Malo omwe anthu akubwerera pa Mwezi ndi Artemis program, zovuta zimene sizamakondwedsedwa yambiri: ndi nthawi yiti pa Mwezi? Pa Aprilo 2, 2024, White House Office of Science and Technology Policy (OSTP) idamala kuti NASA igwire ma nkhawa ndi kumapeto kwa 2026 kuti izikhale ndi standard ya unified lunar time yomwe itchedwa Coordinated Lunar Time, kapena LTC.
Chifukwa chiyani Mwezi amafuna nthawi yake yake
Pa Earth, timadala kugwiritsira Coordinated Universal Time (UTC), yomwe imakonzedwa ndi network ya ma lokasi angapo a atomic mdziko lonse. GPS satellites, mapulogalamu a money, ma grid a magetsi, ndi intaneti onse amadala kugwirizana kwa UTC.
Mwezi umapangitsa vuto limene linalakhala. Chifukwa cha mphamvu ya gravitational pa Mwezi yotsika, ma lokasi pa Mwezi amayenda ~56.02 microseconds mabwinobwino pa tsiku lililonse la Earth kuposa ma lokasi omwe ali m'malo omwe ali ndi mphamvu ya gravitational yomwe ndi yofanana pa Earth. Zomwe izi zimadalembedwa mu theory ya general relativity ya Einstein — izi zimachitika kuti relay ya nthawi ya Earth kwa Mwezi ingachita kuya kwa kufanana ndi ma lokasi pa Mwezi.
Pakupitiriza tsiku limodzi, maminiti 56 amatha kuoneka kuti palibe. Komabe, kwa systems ya navigation, kuya kwakonsechi kumapela zolakwa za malo okukula pangapo pamita pa tsiku. Ndi mwezi, zolakwa idzakwanira pa ma meters mazana — zomwe zimapangitsa kuti precision landings, rover navigation, ndi communication relay timing zisakhale zoyenera.
Momwe LTC idzagwira
Coordinated Lunar Time idzapangidwa pa mifupi yomwe ndi UTC komabe yokonzeketsedwa kwa malo a Mwezi. Lingaliro ndi yokugwiritsira ntchito network ya ma lokasi a atomic omwe azigwiritsidwa ntchito pa Mwezi ndi mu orbit ya Mwezi. Ma lokasi awa azigwiritsidwa ntchito kuti awerengetse kuchuluka kwa weighted average yomwe izatanthauzire nthawi yeniyeni ya lunar.
LTC idzapikisa nthawi yomwe ndi yosinthasintha, komabe imve, ndi relationship ndi UTC kuti nthawi ingasintha pakati pa Earth ndi Mwezi. Zomwe zimayandikira mosiyanasiyana ndi kuti LTC idzawerengetsa offset ya relativistic — kuya kokonkozane komwe kumapangitsa kuti ma lokasi pa Mwezi ayenda mabwinobwino.
National Institute of Standards and Technology (NIST) idafalitsa framework ya technical mu Ogositi 2024 yomwe likulemba momwe lunar time ingawerengedwa kuchokera mu relativistic corrections kwa UTC.
Ntchito ya International
Kunthawiza kwa Mwezi si project ya NASA yokha. United Nations International Committee on Global Navigation Satellite Systems (ICG) idapangitsa gulu lomwe lingakavomela (working group) mu 2024 kuti igwirizanitse kunthawiza kwa Mwezi kwa anthu onse. Artemis Accords — zomwe zapainisa anthu angapo kuposa makumi asanu — zimavomereza kuti pali nthenda ya mapulogalamu omwe akugwitsa ntchito limodzi pa Mwezi, ndipo shared time reference ndi maziko ake.
European Space Agency (ESA) yenso ili kuzindikira kunthawiza kwa Mwezi ngati malinga ndi Moonlight initiative yake, yomwe ikuzamira kupereka mapulogalamu a communication ndi navigation mozungulira Mwezi.
Zomwe LTC zimachitika kwa ine muli
Standard ya unified lunar time idzapangitsa precision navigation kwa landers ndi rovers, reliable communication scheduling pakati pa Earth ndi Mwezi, coordination pakati pa missions kuchokera kwa space agencies zosiyanasiyana, ndi foundational kwa kunthawiza kwa Mars ndi malo ena.
Simulated Coordinated Lunar Time yomwe ikuwonetsedwa pa moontimenow.com imagwiritsira ntchito nthawi ya drift yomwe idafalitsa ya +56.02 microseconds pa tsiku, kumakwanira kuchokera kwa J2000.0 epoch, kuti iwerengetse zomwe official LTC clock ingawonetsedwe lero.