Proximity-1 Space Link Protocol

Proximity-1 Space Link Protocol is a short haul delivery communications protocol designed to establish a two-way communications link between a lander and an orbiter, negotiate data rate and communications mode, and reliably deliver data during short orbiter-to-surface contacts.

Developed by Consultative Committee for Space Data Systems and documented in a number of CCSDS Recommendations

{{cite web

|title = CCSDS Recommendation For Proximity-1 Space Link Protocol. Coding And Synchronization Sublayer

|url = https://public.ccsds.org/Pubs/211x2b1s.pdf

|accessdate = 2017-05-22

}}

{{cite web

|title = CCSDS Recommendation For Proximity-1 Space Link Protocol. Data Link Layer

|url = https://public.ccsds.org/Pubs/211x0b4s.pdf

|accessdate = 2017-05-22

}}

{{cite web

|title = CCSDS Recommendation For Proximity-1 Space Link Protocol. Physical Layer

|url = https://public.ccsds.org/Pubs/211x1b3sec1s.pdf

|accessdate = 2017-05-22

}}

Proximity-1 is implemented on Mars Exploration Rovers, Mars Odyssey, Mars Reconnaissance Orbiter, Mars Express[http://www.spaceref.com/news/viewpr.html?pid=14149 CCSDS Proximity-1 Communications Protocol Enables High-Speed Communication at Mars] as well as on Phoenix Mars Lander.{{cite web

|title = Phoenix Mars Mission FAQ

|url = http://phoenix.lpl.arizona.edu/faq.php

|accessdate = 2008-05-26

}}

The frequency band used by this protocol is in the 70-centimeter band so as to reduce complexity of the ground craft, using these frequencies:

• 437.1000 MHz
• 440.7425 MHz
• 444.3850 MHz
• 448.0275 MHz

However, using this protocol over the standard CCSDS frequency bands is perfectly acceptable if the UHF allocation is not usable.