Update modem-chain.md

Removing reference to Aura to avoid customer confusion as spacecraft does not have a reliable direct broadcast feature like the other NASA public spacecraft. In response to https://github.com/MicrosoftDocs/azure-docs/issues/108189

Author: kellydevens

articles/orbital/modem-chain.md

@@ -55,7 +55,6 @@ We currently support the following named modem configurations.
 |--|--|--|
 | Aqua Direct Broadcast | aqua_direct_broadcast | This is NASA AQUA's 15-Mbps direct broadcast service |
 | Aqua Direct Playback | aqua_direct_playback | This is NASA's AQUA's 150-Mbps direct broadcast service |
-| Aura Direct Broadcast | aura_direct_broadcast | This is NASA Aura's 15-Mbps direct broadcast service |
 | Terra Direct Broadcast | terra_direct_broadcast | This is NASA Terra's 8.3-Mbps direct broadcast service |
 | SNPP Direct Broadcast | snpp_direct_broadcast | This is NASA SNPP 15-Mbps direct broadcast service |
 | JPSS-1 Direct Broadcast | jpss-1_direct_broadcast | This is NASA JPSS-1 15-Mbps direct broadcast service |