ights ▁ ▁Can cel led ▁miss ions ▁One ▁different ▁( 1 9 6 3 ) ▁and ▁seven ▁original ▁( going ▁through ▁to ▁April ▁ 1 9 6 6 ) ▁V ost ok ▁fl ights ▁were ▁originally ▁planned : V ost ok ▁ 6 A ▁- ▁pair ▁to ▁V ost ok ▁ 5 ▁group ▁flight ▁with ▁female ▁cos mon aut ▁instead ▁ful filled ▁V ost ok ▁ 6 ▁flight ▁V ost ok ▁ 7 ▁- ▁ 8 - days ▁high - alt itude ▁flight ▁for ▁radi ological - bi ological ▁studies ▁with ▁natural ▁re - entry ▁from ▁orbit ▁V ost ok ▁ 8 ▁- ▁pair ▁to ▁V ost ok ▁ 9 ▁ 1 0 - days ▁group ▁high - alt itude ▁flight ▁for ▁extended ▁scientific ▁studies ▁with ▁natural ▁re - entry ▁from ▁orbit ▁V ost ok ▁ 9 ▁- ▁pair ▁to ▁V ost ok ▁ 8 ▁ 1 0 - days ▁group ▁high - alt itude ▁flight ▁for ▁extended ▁scientific ▁studies ▁with ▁natural ▁re - entry ▁from ▁orbit ▁V ost ok ▁ 1 0 ▁- ▁ 1 0 - days ▁high - alt itude ▁flight ▁for ▁extended ▁scientific ▁studies ▁with ▁natural ▁re - entry ▁from ▁orbit ▁V ost ok ▁ 1 1 ▁- ▁supp lement al ▁flight ▁for ▁extra - ve h icular ▁activity ▁tests ▁V ost ok ▁ 1 2 ▁- ▁supp lement al ▁flight ▁for ▁extra - ve h icular ▁activity ▁tests ▁V ost ok ▁ 1 3 ' ▁- ▁ 1 0 - days ▁high - alt itude ▁flight ▁for ▁extended