▁The ▁satellite ▁had ▁to ▁be ▁built ▁in ▁a ▁very ▁specific ▁shape ▁and ▁weight , ▁so ▁it ▁could ▁be ▁used ▁in ▁place ▁of ▁one ▁of ▁the ▁weights ▁necessary ▁for ▁bal ancing ▁the ▁payload ▁in ▁the ▁ro cket ▁stage . ▁ ▁OS C AR ▁ 1 ▁was ▁the ▁first ▁satellite ▁to ▁be ▁e ject ed ▁as ▁a ▁secondary ▁payload ▁( the ▁primary ▁payload ▁was ▁Disc over er ▁ 3 6 ) ▁and ▁to ▁subsequently ▁enter ▁a ▁separate ▁orbit . ▁ ▁It ▁carried ▁no ▁on - board ▁prop ulsion ▁and ▁its ▁orbit ▁decay ed ▁quickly . ▁ ▁Despite ▁orbit ing ▁for ▁only ▁ 2 2 ▁days , ▁OS C AR ▁ 1 ▁was ▁an ▁immediate ▁success . ▁ ▁Over ▁ 5 7 0 ▁amateur ▁radio ▁operators ▁in ▁ 2 8 ▁countries ▁forward ed ▁observations ▁to ▁Project ▁OS C AR . ▁ ▁OS C AR ▁ 1 0 ▁ ▁Most ▁of ▁the ▁components ▁for ▁OS C AR ▁ 1 0 ▁were ▁" off ▁the ▁sh elf ". ▁ ▁Jan ▁King ▁led ▁the ▁project . ▁ ▁Sol ar ▁cells ▁were ▁bought ▁in ▁batch es ▁of ▁ 1 0 ▁or ▁ 2 0 ▁from ▁Radio ▁Sh ack , ▁and ▁tested ▁for ▁efficiency ▁by ▁group ▁members . ▁ ▁The ▁most ▁efficient ▁cells ▁were ▁kept ▁for ▁the ▁project ; ▁the ▁rest ▁were ▁returned ▁to ▁Radio Sh ack . ▁ ▁Once ▁ready , ▁OS C AR ▁ 1 0 ▁was ▁mounted ▁ab o ard ▁a ▁private ▁plane , ▁and ▁flow n ▁a ▁couple ▁of ▁times ▁to ▁evaluate ▁its ▁performance ▁and ▁reli ability