Editing Voyager program (section)

===Communications===
The [[uplink]] communications are executed via [[S-band]] [[microwave communications]]. The [[downlink]] communications are carried out by an [[X-band]] [[microwave]] transmitter on board the spacecraft, with an S-band transmitter as a back-up. All long-range communications to and from the two Voyagers have been carried out using their {{convert|3.7|m|ft|adj=on|sp=us}} high-gain antennas. The high-gain antenna has a beamwidth of 0.5° for X-band, and 2.3° for S-band.<ref name=Ludwig2002/>{{rp|17}} (The low-gain antenna has a 7&nbsp;dB gain and 60° beamwidth.)<ref name=Ludwig2002/>{{rp|17}}

Because of the [[inverse-square law]] in [[radio communications]], the digital data rates used in the downlinks from the Voyagers have been continually decreasing the farther that they get from the Earth. For example, the data rate used from Jupiter was about 115,000 bits per second. That was halved at the distance of Saturn, and it has gone down continually since then.<ref name=Ludwig2002>{{cite web|last1=Ludwig|first1=Roger|last2=Taylor|first2=Jim|publisher=NASA|date=March 2002|url=http://descanso.jpl.nasa.gov/DPSummary/Descanso4--Voyager_new.pdf|access-date=26 March 2016|title=Voyager Telecommunications|archive-date=18 March 2021|archive-url=https://web.archive.org/web/20210318092548/http://descanso.jpl.nasa.gov/DPSummary/Descanso4--Voyager_new.pdf|url-status=live}}</ref> Some measures were taken on the ground along the way to reduce the effects of the inverse-square law. In between 1982 and 1985, the diameters of the three main [[parabolic dish antenna]]s of the [[Deep Space Network]] were increased from {{convert|64|to|70|m|abbr=on}}<ref name=Ludwig2002/>{{rp|34}} dramatically increasing their areas for gathering weak microwave signals.

Whilst the craft were between Saturn and Uranus the onboard software was upgraded to do a degree of image compression and to use a more efficient [[Reed–Solomon error correction#Space transmission|Reed-Solomon error-correcting encoding]].<ref name=Ludwig2002/>{{rp|33}}

Then between 1986 and 1989, new techniques were brought into play to combine the signals from multiple antennas on the ground into one, more powerful signal, in a kind of an [[Antenna array (electromagnetic)|antenna array]].<ref name=Ludwig2002/>{{rp|34}} This was done at [[Goldstone, California]], [[Canberra Deep Space Communication Complex|Canberra (Australia)]], and [[Madrid Deep Space Communication Complex|Madrid (Spain)]] using the additional dish antennas available there. Also, in Australia, the [[Parkes Radio Telescope]] was brought into the array in time for the fly-by of Neptune in 1989. In the United States, the [[Very Large Array]] in [[New Mexico]] was brought into temporary use along with the antennas of the Deep Space Network at Goldstone.<ref name=Ludwig2002/>{{rp|34}} Using this new technology of antenna arrays helped to compensate for the immense radio distance from Neptune to the Earth.