On April 6, 2011, the US admitted once again that it would not keep international technology commitments and withdrew from the LISA project (Laser Interferometer Space Antenna) a cooperative agreement with ESA, (the European Space Agency)
LISA was to be a 3 station system in solar orbit to detect gravitational waves from cataclysmic astrophysical events. At this current time, ESA is considering building the system by itself.
This development is the latest in a 40 year string of similar actions, forming a solid tradition of withdrawing the U.S. from the development of true technology.
Why/how did this happen? On page22 of the June 2011 issue of Physics Today, David Kramer has an excellent review of the politics behind NASA’s painful decision.
Technical overview: LISA is an observatory to watch black holes or neutron stars spiral in by monitoring the gravity radiation generated. Such radiation has never been detected before, but we are almost certain that it must exist.
LISA was to be a system of 3 stations that form the corners of an equilateral triangle in solar orbit trailing the earth. The triangle would be 5 million km on a side (3 M miles), and each station would have 2 lasers to coordinate its actions with the other two.
Each of the three stations would have two gold-platinum cubes that drift freely in the orbit. Each station provides shielding for the free cubes and continuously adjusts itself the keep the cubes centered, within.
LISA summary – I’ll bet that you missed the paradigm shattering consequence of this proposal. It is not obvious at first reading, but LISA would have had huge leverage on future space uses.
The LISA project uses the lasers to provide a nearly unbelievably stable platform in which it can observe the reaction by the gold cubes to gravity waves. Think of the 5 M km triangle as on the circumference of a disk 5.7 M km in diameter [D = 2L/√(3) ]. To the gravitation folks, it is an unprecedented next step from the current LIGO program; it is almost certain to produce positive gravity wave results. … Now, what would you do with such a structure?
I enjoy the thought of the gravitation wave experiment, but was really thrilled that an important project would iron out the horrendously difficult techniques to hold this gigantic platform stable. LISA, from my viewpoint, is the prototype test bed for a visible optics observatory. As noted, the LISA triangle defines a stable encompassing circular platform, 5.75 M km diameter.
So here goes my projected “what if:” What would you be able to see through a telescope with a mirror 5.75 million kilometers in diameter? Think 50-80 years in the future, after the launch of the first LISA and its upgrades. We would launch an Observing Station Platform. (The OSP is my dream, not anyone’s official proposal).
OSP capability: At each LISA vertex, put a Hubble-class telescope in interferometric communication with the others. Interferometric imaging is being done today. The three could form an image with resolution of 1.1 km on a target 1,000 light years out . At 100,000 LY out, the system could resolve spots about 100 km apart.
The actual mirrors would be HST-sized, not be able to see objects that are too dim for our own HST, but it would have breathtaking feature resolution. Here is the ability to see detail of nearly every planet in our Milky-Way galaxy.
Why stop a 40 year trend? LISA is not the first American dream that was lost. We stopped the moon landings just as they were beginning.
We launched our space station (Skylab). Note: The USSR launched the first station a few months earlier. We visited Skylab several times but abandoned it. Skylab burned up at re-entry in 1979. Although this was the last Saturn V ever launched, 2 more of these beautiful complex machines that were fully built were abandoned in place, left outdoors in the rain, at the mercy of corrosion.
A discussion of this systematic degrading of U.S. technological ability is one of the goals for this LastTechAge blog site. We won’t go into much more detail but I want to bring up one more stunning abandonment, the MFTF-B fusion test facility at the Laurence Livermore National Laboratory (LLNL).
MFTF-B was the product of the 30 previous years of intense study of fusion processes at LLNL, using the magnetic mirrors. Design started in the mid 1970’s; construction was completed in 1985.
MFTF cost about 1/3 billion US Dollars ($367,000,000 in 1985 dollars). It was dedicated one afternoon in February 1986, the next morning, Reagan’s political team terminated the entire project without allowing it to be be turned on. Ever.
« I am not a completely unbiased observer, they were considering buying a plasma temperature diagnostic from my project, similar to one I had invented and built for the Doublet-III tokamak in San Diego »
I plan a chain of postings to document a number of such historic trashings of our capability, and will go deeper into the various projects. But this will await later times.
LISA is a tragic loss. It is my great hope that the Europeans have the financial will and technical vision to launch the LISA Pathfinder in the next year or so to test the basic communication and coordination concepts the full LISA would need for its launch in 2022 or so. Good luck, bonne chance, viel Glück.
Charles J. Armentrout, Ann Arbor
2011 Jun 14
Listed under Technology … Technology > Aerospace
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d = (1.22 λ/D) L
where λ lambda is the wavelength of light, D is the diameter of the lens, and L is the distance between the object and the lens (all lengths must be in the same units). Use yellow green light, λ = 570 nm (1 nm = 10-12 km), D in km, and L in Lightyears (1 LY = 9.46×1012 km)
d =6.58×103 L/D L in LY, D in km.
for D = 5.75 M km, and L = 1000 LY, d = 1.1 km