By Ron Cowen
Two proposed space missions to study supermassive black holes and other high-energy phenomena have fallen into NASA’s gaping budget hole. Both missions were collaborations between NASA and the European Space Agency. When NASA recently determined that it could not come up with its share of funding for astrophysics research over the next few years, ESA decided it would have to scrap the projects as now envisioned. A third mission, planned by NASA alone, also appears to be in jeopardy.
One of the missions, known as LISA, short for Laser Interferometer Space Antenna, would have been the first dedicated space mission to search for gravitational waves, ripples in spacetime predicted by Einstein’s theory of general relativity. LISA’s design called for three identical spacecraft that would use lasers to detect minute movements of a 2-kilogram gold-platinum alloy cube inside each craft. The tiny motions would be evidence of the passage of a gravitational wave generated by sources such as merging supermassive black holes. Total cost of the mission is estimated at about $2.4 billion, of which NASA’s share would have been $1.5 billion.
The other disbanded mission, the roughly $5 billion International X-ray Observatory, would have cost NASA about $3.1 billion and was slated to use a large X-ray mirror to peer through dust and gas clouds to discover and examine some of the universe’s earliest supermassive black holes. The X-ray mission would have been a successor to two spacecraft now in orbit, NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton Observatory.