Editing Mars Telecommunications Orbiter

{{Short description|Cancelled Mars mission}}
{{infobox spaceflight
| name=Mars Telecommunications Orbiter
| image = PIA07500.jpg
| operator = [[NASA]]
| launch_contractor = [[Jet Propulsion Laboratory|JPL]]
| mission_type = [[Planetary science]], [[Exploration of Mars|Mars exploration]]
| launch_date = Launch cancelled
| launch_rocket = [[Atlas V rocket|Atlas V]](401) or a [[Delta IV rocket|Delta-4M]].
| mission_duration = 1-year cruise plus 10 years in orbit (planned)
| website = {{webarchive |url=https://web.archive.org/web/20050924232548/http://mars.jpl.nasa.gov/missions/future/mto.html |date=September 24, 2005 |title=JPL's MTO web page }}
| orbit_semimajor = 5,000 km (3,106.9 mi)
| instruments_list = * ''' Optical Communications Payload:''' - demonstrate [[laser communication in space]] 
* ''' Narrow Angle Camera:'''- Support canister detection  
* '''Orbiting Sample Demonstration Canister:''' - Technology demonstration 
}}

The '''Mars Telecommunications Orbiter''' ('''MTO''') was a [[Exploration of Mars#Cancelled missions|cancelled Mars mission]] that was originally intended to launch in 2009 and would have established an [[Interplanetary Internet]] between Earth and Mars.<ref name=EEIS-MTO-2006>{{cite web|url=http://hdl.handle.net/2014/38660 |title=End-to-End Information System Concept for the Mars Telecommunications Orbiter |date=March 2006 |publisher=NASA JPL |hdl=2014/38660 |last1=Breidenthal |first1=Julian C.|last2=Edwards|first2=Charles D.|last3=Greenberg|first3=Edwards|last4=Kazz|first4=Greg J.|last5=Noreen|first5=Gary K.}}</ref><ref>[http://www.space.com/spacenews/businessmonday_041115.html NASA To Test Laser Communications With Mars Spacecraft]; By Brian Berger, Space News, 25 May 2005.</ref> The spacecraft would have arrived in a high orbit above Mars in 2010 and relayed data packets to Earth from a variety of Mars landers, rovers and orbiters for as long as ten years, at an extremely high data rate. Such a dedicated communications satellite was thought to be necessary due to the vast quantity of scientific information to be sent to Earth by landers such as the [[Mars Science Laboratory]].<ref>{{cite news|title=NASA Mars Telecom Orbiter Axed As Space Agency Priorities Shift|first=Brian |last=Berger|date=July 25, 2005|url=https://spacenews.com/nasa-mars-telecom-orbiter-axed-space-agency-priorities-shift/|publisher=[[Space News]]|access-date=January 29, 2023}}</ref>

On July 21, 2005, it was announced that MTO had been canceled due to the need to support other short-term goals, including a [[Hubble Space Telescope|Hubble]] servicing mission, [[Mars Exploration Rover]] extended mission operations, launch Mars Science Laboratory in 2009, and to prevent Earth science mission [[Glory (spacecraft)|Glory]] from being cancelled.<ref>[http://www.spaceref.com/news/viewpr.html?pid=17424 Text of a Letter from the President to the Speaker of the House of Representatives July 15, 2005 | SpaceRef]</ref>

== Data transfer technology ==
The Mars Telecommunications Orbiter would have carried [[Mars Laser Communication Demonstration]] to demonstrate [[laser communication in space]] ([[optical communications]]), instead of usual [[radiowave]]s. "Lasercom sends information using beams of light and optical elements, such as telescopes and optical amplifiers, rather than RF signals, amplifiers, and antennas."<ref>{{cite web| author=Townes, Stephen A.| title=The Mars Laser Communication Demonstration| url=http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/38024/1/04-0216.pdf| access-date=April 28, 2008| display-authors=etal| url-status=dead| archive-url=https://web.archive.org/web/20090227080653/http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/38024/1/04-0216.pdf| archive-date=February 27, 2009}}</ref>

MTO would have had two 15 W X-band radio transmitters, and two Ka-band radio transmitters (35 W operational, and 100 W experimental).<ref name=EEIS-MTO-2006/>

== Proposed successors ==
After the cancellation, a broader mission was proposed as the ''Mars Science and Telecommunications Orbiter''.<ref>{{cite web|title=NASA MEPAG: Mars Science and Telecommunications Orbiter (DRAFT)|url=http://www.marstoday.com/news/viewsr.html?pid=20324|archive-url=https://archive.today/20120905125159/http://www.marstoday.com/news/viewsr.html?pid=20324|url-status=dead|archive-date=2012-09-05|author=NASA|date=March 2006}}</ref> However, this mission was soon criticized as lacking well-defined parameters and objectives.<ref>{{cite book | url=http://books.nap.edu/openbook.php?record_id=11717&page=1 | author=National Research Council| title=Assessment of NASA's Mars Architecture 2007-2016 | year=2006 | doi=10.17226/11717| isbn=978-0-309-10273-5}}</ref> Another mission has since been proposed as the ''2013 Mars Science Orbiter''.<ref>{{cite conference |title=Mars Science Orbiter |url=http://mepag.nasa.gov/reports/MSO_SAG_report_071006.pdf |conference=MEPAG |year=2006 |url-status=dead |archive-url=https://web.archive.org/web/20160305031619/http://mepag.nasa.gov/reports/MSO_SAG_report_071006.pdf |archive-date=2016-03-05 }}</ref>

The communications capability provided by the [[Mars Reconnaissance Orbiter]] and [[Mars Express]] science missions has proven substantial, demonstrating that dedicated relay satellites may be unnecessary in the near future. The two newest science orbiters are the [[MAVEN]], which arrived at Mars on September 21, 2014 with an [[Electra (radio)|Electra]] [[transceiver]]; and the 2016 European [[ExoMars Trace Gas Orbiter]], that also carries an [[Electra (radio)|Electra]] [[Ultra high frequency|UHF band]] [[transceiver]].<ref name="trace-gas-orbiter">{{cite web |url=http://exploration.esa.int/jump.cfm?oid=46475 |title=ExoMars Trace Gas Orbiter (TGO) |publisher=European Space Agency |date=12 July 2012 |access-date=8 March 2014}}</ref> But both follow science orbits not designed for relay communications. 

Around 2014, a concern in NASA is that the currently used relay satellite, [[Mars Odyssey]], may fail, resulting in the need to press [[MAVEN]] science orbiter into use as the backup telecommunications relay,<ref>{{cite news |publisher= Space News |url= http://spacenews.com/nasa-eyes-new-mars-orbiter-for-2022/ |title= NASA Eyes New Mars Orbiter for 2022 |author= Dan Leone |date= 24 February 2015 }}</ref> but the highly elliptical orbit of MAVEN will limit its usefulness as a relay for operating landers on the surface.<ref name="Telecom">{{cite news |last=Stephen |first=Clark |url=http://spaceflightnow.com/news/n1407/27marstelecom/#.VCHv_Wd0x4s |title=NASA considers commercial telecom satellites at Mars |work=Space Flight Now |date=July 27, 2014 |access-date=2014-09-23 |quote= It is due to arrive at Mars in September, but MAVEN's planned orbit is not ideal for collecting and sending rover data. }}</ref><ref>[http://www.jpl.nasa.gov/news/news.php?feature=4370 Newest NASA Mars Orbiter Demonstrates Relay Prowess]. November 10, 2014.</ref>

As of 2018, the proposed [[Next Mars Orbiter]] (NeMO) is to be a dedicated telecommunications orbiter with a robust science package,<ref name='SFN'>{{cite news |last=Stephen |first=Clark |url=http://spaceflightnow.com/2015/03/03/nasa-eyes-ion-engines-for-mars-orbiter-launching-in-2022/ |title=NASA eyes ion engines for Mars orbiter launching in 2022 |work=Space Flight Now |date=March 3, 2015 |access-date=2015-03-07}}</ref><ref name="Leone">{{cite news |last=Leone |first=Dan |url=http://spacenews.com/nasa-eyes-new-mars-orbiter-for-2022/ |title= NASA Eyes New Mars Orbiter for 2022 |work=Space News |location=Washington, DC |date=February 24, 2015 |access-date=2015-03-08 }}</ref> tentatively planned for the late 2020s.<ref>{{cite news |url=https://spaceflightnow.com/2018/04/09/nasa-is-counting-on-long-lived-mars-orbiter-lasting-another-decade/ |title=NASA is counting on long-lived Mars orbiter lasting another decade |work=Spaceflight Now |first=Stephen |last=Clark |date=April 9, 2018 |access-date=April 22, 2018}}</ref> It is anticipated to employ a [[Laser communication in space|laser communication]] subsystem, that was successfully tested aboard the [[Lunar Atmosphere and Dust Environment Explorer]] mission in 2013.<ref>[https://web.archive.org/web/20100329231345/http://www.nasa.gov/mission_pages/LADEE/main/ LADEE]</ref>

==See also==
* [[Laser space communication]]
* {{annotated link|Laser Communications Relay Demonstration}}
* {{annotated link|Optical PAyload for Lasercomm Science}} (OPALS)
* {{annotated link|Deep Space Optical Communications}}

==References==
{{Reflist}}

{{Mars spacecraft}}

[[Category:Missions to Mars]]
[[Category:Proposed NASA space probes]]
[[Category:Cancelled spacecraft]]
[[Category:Laser communication in space]]