the possibility of using a future Russian heavy rocket to help build the station and ferry crew.

 

Astronaut John Young of the Apollo 16 mission on the moon. The primary goal of the NASA moon initiative is to return astronauts to the surface.(NASA)

The other NASA moon initiative involves an effort to send many robotic landers to the moon to look for potential water and fuel (hydrogen) to be collected for a cislunar and ultimately lunar economy.

NASA had worked for some time on what was called a Resource Prospector, a mission to study water ice and other volatiles at the lunar poles.  But this spring NASA Administrator Jim Bridenstine announced the Prospector was being cancelled because it was not suited to the what is called the new Exploration Campaign — NASA’s concept for a series of missions that will initially use small, commercially developed landers, followed by larger landers.

So the Prospector project is now considered “too limited in scope for the agency’s expanded lunar exploration focus,” the agency said in a statement. “NASA’s return to the moon will include many missions to locate, extract and process elements across bigger areas of the lunar surface.”

The agency also says it will rely on private companies to design and build the landers, as well as launching them into space.

So these are the out-of-the gate projects NASA has in mind for the moon. They, however, are hardly where the big money is going.  That is directed to the heavy rocket under development and construction for more than a decade (the Space Launch System, or SLS) and the Orion space capsule.

They are designed to be the main conduits to the Gateway and perhaps beyond some day, and they have been enormously costly to build — at least $22 billion to construct up through 2021, NASA officials told the Government Accounting Office in 2014. And that doesn’t include the more costly second SLS rocket scheduled for 2023 with a crew aboard.

What’s more, it is estimated to cost at least $1.5 billion to launch each SLS/Orion voyage in years ahead.

 

Astronauts go into an Orion capsule mock-up. The un-manned spacecraft is expected to be ready for launch in 2020. (NASA/ Bill Stafford and Roger Markowitz)

 

Another mock-up of the inside of the Orion crew module, which carries four astronauts and is scheduled to launch in 2023. It has 316 cubic feet of habitable space, compared with 210 cubic feet for the Apollo capsules. (NASA)

 

Since this column is primarily about space and origins science, I was drawn to the conference held late Feb. in Denver — billed as the Deep Space Gateway Concept Science Workshop.  The idea, surely, was to share and showcase what science might be achievable on the mini-space station.

As you might imagine, a major scientific focus was on the challenges to humans of living in deep space and techniques that might be used to mitigate problems. Abstracts included studies of the effects of radiation on astronauts, on drugs, on food, on the immune system and more.

NASA and others have studied for years radiation and micro-gravity effects on astronauts aboard the International Space Station, but conditions in a deep space environment would be quite a bit different.  Probably most importantly, astronauts aboard the Gateway would be exposed to much more dangerous radiation than those in the ISS because that low-Earth orbit station is protected by the Van Allen radiation belts.

There was also an intriguing proposal to study the ability of lunar regolith (the rock, dust and gravel on the surface) to shield growing plants on the station from radiation, and others on the role and usefulness of plants and micro-organisms in deep space.

Scientists also proposed many different ways to study the moon, the Earth and the sun.  Harley Thronson of NASA Goddard, one of the moderators of the conference, said that sun scientists seemed especially excited by the opportunities the Gateway could offer.

As far as I could tell, there was but one proposal that involved astrobiology or exoplanets.  It was a plan by scientists from SETI and NASA Ames to study Earth with a spectrometer as a way to understand and measure potential bio-markers on exoplanets.

So there’s undoubtedly good science to be done on a lunar space port regarding human space flight, the moon, the Earth and sun.

What I wonder is this:  Will this new, intense and costly lunar focus on the moon take away from what I like to think of as The Golden Age of Space Science — the unending breakthroughs of recent decades in understanding planets and distant moons in our solar system, detecting and characterizing the billions and billions of exoplanets out there,  as well as revealing the structure and history of the cosmos.

 

The Sombrero Galaxy, as imaged by the Hubble Space Telescope, NASA’s Flagship observatory of the 1990s. The James Webb Space Telescope is delayed but is expected to provide the same remarkable images and science as Hubble once it’s up and working.  WFIRST, the planned flagship observatory of the 2020s was cancelled by the administration earlier this year because of a NASA funding shortfall, but its fate remains undecided. (NASA)

I’m not thinking about today but about when costly NASA flagship space observatories or major planetary missions come up for approval, or non-approval, in the future.  Will the funding, and the deep interest, still be there?

Others more knowledgeable about the mechanics of space travel also criticize the Gateway as a costly detour from what long has been considered the main goal of space exploration — sending humans to Mars — and as redundant when it comes to accessing and studying the moon.

On a more encouraged note, a lunar station and lunar base could become part of a much larger space architecture that will allow for all kinds of advances in the decades ahead.  This is precisely the kind of build-out that Thronson, who is Senior Scientist for Advanced Astrophysics Mission Concepts at NASA Goddard and Chief Technologist for the Cosmic Origins and Physics of the Cosmos Program Offices, has been working towards for years.

Ever mindful of the uses of such a space architecture, he pointed out one potential use of a lunar space station that is seldom heard:  If a powerful new telescope in deep space needs repair or upgrading, he wrote in an email, there’s no way to get humans to it now.  The Hubble Space Telescope could be fixed because it was not in deep space and astronauts could get to it.

Thronson sees a potential parallel use for the Gateway, as he described in an email. “My astronomy colleagues, including myself, have been for many years advocating using a Gateway-type facility to assemble, repair, and upgrade the next generation (and beyond) of major astronomical missions. Nothing beats having a human on site, if there are complicated activities that need to be carried out.”

 

 

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A Vision That Could Supercharge NASA

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An artist rendering of an approximately 16-meter telescope in space.  This image was created for an earlier large space telescope feasibility project called ATLAST, but it is similar to what is being discussed inside and outside of NASA as a possible great observatory after the James Webb Space Telescope and the Wide-Field Infrared Survey Telescope.  Advocates say such a large space telescope would revolutionize the search for life on exoplanets, as well as providing the greatest observing ever for general astrophysics. (NASA)

Let your mind wander for a moment and let it land on the most exciting and meaningful NASA mission that you can imagine.  An undertaking, perhaps, that would send astronauts into deep space, that would require enormous technological innovation, and that would have ever-lasting science returns.

Many will no doubt think of Mars and the dream of sending astronauts there to explore.  Others might imagine setting up a colony on that planet, or perhaps in the nearer term establishing a human colony on the moon.  And now that we know there’s a rocky exoplanet orbiting Proxima Centauri — the star closest to our sun — it’s tempting to wish for a major robotic or, someday, human mission headed there to search for life.

All are dream-worthy space projects for sure.  But some visionary scientists (and most especially one well-known former astronaut) have been working for some time on another potential grand endeavor — one that you probably have not heard or thought about, yet might be the most compelling and achievable of them all.

It would return astronauts to deep space and it would have them doing the kind of very difficult but essential work needed for space exploration in the far future. It would use the very costly and very powerful Space Launch System (SLS) rocket and Orion capsule being built now by NASA and Lockheed Martin respectively.  Most important, it would almost certainly revolutionize our understanding of the cosmos near and far.

At a recent meeting of the House Science Committee, chairman Lamar Smith, said of the hearing’s purpose that, “Presidential transitions offer the opportunities to reinvigorate national goals. They bring fresh perspectives and new ideas that energize our efforts.”

That said, here’s the seemingly feasible project that fires my imagination the most.

It has been quietly but with persistence promoted most visibly by John Grunsfeld, the former astronaut who flew to the Hubble Space Telescope three times to fix and upgrade it, who has spent 58 hours on spacewalks outside the Shuttle, and towards the end of his 40 years with the agency ultimately became an associate administrator and head of the agency’s Science Mission Directorate.

A visualization of the assembly in space of a large segmented telescope, with work being done by astronauts and robots.  The honeycomb blocks are parts of the mirror, and the grey cylinders on the right are habitats for astronauts.  (NASA)

His plan:  Build a segmented space telescope mirror that is 16 meters (52 feet) in diameter or larger, package it into one or several payload fairings and launch it into deep space.  Accompanying astronauts would put it together either at its final destination or at a closer point where it could then be propelled to that destination.

This would provide invaluable humans-in-space experience, would put the Orion and SLS to very good use in advance of a projected human mission to Mars, and would deploy the most penetrating telescope observing ever.  By far.

No mirror with a diameter greater than 3.5 meters (11.5 feet)  has ever been deployed in space,  although the the James Webb  Space Telescope mirror will be substantially larger at 6.5 meters (21 feet) when launched in 2018.  The largest ground telescopes are in the 10-meter (33 foot) range.

John Grunsfeld working on the Hubble Space Telescope, some 350 miles above Earth. He said that based on his own experience with spacewalks and space repairs, he thinks that a crew of four astronauts could assembled a 16-meter segmented telescope mirror within four weeks. (NASA)

What Grunsfeld’s space behemoth would provide is an unprecedented power and resolution to see back to the earliest point possible in the history of the universe, and doing that in the ultraviolet and visible wavelengths. But perhaps more significantly and revolutionary, it would supercharge the agency’s ability to search for life beyond Earth.

Like nothing else currently in use or development, it would provide a real chance to answer what is arguably humanity’s most fundamental question:  Are we alone in the universe?

Grunsfeld has been introducing people to the project/vision inside NASA for some time.  He also told me that he has spoken with many members of Congress about it, and that most have been quite supportive.  Now he’s starting to make the case to the public.

“We need our leaders to be bold if we want to stay in the forefront of science and engineering,” he said.  “Assembling a 16-meter telescope in space would not be easy by any means.  But we can do it and — this is the key — it would be transformational. It’s a rational thing to do.”

His confidence in the possibility of launching the segmented mirror parts and having astronauts assemble them in space comes, he says, from experience.  Not only has he flown on the space shuttle five times and has his three very close encounters with the Hubble, but he has also overseen the difficult process of getting the JWST project — with its pioneering segmented, folding mirror — back on track after large budget overruns and delays.  He’s also trained in astrophysics and is enamored of exoplanets.

“If your goal is to search for inhabited planets, you just have to go up to the 16-meter range for the primary telescope mirror,” he said.

“Think about it:  if we sent up something smaller, it will give us important and potentially very intruiging information about what planets might be habitable, that could potentially support life.  But then we’d have to send up a bigger mirror later to actually make any detection.  Why not just go to the 16-meter now?”

The strongest driver on the size of the LUVOIR telescope is the desire to have a large sample of exoEarth candidates to study. This figure shows the real stars in the sky for which a planet in the habitable zone can be observed. The color coding shows the probability of observing an exoEarth candidate if it’s present around that star (green is a high probability, red is a low one). This is a visualization of the work of Chris Stark at Space Telescope Science Institute, who created an advanced code to calculate yields of exoplanet observations with different facilities.  (C. Stark and J. Tumlinson, STScI)

While all this may sound to many like science fiction, NASA actually has a team in place studying the science and technology involved with a very large space telescope, and has funded studies of in-space assembly as well.

The current team is one of four studying different projects for a grand observatory for the 2030s.  Their mission is called LUVOIR (the Large UV/Optical/IR Surveyor), and both it and a second mission under study (Hab-Ex) have exoplanets as a primary focus. It was Grunsfeld and Paul Hertz, director of NASA’s astrophysics division, who selected the four concepts for more in-depth study based in large part on astronomy and astrophysics community thinking and aspirations, especially as laid out in the 2013 Thirty-Year Astrophysics Visionary Roadmap.

The LUVOIR team started out with the intention of studying the engineering and technological requirements — and science returns — of a space telescope between 8 and 16 meters in diameter, while Hab-Ex would look at the 4 to 7 meter option for a telescope designed to find exoplanets.  Grunsfeld addressed the LUVOIR study team and encouraged them to be ambitious in their thinking — a message delivered by quite a few others as well.  What’s more, a number of study team members were inclined towards the 16-meter version from the onset.

Aki Roberge of the Goddard Space Flight Center is the team scientist for the LUVOIR Science and Technology Definition Team.

The LUVOIR team has not addressed the issue of assembly in space — their goals are to understand the science made possible with telescopes of different sizes, to design an observatory that can be repaired and upgraded, and to determine if the technology to pull it all together is within reach for the next decade or two.

A key issue is how large a folded up mirror the launch vehicle rocket nose cone (the fairing) can hold.  While the current version of the SLS would certainly not accommodate a 16-meter segmented mirror, team study scientist Aki Roberge — an astrophysicist at the Goddard Space Flight Center — said that the team just recently got the good news that a next generation SLS fairing looks like it could well hold a folded mirror of up to 15 meters. Quite a few “ifs” involved, but still promising.

“We’re still in the midst of our work, but it’s clear that a LUVOIR with a large aperture (mirror) gives us a major science return,” she said.  “Going up to nine meters would be a major leap forward, and going to 16 would be a dramatic advance on that.”

“But we have to assess what we gain in terms of going large and what we might lose in terms of added technical difficulty, cost and time.”  As is, the 9 or 16-meter project — if selected — would not be ready to launch until the mid 2030s.  All the great space observatories and missions have had decades-long gestation periods.

The results from the LUVOIR and other formal NASA study teams will be reviewed by the agency and then assessed by a sizeable group of experts convened by the National Academy of Sciences for the 2020 Astrophysics Decadal Survey.  They set the next decade’s topic and mission priorities for the astronomy and astrophysics communities (as well as others) — assessments that are sent back to NASA and generally followed.

One of Grunsfeld’s goals, he told me, is to make the assembled-in-space 16-meter telescope a top Decadal Survey priority.  While supportive of the LUVOIR efforts, he believes that including astronauts in the equation, deploying a somewhat larger mirror even if the difference in size is not great, and making a mirror that he says will be easier to fix and upgrade than a folded up version, gives the assembled-in-space option the advantage.

These images, which are theoretical simulations using the iconic Hubble Deep Field image, are adjusted to reflect the light collected by telescopes of different sizes. They show the increased resolution and quality of images taken by a 16-meter telescope, a 9-meter, and the Hubble Space Telescope, which is 2.4 meters in diameter.  They illustrate pretty clearly why astronomers and exoplanet hunters want ever larger telescope mirrors to collect those photons from galaxies, stars and planets.

Simulated views of galaxies in deep space, as seen with a proposed 16-meter telescope. This and the two images below are of the same part of the sky. The exposure time for each image was assumed to be the same, to make them comparable. Scientists get higher resolution images with the larger telescopes.  (G. Snyder, STScI /M. Postman, STScI.)

 

Deep space galaxies as seen with nine meter telescope.

 

Once again the same view, taken with Hubble’s 2.4-meter telescope for the same period of time as the images above.  The iconic Hubble Deep Field images are much clearer than this one, and that’s because the telescope was collecting light for a much longer period of time.

Whether or not the LUVOIR project is selected to be a future NASA flagship observatory, and whether or not it will be an assembled-in-space version of it, many at the agency clearly see human activity and habitation in space (as well as on planets or moons) as a necessary and inevitable next step.

Harley Thronson is the senior scientist for Advanced Concepts in Astrophysics at Goddard, and he has worked on several projects related to how and where astronauts might live and work in space.

Harley Thronson, the senior scientist for Advanced Concepts in Astrophysics at the Goddard Space Flight Center, standing outside the JWST clean room. (NASA)

He said this research goes back decades, having gained the attention of then-NASA Administrator Dan Goldin around 2000.  It has recently experienced another spurt of interest as the agency has been assessing opportunities for human operations beyond the immediate vicinity of the Earth.

“It’s inevitable that the astronomy community will want and need larger space observatories, and so we have to work out how to design and build them, how and where they might be assembled in space, and how they can be serviced,” Thronson said.  The JWST will not be reachable for upgrades and servicing, and Congress responded to that drawback by telling NASA will make sure future major observatories can be serviced if at all possible.

Thronson said that he supports and is inspired by the idea of a 16-meter space telescope, and he agrees with Grunsfeld that assembly in space is the wave of the future.  But he said “I’m not quite as optimistic as John that we’re ready to attack that now, though it would be terrific if we were.”

Part of Thronson’s work involves understanding operation sites where space telescopes would be most stable, and that generally involves the libration points, where countervailing gravity pulls are almost neutralized.  LUVOIR, like JWST, is proposed for the so-called Sun-Earth L-2 point, about one million miles outward from Earth where the Earth and sun create a gravitational equilibrium of sorts.

Thronson said there has been some discussion about the possibility of assembling a telescope at a closer Earth-moon libration point and then propelling it towards its destination.  That assembly point could, over time, become a kind of depot for servicing space telescopes and as well as other tasks.

As a sign of the level of interest in these kind of space-based activities, NASA last year awarded $65 million to six companies involved in creating space habitats for astronauts on long-duration missions in deep space.

One of the locations in relatively nearby space where a space telescope would have a stable gravitational environment. (NASA

At the time, the director of NASA’s Advanced Exploration Systems, Jason Crusan,  said that “the next human exploration capabilities needed beyond the Space Launch System rocket and Orion capsule are deep space, long duration habitation and in-space propulsion. We are now adding focus and specifics on the deep space habitats where humans will live and work independently for months or years at a time, without cargo supply deliveries from Earth.”

Not surprisingly, building and maintaining telescopes and habitats in space will be costly (though less so than any serious effort to send humans to Mars).  As a result, how much support NASA gets from the White House, Congress and the public — as well as the astronomy and astrophysics communities — will determine whether and when this kind of space architecture becomes a reality.

John Grunsfeld, who has walked the walk like nobody else, plans to be stepping up his own effort to explain how and why this is a vision worth embracing.

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