New Life for Gravitational Waves in Space?

Last year we brought the bad news that NASA had pulled back from the LISA project, an ambitious proposal to build a gravitational wave detector in space. The science reach of LISA would be amazing, teaching us a great deal about black holes, general relativity, and cosmology.

Fortunately, the European Space Agency did not give up on the idea, and has kept it in the queue of possibilities without actually saying they will do it. They began to design a somewhat down-scaled mission, now dubbed NGO for “New Gravitational wave Observatory.” (Hey, nobody said NASA had a monopoly on dopey acronyms.) NGO was put into the hopper along with two other proposals as part of a selection process to decide on the ESA’s next large-scale mission, dubbed L1 (“L” for “large”), as part of the Cosmic Vision program. It lost out to JUICE, a mission to Jupiter’s moons with admittedly a much cooler acronym as well as some very good science behind it.

But if there is an L1, that implies that someday there might be an L2, and NGO is still in the running to be Europe’s next big mission in astrophysics from space. Now comes an email passed around by the Topical Group on Gravitation of the American Physical Society, which seems to bring good news. To be honest, I’m not very good at decoding the bureaucratese in which the memo is written, but overall it seems optimistic, don’t you think? In particular, they are calling for scientists to join the GW-SAG (“Gravitational Wave Science Analysis Group”), with the admonition that the more people who are on the mailing list the more impressive the proposal seems to the higher-ups. (Only working scientists with an interest in gravitational waves should join, obviously.)

Here’s hoping that we build a gravitational-wave observatory in space in my lifetime.

Dear Colleagues,

After 15 months of fairly disappointing news, the dust finally settled and a clearer picture evolved. And I believe this picture is as encouraging as it can be these days.

Following the L1 selection in Europe, the European Space Agency immediately turned around and prepared for the next call for a large mission (L2). This call will be made as early as 2013 in the form of a Cornerstone call. A Cornerstone approach favors LISA. It deemphasizes the fact that LISA pathfinder will not have been launched by then; launch is still expected for 2014 and we expect results in 2015. The European Consortium is now preparing a proposal similar to the L1 proposal for this call. The schedule for implementation is also well aligned with even pessimistic future NASA budget assumptions and should allow to join the effort at least as a junior partner providing a robust overall level of funding. Now we need to show our world wide support for LISA!

At the Physics of the Cosmos Science Analysis Group (PHYSPag) meeting in DC (http://pcos.gsfc.nasa.gov/physpag/physpag-meeting-2012.php), we formed the Gravitational-wave Science Analysis Group (http://pcos.gsfc.nasa.gov/sags/gwsag.php) which will take over some of the responsibilities of the US-part of the former LISA International Science Team (LIST). However, in contrast to the LIST, the GW-SAG is completely open and I encourage everyone even remotely interested in the future of LISA to join the mailing list (http://pcos.gsfc.nasa.gov/sags/gwsag/gwsag-maillist.php). Numbers count; similar SAG’s in other areas exist within PHYSPag and the number of people signing up to the mailing lists are seen by the PCOS office as an indication of the interest and support within the scientific community. Signing up for the GW-SAG does not commit you to any work; the main role of the GW-SAG is to gather and distribute information within the community and between the community and the PCOS office. Most members of the GW-SAG will just receive occasional emails like this one, keeping them up to date on LISA. Others, who like to play a more active role, are encouraged to join the subgroups (Science, led by Neil Cornish; Technology, led by TBD; Advocacy, led by Scott Hughes) that we are in the process of setting up.

Go LISA and please join the mailing list!

Guido Mueller
GW-SAG, Chair

12 Comments

12 thoughts on “New Life for Gravitational Waves in Space?”

  1. Pingback: New Life for Gravitational Waves in Space? | Science Actuality

  2. How come the Europeans always waltz in where the Americans fear to tread? It happened with the LHC and now it’s happening with LIGO. Has American particle physics lost its edge for good?

  3. Charles, this is a bit different. The concepts you focused on in your article were geared toward a US-only GW mission. Those concepts have been analyzed, and the community is digesting the report. The punchline seems to be that a US-only mission is unlikely given budget realities and all that is on NASA’s plate at the moment. However, it may be possible to support a role within a Europe-led mission. The email Sean quotes here announces our plans to begin figuring out what role we might be able to play in such a framework.

    Sorbet, LIGO is a US project, and the ground-based GW community (which involves projects and collaborators in Europe, Japan, India, and Australia) has a *lot* of US involvement. LISA was developed quite a bit under NASA support (in partnership with the European Space Agency) for quite a while, but NASA is simply spread too thin to do everything that has been identified as important and interesting. We’re lucky that Europe hasn’t pulled back, and that there may be an opportunity to join their efforts.

  4. The Europeans are under quite a bit of budget pressure too, it seems to me. Unless they have the resources to bail out their weaker members and continue with more or less normal research activity levels?

  5. I recently had a chance to ask one of the leaders of the European side about the likelihood of Europe’s budgetary woes impacting their plans. He didn’t seem too concerned, which surprised me. I cannot claim to understand how the European agencies develop their funding plans, but the claim which this guy made to me is that their process is slower and steadier than the way we do things in the US. I hope this proves correct …

  6. I think it’s clear to all that the idea would never go away, even if all the politicians in the world were to blacklist it. And it’s pretty clear that it will eventually happen. Just don’t hold your breath.

    It will take on strong new life once gravitational waves are observed terrestrially, and even stronger once they are seen in the polarized CMB. But even then don’t hold your breath. But it will happen eventually. 2030 – 2035 might be a good estimate for launch and science.

  7. “It lost out to JUICE, a mission to Jupiter’s moons with admittedly a much cooler acronym as well as some very good science behind it.”

    You are being very diplomatic. A mission to the moons of Jupiter is garbage compared to something that might have given us detailed information on gravitational waves and their sources.

    But it will produce more pretty pictures (in false color).

  8. Jupiters icy moons are the #1 interesting unexplored places in the solar system. kilometer-deep water oceans covered by permanent ice for example.

    there is other interesting stuff out there than gravitaional waves and other interesting fields of science. besides, ground based gravitational wave detectors are easier that ground based planetary science.

    I think it makes much more sense to wait a bit until we know what kind of signal we can expect before embarking on a “large” mission. compare that to the planetology of Jupiters icy moons: we know exactly that there is interesting stuff going on, the field is well developed and it is about time to make a large scale effort to study them.

  9. “The Europeans are under quite a bit of budget pressure too, it seems to me. Unless they have the resources to bail out their weaker members and continue with more or less normal research activity levels?”

    “I recently had a chance to ask one of the leaders of the European side about the likelihood of Europe’s budgetary woes impacting their plans. He didn’t seem too concerned, which surprised me.”

    Phil Plait has pointed out on a few occasions how small even Nasa’s budget is compared to other costs. Remember, the US military spends a couple of million dollars—per minute. Even those European countries which spend more than 1% (which is a lot) of the GNP on pure science still spend little when compared to other costs. So, what should if matter if the other, bigger costs increase somewhat?

    Say you normally go out to eat once a week. Say your car dies and you unexpectedly have to buy a new one. This is a large, unplanned cost. Would you skip going out to eat that week, or indeed every week until the new car is paid off? Probably not. (If your new car is so expensive that you can’t afford to go out to eat once a week, you are doing something wrong.)

    ” I cannot claim to understand how the European agencies develop their funding plans, but the claim which this guy made to me is that their process is slower and steadier than the way we do things in the US. I hope this proves correct …”

    There is probably something to this. The advantage of several sovereign countries collaborating on a large project is that a country will usually make a commitment only if enough other countries do. As a result, contracts are drawn up which one can’t simply back out of, like the US Congress did with the SCS. This is at least part of the reason why CERN, ESO, ESA etc are actually quite good in terms of scientific output for a given amount of money. The bigger the science, the longer the timescale one has to plan on, much longer than a typical legislature period (i.e. time between elections).

  10. I spoke to someone who has some connection to the bidding process for L1. From my conversation I’ll bet that LISA is just a bit too risky at the momnet for ESA. Thats why they have LISA pathfinder and I doubt LISa will get selected at the next call until LISA pathfinder has flown and is proven. My money would be on the next gen X ray telescope unless LISA pathfinder is flown and shown to work. Hence I think an earlier date for selection for the next big ESa mission could be bad news for LISA or NGO or whatever it’ll be called.

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