Ukugcizelelana kusiza: i-slingshot ekhululekile

Ngo-1977 izindiza ezimbili zeVoyager zashiya iplanethi emhlabeni ngendlela esebenzisa ukufana okungavamile kweJupiter, Saturn, Uranus neNeptune, okuzokwenzeka kabili ngonyaka weminyaka engu-175 noma njalo. Iplanethi ngayinye ibeke indlela yabo futhi yazifaka phambili ngokushesha. Ngaphandle kwalezi zikhuthazo ezimahhala, i-Voyager 2 ayikwazi ukufinyelela kuNeptune eminyakeni eyisithupha.

Iplanethi ayinikezanga amandla. Inikeza ushintsho.

Bona

Thola ibhola le-tennis elithunyelwe phambi kwebhasi elihambayo. Ibuyela emuva ngokushesha kunalokho okuthunyelwe, ngoba ibhasi lihamba phambili. Usizo lwe-gravity luyiqiniso elifanayo, nge-gravity endaweni yokungqubuzana:

1. Ibonakale kusuka eplanethi, indiza yendawo yomhlaba iwela ngaphakathi, ijikeleza futhi ikhuphuka ngaphandle nge ijubane elifanayo elafika nalo. Ukushintsha kwendlela kuphela.
2. Ibonakale kusuka ku-Sun, iplanethi iyahamba ngemizuzwana eminingi. Engeza lo mjikelezo ku-spacecraft ngaphambi nangemva kokuhamba: ngoba indlela ishintshile, isivinini esiphelele singaba sikhulu kakhulu ngemuva.

Ukudlula emuva kweplanethi, engxenyeni yeplanethi, ongeza isivinini. Ukudlula emfushane kuyothatha; lokhu kuyindlela i-Messenger ehamba ngayo kancane ukufinyelela ku-Mercury.

Ukuqonda

Kulesi sibonelo, isindiza somhlaba sifinyelela kuJupiter ku v∞ = 7.5 km/s futhi sidlula ama-radii angama-5 kaJupiter kusuka engxenyeni yephakathi. I-hyperbola ibekezelela indlela yayo

δ = 2 arcsin(1/e),   e = 1 + r_p v∞² / μ

Nge-μ_Jupiter = 1.267 × 10⁸ km³/s², e = 1.16 futhi ukujikeleza kuyibanga lama-119 degrees. Ukungeza ijupiter’s orbital velocity (13.1 km/s):

• Phambi: cishe 7.6 km/s ngokuphathelene nelanga.
• Phakathi: cishe 19.9 km/s ngokuphathelene nelanga.

Indiza yathola ngaphezulu kwe-12 km/s ngaphandle kokushaya injini. IJupiter, 10²⁴ izikhathi ezinzima kakhulu, ilahlekelwa yimomentum efanayo futhi yahamba kancane ngenani elincane kakhulu.

Umphathi

Ushintsho olukhulu olunokwenzeka kwijubane le-heliocentric yi-2 v∞ sin(δ/2), olufinyelelwa lapho ijubane eliphumayo nelingaphumayo libekwe ngokufanayo ngejubane leplanethi. Uma kuqhathaniswa ne-pass (incane r_p) kanye neplanethi enamandla, i δ ingaba mkhulu, kuze kube yilapho umkhawulo ubekwe yi-atmosphere yeplanethi noma i-radius.

Ukugcizelelana kwengcindezi kusiza ukudlulisa amandla e-orbital kunkinga yezinto ezintathu: engxenyeni yeplanethi, amandla agcinwa; engxenyeni yelanga, amandla wendiza yomhlaba ayashintsha nge Δ = v_planet · Δv_rel. Abaklami bemisiyo bahlanganisana nabo (iCassini: iVenus, iVenus, i-Earth, iJupiter) bese bafaka ama-flybys anamandla amancane lapho ukudlidliza okuncane kufinyelela khona ekukhuleni kwe-Oberth.