Ukubuyela ekhaya: ukungenisa kabusha

Wonke umgibeli we-astronaut ubuyela ekhaya ngendlela efanayo: ngokushintsha isivinini sibe wukushisa. I-capsule efika kusuka ku-orbit ithatha amandla adingekayo ngekililitha ukuxuba ubunzima bayo bensimbi izikhathi eziningi. Umsebenzi wonke wokubuyela emuva ukukhipha amandla ngokucophelela ukuze uphile, futhi ngokushesha ngokwanele ukuthi ungabuyanga endaweni.

Ama-engine aqala ukuwa. Umoya usebenza njenge-brake.

Bona

1. I-deorbit ikhanya. Isho emuva, i-capsule ivula injini yayo imizuzu embalwa futhi ihamba kancane ngamakhilomitha ayi-100/s. Okunciphisa ingxenye ephakathi ye-orbit yayo esiya ezindaweni ezibandayo.
2. Isixhumi sokungena, cishe amakhilomitha angama-120 phezulu. I-capsule ihlangana nezimpawu zokuqala ezincane zezulu ezihamba ngamakhilomitha ayi-7.8/s.
3. Ibhola lomlilo. Umoya ongaphambili kwesihlungi sokushisa ucindezelwe kakhulu, yenza i-plasma ekhanyayo, amaphesenti ayizigidi ezincane zokushisa. Amasignali e-radio angafinyelela emizuzwini embalwa. Isihlungi sokushisa sihamba kancane futhi sishiya ama-flakes, sithwala ukushisa.
4. I-corridor. Ukubuyela kusuka kuMhlaba ku 11 km/s, i-angle yokungenisa kufanele ibe phezulu kuye ngengxenye yedegree: iphakeme kakhulu futhi ukuncipha kuzocindezela abaphathi, iphansi kakhulu futhi i-capsule izophuma emkhathini njengetshe elingaphandle kwamanzi.
5. Parachutes. Engezansi kwe-10 km i-capsule iwela ngamakhilomitha angamakhulu amabili ngehora. I-parachute ivula, futhi iwela ngemitha embalwa ngomzuzu.

Ukuqonda

Kusuka ku-400 km orbit ejikelezayo (r = 6,778 km) ijubane liyi-7.67 km/s. I-ellipsis enendawo ephansi engu-50 km phezulu ine-a = 6,603 km, futhi ku-400 km ijubane layo kufanele libe ngu-7.57 km/s. Ukulahleka kwe-orbit burn kuyinto ehlukile: cishe 102 m/s, kuphela i-1.3% yejubane le-orbit.

Umphumela wokudonsa yi-½ ρ v² C_D A. Ubukhulu be-air density ρ buncane kakhulu ngamamitha ayi-5 okuphuma (ubukhulu bokulinganisa ngamakhilomitha angama-7.2), ngakho-ke ukuncipha kwejubane kukhuphuka ngokuqinile, kufinyelela ezingeni eliphezulu, futhi kuwela njengoba i-capsule ihamba kancane. Kulesi simo esiphezulu:

Ungeniso	Isivinini	I-Angle	Ukuncipha okuphezulu
Ukusuka e-orbit eseduze	7.85 km/s	1.5°	mayelana 8 g
Kusuka kuMhlaba, phezulu kakhulu	11 km/s	8°	mayelana 31 g
Kusuka kuMhlaba, egumbini	11 km/s	5.6°	mayelana 7 g
Kusuka kuMhlaba, phezulu kakhulu	11 km/s	4.8°	idlula emuva ngaphandle

I-capsules engokoqobo indiza nge lift encane (iphakathi kwabo kwesisindo singaphandle kwesizinda, ngakho baphila ngokunethezeka) futhi bajikeleze ukulilawula, okunciphisa isiphetho kungaphezu kuka-4 g yeSoyuz futhi kunciphisa umgwaqo we-Apollo cishe amadigri angama-2.

Umphathi

Imodeli ihlanganisa izilinganiso ze-planar zokunyakaza nge-gravity ne-drag kuphela:

dv/dt = −μ r/|r|³ − (ρ(h) |v| / 2β) v,   ρ(h) = ρ₀ e^(−h/H)

nge β = m/(C_D A) = 350 kg/m² (i-capsule-like) ne H = 7.2 km. Ukungeniswa kwe-balistic ephakeme, uAllen noEggers (1958) babonisa ukuthi ukuncipha okuphezulu kuncane kakhulu ku β:

a_max ≈ v_E² sin γ / (2 e H)

Isibonelo esiqinile senyanga (γ = 8°) sinikeza cishe i-44 g; isilinganisi esigcwele sinikeza i-31 g, ngoba ukunyakaza kwelanga ligcina licindezela indlela ephansi njengoba i-capsule ikhuphuka. Nganoma iyiphi indlela, i-angle yokungenisa, hhayi ubukhulu bemoto, ibeka i-g-load, ngakho-ke yonke indiza ebuyela emuva ihamba nge corridor ecacile.