Here's Your Chance to Help LISA Happen!

A depiction of a LISA satellite with its lasers.

I've written about LISA several times on this blog and most of those times the news hasn't been good.  Today I have a bit of encouraging news and a way for you to help!

For readers who've recently found Living LIGO, LISA is a space-based gravitational wave detector that will be sensitive to lower frequency gravitational waves than any Earth-based counterpart ever will be.  Gathering gravitational-wave information from low frequencies will help complete the picture that gravitational-wave astronomy can paint; Earth-based detectors are really only sensitive to the "death throes" of violent astrophysical interactions while LISA will be sensitive to these same sources in their youth.  This youth stage is so long that the predominant noise source for LISA is continually measuring the gravitational waves from these young sources coming from all over the sky at the same time.  This is called the "confusion limit" and it is like trying to listen to a conversation on the other side of the room at a busy party.  This can be overcome, but what a wonderful problem to have! The noise you measure is really just measuring so many gravitational waves at the same time that they mix together!

You can follow the unfolding of the LISA drama through these Living LIGO posts:

• News on LISA  [25 May 2012]
• More on LISA/NGO  [3 May 2012]
• The Likely End to a Space-Based GW Detector  [19 April 2012]  (The title turned out to be over dramatic - I'm glad!)

In the "News on LISA" (25 May 2012) post, the statement from the eLISA Consortium was that they were going to push for the next launch opportunity.  The European Space Agency has initiated the process to choose candidate missions for the next launch.  The eLISA mission team is looking for your support! 


HOW YOU CAN HELP...

Please go to the eLISA - Make History page and sign your name as a supporter.  Anyone from around the would can lend their support.  If you are a scientist, you can also opt to have your name and institution listed in the eLISA white paper.  (You can see the ESA's call for white papers here.)

If you support gravitational-wave science at any level, please consider putting your name on the list!  Let's show the world that there is true support for this science!

HURRY!  There are only 2 days (or less) to add your name to the list of supporters! 
eLISA - Make History

NEW LISA YOUTUBE CHANNEL

The LISA Mission has also created their own YouTube channel and is starting to post some truly exceptional animated educational videos.  Right now, two are available:

Gravity Ink. - Einstein's Gravity (Episode 1)

Gravity Ink. - The Future of Astronomy (Episode 2)

Consider subscribing to their YouTube channel to keep up on new installments (I will most likely feature them here too!). 

Q: What's the Difference Between a "Gravitational Wave" and a "Gravity Wave"?

The things that LIGO looks for are called gravitational waves (which are discussed in depth here on my blog and on the LIGO website).  That can be a mouthful, especially when having a conversation about them.  People, including us professionals, realize this and often take the shortcut of calling them "gravity waves".  It sounds so similar that this must mean the same thing, right?  Well, no!


GRAVITY WAVES ARE NOT GRAVITATIONAL WAVES

The proper technical use of gravity wave refers to waves on the interface of two fluids, which can be liquid and/or gas.  Where this boundary is disturbed, gravity will pull it down and buoyancy will push it up.  This combination of opposite push and pull creates a wave that moves out over the surface.  You can make your own interface of two fluids by filling a glass with some water and oil:

A glass containing oil and water.  Oil settles at the top because it is less dense (more buoyant).  [Source: Wikipedia]

Water and oil will separate if left alone.  This separation creates a boundary between the oil and water with the oil on top since it is less dense.  Now imagine gently tapping on the side of the glass.  The vibration from your tap will transfer into the separated oil and water which will produce a gravity wave on their boundary.  If you actually do this carefully enough, you can produce a gravity wave ONLY on the oil/water boundary and not on the surface of the oil (though a surface wave on the oil is technically a gravity wave too since that is a liquid/gas fluid boundary).

While the oil and water example technically illustrates a gravity wave, the term is usually applied to gravity waves that occur in nature.  Examples include:

• The waves on water caused by wind from large ocean waves to ripples in a puddle; these are examples of gravity waves on an gas/liquid boundary.  
• Waves of different density waters under the oceans' surface (like warm/cool water, or fresh/salt water); these are examples of a liquid/liquid boundary.
• The rippling of clouds, like in the movie below; this is an example of a gravity wave on a gas/gas boundary.

CAN A GRAVITATIONAL WAVE DETECTOR DETECT GRAVITY WAVES TOO?

We've now established that a gravity wave is very different from the gravitational waves that LIGO is looking for.  But can LIGO detect them anyway?  Indirectly, yes!  Almost three-quarters of the Earth is covered by oceans.  These oceans are roiling with gravity waves both within the water and on top of it.  When these waves encounter solid earth, much of the wave is reflected but some of the energy is absorbed.  This absorbed energy can then create surface waves on the remaining part of the Earth's surface that is solid.  These ground vibrations are called microseism.

Since LIGO lives on the Earth's surface (many people think that LIGO is underground but it really is built above ground), these vibrations shake the detector and contribute to the measured detector noise.  So much so that, compared to the gravitational waves we seek, we don't expect to be able to detect low frequency (less than about 10 Hz or so) gravitational waves.  And it doesn't matter that both LIGO detectors are near shores since the microseism shakes the entire Earth - we could have built LIGO in the middle of Nebraska and the microseism would still negatively affect us. 

In order to detect low frequency gravitational waves, we need to get away from the microseism.  The proposed gravitational wave detector that can do this is the space-based eLISA satellites.  (I've also discussed eLISA and associated drama on this blog previously.)  eLISA would be exclusively sensitive to low frequency gravitational wave and would compliment LIGO well: there are many young systems producing low frequency gravitational waves all the time while there are few producing the high frequency death throes that LIGO can detect.  Together, LIGO and eLISA will provide a more complete gravitational-wave picture of the life cycle of some of the most energetic, violent objects in the Universe.


CONCLUSION

"Gravitational waves" and "gravity waves" are very different entities.  However, you may hear us refer to a gravitational wave as a "gravity wave".  This is a personal pet peeve of mine (can't you tell?).  While I work hard to use the term "gravitational wave" correctly, I am often hesitant to say anything to colleagues I hear using "gravity wave" instead.  Watch the NSF documentary Einstein's Messengers (also on the "Viewing Fun" page on this blog) and you will see some highly respected LIGO scientists refer to "gravity waves"; it makes me cringe a little every time but I'm not one to gainsay my betters.  Now that you've read this, you'll know what we really mean ;)


Read more:

• Another explanation of the difference between gravitational waves and gravity waves (this is correct but a little outdated on its discussion of gravitational waves)

News on LISA and Some Personal Stuff

LISA NEWS...

The LISA Symposium was in Paris this week and the result of this meeting was a strengthening of the efforts to put a gravitational-wave detector into space and the formation of the eLISA Consortium.  Below is a statement issued by the Consortium:

Getting ready for next time:

European gravitational wave community strengthens its space collaboration

During the 9th international LISA Symposium, held May 21 – 25 in Paris, the international LISA* community analyzed the new situation after ESA´s decision to choose JUICE for Europe´s next large space science mission. As the eLISA** mission, despite not being selected, was reported to have been unanimously ranked first by ESA´s scientific review committee in terms of scientific interest, strategic value for science and strategic value for the projects in Europe, the community is in good spirits: this is the first time that any space agency committee has ranked a gravitational wave observatory as its highest scientific priority. In order to prepare a strongest possible bid for the next launch opportunity the community has decided to continue its collaboration as the self-funded and independent eLISA consortium.

Besides preparing for the next competition the consortium will strongly support ESA's LISA Pathfinder mission, whose launch in 2014 will finally open the door to approval of a full gravitational wave mission. LPF will demonstrate key gravity-measuring technologies in space for the first time, preparing the way not only for gravitational wave detectors but also for next-generation Earth and planetary gravimetry.

The eLISA consortium consists of a management board, a steering committee, and working groups in science, technology and data analysis. It represents the European states involved in eLISA, i.e. Denmark, France, Germany, Italy, Netherlands, Spain, Switzerland, and UK. The consortium is led by Prof. Dr. Karsten Danzmann, who chaired the former LISA International Science Team and is a director at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI) and a professor at the Leibniz Universität in Hannover, Germany.

“Our goal is to keep this highly motivated and effective scientific community together. It has attracted many young and excellent researchers. The knowledge and innovative potential of our community is documented in more than 2000 published scientific papers - we want to keep it working on a strong science, technology and data analysis programme”, says Karsten Danzmann, describing the role of the eLISA consortium.

Colleagues from the US, China and possibly other interested countries will be invited to participate. At the LISA Symposium, US participants presented results on a comparative study of low-cost LISA variants and expressed interest in contributing to an ESA-led mission. And for the first time, a large Chinese delegation participated in the LISA Symposium and announced their scientific interest in a close collaboration on a gravitational wave mission. The Chinese Academy of Sciences and the Chinese Space Agency are developing their own plans for a gravitational wave detector in space.  

LISA*: Laser Interferometer Space Antenna

eLISA**: evolved Laser Interferometer Space Antenna, also known as NGO (New Gravitational-Wave Observatory)

PERSONAL STUFF...

It's been a long while since I posted on here about myself.  One of the reasons I started this blog was that I wanted to humanize scientists and the work they do; you wouldn't believe how often visitors tell me that I'm not what they expected from a scientist (they mean that as a compliment) or that I was more normal than they expected.  I pulled back on writing much about myself simply because I wasn't nearly as interesting as I first thought.  I can be summed up pretty well by: loves vampires, has migraines, and is sometimes insecure about her professional worth.  (This post is even being published a day late because a migraine.)


But there has been some excitement in my life.  Over the last two weeks I have been catching up on all of my routine doctors appointments I have been putting off due to my work schedule and my husband's (and we share a car since we work at the same place).  He was out of town for nearly 2 weeks so I had the car to myself!  I've seen by dermatologist (I am very fair skinned and I get checked out for skin cancer), my gynecologist, my dentist, my cardiologist, and my urologist.  The good news is that everything is going well even though I was up to 6 months behind on being seen.  The bad news is that I've let my depression get the better of me these past few months and I didn't realize what a bad place I was in until I had time to myself.

I've been wondering whether or not to talk about this on my blog since I have had some outright ignorant reactions when I mention that I have depression.  But, May is Mental Health Month and I would like to talk a little about dealing with depression and anxiety and why you should seek treatment if you suffer from this as well.

I was an anxious little kid who was sad a lot.  As I grew up and started to have more adult problems, these tendencies became more pronounced.  It took a traumatic event for a doctor to recommend treatment for depression.  This treatment took some time to work, but when it did I realized that I had basically lived my whole life depressed to some extent and simply thought that was what normal was.  I don't need constant treatment for it, but if I'm not careful depression can sneak up on me so slowly that I don't notice it happening until it becomes horrible.  That is what happened for me recently and even then it took a doctor to bring the point up (I guess I'm not as good at covering it up as I thought I was).  I'm being treated again and things are starting to look brighter.  At least I don't feel alone and isolated even when I am surrounded by friends and colleagues.

My point is, if you think you are depressed or feel anxious for extended periods of time, talk to a doctor, medical or psychological.  I've been told to just "get over it" or called weak because I have sought treatment for my depression.  Well, will power can only help you look like nothing is wrong but you will still be depressed.  And I have discovered that most of the people who call me weak have similar problems of their own that they won't seek help for.  Truly, treating my depression is the best thing that I have ever done and I am not sure if I would be where I am today if I had not.

More on LISA/NGO and What Would You Ask a Scientist?

LISA/NGO Update

On May 2^nd, the ESA officially decided to accept their Science Programme Committee's recommendation to choose the JUICE (JUpiter ICy moons Explorer) mission for the 2020ish launch opportunity.  While this is unexpected, it is still a disappointment.  A thoughtful article on possible factors contributing to why LISA/NGO was passed over can be found here.

While this is disappointing, all isn't lost.  The scuttlebutt is that LISA may have a good shot at being the next mission chosen when the next mission selection takes place in 2015. (I know...  That's still a long while off.)  The science case for LISA/NGO has always been strong and by then the results of the LISA Pathfinder mission will be in (it appears that it will fly in 2014, not in June like I cited from the NASA website on my last LISA post).  Assuming success, many of the technical concerns should be resolved.

As LISA/NGO detects lower frequency gravitational waves than LIGO ever can (since seismic vibrations create too much noise for LIGO to be sensitive there), it is a beautifully complimentary observatory.  Who wouldn't love a detector where your main noise source is detecting too many gravitational waves at the same time (which is exactly the case for LISA/NGO)?

I'm looking forward to it!

What Would You Ask A Scientist (or Engineer, etc.)?

One of the reasons that I started this blog is that I wanted to show people that scientists are real people.  I've been told too many times to count that I look too young, normal, etc. to be a "real" scientist.  I know that they are trying to compliment me, but the subtext of this is that they thought I wouldn't be human like them.  So, since not all of you can come to visit me, I figured I would share some of my experience and life with you.

Well, it turns out that I am not as interesting as I thought I was (actually, I never thought that - I like vampire books, I have migraines, and I love my job at LIGO - that is me in a nutshell).  But the LIGO Scientific Collaboration is made up of over 800 scientists from across the country and around the world and I am guessing that you may like to find out more about them.

Here is what I am thinking...  I have a few basic questions I would like anyone profiled here to answer:

• What is it that you do for a living?
• What motivated you to choose this career?
• What kind of education do you have/need to do your work?
• Where are you from?
• Please tell us something unique about yourself.

I also have a list of questions that I would like the person being profiled to pick and choose from (not all are appropriate for everyone or would produce interesting answers).  Of these, I would love to know that you think is most interesting.  This may help guide the person being profiled in choosing what they wish to answer (or I can ask that your favorites be answered).

So, what would you like to ask someone who works on LIGO?  I have a survey you can click below and there is also a link just below the blog banner called "Survey" where you can respond.  Please note that the last option is where you can put your pressing question that isn't already listed.  Also, feel free to let me know if there is anyone in particular from LIGO that you would like me to profile!  Hope to hear from you!!!

The Likely End to a Space-Based GW Detector

LISA...

(The video below is large [~44 MB] and dated, but gives good background on the motivation and specifics of a space-based gravitational-wave detector:)

About this time last year, I wrote a blog post about the NASA withdrawal from being a full partner in the LISA (Laser Interferometer Space Antenna) with the ESA (European Space Agency).  At that time, it meant that US scientists would still be able to receive funding to develop research programs and contribute to the LISA effort but the ESA would be responsible for the bulk of the work.  This withdrawal by NASA was caused by the poor state of the agency's funding and the cost of the James Webb Space Telescope.  For all of us in doing research in gravitational waves, it was a horrible setback; LISA was once a flagship mission of NASA's Physics of the Cosmos program and the best hope we had of detecting low frequency gravitational waves (< 10 Hz). 

This then led the ESA to redevelop their plans for a new version of LISA (that is referred to as eLISA but is officially known as NGO [New Gravitational-wave Observatory]) in order to lower the cost of the mission by at least 20% and preserve as much of the science as possible.  This new design was published in their "Yellow Book" at the beginning of the year which included, among other things, only 2 arms in a triangular formation (previously there were 3 arms and each corner pair of arms could function as an independent detector), reduced distance between satellites (1 million kilometers instead of 5 million), and a new orbit which is similar to the LISA orbit (in orbit around the Sun about 20^o behind Earth in its orbit) but will allow the detector to drift away into the solar system over time.  Below is a short movie illustrating a few orbits - the "drift away" is not noticeable:

The newly designed eLISA/NGO received the highest science ratings of the projects up for funding at the ESA.  However, the ESA Science Programme Committee has concerns about the technological readiness of eLISA/NGO to fly in the 2020 time frame and has passed it over to recommend the JUICE (JUpiter ICy moons Explorer).  This is likely the last nail in the coffin for a space-based gravitational-wave detector in the foreseeable future.  (Note:  NGO can be considered for future launch opportunities but that is way down the road.)  There is a slight chance that the recommendation could be rejected in favor of gravitational waves when the 19 member states of the ESA make the final decision on May 2.  However, I heard the news of this recommendation from a friend who specializes in LISA science and he didn't seem hopeful for the 11th hour pardon.

I wonder what will happen to the LISA Symposium that is supposed to take place in Paris at the end of May...  Or for that matter, the LISA Pathfinder mission (which will demonstrate the basic abilities that LISA would have needed to have) which is scheduled to launch on June 30.

UPDATE:  I've heard from a LISA colleague that LISA Pathfinder is still a go!  Thanks!

***

On a more uplifting front, I had the wonderful opportunity to speak at Ole Miss (this link will take you to their gravity research group - they do great work!) about the importance of outreach, useful skills for it, and different ways to do outreach (and this blog was featured!).  That night, I also got to demonstrate my points by giving one of their monthly public science cafes.  This experience gave me the chance to really consider what it is that I have been doing professionally for the last 5 years...  What have I learned?  What mistakes did I make?  What surprised me?  What ideas can I pass along on how to do outreach to those who are expected to do it but aren't afforded the extra time like I am?  I'm thinking about posting a summary of my thoughts and speaking points in next week's post (unless something else newsworthy happens in the mean time)!

March LIGO-Virgo Meeting in Boston

So, I am at the LIGO-Virgo Meeting in Boston right now.  As you may (or may not) know, our two collaborations are very close knit.  We schedule our upgrades to be around the same time, we always share our data, and we collaborate on our science to get the most from our work.  Being a part of a big international collaboration is exciting and gives you a new perspective on international politics - in science they exist, but are much easier to deal with since we are all working for the same goal.

Here is the gorgeous view from my hotel window:

Personal Complexes:

Another thing about being one of over 800 scientists and engineers working on a project is that you can feel small.  I've written before about the Impostor Syndrome - when people who are fully qualified and competent feel inadequate.  Sometimes, these meetings bring those feelings back to me.  Every time someone comes to me and asks me what I do, I feel like my worth is being weighed.  But it absolutely isn't!  After all, I do the same thing to new colleagues that I meet and I am only interested in learning more about them and maybe working with them in the future.

I was starting to feel inferior while I was traveling here...  I was sitting at my gate during a layover and a colleague I consider a friend was sitting in his seat diligently working on his computer.  What was I doing?  Reading a vampire book.  The self-loathing voice in my head immediately chimed in with, "See, there is someone who is deserves the esteem of the collaboration.  He works hard and makes the most of his time.  What are you doing?  Reading a book about things that don't even exist!"  As I was resigning myself to mediocrity, he put his computer aside and started talking with me.  During our short conversation, he paid me the most unexpected complement.  I'm not going to repeat it here, but I was speechless and ecstatic at the same time and tried not to tear up.  I smiled and thanked him because his words forced me to think well of myself (not that I told him that).  If he is reading this, you know who you are and what you said even though you don't know how much it mattered to me - THANK YOU!

I've been trying to work more on these issues but I don't ever expect to completely get over feeling inferior to my peers.  Not that I really want to - I've met many scientists who thought they were a divine gift to science and I can't stand them (even if they are right)!

The Science:

The final data analysis from our last data run is finishing up and we've been talking about these results and preparing for the demands the MUCH more sensitive Advanced LIGO and Advanced Virgo detectors will place on our analysis infrastructure.  This has been a time of reorganization.  I gave a short talk about the functionality of the gravitational wave simulation software (called GravEn) I wrote while I was a graduate student.  This has been the standard software we've used to measure the sensitivity of of our burst data analysis methods.  We are also taking time to consider if there is a better way of doing it.  So far, it seems like GravEn is still the bee's knees and that makes me very happy!  (The science summary of the last burst data analysis paper is here.  The plots that show the sensitivity of our methods to different kinds of signals [the second and the third] were made using the simulations I produced.)

There have also been talks on the status of LIGO, Virgo, GEO, the Japanese KAGRA detector, and the status of what used to be the LISA space-based detector (this was a partnership between the ESA and NASA until budget issues forced NASA to cancel being a full partner).  There is progress being made on all of these fronts - even LISA (which is now led by the ESA and known as NGO for the New Gravitational-wave Observatory).  Every where you walk around the conference hotel, you see small groups working together on a project and a few very tall people in red uniforms (the Wisconsin Badgers are staying in our hotel for their NCAA Sweet 16 game tonight against Syracuse).

What Would YOU Like to Ask a LIGO Scientist/Engineer?

As part of a talk on the collaboration's outreach activities, this blog was featured!  (Those who don't know my science work will often still know me as the "Living LIGO Lady".)  It was also announced that I would like to feature interviews of gravitational wave people (scientists, engineers, etc.) on this blog.  When I originally started writing this, I wanted to make science human and accessible.  I feel like I am running out of human things about me to talk about (I'm not all that interesting).  But there are so many others with different backgrounds and stories that I would like to share with you.  I already have a list of questions I am thinking about asking (not all of them will be mandatory, of course) but I want to invite you to tell me what questions you would like to as a LIGO person?  Tweet them to me @livingligo or leave a comment here (below).  You can also email me at amber@livingligo.org.  I'm thinking of using my husband, a mechanical engineer for LIGO, as a Guinea pig (he can't cook and likes to eat, so I think I can convince him :P ).

Until next week!

More on LISA & Giving Public Tours with My Hubby

Since I've last posted, I've gotten to work with my husband (Derek) on two public tours of LIGO.  That's something that doesn't usually happen since he doesn't work with visitors on a regular basis.

1:  The first tour was on the 9th to the local chapter of the AIAA (to which my husband is a life member) based out of Stennis Space Center in MS.  I took the engineers and their families around the site and answered their science questions while Derek discussed his work at LIGO and his dissertation work (helicopters).

2:  The second tour was the monthly Science Saturday open house this past weekend.  The theme this month was "Rockets" in honor of the 50th anniversary of humans in space and the last shuttle launch later this year.  Since Derek is an aerospace engineer, he was recruited as our local "rocket scientist" to interact with the visitors.  I helped find some interesting footage of rockets for him to discuss during a short presentation which he presented wonderfully (yes, I am a proud wife).  As usual, I took visitors on tours of the site, but you are probably getting tired of listening to me go on about that :).  Below is a super-slow motion video of the Saturn V rocket for Apollo 11.  It was filmed at 500 frames/second over a little more than 30 seconds.  This video is over 8 minutes with commentary on what is going on.  It's awesome (and even better in full screen)!

If you want to see it in real time, it's here (with corny music):

In my last post, I discussed LISA, what it is and how NASA had recently withdrawn its partnership with the ESA (European Space Agency) in this project.  Below is the official statement from the Albert Einstein Institute on the ESA's response.  The original document can be read here, but since it is a PDF, I copied the text below for your easy reading:

NASA withdraws from partnership with Europe. ESA Science team begins to rethink LISA design.

It was just in February this year that ESA kicked off the process of picking the next major mission in its Cosmic Vision program, with presentations at a meeting of Europe's astronomers and planetary scientists in Paris. Among the favorites was the first gravitational wave observatory in space, called LISA, which had already been given a high scientific priority in the USA by NASA's 2007 Beyond Einstein review and by American astronomers' 2010 Decadal Review of Astronomy. But now NASA has admitted that cost overruns on its James Webb Space Telescope mission will remove so much money from its program that it cannot commit to being an equal partner with ESA on any major science mission in the near future.

ESA's management has reacted swiftly to this news because it must still find the best use for the whole of its space science budget for the rest of this decade. The LISA project team, as well as those of the other two missions -- IXO (a proposed space X- ray observatory) and JGO (a proposed mission to explore Jupiter's moons) -- have been asked to rethink their designs and scientific objectives to see if they can fit within a European-only funding envelope and still return good scientific results. Over the next year it is expected that ESA will officially adopt a new strategy in view of the NASA withdrawal, and then decide which of the three missions will best fit that strategy. Meanwhile, ESA scientists and engineers are supporting the science team of LISA as well as the other missions so that they arrive at the best possible redesign in a very short time.

The Albert Einstein Institute, as the world's largest research institute dedicated to exploring all aspects of Einstein's theory of gravitation, general relativity, is a major contributor to the LISA mission. “The European LISA team is working hard on the redesign now. We are optimistic that we can fit the new conditions and still deliver outstanding science by opening the gravitational wave window in space”, says Karsten Danzmann, European Mission Scientist for LISA and director at the Albert Einstein Institute in Hannover, Germany. “We hope that NASA will at least become a minor partner in a redesigned, smaller and less expensive LISA mission, and meanwhile we are benefiting greatly from the input of our US colleagues, who want to see LISA fly and do its unique science even if they do not get full partnership in it."

NASA Cancels LISA and More Info on the "Big Dog"

"BIG DOG" UPDATE:

LIGO has updated its news page giving more details about the "Big Dog" event that I discussed in a previous post.  Please go here if you would like more details!

NASA DISCONTINUES LISA INVOLVEMENT:

An artist's depiction of LISA, in the foreground, in solar orbit behind the Earth with gravitational waves from a black hole, in the background, arriving.

In breaking news today, NASA has officially wiped its hands of the LISA (Laser Interferometer Space Antenna) project.  Before today, this was a NASA/ESA collaboration to build a space-based detector (similar to LIGO) orbiting the Sun 20 degrees behind Earth in its orbit.  Below is an animation by the Rutherford Appleton Laboratory, UK that shows the LISA satellites in orbit around the Sun (be patient, it will seem like the animation isn't working for the first second or so):

LISA is important to exploring the Universe with gravitational waves since it will be able to detect gravitational waves with very low frequencies (few cycles of the wave every second) that will be impossible to do on Earth due to the constant seismic activity that is going on (just the waves in the oceans shake the Earth constantly - this is called the microseism).  LIGO has its best sensitivity between 100 Hz - 1000 Hz which is perfect to catch the merger of dense, massive objects (like black holes) and the death throes of stars (supernovae).  [See illustration below.]  But black holes can orbit each other for millions of years before merging into one while giving off low frequency gravitational waves the entire time.  LISA would be able to detect those.  As a matter of fact, since there is such a large number of low frequency systems producing gravitational waves all the time, the major noise source for LISA was the confusion limit (when you are detecting so many gravitational waves from many sources at the same time it is difficult to distinguish one from another).  Imagine that - having a major source of noise be gravitational waves themselves!  That would be a wonderful (and unattainable) problem to have here at LIGO!

Below is a gravitational wave amplitude vs. gravitational wave frequency graph showing where LISA and LIGO are sensitive along with what sources they could detect (this is not an all inclusive list).  Note that BH = black hole, NS = neutron star, and SN = supernova:

All of this does not mean that LISA is dead - it has just taken a major hit.  The ESA is still committed to this venture and there will be a flurry of new proposals to make LISA without the investment from NASA.  Will this mean that it will sacrifice sensitivity?  Perhaps.  But LISA has been a project for over 14 years now and there have been many advances in technology in that time.  I am not an expert in this so I cannot talk in specifics, but hope is not lost!  However, I have a few friends doing LISA research funded by NASA that very well may lose their jobs.

Read more about it here:  Cosmic Variance | Dynamics of Cats