Launch Vehicles from NASA

 

                      L A U N C H    V E H I C L E S

                               (Overview)

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     Overcoming the pull of Earth's gravity is the first challenge of

any  space  mission.  Whether  small  and  suborbital  or  large  and

traveling to another planet, every spacecraft must  be  carried  into

space  before  it  can  do  its  job.  NASA  has  a  family of launch

vehicles--a graduated series  of  multistage  rockets--to  accomplish

its space programs.

     A  family  of  launch vehicles was developed because a number of

different vehicles were required for missions that ranged from simple

to complex. The vehicles are combinations  of  two  or  more  stages,

which  burn  one  after the other, each being discarded when it is no

longer needed,  so  only  a  small  part  of  the  whole  vehicle  is

necessary  to  propel  the  spacecraft  into the final orbit or space

trajectory.

     When NASA was formed, its launch capability depended  upon  what

was available and most of the vehicles were derived from the military

missile  program.  In time, additional vehicles were developed, using

both solid and liquid propellant rockets, specifically to  acquire  a

variety  of  launch vehicle combinations suited to the expanded space

exploration program.

     NASA owns launch sites at the  Eastern  and  Western  Space  and

Missile  Centers  (ESMC  and  WSMC) in Florida and California and the

Wallops Flight Facility in Virginia, and has access to the San  Marco

launch complex off the east coast of Africa owned by Italy.

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R E D S T O N E

STATUS: Inactive

Adapted by NASA from an Army ballistic missile, the Redstone was used

to  launch Project Mercury suborbital flights from 1960-61.  Redstone

flew successfully five times after an initial failure.  Two  unmanned

flights  and  one  with  the  chimpanzee  Ham preceded the first U.S.

manned spaceflight by Alan B. Shephard, Jr. in May 1961,  and  Virgil

I. Grissom's flight in July 1961.

Redstone measured 25 meters (83 ft) in height with capsule and escape

tower.  It  was a single stage launch vehicle using liquid propellant

(alcohol and liquid oxygen) and developed 35,380 kg (78,000  lbs)  of

thrust.

M E R C U R Y - A T L A S

STATUS: Inactive

Mercury-Atlas  was  a modified Air Force missile.  It stood 29 meters

(95.3 feet) high with capsule and escape tower.  The  vehicle  was  a

stage-and-a-half  rocket  that  produced  139,797 kg (308,000 lbs) of

thrust, burning RP-1 (kerosene) and liquid oxygen.

Mercury-Atlas was first used for John Glenn's orbital flight in 1962.

It launched all succeeding Project Mercury orbital flights.

G E M I N I - T I T A N

STATUS: Inactive

Titan, an Air Force ICBM, was  modified  by  NASA  as  Titan  II  for

Project  Gemini  (1965-66).   Titan  was a two-stage rocket, standing

109 ft in height, burning  Aerozine-50  and  nitrogen  tetroxide  and

produced  430,000  lbs  of  thrust in the first stage, 100,000 lbs of

thrust in the second.

A T L A S / A G E N A

STATUS: Inactive

The  Atlas/Agena  was  a  multipurpose  two-stage  liquid  propellant

rocket.  It  was used to place unmanned spacecraft in Earth orbit, or

inject them into the proper trajectories for planetary or deep  space

probes.

The programs in which the versatile Atlas/Agena was utilized included

early  Mariner probes to Mars and Venus, Ranger photographic missions

to the Moon, the Orbiting Astronomical Observatory (OAO),  and  early

Applications  Technology  Satellites (ATS). The Agena upper stage was

used as the rendezvous  target  vehicle  for  the  Gemini  spacecraft

during  this  series of two-man missions in 1965-1966. In preparation

for the manned lunar landings,  Atlas/Agena  launched  lunar  orbiter

spacecraft which went into orbit around the Moon and took photographs

of possible landing sites.

The  Atlas/Agena  stood  36.6  meters  (120 ft) high, and developed a

total thrust at liftoff of approximately 1,725,824  newtons  (288,000

lbs).  It was the last used in 1968 to launch an Orbiting Geophysical

Observatory (OGO).

S A T U R N  I B

STATUS: Inactive

The Saturn IB was originally used to launch Apollo  lunar  spacecraft

into  Earth orbit, to train for manned flights to the Moon. The first

launch of a Saturn IB with an unmanned Apollo spacecraft  took  place

in  February  1966.  A  Saturn  IB  launched  the first manned Apollo

flight, Apollo 7, on October 11, 1968.

After the completion of the Apollo program, the  Saturn  IB  launched

three  missions  to  man the Skylab space station in 1973. In 1975 it

launched  the  American  crew  for  the  joint  U.S./U.S.S.R  docking

mission.

Saturn  IB was 69 meters (223 ft) tall with the Apollo Spacecraft and

developed 7.1 million newtons (1.6 million lbs) of thrust at liftoff.

S A T U R N  V

STATUS: Inactive

The Saturn V, America's most powerful staged rocket, carried out  the

ambitious  task of sending astronauts to the Moon. The first Saturn V

vehicle, Apollo 4, was launched on November 9, 1967.  Apollo  8,  the

first manned flight of the Saturn V, was also the first manned flight

to  the  Moon; launched in December 1968, it orbited the Moon but did

not land. Apollo 11, launched  on  a  Saturn  V  on  July  16,  1969,

achieved the first lunar landing.

Saturn  V  began its last manned mission on December 7, 1972, when it

sent Apollo 17 on the final lunar exploration  flight.  It  was  last

used  on  May  14,  1973,  when  it  lifted the unmanned Skylab space

station into Earth orbit, where it was occupied by  three  crews  for

171 days.

All  three stages of the Saturn V used liquid oxygen as the oxidizer.

The first stage burned kerosene with the oxygen, while the  fuel  for

the  two  upper stages was liquid hydrogen. Saturn V, with the Apollo

spacecraft and its small emergency escape rocket on  top,  stood  111

meters  (363  ft)  tall,  and  developed  34.5  million newtons (7.75

million lbs) of thrust at liftoff.

T I T A N  I I I - E / C E N T A U R

STATUS: Inactive

The Titan III-E/Centaur, first  launched  in  1974,  had  an  overall

height  of 48.8 meters (160 ft). Designed to use the best features of

three proven rocket propulsion systems, this vehicle gave the U.S. an

extremely  powerful  and  versatile  rocket   for   launching   large

spacecraft on planetary missions.

The  Titan  III-E/Centaur  was  the  launch  vehicle  for  two Viking

spacecraft to Mars, and two Voyager spacecraft  to  Jupiter,  Saturn,

Uranus and Neptune. It also launched two Helios spacecraft toward the

Sun.  All provided remarkable new information about our solar system.

The Vikings and Voyagers produced spectacular  color  photographs  of

the planets they explored.

The Titan III-E booster was a two-stage liquid-fueled rocket with two

large  solid-propellant  rockets  attached.  At  liftoff,  the  solid

rockets provided 10.7 million newtons (2.4 million lbs) of thrust.

The Centaur stage, still  in  use  today,  produces  133,440  newtons

(30,000  lbs)  of  thrust  from two main engines, and burns for up to

seven and one-half minutes. The  Centaur  can  be  restarted  several

times which allows for more flexibility in launch times.

D E L T A

STATUS: Active

Delta  is called the workhorse of the space program. This vehicle has

successfully transported over 160 scientific, weather, communications

and applications satellites into  space.  These  include  the  TIROS,

Nimbus and ITOS satellites, and many Explorer scientific spacecraft.

First launched in May, 1960, the Delta has been continuously upgraded

over  the years. Today it stands 35.4 meters (116 ft) tall. Its first

stage is augmented  by  nine  Caster  IV  strap-on  solid  propellant

motors,  six of which ignite at liftoff and three after the first six

burn out 58 seconds into the flight. The average  first-stage  thrust

with  the  main  engines  and  six solid-propellant motors burning is

3,196,333 newtons (718,000 lbs). Delta has  liquid-fueled  first  and

second  stages  and a solid-propellant third stage. For most launches

today, this third stage has been replaced by a Payload Assist  Module

(PAM) stage attached to the satellite.

The  new  PAM  upper stage is also used on Space Shuttle launches. It

boosts spacecraft from  low  Earth  orbit  achieved  by  the  Shuttle

orbiter  into higher ones. Many spacecraft, especially communications

satellites, operate in a geosynchronous  (geostationary)  orbit  some

35,792  kilometers (22,240 miles) above the equator. With the PAM and

a recent change to a more powerful second stage, the Delta  can  lift

some  1,270 kilograms (2,800 lbs) into a highly elliptical orbit, for

transfer  into  geosynchronous  orbit  by  a  motor  built  into  the

spacecraft.  This  is  almost  double the 680 kilograms (1,500 lbs) a

Delta could manage ten years ago.

A T L A S / C E N T A U R

STATUS: Active

The Atlas/Centaur is NASA's standard launch vehicle for  intermediate

payloads. It is used for the launch of Earth orbital, geosynchronous,

and interplanetary missions.

Centaur   was   the   nation's   first  high-energy,  liquid-hydrogen

liquid-oxygen launch vehicle stage. It  became  operational  in  1966

with the launch of Surveyor 1, the first U.S. spacecraft to soft-land

on the Moon.

Since  1966, both the Atlas booster and the Centaur second stage have

undergone many improvements. At  present,  the  combined  stages  can

place  over  4,530  kilograms  (10,000 lbs) in low-Earth orbit, about

2,020 kilograms (4,453 lbs) in  geosynchronous  transfer  orbit,  and

over 1,000 kilograms (2,205 lbs) on an interplanetary trajectory.

An  Atlas Centaur stands 41.9 meters (137.6 ft) tall. At liftoff, the

Atlas booster develops over 1.9  million  newtons  (438,400  lbs)  of

thrust.  The  Centaur  second  stage develops 146,784 newtons (33,000

lbs) of thrust in a vacuum.

Spacecraft launched by Atlas/Centaurs include  Orbiting  Astronomical

Observatories;  Applications Technology Satellites; Intelsat IV, IV-A

and V communications satellites; Mariner  Mars  orbiters;  a  Mariner

spacecraft which made a fly-by of Venus and three of Mercury; Pioneer

spacecraft  which  accomplished  fly-bys  of  Jupiter and Saturn, and

Pioneers that orbited Venus and plunged through its atmosphere to the

surface.

S C O U T

STATUS: Active

The Scout launch vehicle, which became operational in 1960, has  been

undergoing  systematic  upgrading  since  1976.  The  standard  Scout

vehicle  is   a   solid-propellant,   four   stage   booster   system

approximately  23  meters  (75  ft) in length with a launch weight of

21,600 kilograms (46,620 lbs) and liftoff thrust of  588,240  newtons

(132,240 lbs).

Recent  improvements  include  an  uprated  third-stage  motor  which

increases the Scout's payload capability. It can now place up to  211

kilograms (465 lbs) in low-Earth orbit. The third stage also has been

provided with an improved guidance system.

Over  100  scouts  have been launched to date. They have been used to

place a variety of U.S. and  international  payloads  into  inclined,

equatorial and polar orbits for orbital, probe and reentry missions.

S P A C E  S H U T T L E

STATUS: Active

The  Space  Shuttle  consists  of  a reusable delta-winged spaceplane

called the orbiter; two solid-propellant rocket boosters,  which  are

recovered and also reused; and an expendable external tank containing

liquid propellants for the orbiter's three main engines.

The assembled Space Shuttle is approximately 56 meters (184 ft) long,

23.3  meters (76 ft) high (to tip of orbiter's vertical tail), and 24

meters (78 ft) wide, measured across the orbiter's wingtips.  Liftoff

weight  of  the  Shuttle vehicle is approximately 2,041,168 kilograms

(4,500,000 lbs).

At  launch,  the  orbiter's  three   liquid-fueled   engines--drawing

propellants  from  the  external  tank--and  the two solid propellant

rocket boosters burn simultaneously. Together,  they  generate  about

28,650,000 newtons (6,400,000 lbs) of thrust at liftoff. As the Space

Shuttle reaches an altitude of about 50 kilometers (31 mi), the spent

solids  are  detached  and  parachuted  into the ocean where they are

recovered by waiting ships for eventual refurbishment  and  reuse  on

later missions. The orbiter and external tank, still attached to each

other,  continue  toward Earth orbit. When the orbiter's main engines

cut off,  just  before  orbit  is  achieved,  the  external  tank  is

jettisoned,  to  impact in a remote ocean area. Using onboard orbital

maneuvering  engines,  the  orbiter  with  its   crew   and   payload

accelerates  into orbit to carry out an operational mission, normally

lasting from two to seven days.

When the mission is completed, the orbiter reenters  the  atmosphere,

and  returns  to  Earth,  gliding  to an unpowered landing. Touchdown

speed is above 335 kilometers (210 mi) per hour.

E X P E N D A B L E  L A U N C H  V E H I C L E S

For the decade of the 1990s and beyond, NASA plans to employ a  mixed

fleet  of  launch  vehicles  in  which  the  Space  Shuttle  will  be

complemented  by  expendable  launch  vehicles  (ELVs).  The   latter

vehicles  will  not  be  purchased  for  NASA  operation;  NASA  will

contract for launch services  with  aerospace  companies  or  procure

such services through the Department of Defense.

The  intent of the plan is to reduce dependence on the Space Shuttle,

add flexibility to the space program, and free the Shuttle for manned

scientific, Shuttle-unique and important national security  missions.

A  major  objective  is  to  accelerate  deployment  of space science

missions backlogged by the Shuttle's temporary removal from service.

The  number  of  ELV  launches  required  annually  cannot  be  fixed

precisely  since  it  is  dependent  upon  future  program approvals.

Generally, NASA foresees possible  annual  need  for  three  to  five

medium  ELVs,  one or two each in the intermediate and large classes,

and an  undetermined  number  in  the  small  vehicle  category.  The

vehciles  available  or  being  developed in these categories are the

medium ELV Delta II, built  by  McDonnell  Douglas  Corporation;  the

intermediate  Atlas  Centaur (General Dynamics Corporation) and Titan

III (Martin Marietta Corporation);  and  the  large  Titan  IV  (also

Martin Marietta). LTV Aerospace Corporation manufactures the standard

small launch vehicle, the Scout.

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NASA Information Summaries, Countdown! NASA Launch Vehicles and

Facilities, PMS 018 (KSC), Nov 1986

NASA, The First 25 Years 1958-1983, A Resource For Teachers, EP-182

NASA FACT SHEET, Space Launch Vehicles , KSC 49-80

SPINOFF 1987, Washington Headquarters, 1987-190-760