Deep space dial-up: How NASA speeds up its interplanetary communications

(video link)

On November 26, 2018 at 2:52:59 ET, NASA did it again—the agency’s InSight probe successfully landed on Mars after an entry, descent, and landing maneuver later dubbed 'six and a half minutes of terror.” The moniker fits because NASA engineers couldn't know right away whether the spacecraft had made it safely down to the surface because of the current time delay (roughly 8.1 minutes) for communications between Earth and Mars. During that window of time, InSight couldn't rely on its more modern, high-powered antennas—instead, everything depended on old-fashioned UHF communications (the same method long utilized in everything from TV antennas and walkie-talkies to Bluetooth devices).
Eventually, critical data concerning InSight's condition was transmitted in 401.586Mhz radio waves to two CubeSats called WALL-E and EVE, which in turn relayed the data at 8Kbps back to huge 70 meter antennas on Earth. The CubeSats had been launched on the same rocket as InSight, and they followed along on the trip to Mars in order to observe the landing event and send back data immediately. Other Mars orbiters like Mars Reconnaissance Orbiter (MRO) were out of position and couldn't initially provide real-time communications with the lander. That’s not to say that the entire landing coverage hinged on two experimental CubeSats (each the size of a briefcase), but the MRO would have relayed InSight's landing data only after further delay.
Read 37 remaining paragraphs | Comments