Reaching orbit

Fasaha tana da nisan kilomita 100 kawai, mafi kusa da tafiyar mutane. Getting up there is easy: sounding rockets do it with a few minutes of flight and fall straight back. Staying up there is the difficult part. Domin ka zauna kana buƙata da kusan 7.8 km / s na gudun gefe, kuma kusan dukkan man fetur na roket an kashe shi a kan wannan.

Sai ka yi tafiyar minti goma. Yana tafiya a gefe da sauri yana ɗaukar kusan duk man fetur.

Look

A farawa yana da hujjoji huɗu:

1. Yana tsaye na wasu sakan kaɗan, don tsaftace tashar da kuma mafi yawan haske.
2. Gravitation turn. Wani dan tsayi, digiri biyu, da kuma matsin lamba na yi sauran: hanya tana canzawa ta kanta yayin da injinan ke jan ta. Ba sharp juyawa, wanda zai karya wani rufi a cikin ruwa.
3. Saukarwa. Bayan minti biyu da rabi, saukarwar farko tana cikin ɓoye kuma tana faɗuwa. Mataki na sama, mai haske sosai, yana ci gaba da tĩlasta.
4. Yana tashi kusan daidai, yana gina gudun gefe har ya kai gudun orbit. Mai sarrafawa ya rufe. Jirgin sama na cikin orbit, yana kẽwayẽwa da ƙasa kowace minti 88 ko haka.

Yaƙin gabas na taimakawa: Spin ɗin ƙasar kansa yana ba da 0.465 km / s a kan iyaka. Wannan shi ne dalilin da ya sa mafi yawan wuraren farawa ke fuskantar tekun zuwa gabas.

Understand

A cikin simulation a sama, motar kashe kusan 9.3 km/s na “delta-v” (duk canjin gudun da injiniyoyinta za su iya samarwa) don isa ga sauri na 7.8 km/s a 200 km. Da bambanci Gravity Loss: yayin da roket ke ci gaba da nuna wani yanki zuwa sama, wani yanki na ƙarfinsa yana riƙe shi kawai a kan matsin lamba mai yawa ba tare da ya ƙara sauri ba.

Real rokets kuma yaƙi da iska drag da rasa wasu inganci ga shige. An yi amfani da wannan a cikin tsarin lissafi na duniyar ƙasa, wanda ya kasance daga 9.3 zuwa 10 km/s, wanda ya dace.

Dakata cikin simuli	Time	Altitude	Speed
First-stage engine cut-off	about 2 min 24 s	about 90 km	a kan 3.0 km/s
Second-stage cut-off, in orbit	about 7 min 37 s	about 200 km	7.8 km/s

Mataki na farko, ya yanke a 3 km / s, shi ne sosai da sauri ga orbit kuma ya fadi baya (Falcon 9 boosters sa’an nan kuma su shirya kansu zuwa ƙasa).

Master

Mataki na sama a cikin wannan siffar yana amfani da doka mai sauƙin shiryarwa ta rufi. A kowace lokaci yana zaɓar wani bangare na tsayi θ don haka da ƙarfin gudun tsaye zai gyara girma da kuma adadin tashi:

a_T sin θ = μ/r² − v_h²/r + k₁(r_target − r) − k₂·v_r

Waɗannan kalmomi biyu na farko sune ƙarfin jujjuyawar ƙasa da “centrifugal” relief na gudun matsakaici. Kamar yadda v_h ya kusanci gudun √(μ/r), waɗannan biyun sun daina kuma maɓallin matakin ya yi kama. Wasu motocin da ake amfani da su suna amfani da wasu shirye-shirye masu kyau (misali, yanayin shiryarwa na Apollo-era, ko kuma jagorancin bayyananne mai ƙarfi a kan jirgin sama) waɗanda ke rage fitarwa, amma tsarin shine daidai.

Inserting into orbit is ending with zero vertical speed exactly at the target height, and horizontal speed equal to √(μ/r). Miss either and the orbit is an ellipse, with its low point possibly inside the atmosphere.