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The Gravity Probe B Bailout

Perhaps the most sophisticated satellite ever flown was nearly doomed by a tiny error, and NASA planned to end the experiment. But with a little creative fund-raising, the project may have bought enough time to prove its worth

12 min read

In 1964, before the term ”black hole” was even coined, NASA began funding a project that would test the outer limits of the theory behind black holes, Einstein’s general theory of relativity. Last May, with the project, called Gravity Probe B (GP-B), looking like a US $650-million flop, a NASA review board recommended that all funding be cut off by the end of September.

Now, in a dramatic turnaround, the Gravity Probe B team has secured non-NASA funding to press forward with data analysis of an experiment that has been bogged down by unexpected sources of noise. With the latest round of stopgap funds in place, the group holds out hope that it will either be able to verify or refute one of the most extreme predictions of Einstein’s general theory of relativity.

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Two men fix metal rods to a gold-foiled satellite component in a warehouse/clean room environment

Technicians at Northrop Grumman Aerospace Systems facilities in Redondo Beach, Calif., work on a mockup of the JWST spacecraft bus—home of the observatory’s power, flight, data, and communications systems.


For a deep dive into the engineering behind the James Webb Space Telescope, see our collection of posts here.

When the James Webb Space Telescope (JWST) reveals its first images on 12 July, they will be the by-product of carefully crafted mirrors and scientific instruments. But all of its data-collecting prowess would be moot without the spacecraft’s communications subsystem.

The Webb’s comms aren’t flashy. Rather, the data and communication systems are designed to be incredibly, unquestionably dependable and reliable. And while some aspects of them are relatively new—it’s the first mission to use Ka-band frequencies for such high data rates so far from Earth, for example—above all else, JWST’s comms provide the foundation upon which JWST’s scientific endeavors sit.

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