A Further Note on SETI’s Charismatic Megafauna
Space-Based Assets for Technosignature Searches
In my Centauri Dreams post SETI’s Charismatic Megafauna (which was a revised and expanded version of Parasitic SETI and Parasitic Space Science) I wrote the following:
“It seems pretty weak to me to argue that SETI is intrinsically about ground-based observations, as SETI observations from space-based telescopes would be a great boost for the discipline, if only these resources were made available to SETI research.”
Unbeknownst to me when I wrote this, in December 2018 Lee Billings had an article on the Scientific American website, Finding Alien Life May Require Giant Telescopes Built in Orbit: Scientific American reports on new efforts from NASA and other federal agencies seeking to service and assemble large structures — such as life-finding telescopes — in space.
In this article Billings cites the NASA in-Space Assembled Telescope (iSAT) Study, which has been convened to answer the question: “When is it advantageous to assemble space telescopes in space rather than to build them on the Earth and deploy them autonomously from individual launch vehicles?”
Building in-space assembled telescopes purposefully for the detection of biosignatures obvious suggests the parallel question of when it is advantageous to assemble telescopes in space to search for technosignatures rather than to build them on Earth and deploy them autonomously from individual launch vehicles. The obvious answer to this is that it is advantageous to do so when you want to build an instrument that is too large to fit inside a rocket fairing, and this is equally true whether we are talking about instruments to search for biosignatures, for technosignatures, or for anything else.
Like most NASA documents, the iSAT Study is presented in the most conservative and circumspect terms imaginable:
“Envisioning the need for future large segmented telescopes to one day exceed the fairing size of existing or even planned launch vehicles, NASA will need to begin considering the in-space assembly (iSA) of these future assets. In addition, robotically assembling space telescopes in space rather than deploying them from single launch vehicles offers the possibility, in some circumstances, of reduced cost and risk for even smaller telescopes. This possibility, however, has not been proven.”
Given the fact that, the bigger the instrument, the greater the sensitivity, we would obviously like to build enormous telescopes in Earth orbit (or elsewhere in the solar system) — e.g., the James Webb Space Telescope will be stationed at a Lagrange point — so while NASA is talking about reduced cost and reduced risk, which are understandable considerations, what is not being said here is that in-space assembled telescopes could eventually be very large and very sensitive scientific instruments. And when you build a very large and very sensitive scientific instrument off Earth’s surface, this is something that you would want to maintain and improve.
Space-based scientific instruments could be built out as the ISS has been built out over time (and could still be further expanded with additional inflatable modules). I have several times called attention to the paper, “An infinitely expandable space radiotelescope,” which suggests the construction of an expandable radiotelescope built in space. The modular design of the instrument would allow it to be expanded indefinitely. This upgradable instrument could be made more sensitive as modules are added over time, and wouldn’t have to be as radically rebuilt as is the case, for example, with the LHC, which has to close down for years each time its systems are upgraded.
Eventually — assuming the continued development of our civilization (i.e., assuming that a failure condition is not met) — this is something that will be done. However, something like this is best done when we have space-based infrastructure so that there are astronauts and vehicles and repair facilities in space that would allow either for a continuing human presence on a large scientific installation in space, or a regularly visiting crew to maintain or expand the installation. Thus one of the benefits of the O’Neill paradigm (space-based infrastructure) over the Zubrin paradigm (direct to destination) is that the O’Neill paradigm for space settlement provides for the space-based infrastructure that would allow for the maintenance of space-based scientific instruments (cf. my post The Return of the Space Settlement Vision on the contrast between these two visions of space settlement).
Since large, expandable space-based scientific instruments will be an integral component in the obvious future of space-based infrastructure, why is this being put forward now in such tentative terms? Because now it is getting real. Money may be at stake. There is a real chance of iSAT being incorporated into the upcoming Decadal Survey, which will have an enormous impact on what gets funded and what does not get funded between 2020 and 2030.
The iSAT study — which will mostly be conducted in invitation-only meetings — is part of the maneuvering prior to the next Decadal Survey. Everyone has a project that they would like to see included, and every space scientist has a space science mission that they would like to see included in the Decadal Survey. As I noted in an article that I cited in my Centauri Dreams post about Jason Wright assembling a group to write papers in support of SETI as an integral part of astrobiology — It’s time to start taking the search for E.T. seriously, astronomers say: Some scientists are pushing for NASA to make looking for alien technology an official goal, by Lisa Grossman — this is also about trying to get included in the Decadal Survey.
Scientists need to learn how to work together and be partners rather than rivals in funding their research and missions. The present instance ought to make that clear: iSAT, biosignature, and technosignature methods and initiatives could all be working together to propose the kind of large, visionary effort implied in the above-linked article by Lee Billings, in which Ken Sembach of the Space Telescope Science Institute is quoted as saying:
“I talk all the time to younger researchers, Congress and the public, and they all ask, ‘Why aren’t we thinking bigger?’ People want to support ambitious things.”
A space-based scientific instrument designed to be maintained and expanded over time, and which could be repaired and serviced for decades to come, could be an ambitious project that would garner attention and support and would be an asset to the entire scientific community.
All the sciences can benefit from more data on the universe. Astronomy, astrophysics, physics, cosmology, SETI, and astrobiology could all work together in designing a space-based platform for mutual research. Parasitic, piggyback, or opportunistic research programs should become the norm in science, with meetings between representatives of the special sciences to converge upon common data sets that could benefit all the sciences. And I believe that if many special sciences spoke with one voice in support of a major project, that project would have a good chance of getting the political support necessary for funding. This would be preferable to maneuvering to see who can get included in the Decadal Survey, and whose project ends up in the circular file.