NASA yesterday released the first full-color images taken by the James Webb Space Telescope (JWST), the largest and most powerful space observatory in human history, costing nearly 10 billion The US dollar's Webb Space Telescope is at the forefront of human ingenuity. Surprisingly, however, the built-in storage space of this telescope is only 68GB.
It is reported that the Webb Space Telescope has a built-in 68GB SSD (solid-state drive). Of course, this is not an ordinary solid-state drive. It is officially called a solid-state recorder (Solid State Recorder). All Webb Space Telescope electronic components must go through a rigorous certification process that includes criteria for reliability, speed, redundancy, and radiation resistance.
It is reported that the Webb Space Telescope can generate up to 58.8GB of image data per day, compared with the Hubble Space Telescope, which can only generate up to 2GB of data per day. The data writing itself is handled by the Webb Space Telescope's ISIM Command and Data Processing Subsystem (ICDH), which can maintain a maximum data rate of approximately 48Mbps, enabling the telescope to save approximately six 2048x2048 image files every 10.7 seconds.
That is, the storage space of the Webb Space Telescope can be completely filled in one day. In fact, depending on the schedule, the Webb Space Telescope's solid-state drive can fill up in as little as 120 minutes. This means that data must be continually emptied from the SSD, traveled 1.5 million kilometers back to Earth, and safely stored on NASA's servers. Therefore, the Webb Space Telescope not only takes images but also sends them frequently to Earth.
The Webb Space Telescope's main communication system is based on Ka-band frequencies, transmitting data back to Earth at speeds up to 28Mbps on the 25.9GHz channel. To empty its database, the Webb Space Telescope sends back science data in two 4-hour windows of contact each day, each time transmitting at least 28.6GB of science data to the ground.
A pair of slower radio channels in the S-band handle other necessary issues, with a 2.09GHz uplink at 16kbps to the telescope for future transmissions and scientific observations scheduled 12 to 20 weeks in advance. Another 2.27GHz, 40kbps downlink transmits the telescope's engineering and telemetry data, including operational status and system health.
It's unclear why the $10 billion-plus Webb Space Telescope has only 68GB of storage, and 3% of that 68GB is unavailable because it's reserved for the aforementioned engineering and telemetry data storage. Foreign media speculate that the contract for the Webb Space Telescope was signed as early as 2003, which is likely to be related to this, but it may also be that scientists feel that 68GB is enough.
Engineers further estimate that at the end of the Webb Space Telescope's projected 10-year lifespan, only 60GB of usable storage will remain.