With the James Webb Space Telescope (JWST) now powered up and snapping some spectacular photos, you could marvel precisely the way it’s storing them. Surprisingly sufficient, it carries a comparatively tiny 68GB SSD, in accordance with IEEE Spectrum — sufficient to deal with a day’s price of JWST photos, however not much more.

While that may sound ludicrously small for a $10 billion satellite tv for pc, there are a number of causes NASA selected the system. To begin with, the JWST is one million miles from Earth the place it will get bombarded by radiation and operates at a temperature of lower than 50 levels above absolute zero (-370 levels F). So the SSD, like all different components, should be radiation hardened and survive a grueling certification course of. 

While not practically as quick as shopper SSDs, it may nonetheless be practically crammed in as little as 120 minutes by way of the telescope’s 48 Mbps command and knowledge dealing with subsystem (ICDH). At the identical time, the JWST can transmit knowledge again to Earth at 28 Mbps by way of a 25.9 Ghz Ka-band connection to the Deep Space Network. 

That signifies that whereas it collects way more knowledge than Hubble ever did (57GB in comparison with 1-2GB per day), it may switch all that knowledge again to Earth in about 4.5 hours. It does so throughout two 4-hour contact home windows every day, with every permitting the transmission of 28.6GB of science knowledge. In different phrases, it solely wants sufficient storage to gather a day’s price of photos — there is not any must maintain them on the telescope itself.

There is one puzzler, although. NASA estimates that solely 60GB of storage can be obtainable on the finish of the JWST’s 10-year lifespan on account of put on and radiation — and three % of the drive is used for engineering and telemetry knowledge storage. That will depart the JWST little or no margin, making us marvel if it can have anyplace close to the longevity of Hubble — nonetheless going sturdy after 32 years.