U.S. Marned Spacecraft Launch Vehicle Size Comparison

This illustration depicts a comparison of two space vehicles, the U.S.'s Saturn IB launch vehicle and the U.S.S.R.'s Soyuz launch vehicle, for the Apollo-Soyuz Test Project. The ASTP was the first international docking of the U.S.'s Apollo spacecraft and the U.S.S.R.'s Soyuz spacecraft in space. A joint engineering team from the two countries met to develop a docking system that permitted the two spacecraft to link in space and allowed the two crews to travel from one spacecraft to the other. This system entailed developing a large habitable Docking Module (DM) to be carried on the Apollo spacecraft to facilitate the joining of two dissimilar spacecraft. The Marshall Space Flight Center was responsible for development and sustaining engineering of the Saturn IB launch vehicle during the mission.

This is a comparison illustration of the Redstone, Jupiter-C, and Mercury Redstone launch vehicles. The Redstone ballistic missile was a high-accuracy, liquid-propelled, surface-to-surface missile. Originally developed as a nose cone re-entry test vehicle for the Jupiter intermediate range ballistic missile, the Jupiter-C was a modification of the Redstone missile and successfully launched the first American Satellite, Explorer-1, in orbit on January 31, 1958. The Mercury Redstone lifted off carrying the first American, astronaut Alan Shepard, in his Mercury spacecraft Freedom 7, on May 5, 1961.

As landing technology improves and these landing ellipses shrink, missions can aim for more precise landings, opening up new areas of Mars to explore. Perseverance takes it two steps further than previous missions. First, it uses a new algorithm to time its parachute deployment based on distance to its target rather than vehicle velocity. This shrinks the landing ellipse to 4.8 miles by 4.1 miles (7.7 kilometers by 6.6 kilometers). Second, the rover uses maps stored in its memory to avoid landing hazards within that smaller ellipse during its propulsive descent phase. This allows Perseverance to target safe landing locations within Jezero Crater. The rover is set to land on Feb. 18, 2021. Improvements in interplanetary navigation tightened the landing ellipse of Mars Pathfinder in comparison with missions before it. It landed by bouncing on the surface with airbags, and has the largest ellipse in this image, measuring 124.3 miles by 43.5 miles (200 by 70 kilometers). The Phoenix and InSight landers used retrorockets to land on three legs, but still had large possible landing areas about 80.8 miles (130 kilometers) long. In 2012, the Curiosity team developed guided entry technology, shrinking its landing ellipse further. The spacecraft used small rockets to steer itself through the atmosphere as it headed toward Gale Crater. https://photojournal.jpl.nasa.gov/catalog/PIA24349

Assembling the Little Joe capsules. The capsules were manufactured in-house by Langley technicians. Three capsules are shown here in various stages of assembly. The escape tower and rocket motors shown on the completed capsule would be removed before shipping and finally assembly for launching at Wallops Island. Joseph Shortal wrote (vol. 3, p. 32): Design of the Little Joe capsules began at Langley before McDonnell started on the design of the Mercury capsule and was, therefore, a separate design. Although it was not designed to carry a man, it did have to carry a monkey. It had to meet the weight and center of gravity requirements of Mercury and withstand the same aerodynamic loads during the exit trajectory. Although in comparison with the overall Mercury Project, Little Joe was a simple undertaking, the fact that an attempt was made to condense a normal two-year project into a 6-month one with in house labor turned it into a major undertaking for Langley. Project Mercury: Little Joe: Boilerplate Mercury spacecraft undergo fabrication at the shops of the Langley Research Center. They will launched atop Little Joe rockets to test the spacecraft recovery systems. -- Published in Joseph A. Shortal, History of Wallops Station: Origins and Activities Through 1949, (Wallops Island, VA: National Aeronautics and Space Administration, Wallops Station, nd), Comment Edition. L59-4947 Technicians prepare a Little Joe launch vehicle prototype for the Mercury space program, 1959. Photograph published in Winds of Change, 75th Anniversary NASA publication, page 76, by James Schultz

Assembling the Little Joe capsules. The capsules were manufactured in-house by Langley technicians. Three capsules are shown here in various stages of assembly. The escape tower and rocket motors shown on the completed capsule would be removed before shipping and finally assembly for launching at Wallops Island. Joseph Shortal wrote (vol. 3, p. 32): Design of the Little Joe capsules began at Langley before McDonnell started on the design of the Mercury capsule and was, therefore, a separate design. Although it was not designed to carry a man, it did have to carry a monkey. It had to meet the weight and center of gravity requirements of Mercury and withstand the same aerodynamic loads during the exit trajectory. Although in comparison with the overall Mercury Project, Little Joe was a simple undertaking, the fact that an attempt was made to condense a normal two-year project into a 6-month one with in house labor turned it into a major undertaking for Langley. Project Mercury: Little Joe: Boilerplate Mercury spacecraft undergo fabrication at the shops of the Langley Research Center. They will launched atop Little Joe rockets to test the spacecraft recovery systems. -- Published in Joseph A. Shortal, History of Wallops Station: Origins and Activities Through 1949, (Wallops Island, VA: National Aeronautics and Space Administration, Wallops Station, nd), Comment Edition. L59-4947 Technicians prepare a Little Joe launch vehicle prototype for the Mercury space program, 1959. Photograph published in Winds of Change, 75th Anniversary NASA publication, page 76, by James Schultz

Assembling the Little Joe capsules. The capsules were manufactured in-house by Langley technicians. Three capsules are shown here in various stages of assembly. The escape tower and rocket motors shown on the completed capsule would be removed before shipping and finally assembly for launching at Wallops Island. Joseph Shortal wrote (vol. 3, p. 32): Design of the Little Joe capsules began at Langley before McDonnell started on the design of the Mercury capsule and was, therefore, a separate design. Although it was not designed to carry a man, it did have to carry a monkey. It had to meet the weight and center of gravity requirements of Mercury and withstand the same aerodynamic loads during the exit trajectory. Although in comparison with the overall Mercury Project, Little Joe was a simple undertaking, the fact that an attempt was made to condense a normal two-year project into a 6-month one with in house labor turned it into a major undertaking for Langley. Project Mercury: Little Joe: Boilerplate Mercury spacecraft undergo fabrication at the shops of the Langley Research Center. They will launched atop Little Joe rockets to test the spacecraft recovery systems. -- Published in Joseph A. Shortal, History of Wallops Station: Origins and Activities Through 1949, (Wallops Island, VA: National Aeronautics and Space Administration, Wallops Station, nd), Comment Edition. L59-4947 Technicians prepare a Little Joe launch vehicle prototype for the Mercury space program, 1959. Photograph published in Winds of Change, 75th Anniversary NASA publication, page 76, by James Schultz

Assembling the Little Joe capsules. The capsules were manufactured in-house by Langley technicians. Three capsules are shown here in various stages of assembly. The escape tower and rocket motors shown on the completed capsule would be removed before shipping and finally assembly for launching at Wallops Island. Joseph Shortal wrote (vol. 3, p. 32): Design of the Little Joe capsules began at Langley before McDonnell started on the design of the Mercury capsule and was, therefore, a separate design. Although it was not designed to carry a man, it did have to carry a monkey. It had to meet the weight and center of gravity requirements of Mercury and withstand the same aerodynamic loads during the exit trajectory. Although in comparison with the overall Mercury Project, Little Joe was a simple undertaking, the fact that an attempt was made to condense a normal two-year project into a 6-month one with in house labor turned it into a major undertaking for Langley. Project Mercury: Little Joe: Boilerplate Mercury spacecraft undergo fabrication at the shops of the Langley Research Center. They will launched atop Little Joe rockets to test the spacecraft recovery systems. -- Published in Joseph A. Shortal, History of Wallops Station: Origins and Activities Through 1949, (Wallops Island, VA: National Aeronautics and Space Administration, Wallops Station, nd), Comment Edition. L59-4947 Technicians prepare a Little Joe launch vehicle prototype for the Mercury space program, 1959. Photograph published in Winds of Change, 75th Anniversary NASA publication, page 76, by James Schultz

Assembling the Little Joe capsules. The capsules were manufactured in-house by Langley technicians. Three capsules are shown here in various stages of assembly. The escape tower and rocket motors shown on the completed capsule would be removed before shipping and finally assembly for launching at Wallops Island. Joseph Shortal wrote (vol. 3, p. 32): Design of the Little Joe capsules began at Langley before McDonnell started on the design of the Mercury capsule and was, therefore, a separate design. Although it was not designed to carry a man, it did have to carry a monkey. It had to meet the weight and center of gravity requirements of Mercury and withstand the same aerodynamic loads during the exit trajectory. Although in comparison with the overall Mercury Project, Little Joe was a simple undertaking, the fact that an attempt was made to condense a normal two-year project into a 6-month one with in house labor turned it into a major undertaking for Langley. Project Mercury: Little Joe: Boilerplate Mercury spacecraft undergo fabrication at the shops of the Langley Research Center. They will launched atop Little Joe rockets to test the spacecraft recovery systems. -- Published in Joseph A. Shortal, History of Wallops Station: Origins and Activities Through 1949, (Wallops Island, VA: National Aeronautics and Space Administration, Wallops Station, nd), Comment Edition. L59-4947 Technicians prepare a Little Joe launch vehicle prototype for the Mercury space program, 1959. Photograph published in Winds of Change, 75th Anniversary NASA publication, page 76, by James Schultz

Assembling the Little Joe capsules. The capsules were manufactured in-house by Langley technicians. Three capsules are shown here in various stages of assembly. The escape tower and rocket motors shown on the completed capsule would be removed before shipping and finally assembly for launching at Wallops Island. Joseph Shortal wrote (vol. 3, p. 32): Design of the Little Joe capsules began at Langley before McDonnell started on the design of the Mercury capsule and was, therefore, a separate design. Although it was not designed to carry a man, it did have to carry a monkey. It had to meet the weight and center of gravity requirements of Mercury and withstand the same aerodynamic loads during the exit trajectory. Although in comparison with the overall Mercury Project, Little Joe was a simple undertaking, the fact that an attempt was made to condense a normal two-year project into a 6-month one with in house labor turned it into a major undertaking for Langley. Project Mercury: Little Joe: Boilerplate Mercury spacecraft undergo fabrication at the shops of the Langley Research Center. They will launched atop Little Joe rockets to test the spacecraft recovery systems. -- Published in Joseph A. Shortal, History of Wallops Station: Origins and Activities Through 1949, (Wallops Island, VA: National Aeronautics and Space Administration, Wallops Station, nd), Comment Edition. L59-4947 Technicians prepare a Little Joe launch vehicle prototype for the Mercury space program, 1959. Photograph published in Winds of Change, 75th Anniversary NASA publication, page 76, by James Schultz