Cricket2019-07-08

Thepathtothemoon determinedbyKatherineandNASAengineersinvolved

f irstlaunchingtheastronauts intoEarthorbitbeforepropellingthecommand

moduletothemoon.Flight maneuvershadtobepreciselytimed,takinginto

account the constantmotionofbothEarthandthemoon.

trajectorywouldbea parabola,a geometric

shaperesemblinganarch,andwouldneedto

beprecise,astheloneastronautwouldhave

tobedeliveredtoa specificsiteintheAtlantic

OceanwhereNavyshipswouldbewaitingto

retrievehim.Thejobofchartingthemission’s

trajectoryfelltoKatherine,whohadproven

herselfasa capableresearcheranda reliable

mathematician.“Letmedoit,”shetoldthe

NASAengineers.“Tellmewhenyouwantit

andwhereyouwantit toland,andI’lldoit

backwardsandtellyouwheretotakeoff.”

Usinganalyticgeometry,Katherinefigured

outwhattheFreedom 7 rocket’sspeedand

altitudeshouldbetoreachbothspaceandthe

splashdownlocation.Witha flightachieving

a peakaltitudeof 116miles(187kilometers)

anda topspeedof 5,180miles(8,336kilome-

ters)perhour,AlanShepard

becamethefirstAmerican

inspaceonMay5, 1961.

ThankstoKatherine’s

calculations,Shepardwas

grinningaboarda Navy

shipwithinelevenmin-

utesof splashdown.His

fifteen-minutespaceflight

wasconsidereda triumph

andsparkedPresidentJohn

F. Kennedytocallforthe

UnitedStatestolanda per-

sononthemoonandreturn

himsafelytoEarthbythe

endof thedecade.

Earlythefollowing

year,NASAwasfinally

ready to attempt its first orbital flight. Katherine’s

equations would help determine the launch trajectory

and flight path for the new mission, which would

be much more complex than a simple parabola.

Reaching orbital velocity would require greater speed

and power—although acceleration could not be so

rapid as to create gravitational forces, or g-forces,

severe enough to leave the astronaut incapacitated.

By 1962, NASA had begun relying more on

machines for complex calculations. A large but rather

primitive computer by today’s standards, the IBM

7090, plotted the complicated coordinates for the

orbital flight path. But before astronaut John Glenn

would launch aboard Mercury’s powerful Atlas

rocket, he had a demand for NASA’s leadership:

Katherine Johnson needed to review the computa-

tions. “If she says they’re good, then I’m ready to go,”

he told them.

Launch

Splashdown

Trans-lunar

injection

Rendezvous with

commandmodule

Tr a n s - E a r t h

injec

Lunarmodule

To u c h d ow n

APOLLO

LUNARLANDING

MISSIONPROFILE

SO HEREIS YOUR

PARABOLA, SEE? A NICE

SYMMETRICAL CURVE.

OHHHHH-KAY.

FIRST, THE ROCKET
BLASTS OFF,
LAUNCHING THREE
ASTRONAUTS IN THE
COMMAND MODULE UP
TO THE MOON!

YAY

BLASTOFF!

Pathtomo

on

Retu ascentt

rn (^) to
Earth
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