Category Archives: rockets

Centauri Dreams: To Build the Ultimate Telescope

Paul Gilster posts:

In interstellar terms, a ‘fast’ mission is one that is measured in decades rather than millennia. Say for the sake of argument that we achieve this capability some time within the next 200 years. Can you imagine where we’ll be in terms of telescope technology by that time? It’s an intriguing question, because telescopes capable of not just imaging exoplanets but seeing them in great detail would allow us to choose our destinations wisely even while giving us voluminous data on the myriad worlds we choose not to visit. Will they also reduce our urge to make the trip?

Former NASA administrator Dan Goldin described the effects of a telescope something like this back in 1999 at a meeting of the American Astronomical Society. Although he didn’t have a specific telescope technology in mind, he was sure that by the mid-point of the 21st Century, we would be seeing exoplanets up close, an educational opportunity unlike any ever offered. Goldin’s classroom of this future era is one I’d like to visit, if his description is anywhere near the truth:

“When you look on the walls, you see a dozen maps detailing the features of Earth-like planets orbiting neighboring stars. Schoolchildren can study the geography, oceans, and continents of other planets and imagine their exotic environments, just as we studied the Earth and wondered about exotic sounding places like Banghok and Istanbul … or, in my case growing up in the Bronx, exotic far-away places like Brooklyn.”

Webster Cash, an astronomer whose Aragoscope concept recently won a Phase I award from the NASA Innovative Advanced Concepts program (see ‘Aragoscope’ Offers High Resolution Optics in Space), has also been deeply involved in starshades, in which a large occulter works with a telescope-bearing spacecraft tens of thousands of kilometers away. With the occulter blocking light from the parent star, direct imaging of exoplanets down to Earth size and below becomes possible, allowing us to make spectroscopic analyses of their atmospheres. Pool data from fifty such systems using interferometry and spectacular close-up images may one day be possible.

starshade

Image: The basic occulter concept, with telescope trailing the occulter and using it to separate planet light from the light of the parent star. Credit: Webster Cash.

Have a look at Cash’s New Worlds pages at the University of Colorado for more. And imagine what we might do with the ability to look at an exoplanet through a view as close as a hundred kilometers, studying its oceans and continents, its weather systems, the patterns of its vegetation and, who knows, its city lights. Our one limitation would be the orbital inclination of the planet, which would prevent us from mapping every area on the surface, but given the benefits, this seems like a small issue. We would have achieved what Dan Goldin described.

Seth Shostak, whose ideas we looked at yesterday in the context of SETI and political will, has also recently written on what large — maybe I should say ‘extreme’ — telescopes can do for us. In Forget Space Travel: Build This Telescope, which ran in the Huffington Post, Shostak talks about a telescope that could map exoplanets with the same kind of detail you get with Google Earth. To study planets within 100 light years, the instrument would require capabilities that outstrip those of Cash’s cluster of interferometrically communicating space telescopes:

At 100 light-years, something the size of a Honda Accord — which I propose as a standard imaging test object — subtends an angle of a half-trillionth of a second of arc. In case that number doesn’t speak to you, it’s roughly the apparent size of a cell nucleus on Pluto, as viewed from Earth.

You will not be stunned to hear that resolving something that minuscule requires a telescope with a honking size. At ordinary optical wavelengths, “honking” works out to a mirror 100 million miles across. You could nicely fit a reflector that large between the orbits of Mercury and Mars. Big, yes, but it would permit you to examine exoplanets in incredible detail.

Or, of course, you can do what Shostak is really getting at, which is to use interferometry to pool data from thousands of small mirrors in space spread out over 100 million miles, an array of the sort we are already building for radio observations and learning how to improve for optical and infrared work on Earth. Shostak discusses a system like this, which again is conceivable within the time-frame we are talking about for developing an actual interstellar probe, as a way to vanquish what he calls ‘the tyranny of distance.’ And, he adds, ‘You can forget deep space probes.’

I doubt we would do that, however, because we can hope that among the many worlds such a space-based array would reveal to us would be some that fire our imaginations and demand much closer study. The impulse to send robotic if not human crews will doubtless be fired by many of the exotic scenes we will observe. I wouldn’t consider this mammoth space array our only way of interacting with the galaxy, then, but an indispensable adjunct to our expansion into it.

Of course Shostak takes the long, sensor derived view of exploring the Universe, his life’s work is radio telescopes.

Gilster is correct that interferometry will be an adjunct to sending robotic probes to distant interstellar worlds, you can’t make money by just gawking at places.

Or can you? 

Original post.

Centauri Dreams: Creative Constraints and Starflight

I discovered Karl Schroeder’s work when I was researching brown dwarfs some years ago. Who knew that somebody was writing novels about civilizations around these dim objects? Permanence (Tor, 2003) was a real eye-opener, as were the deep-space cultures it described. Schroeder hooked me again with his latest book — he’s dealing with a preoccupation of mine, a human presence in the deep space regions between ourselves and the nearest stars, where resources are abundant and dark worlds move far from any sun. How to maintain such a society and allow it to grow into something like an empire? Karl explains the mechanism below. Science fiction fans, of which there are many on Centauri Dreams, will know Karl as the author of many other novels, including Ventus (2000), Lady of Mazes (2005) and Sun of Suns (2006).

by Karl Schroeder

karl.schroeder_2

My newest science fiction novel, Lockstep, has just finished its serialization in Analogmagazine, and Tor Books will have it on the bookshelves March 24. Reactions have been pretty favourable—except that I’ve managed to offend a small but vocal group of my readers. It seems that some people are outraged that I’ve written an SF story in which faster than light travel is impossible.

I did write Lockstep because I understood that it’s not actual starflight that interests most people—it’s the romance of a Star Trek or Star Wars-type interstellar civilization they want. Not the reality, but the fantasy. Even so, I misjudged the, well, the fervor with which some people cling to the belief that the lightspeed limit will just somehow, magically and handwavingly, get engineered around.

This is ironic, because the whole point of Lockstep was to find a way to have that Star Wars-like interstellar civilization in reality and not just fantasy. As an artist, I’m familiar with the power of creative constraint to generate ideas, and for Lockstep I put two constraints on myself: 1) No FTL or unknown science would be allowed in the novel. 2) The novel would contain a full-blown interstellar civilization exactly like those you find in books with FTL.

Creativity under constraint is the best kind of creativity; it’s the kind that really may take us to the stars someday. In this case, by placing such mutually contradictory — even impossible — restrictions on myself, I was forced into a solution that, in hindsight, is obvious. It is simply this: everyone I know of who has thought about interstellar civilization has thought that the big problem to be solved is the problem of speed. The issue, though (as opposed to the problem), is how to travel to an interstellar destination, spend some time there, and return to the same home you left. Near-c travel solves this problem for you, but not for those you left at home. FTL solves the problem for both you and home, but with the caveat that it’s impossible. (Okay, okay, for the outraged among you: as far as we know. To put it more exactly, we can’t prove that FTL is impossible any more than we can prove that Santa Claus doesn’t exist. I’ll concede that.)

 

Read the rest here…

Falcon Heavy or Space Launch System For Lunar Exploration ?

From America Space:

There have been occasional suggestions that NASA should scrap its Space Launch System (SLS) in favor of SpaceX’s Falcon Heavy for fulfilling its beyond low-Earth orbit needs [1]. The claim forwarded by some is that the as-yet-untested-and-unflown 53 mt low-Earth orbit (LEO) (200 km @ 28°) Falcon Heavy is now “cheaper” than the as-yet-untested-and-unflown SLS. Furthermore, canceling the SLS would supposedly save NASA $10 billion—money that could otherwise be used to fund such programs as the Commercial Crew integrated Capability (CCiCap), to conduct a flight test of Orion on a Falcon Heavy, and to focus on building a small-scale space station in the area near the Moon. One issue not addressed by proponents of canceling SLS is whether it is a good idea to couple a nation’s human exploration spaceflight capabilities to a private company. An issue which appears to be altogether ignored, is the Falcon Heavy’s small lunar payload capability and the impact this would have on an already complex and risky endeavor such as lunar exploration.

According to SpaceX, the Falcon 9 Heavy, also called the Falcon Heavy, will have a 53 mt (metric ton) payload capacity to LEO of 200 km with an inclination of 28° [2]. Such a LEO payload capability will be impressive, allowing SpaceX to launch nearly twice the payload of a Delta IV Heavy or an Atlas V, and to do so more cheaply than either. But when it comes to launching payload to a geostationary transfer orbit (GTO) or beyond, the Falcon 9 Heavy falls far short of either the Delta or Atlas launchers. With a GTO payload of barely over 12 mt, the Falcon 9 Heavy is at least 1 metric ton, or 1,000 kg, under what either the Delta IV Heavy or Atlas V can deliver to the same point in space.

The Falcon 9 Heavy is, much like United Launch Alliance's Delta IV Heavy, a triple-bodied version of the company's Falcon 9 launch vehicle. Photo Credit: SpaceX

The Falcon 9 Heavy is, much like United Launch Alliance’s Delta IV Heavy, a triple-bodied version of the company’s Falcon 9 launch vehicle. Photo Credit: SpaceX

The Falcon 9 Heavy’s GTO payload deficiency relative to the existing EELV launch vehicles has other down-stream effects as to its appropriateness for beyond-Earth orbit (BEO) crewed exploration. It is safe to assume that the Falcon Heavy’s low-lunar orbit (LLO) payload capacity will not top much above 10 mt [3]. How will the Falcon 9 Heavy’s meager LLO payload capacity enable a meaningful return to the Moon? And why even talk about the Falcon Heavy as a possible launcher of crewed lunar exploration when each of the Delta IV Heavy and Atlas V launchers can send over 1,000 kg more than the Falcon Heavy to the Moon? Moreover, while the Delta IV and Atlas V have extensive flight histories, the Falcon Heavy has no such experience.

Advocates of using the Falcon Heavy don’t just want to rewrite who takes us beyond-Earth orbit, but more fundamentally how such missions are built. Reliance upon the Falcon Heavy for launching a beyond-Earth exploration program means some hard choices as to mission architecture. Traditionally, crewed exploration beyond low-Earth orbit has focused on minimizing complexity, and therefore risk and cost, by using a heavy-lift rocket (HLV). The logic behind using an HLV for lunar exploration in the past was that fewer launches correlated to less risk. The Falcon Heavy’s 10 mt capability means that any lunar exploration program will have to be one of assembling pieces/parts in low-Earth orbit, where the Falcon Heavy’s (LEO) 53 mt payload capacity can really shine. Some have claimed that centering a beyond-Earth exploration program on the Falcon Heavy does not mean ending the Orion spacecraft program. They point this out because Orion is the only spacecraft designed from the ground up for beyond-Earth exploration. Certainly, a Falcon Heavy can place an Orion crewed and service module in low-Earth orbit. But several additional launches will be needed to send Orion and her crew to the Moon. A lunar crewed mission using the Falcon Heavy would mean assembling, at necessary LEO locations, a crewed vehicle, a lander, a trans-lunar injection stage, a stage to get the crewed spacecraft and lander into LLO, and possibly a separate stage to enable the crewed spacecraft to return to Earth [4].

While supporters of an all-commercial approach frequently tout the company's laudable accomplishments - they just as frequently ignore the limitations of both the Falcon Heavy launch vehicle as well as the Dragon spacecraft. Photo Credit: SpaceX

While supporters of an all-commercial approach frequently tout the company’s laudable accomplishments, they just as frequently ignore the limitations of both the Falcon Heavy launch vehicle and the Dragon spacecraft. Photo Credit: SpaceX

One problem with a non-HLV approach to lunar exploration is that if a replacement Falcon Heavy and payload are not handy, any launch failure could very well mean a scrubbed mission. So a non-HLV approach necessarily means an inventory of not just a spare Falcon Heavy, but of duplicate spaceflight hardware—or designing hardware and refueling stations such that a delay of weeks or months would have only a marginal impact on the mission. Solving all of these unknown-unknowns (or unk-unks in engineering speak) associated with multiple launches, assembling a mission in LEO, in-space refueling at an orbiting location, among others flowing from a non-HLV approach to beyond-Earth exploration, could see the cost advantage of using the relatively unproven Falcon Heavy largely, if not completely, evaporate.

A beyond-Earth exploration program using the Falcon Heavy in an HLV architecture has its own downsides and associated costs. In order to enable the Falcon 9 Heavy to be a capable beyond low-Earth orbit launcher, funds will certainly be needed to create a new cryogenic second-stage. This will be needed because, in its current configuration, a Falcon 9 Heavy could not even launch one 11.6 mt Unity node module, much less a 20 mt Bigelow BA 330 Nautilus module. Even with a brand new second-stage, reliance upon the Falcon 9 Heavy to build, visit, and maintain a lunar orbiting outpost will dictate doing so in very small chunks; the number of launches will then begin to add-up, as will the complexity, risk, and cost. A Falcon Heavy cannot place an Orion spacecraft even in high-Earth, much less lunar, orbit. So reliance upon the Falcon 9 Heavy for beyond low-Earth missions in an HLV-based lunar mission architecture would only set NASA up to cancel Orion and go with Dragon for our nation’s crewed space exploration needs.

As it currently stands, neither NASA's Space Launch System nor SpaceX's Falcon Heavy have a proven track record. However, it would take multiple launches to accomplish what SLS could in a single flight. Image Credit: NASA

While it may be true that the Dragon spacecraft has a heatshield capable of allowing the spacecraft safe reentry into the Earth’s atmosphere, little else of Dragon is crew, much less lunar mission, capable. SpaceX’s Dragon is currently a participant in NASA’s commercial crew and cargo programs. One goal of NASA’s commercial crew program is to enable spacecraft built and operated by commercial space companies to get crews to and from the International Space Station by late 2017. But the requirements for a crewed spacecraft tailored for low-Earth orbit are different than those for beyond-Earth orbit. For one, a LEO capable spacecraft need only be capable of hours of operation, where a lunar spacecraft needs a capability of days. This means that the use of the Falcon Heavy as a means to returning humans to the Moon very likely means funding further enhancements, and verifying those enhancements to the Dragon spacecraft. As with over 90 percent of the funding for Falcon 9 and Dragon, this additional financial burden would fall upon NASA’s, and therefore the U.S. taxpayer’s, shoulders. Even with an enhanced Falcon Heavy launcher and Dragon spacecraft, more than one Falcon Heavy launch would still be needed to support a crewed lunar landing mission. Several Falcon Heavy launches would be needed to build a lunar orbiting outpost.

NASA's SLS has the full support, to include funding, of Congress, as such, efforts to cancel the system in lieu of one that favors the company that SpaceX supporters approve of - is not likely to occur. Image Credit: NASA

NASA’s SLS has the full support, to include funding, of Congress. As such, efforts to cancel the system in lieu of one that favors the company that SpaceX supporters approve of is not likely to occur. Image Credit: NASA

Or NASA could send a crewed lunar mission or build a lunar outpost with far fewer SLS launches. That’s because the very first iteration of the SLS, the Block I, will carry twice the payload of a Falcon Heavy to the Moon. The SLS Block II will have a lunar payload capacity nearly 3–4 times that of the Falcon Heavy, depending upon what engines are selected for the SLS’s advanced booster.

Beyond the SLS’s substantial payload advantage for lunar missions, the question of cost remains. Are 3 or 4 Falcon Heavy launches really cheaper than just one SLS Block II launch? That is a hard question to answer given that both launchers are still effectively “paper” rockets. In factoring launch costs, there is the cost of the launch vehicle, the launch pad, launch support, and post-launch management, just to name a few.

The bigger problem for those wishing to end the Space Launch System program is that it is currently ahead of schedule. According to John Elbon, Boeing VP & General Manager, Space Exploration, “We’re on budget, ahead of schedule. There’s incredible progress going on with that rocket” [5]. Canceling a rocket that is ahead of schedule would be difficult at best. Given that Congress has, over three votes, not only supported SLS but increased its funding over amounts sought by the Obama Administration, the odds of opponents getting SLS canceled are slim-to-none.

Space Launch System opponents suggest that the SLS program should cancel until a mission requiring such a rocket is identified. John Shannon, also with Boeing, recently stated, “This ‘SLS doesn’t have a mission’ is a smokescreen that’s been put out there by people who would like to see that [program’s] budget go to their own pet projects. SLS is every mission beyond low Earth orbit. The fact that NASA has not picked one single mission is kind of irrelevant” [6]. It bears mentioning that a good part of the reason there is no meaningful mission for the Orion-SLS is because the Obama Administration has not agreed with Congress that, as Congress noted in its 2010 NASA Authorization Act, cislunar space is the next step in our efforts beyond Earth and that the SLS is an integral part of that step.

Moreover, both short- and long-term missions for SLS have emerged in recent months. Within the 2014 FY Budget Proposal Request, NASA was directed to retrieve an asteroid, place it in lunar orbit, and then send astronauts to study it. The vehicle of choice is SLS. During a recent interview, NASA Deputy Associate Administrator for Exploration Systems in the Human Exploration and Operations Mission Directorate Dan Dumbacher stated on AmericaSpace that the long-term mission for SLS was to send astronauts to Mars.

Mr. Jillhouse sings the acolades of the Space Launch System as others sing them about SpaceX’s Falcon9 rockets. What he fails to mention is the SLS’s massive program slippages and muti-billion dollar cost overruns, versus commercial’s million dollar overruns and schedule slippages. It’s not even in the same ballgame, let alone ballpark.

Also the point should be that NASA should’ve bid the SLS job out in order to save the taxpayers money, but the function of SLS isn’t primarily for beyond Earth orbit exploration.

It’s to provide jobs in states that have NASA centers. And that’s why these projects are perpetually underfunded, just enough money is sent in order to keep people employed as long as the politicians can make it possible.

Maybe in the end the SLS will get finished and work as advertised. If I live long enough.

Falcon Heavy: Uncertain Case For Lunar Exploration

Orbital Sciences Launches It’s Antares Rocket

From spaceref.biz:

Orbital Sciences Corporation Sunday launched its Antares rocket at 05:00 p.m. EDT from the new Mid-Atlantic Regional Spaceport Pad-0A at the agency’s Wallops Flight Facility in Virginia.

The test flight was the first launch from the pad at Wallops and was the first flight of Antares, which delivered the equivalent mass of a spacecraft, a so-called mass simulated payload, into Earth’s orbit.

“Today’s successful test marks another significant milestone in NASA’s plan to rely on American companies to launch supplies and astronauts to the International Space Station, bringing this important work back to the United States where it belongs,” said NASA Administrator Charles Bolden. “Congratulations to Orbital Sciences and the NASA team that worked alongside them for the picture-perfect launch of the Antares rocket. In addition to providing further evidence that our strategic space exploration plan is moving forward, this test also inaugurates America’s newest spaceport capable of launching to the space station, opening up additional opportunities for commercial and government users.

“President Obama has presented a budget for next year that ensures the United States will remain the world leader in space exploration, and a critical part of this budget is the funding needed to advance NASA’s commercial space initiative. In order to stop outsourcing American space launches, we need to have the President’s budget enacted. It’s a budget that’s good for our economy, good for the U.S. Space program — and good for American taxpayers.”

The test of the Antares launch system began with the rocket’s rollout and placement on the launch pad April 6, and culminated with the separation of the mass simulator payload from the rocket.

The completed flight paves the way for a demonstration mission by Orbital to resupply the space station later this year. Antares will launch experiments and supplies to the orbiting laboratory carried aboard the company’s new Cygnus cargo spacecraft through NASA’s Commercial Resupply Services (CRS) contract.

“Today’s successful test flight of Orbital Sciences’ Antares rocket from the spaceport at Wallops Island, Virginia, demonstrates an additional private space-launch capability for the United States and lays the groundwork for the first Antares cargo mission to the International Space Station later this year,” said John Holdren, director of the Office of Science and Technology Policy. “The growing potential of America’s commercial space industry and NASA’s use of public-private partnerships are central to President Obama’s strategy to ensure U.S. leadership in space exploration while pushing the bounds of scientific discovery and innovation in the 21st century. With NASA focusing on the challenging and exciting task of sending humans deeper into space than ever before, private companies will be crucial in taking the baton for American cargo and crew launches into low-Earth orbit.

“I congratulate Orbital Sciences and the NASA teams at Wallops, and look forward to more groundbreaking missions in the months and years ahead.”

Orbital is building and testing its Antares rocket and Cygnus spacecraft under NASA’s Commercial Orbital Transportation Services (COTS) program. After successful completion of a COTS demonstration mission to the station, Orbital will begin conducting eight planned cargo resupply flights to the orbiting laboratory through NASA’s $1.9 billion CRS contract with the company.

NASA initiatives, such as COTS, are helping to develop a robust U.S. commercial space transportation industry with the goal of achieving safe, reliable and cost-effective transportation to and from the International Space Station and low-Earth orbit. NASA’s Commercial Crew Program also is working with commercial space partners to develop capabilities to launch U.S. astronauts from American soil in the next few years.

http://www.youtube.com/watch?feature=player_embedded&v=V3L7crGudVU

Although Orbital had to reschedule three times, they got their test launch off.

Let’s hope they solved their fairing separation issues before the main Cygnus missions start.

Orbital Sciences Test Launches Antares Rocket

Did Voyager 1 Leave The Solar System?

From nytimes.com:

For about three hours on Wednesday, Voyager 1 had left the solar system — before a rewritten news release headline pulled it back in. Voyager 1, one of two spacecraft NASA launched in 1977 on a grand tour of the outer planets, is now nearly 11.5 billion miles from the Sun, speeding away at 38,000 miles per hour. In a paper accepted by the journal Geophysical Review Letters, William R. Webber of New Mexico State University and Frank B. McDonald of the University of Maryland reported that on Aug. 25 last year, the spacecraft observed a sudden change in the mix of cosmic rays hitting it.

Cosmic rays are high-speed charged particles, mostly protons. Voyager 1’s instruments recorded nearly a doubling of cosmic rays from outside the solar system, while the intensity of cosmic rays that had been trapped in the outer solar system dropped by 90 percent.

The American Geophysical Union, publisher of the journal, sent out the news Wednesday morning: “Voyager 1 has left the solar system.” NASA officials, surprised, countered with a contrary statement from Edward C. Stone, the Voyager project scientist. “It is the consensus of the Voyager science team that Voyager 1 has not yet left the solar system or reached interstellar space,” Dr. Stone said. He said that the critical indicator would be a change in the direction of the magnetic field, not cosmic rays, for marking the outermost boundary of the solar system. In their paper, Dr. Webber and Dr. McDonald (who died only six days after Voyager observed the shift in cosmic rays) did not claim that Voyager 1 was in interstellar space, but had entered a part of the solar system they called the “heliocliff.” The geophysical union then sent out another e-mail with the same article but a milder headline: “Voyager 1 has entered a new region of space.”

Eventually Voyager 1 will leave the Solar System and there will be no dispute about it.

In the meantime, mainstream science will learn and post about the outer edges of the Solar System as Voyager 1 creeps along at .00002 lightspeed ( 37,500 mph ) .

Of course there are those in mainstream media and science who believe that mankind will never leave the Solar System because they proclaim that spacecraft will never be built that go faster than that.

Already the Pluto probe New Horizon traveling at 54,500 mph is breaking Voyager’s speed record and will probably leave the Solar System before Voyager does!

I’m certain in 100 years star probes will be launched toward Alpha Centauri and Tau Ceti that reach appreciable percentages of lightspeed bypassing all of our old interplanetary probes and perhaps in several centuries, mankind’s interstellar colonies will be picking up these old probes to study them, like old time capsules!

Where’s Voyager 1? That Depends.

Hat tip to the Daily Grail.

Of NERVA and the Solar System

From Centauri Dreams:

Tim Folger and Les Johnson (NASA MSFC) stood last summer in front of a nuclear rocket at Marshall Space Flight Center in Huntsville, Alabama. Johnson’s work in advanced propulsion concepts is well known to Centauri Dreams readers, but what he was talking to Folger about in an article for National Geographic was an older technology. NERVA, once conceived as part of the propulsion package that would send astronauts to Mars, had in its day the mantle of the next logical step beyond chemical propulsion. A snip from the story:

nerva

Johnson looks wistfully at the 40,000-pound engine in front of us… “If we’re going to send people to Mars, this should be considered again,” Johnson says. “You would only need half the propellant of a conventional rocket.” NASA is now designing a conventional rocket to replace the Saturn V, which was retired in 1973, not long after the last manned moon landing. It hasn’t decided where the new rocket will go. The NERVA project ended in 1973 too, without a flight test. Since then, during the space shuttle era, humans haven’t ventured more than 400 miles from Earth.

I’m looking forward to getting back to Huntsville and seeing Les, as well as a number of other friends in the interstellar community, at the 2nd Tennessee Valley Interstellar Workshop, coming up this February, where it may be that NERVA will have a place in the discussion of how we go about building a system-spanning civilization. You’ll want to give Folger’s article a look for comments not only from Les but Freeman Dyson and Andreas Tziolas (from the Icarus team), as well as Elon Musk, the 100 Year Starship’s Mae Jemison, and NASA’s Mason Peck.

Image: NERVA nuclear rocket being tested. (Smithsonian Institution Photo No. 75-13750).

In fact, there are a number of issues presented here that I’ll want to get back to later, but I can’t cover the rest of the story today. I’m all but out the door for a brief but intense period of Tau Zero work that will leave me no time to keep up regular posts here or even to moderate comments. More about this later, and more about Folger’s essay as well, and please bear with me through the temporary slowdown. Things should get back to normal by mid-day Thursday.

Speaking of NERVA, though, I’ll leave you with an interesting petition Gregory Benford alerted me to with regard to the development of nuclear thermal rockets, one that calls for an effort to:

Harness the full intellectual and industrial strength of our universities, national laboratories and private enterprise to rapidly develop and deploy a nuclear thermal rocket (NTR) adaptable to both manned and un-manned space missions. A NTR (which would only operate in outer space) will jump-start our manned space exploration program by reducing inner solar system flight times from months to weeks. This is not new technology; NTRs were tested in the 1960s (President Kennedy was a guest at one test). The physics and engineering are sound. In addition to inspiring young Americans to careers in science, technology, engineering and mathematics, a working NTR will herald a speedy and economical expansion of the human presence in the cosmos.

Going significantly beyond the Moon demands advances in propulsion of the kind that nuclear thermal rockets can deliver. Getting NERVA concepts out of mothballs and updating them with modern materials are necessary steps as we push out into the Solar System.

 

Going to Mars does require a serious upgrade to nuclear rocket technology, but somehow I don’t think the taxpaying public will go for funding research by the government, especially in this era of deficits and flat budgets.

This kind of research will probably be taken up by the private sector, perhaps with some seed money from the government, but only if there’s an economic need to exploit the resources of the Solar System, including planetary bodies like Mars.

It would be nice for such research like NERVA could be funded for the future of Mankind, but unfortunately that’s not how the world is set up now.

One can only hope.

The Nuclear Rocket Option

 

 

 

 

 

Future Interstellar Voyages

From Centauri Dreams:

Stretch out your time horizons and interstellar travel gets a bit easier. If 4.3 light years seems too immense a distance to reach Alpha Centauri, we can wait about 28,000 years, when the distance between us will have closed to 3.2 light years. As it turns out, Alpha Centauri is moving in a galactic orbit far different from the Sun’s. As we weave through the Milky Way in coming millennia, we’re in the midst of a close pass from a stellar system that will never be this close again. A few million years ago Alpha Centauri would not have been visible to the naked eye.

The great galactic pinball machine is in constant motion. Epsilon Indi, a slightly orange star about an eighth as luminous as the Sun and orbited by a pair of brown dwarfs, is currently 11.8 light years out, but it’s moving 90 kilometers per second relative to the Sun. In about 17,000 years, it will close to 10.6 light years before beginning to recede. Project Ozma target Tau Ceti, now 11.9 light years from our system, has a highly eccentric galactic orbit that, on its current inbound leg, will take it to within the same 10.6 light years if we can wait the necessary 43,000 years.

And here’s an interesting one I almost forgot to list, though its close pass may be the most intriguing of all. Gliese 710 is currently 64 light years away in the constellation Serpens. We have to wait a bit on this one, but the orange star, now at magnitude 9.7, will in 1.4 million years move within 50,000 AU of the Sun. That puts it close enough that it should interact with the Oort Cloud, perhaps perturbing comets there or sending comets from its own cometary cloud into our system. In any case, what a close-in target for future interstellar explorers!

I’m pulling all this from Erik Anderson’s new book Vistas of Many Worlds, whose subtitle — ‘A Journey Through Space and Time’ — is a bit deceptive, for the book actually contains four journeys. The first takes us on a tour of ten stars within 20 light years of the Sun, with full-page artwork on every other page and finder charts that diagram the stars in each illustration. The second tour moves through time and traces the stars of an evolving Earth through text and images. Itinerary three is a montage of scenes from known exoplanets, while the fourth tour takes us through a sequence of young Earth-like worlds as they develop.

Anderson’s text is absorbing — he’s a good writer with a knack for hitting the right note — but the artwork steals the show on many of these pages, for he’s been meticulous at recreating the sky as it would appear from other star systems. It becomes easy to track the Sun against the background of alien constellations. Thus a spectacular view of the pulsar planet PSR B1257+12 C shows our Sun lost among the brighter stars Canopus and Spica, with Rigel and Betelgeuse also prominent. The gorgeous sky above an icy ocean on a planet circling Delta Pavonis shows the Sun between Alpha Centauri and Eta Cassiopeiae. Stellar motion over time and the perspectives thus created from worlds much like our own are a major theme of this book.

From Epsilon Eridani, as seen in the image below, the Sun is a bright orb seen through the protoplanetary disk at about the 4 o’clock position below the bright central star.

Image: The nearby orange dwarf star Epsilon Eridani reveals its circumstellar debris disks in this close-up perspective. Epsilon Eridani is only several hundred million years old and perhaps resembles the state of our own solar system during its early, formative years. Credit: Erik Anderson.

Vistas of Many Worlds assumes a basic background in astronomical concepts, but I think even younger readers will be caught up in the wonder of imagined scenes around planets we’re now discovering, which is why I’m buying a copy for my star-crazed grandson for Christmas. He’ll enjoy the movement through time as well as space. In one memorable scene, Anderson depicts a flock of ancient birds flying through a mountain pass 4.8 million years ago. At that time, the star Theta Columbae, today 720 light years away, was just seven light years out, outshining Venus and dominating the sunset skies of Anderson’s imagined landscape.

And what mysteries does the future hold? The end of the interglacial period is depicted in a scene Anderson sets 50,000 years from now, showing a futuristic observation station on the west coast of an ice-choked Canada. The frigid landscape and starfield above set the author speculating on how our descendants will see their options:

Will the inhabitants of a re-glaciating Earth seek refuge elsewhere? Alpha Centauri, our nearest celestial neighbor, has in all this time migrated out of the southern skies to the celestial equator, where it can be sighted from locations throughout the entire globe. It seems to beckon humanity to the stars.

And there, tagged by the star-finder chart and brightly shining on the facing image, is the Alpha Centauri system, now moving inexorably farther from our Sun but still a major marker in the night sky. Planet hunter Greg Laughlin has often commented on how satisfying it is that we have this intriguing stellar duo with accompanying red dwarf so relatively near to us as we begin the great exoplanet detection effort. We’re beginning to answer the question of planets around Alpha Centauri, though much work lies ahead. Perhaps some of that work will be accomplished by scientists who, in their younger years, were energized by the text and images of books like this one.

What I find facinating is a comment by a reader ( kzb ) of this post concerning the Fermi Paradox:

One frequently-seen explanation of the Fermi paradox is that interstellar travel is just too difficult: the distances are so great that no intelligent species has ever cracked the problem.

This article highlights an argument against this outlook.  One scale-length towards the galactic centre, and the space density of stellar systems is 2.7 times what it is around here.  Two scale lengths in and the density is 7.4 times greater.  The scale-length of our galaxy is around only 2.1-3kpc according to recent literature.

Intelligent species that evolve in the inner galactic disk will not have the same problem that we have.  Over galactic timescales, encounters between stellar systems within 1 light-year will not be uncommon.

I think you can see what I am saying, and I think this is one aspect of the FP discussion that is poorly represented currently.

And Erik Anderson’s response:

@ kzb: I give an overview of the Fermi Paradox on page 110 and I didn’t miss your point.  It was definitely articulated by Edward Teller, whom I explicitly quote: “…as far as our Galaxy is concerned, we are living somewhere in the sticks, far removed from the metropolitan area of the Galactic center.”

Of course this precludes the explanations that there is no such thing as speedy interstellar travel ( be they anti-matter or warp drives ) and UFOs are really just mass hallucinations.

However Anderson’s book is novel in its’ treatment of interstellar exploration over vast timescales and that closer to the Galactic Center, possible advanced civilizations could have stellar cultures due to faster stellar movements and much shorter distances between stars. And I find that novel in an Olaf Stapledon kind of way!

That and the fact as we are discovering using the Kepler and HARP interstellar telescopes multiple star systems that have their own solar systems and many of them could have intelligent life lends credence to Mr. Anderson’s themes.

So I might treat myself to an early Christmas present by purchasing Anderson’s book!

Images of Exoplanetary Journeys

Elon Musk Interview

From Wired Science:

When a man tells you about the time he planned to put a vegetable garden on Mars, you worry about his mental state. But if that same man has since launched multiple rockets that are actually capable of reaching Mars—sending them into orbit, Bond-style, from a tiny island in the Pacific—you need to find another diagnosis. That’s the thing about extreme entrepreneurialism: There’s a fine line between madness and genius, and you need a little bit of both to really change the world.
——–
All entrepreneurs have an aptitude for risk, but more important than that is their capacity for self-delusion. Indeed, psychological investigations have found that entrepreneurs aren’t more risk-tolerant than non-entrepreneurs. They just have an extraordinary ability to believe in their own visions, so much so that they think what they’re embarking on isn’t really that risky. They’re wrong, of course, but without the ability to be so wrong—to willfully ignore all those naysayers and all that evidence to the contrary—no one would possess the necessary audacity to start something radically new.

I have never met an entrepreneur who fits this model more than Elon Musk. All of the entrepreneurs I admire most—Musk, Jeff Bezos, Reed Hastings, Jack Dorsey, Sergey Brin and Larry Page, Bill Gates, Steve Jobs, and a few others—have sought not just to build great companies but to take on problems that really matter. Yet even in this class of universe-denters, Musk stands out. After cofounding a series of Internet companies, including PayPal, the South African transplant could simply have retired to enjoy his riches. Instead he decided to disrupt the most difficult-to-master industries in the world. At 41 he is reinventing the car with Tesla, which is building all-electric vehicles in a Detroit-scale factory. (Wired profiled this venture in issue 18.10.) He is transforming energy with SolarCity, a startup that leases solar-power systems to homeowners.

And he is leading the private space race with SpaceX, which is poised to replace the space shuttle and usher us into an interplanetary age. Since Musk founded the company in 2002, it has developed a series of next-generation rockets that can deliver payloads to space for a fraction of the price of legacy rockets. In 2010 SpaceX became the first private company to launch a spacecraft into orbit and bring it back; in 2012 it sent a craft to berth successfully with the International Space Station.

It’s no wonder the character of Tony Stark in Iron Man, played by Robert Downey Jr., was modeled on Musk: This is superhero-grade stuff. I sat down with him at Tesla’s Fremont, California, factory to discuss how cheaper and (eventually) reusable rockets might someday put humans on Mars.

Chris Anderson: You’re not a rocket scientist by training. You’re not a space engineer.

Elon Musk: That’s true. My background educationally is physics and economics, and I grew up in sort of an engineering environment—my father is an electromechanical engineer. And so there were lots of engineery things around me. When I asked for an explanation, I got the true explanation of how things work. I also did things like make model rockets, and in South Africa there were no premade rockets: I had to go to the chemist and get the ingredients for rocket fuel, mix it, put it in a pipe.

Anderson: But then you became an Internet entrepreneur.

Musk: I never had a job where I made anything physical. I cofounded two Internet software companies, Zip2 and PayPal. So it took me a few years to kind of learn rocket science, if you will.

Anderson: How were you drawn to space as your next venture?

Musk: In 2002, once it became clear that PayPal was going to get sold, I was having a conversation with a friend of mine, the entrepreneur Adeo Ressi, who was actually my college housemate. I’d been staying at his home for the weekend, and we were coming back on a rainy day, stuck in traffic on the Long Island Expressway. He was asking me what I would do after PayPal. And I said, well, I’d always been really interested in space, but I didn’t think there was anything I could do as an individual. But, I went on, it seemed clear that we would send people to Mars. Suddenly I began to wonder why it hadn’t happened already. Later I went to the NASA website so I could see the schedule of when we’re supposed to go. [Laughs.]

Anderson: And of course there was nothing.

Musk: At first I thought, jeez, maybe I’m just looking in the wrong place! Why was there no plan, no schedule? There was nothing. It seemed crazy.

Anderson: NASA doesn’t have the budget for that anymore.

Musk: Since 1989, when a study estimated that a manned mission would cost $500 billion, the subject has been toxic. Politicians didn’t want a high-priced federal program like that to be used as a political weapon against them.

Anderson: Their opponents would call it a boondoggle.

Musk: But the United States is a nation of explorers. America is the spirit of human exploration distilled.

Anderson: We all leaped into the unknown to get here.

Star Man

To put Elon Musk’s astronomical goals in perspective, here’s a look at some of his stellar achievements so far.—Victoria Tang

1983

At the age of 12, designs a videogame called Blast Star and sells it to a computer magazine for $500.

1995

After spending two days in a graduate physics program at Stanford, drops out to start Zip2, an online publishing platform for the media industry.

1999

Sells Zip2 to Compaq for $307 million.

2000

Forms PayPal by merging his new online-payments startup, X.com, with Max Levchin and Peter Thiel’s Confinity.

2001

Establishes the Musk Foundation to provide grants for renewable energy, space, and medical research as well as science and engineering education.

2002

PayPal goes public; its stock rises more than 54 percent on the first day of trading. Eight months later, eBay acquires PayPal for $1.5 billion. Musk founds SpaceX.

2004

Invests in Tesla Motors, a company that manufactures high-performance electric cars.

2006

Helps create SolarCity, which provides solar-power systems to some 33,000 buildings. Will serve as the company chair.

2008

NASA selects the SpaceX Falcon 9 launch vehicle and the reusable Dragon spacecraft to deliver cargo to the International Space Station after the space shuttles retire.

2010

Makes a cameo appearance in Iron Man 2. Director Jon Favreau cites Musk as an inspiration for Tony Stark.

2012

SpaceX’s Dragon becomes the first commercial spacecraft to berth with the ISS

———

Few people change the course of human history and less realize that witnessing that change is important. Mainstream science is slow to change and it takes a hard-headed individual to fight against it.

Musk is such an individual and it will be interesting to see him outsmart ignorant public and political forces to achieve his stated goal of making mankind a multi-planetary species.

It will be fun to watch!

Elon Musk’s Mission to Mars

Hat tip to Nasa Watch.

Artificial Life-Form Inventer Venter To Build Martian DNA Teleporter

From Technology Review:

Two high-profile entrepreneurs say they want to put a DNA sequencing machine on the surface of Mars in a bid to prove the existence of extraterrestrial life.

In what could become a race for the first extraterrestrial genome, researcher J. Craig Venter said Tuesday that his Maryland academic institute and his company, Synthetic Genomics, would develop a machine capable of sequencing and beaming back DNA data from the planet.

Separately, Jonathan Rothberg, founder of Ion Torrent, a DNA sequencing company, is collaborating on an effort to equip his company’s “Personal Genome Machine” for a similar task.

“We want to make sure an Ion Torrent goes to Mars,” Rothberg told Technology Review.

Although neither team yet has a berth on Mars rocket, their plans reflect the belief that the simplest way to prove there is life on Mars is to send a DNA sequencing machine.

“There will be DNA life forms there,” Venter predicted Tuesday in New York, where he was speaking at the Wired Health Conference.

Venter said researchers working with him have already begun tests at a Mars-like site in the Mojave Desert. Their goal, he said, is to demonstrate a machine capable of autonomously isolating microbes from soil, sequencing their DNA, and then transmitting the information to a remote computer, as would be required on an unmanned Mars mission. (Hear his comments in this video, starting at 00:11:01.) Heather Kowalski, a spokeswoman for Venter, confirmed the existence of the project but said the prototype system was “not yet 100 percent robotic.”

Meanwhile, Rothberg’s Personal Genome Machine is being adapted for Martian conditions as part of a NASA-funded project at Harvard and MIT called SET-G, or “the search for extraterrestrial genomes.”

Christopher Carr, an MIT research scientist involved in the effort, says his lab is working to shrink Ion Torrent’s machine from 30 kilograms down to just three kilograms so that it can fit on a NASA rover. Other tests, already conducted, have determined how well the device can withstand the heavy radiation it would encounter on the way to Mars.

NASA, whose Curiosity rover landed on Mars in August, won’t send another rover mission to the planet before at least 2018 (see “The Mars Rover Curiosity Marks a Technological Triumph“), and there’s no guarantee a DNA sequencing device would go aboard. “The hard thing about getting to Mars is hitting the NASA specifications,” says George Church, a Harvard University researcher and a senior member of the SET-G team. “[Venter] isn’t ahead of anyone else.”

Venter has a great idea here, but it reminds me of a certain movie in which sequencing alien DNA wasn’t such a great plan.

Species !

Genome Hunters Go After Martian DNA

Interview: Lee Billings

From blogs.plos.org:

Like many geeks of the post-Sputnik generation, I grew up hoping that space travel would be common by the time I reached middle age. Weaned on a youthful diet of speculative fiction by the likes of Ray Bradbury and Arthur Clarke, raised on Star Trek and The Outer Limits, and thrilled by real-life hero Neil Armstrong’s “one small step” onto the gravelly surface of the Moon when I was in elementary school, it never occurred to me that humankind’s manifest destiny in the stars would be undone by changing political winds, disasters like the Challenger explosion, and a mountain of debt to pay for misguided military adventures like the War in Iraq.

It’s true that, in some ways, we’re living in a new golden age for space nerds. Bard Canning’s gorgeously enhanced footage of Curiosity’s descent to Mars — made instantly available by the global network we built instead of a Hilton on the Moon — certainly beats  grainy snippets beamed down from Tranquility Base. A newly discovered exoplanet that “may be capable of supporting life” seems tomake headlines every few months. Cassini’s ravishing closeups of Saturnregularly put the fever dreams of ILM’s animators to shame. But wasn’t I supposed to be “strolling on the deck of a starship” by now, as Paul Kantner’s acid-fueled hippie space epic Blows Against the Empire promised me when it was nominated for a Hugo award in 1971?

The problem, it turns out, isn’t just a loss of political will to finance manned space flight. Rocket science turns out to be rocket science — not easy, and constrained by some very real limitations dictated by material science, the physics of acceleration, and the unwieldy economics of interstellar propulsion. Until a real-life Zefram Cochrane comes along to invent a practical warp drive, I may not be sightseeing on any Class M planets anytime soon.

One of the best briefings on the state of the art of interstellar exploration is Lee Billings’ essay “Incredible Journey,” recently reprinted in a wonderful new anthology called The Best Science Writing Online 2012, edited by Scientific American’s Bora Zivkovic and Jennifer Ouellette. I’m very honored to have a piece in the anthology myself: my NeuroTribes interview with John Elder Robison, author of the bestselling memoir of growing up with autism, Look Me in The Eye, and other books. When SciAm’s editors suggested that each author in the book interview one of the other authors, I jumped at the chance to interview Billings about his gracefully written and informative article about the practical challenges of space flight. Billings is a freelance journalist who has written forNatureNew ScientistPopular Mechanics, and Seed. He lives outside New York City with his wife, Melissa.

[...]

Steve Silberman: Before we even get into the meat of your piece, I want to mention how impressed I was by the power and lyricism of your writing. Phrases like “the cosmos suddenly becomes less lonely” and “the easiest way the Daedalus volunteers found to fuel their starship was, in effect, the industrialization of the outer solar system” make vast and highly abstract concepts immediately comprehensible and visceral to lay readers. What made you want to become a science writer, and who are your role models for writing, in any genre?

Lee Billings: My attraction to science preceded my attraction to the act of writing, perhaps because, like every child, I was intensely curious about the world around me. Science, more so than any other source of knowledge I could find, seemed to change the world into something at once eminently understandable and endlessly mysterious.

I became interested in science writing, science journalism, at approximately the same time I realized I would make a poor scientist. I was midway through my college prerequisites, thinking I was on a path to a career in neuroscience. I’d been having a lot of trouble with the more quantitative courses — calculus, organic chemistry, and so on. Many of my friends would ace their assignments and tests after sleeping through lectures and rarely cracking a book. I would study hard, only to receive poor grades. Meanwhile I was breezing through courses in English, literature, history, and art. After a particularly fervent all-night cram-session for a final exam that I still almost flunked, I decided if I wasn’t destined to excel within science itself, perhaps I could instead try to make my mark by helping communicate the world-changing discoveries scientists were making. So I switched my academic emphasis from neuroscience to journalism, and became something of a camp follower, scavenging and trailing behind the gifted few at the front lines of research. I’ve never looked back, and have no regrets. The job never gets old: Rather than being at best a mediocre, hyper-specialized bench worker, being a science writer lets me parachute in to varied fields on a whim, and invariably the brilliant individuals I find upon landing are welcoming and happy to talk to me.

As for influences… I still have a long way to go, but if my writing ever comes to possess a fraction of Carl Sagan’s charisma and elegance, John McPhee’s structure and eye for detail, Richard Preston’s depth of focus and cinematic flair, Stanislaw Lem’s imagination and analytic insight, or Ray Bradbury’s lyrical beauty, I will be a happy man.

Ray Bradbury's "The Martian Chronicles"

Ray Bradbury’s “The Martian Chronicles”

Silberman: Several times a year now, we hear about the discovery of a new exoplanet in the “Goldilocks zone” that could “potentially support life.” For example, soon after he helped discover Gliese 581g, astronomer Steven Vogt sparked a storm of media hype by claiming that “the chances for life on this planet are 100 percent.” Even setting aside the fact that the excitement of discovering a planet in the habitable zone understandably seems to have gone to Vogt’s head at that press conference, why are such calculations of the probability of life harder to perform accurately than they seem?

Billings: The question of habitability is a second-order consideration when it comes to Gliese 581g, and that fact in itself reveals where so much of this uncertainty comes from. As of right now, the most interesting thing about the “discovery” of Gliese 581g is that not everyone is convinced the planet actually exists. That’s basically because this particular detection is very much indirect — the planet’s existence is being inferred from periodic meter-per-second shifts in the position of its host star. The period of that shift corresponds to the planet’s orbit as it whips from one side of the star to the other; the meter-per-second magnitude of the shift places a lower limit on the planet’s mass, but can’t pin down the mass exactly. So that’s all this detection gives you — an orbit and a minimum mass. That’s not a lot to go on in determining what a planet’s environment might actually be like, is it?

Now, get up and walk around the room. You’re moving at about a meter per second. Imagine discerning that same rate of change in the motion of a million-kilometer-wide ball of plasma, a star many light-years away. Keep in mind this star’s surface is always moving, in pounding waves and swirling eddies, in rising and falling convection cells, in vast plasmatic prominences arcing above the surface, often at many kilometers per second. At any particular moment, all that stellar noise can swamp the faint planetary signal. Only by building up hundreds or thousands of careful measurements over time can you get that crucial periodicity that tells you what you’re seeing might be a planet. So the measurement is quite statistical in nature, and its interpretation can change based on the statistical assumptions being used. This is further complicated by the fact that planets are rarely singletons, so that any given stellar motion may be the product of many planets rather than one, requiring careful long-term study to tease apart each world’s contribution to the bulk signal. It’s also complicated by the instability of astronomical instruments, which must be kept carefully, constantly calibrated and stabilized lest they introduce spurious noise into the measurements. In the case of Gliese 581g, not everyone agrees on the putative planetary signal actually being caused by a planet, or even being real at all — the signal doesn’t seem to manifest equally in the handful of instruments purportedly capable of detecting it.

So it’s very difficult to just detect these things, and actually determining whether they are much like Earth is a task orders of magnitude more difficult still. Notice how I’m being anthropocentric here: “much like Earth.” Astrobiology has been derisively called a science without a subject. But, of course, it does have at least one subject: our own living planet and its containing solar system. We are forced to start from what we know, planting our feet in the familiar before we push out into the alien. That’s why we, as a species, are looking for other Earth-like planets — they probably offer us the best hope of recognizing anything we might consider alive. It’s not the strongest position to be in, but it’s the best we’ve got. Calculating the probability of life on an utterly alien world outside the solar system for which we know only the most basic information — its mass, its orbit, maybe its radius — is at this stage a very crude guess. The fact is, we still don’t know that much about how abiogenesis occurred on Earth, how life emerged from inanimate matter. There are very good physical, chemical, thermodynamic reasons to believe that life arose here because our planet was warm, wet, and rocky, but we really don’t yet know all the cogent occurrences that added up to build the Earth’s earliest organisms, let alone our modern living world. A warm, wet, rocky planet may be a necessary but not a sufficient condition for life as we know it to form and flourish.

Lee Billings with planet hunter Geoff Marcy

Lee Billings with planet hunter Geoff Marcy

This is really a chicken-and-egg problem: To know the limits of life in planetary systems, we need to find life beyond the Earth. To find life beyond Earth, it would be very helpful to know the limits of life in planetary systems. Several independent groups are trying to circumvent this problem by studying abiogenesis in the lab — trying to in effect create life, alien or otherwise, in a test tube. If they manage to replicate Earth life, the achievement could constrain just how life emerged on our own planet. If they somehow manage to make some single-celled organism that doesn’t use DNA, or that relies on silicon instead of carbon to build its body, or that prefers to swim in liquid ethane rather than liquid water, that gives us a hint that “Earth-style” biologies may only be one branch in a much larger and more diverse cosmic Tree of Life.

Silberman: Going deeper than the notion of the cosmos feeling “less lonely” – as well as the fact that we all grew up watching Star Trek and Star Wars and thinking that aliens are frickin’ cool (as long as they’re not the mama alien fromAlien) — why do you think people are so motivated to daydream about extraterrestrial life? What need in us do those dreams fulfill?

Billings: I don’t really think most people are necessarily motivated to daydream about just any sort of extraterrestrial life. It will probably take more than a microbe or a clam to excite most of our imaginations, even if that microbe happens to be on Venus or that clam happens to be on Mars.

I do think humans are motivated to daydream about extraterrestrial intelligence, and, to put a finer point on it, extraterrestrial “people.” They are motivated to dream about beings very much like them, things tantalizingly exotic but not so alien as to be totally incomprehensible and discomforting. Maybe those imagined beings have more appendages or sense organs, different body plans and surface coverings, but they typically possess qualities we recognize within ourselves: They are sentient, they have language, they use tools, they are curious explorers, they are biological, they are mortal — just like humans. Perhaps that’s a collective failure of imagination, because it’s certainly not very easy to envision intelligent aliens that are entirely divergent from our own anthropocentric preconceptions. Or perhaps it’s more diagnostic of the human need for context, affirmation, and familiarity. Why are people fascinated by their distorted reflections in funhouse mirrors? Maybe it’s because when they recognize their warped image, at a subconscious level that recognition reinforces their actual true appearance and identity.

More broadly, speculating about extraterrestrial intelligence is an extension of three timeless existential questions: What are we, where do we come from, and where are we going? The late physicist Philip Morrison considered SETI, the search for extraterrestrial intelligence, to be the “archaeology of the future,” because any galactic civilizations we could presently detect from our tiny planet would almost certainly be well more advanced than our own. It’s unlikely that we would ever receive a radio message from an alien civilization in the equivalent of our past Stone Age, and it’s unlikely Earth would ever be visited by a crewed starship that powered its voyage using engines fueled by coal or gasoline. Optimists consider this, and say that making contact with a superior alien civilization could augur a bright future for humanity, as it would suggest there are in fact solutions to be found for all the current seemingly intractable problems that threaten to destroy or diminish our species. It’s my opinion that most people think about aliens as a way of pondering our own spectrum of possible futures.

I’m inclined to believe some of the things Billings has to say in that it’s doubtful we’ll build anything like a starship in the near future and folks ( taxpayers ) just won’t fund those kinds of projects. Entrepreneurs such as Elon Musk, James Cameron and Peter Diamandis could in the future fund projects such as starprobes and starships – only if they prove profitable.

IMO it looks like stronger telescopes both on Earth and in space will be the only human built machines exploring the closer solar systems for any signs of life and extant civilizations because they can be economically constructed – and if they found anything interesting, the items are still a safe distance away.

Five Billion Years of Solitude: Lee Billings on the Science of Reaching the Stars

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