It seems that we’re not allowed to have any good news these days without a bit of bad to go with it. This week it has emerged here and there that the US National Aeronautics and Space Administration (better known as NASA) is pulling the plug on one of the most exciting space missions on its drawing board. Feeling the pressure of budget constraints and a ballooning overspend on the James Webb Space Telescope (JWST), NASA has decided not to participate further in the Laser Interferometric Space Antenna, a.k.a. LISA. The project teams working on LISA have been disbanded, and the shutters have been pulled down on a project which would have revolutionised astrophysics by opening up new possibilities of observing astronomical objects using gravitational waves, rather than electromagnetic radiation.
This does not mean that LISA is necessarily completely dead. For one thing, it was always planned to be a partnership between NASA and its European counterpart ESA (the European Space Agency); you can find ESA’s LISA page here. In fact a technological demonstrating mission LISA-Pathfinder, operated by ESA, is scheduled for launch in 2013.
It remains possible that ESA will proceed on its own with some version of LISA, although given its own financial constraints it is unlikely that it will be able to fund the full original mission concept. The best we can hope for, therefore, is probably some slimmed-down low-budget version and perhaps an even later launch date.
I still hold out some hope that LISA might come out of mothballs when gravitational waves are actually detected. This may well be accomplished by Advanced LIGO, a ground-based interferometric system based in the states, although it has to be said that gravitational waves have been “on the brink of detection” for at least 30 years and still haven’t actually been found. When detection does become a reality it might galvanise NASA into finding room in its budget again.
This news will be a particularly concern for the sizeable Gravitational Physics group here in the School of Physics & Astronomy at Cardiff University. However, LISA was very much in the planning and development stages so it won’t impact their current work. I haven’t had the chance to discuss the news about LISA with members of this group, so I’d be interested to receive comments from them, or indeed anyone else who knows more about what NASA’s decision may or not mean for the future of gravitational wave physics.