Mastering Space Beyond Near-Earth – Part 2: How We Got Started – The American Story

From the ashes of Germany’s Second World War V-rocket program, the United States and Soviet Union developed space programs of their own. They did this by bringing the German scientists from Peenemunde to their respective countries along with the factories and remaining rocket inventories.

It should be no surprise that so many of the ideas and technology developments behind the programs of both countries appeared similar in design. While the Soviets managed to achieve the most notable firsts in their space exploration program from the launch of Sputnik to the first lunar  landers and orbiters, their American counterparts, with muscle and money, and managed by a single organization NASA, soon caught up.

America Goes Translunar

The United States launched Explorer-1 in January of 1958, almost 4 months after Sputnik-1. Built by the Jet Propulsion Laboratory (JPL) in California, the satellite contained instruments for detecting cosmic rays. The launch vehicle was a direct descendant of the German A-4, renamed the Jupiter-C. Explorer-1 weighed approximately 14 kilograms (30 pounds). Compare that to Sputnik-1 at 83.6 kilograms (183.9 pounds). Could the Americans have launched a satellite the size of Sputnik-1? Not in 1958.

The R-7 seen on the left was bigger than any American competitor. It produced sufficient thrust to put large payloads into low-Earth orbit, and in multi-stage versions was capable of translunar flight. In 1958 the 3 American competitors could put small satellites into Earth orbit but none had the thrust and payload capacity for translunar flight. Source: M. Gruntman, Blazing the Trail. The Early History of Spacecraft and Rocketry

The Soviet R-7 made American rocket boosters look feeble in comparison. The Jupiter-C’s Juno-1 version used in the Explorer-1 launch provided approximately 50,000 kilograms (110,000 pounds) of thrust. The R-7 in comparison with its four rocket engines could deliver 408,000 kilograms (900,000 pounds) of thrust, enough to launch payloads as large as 8,000 kilograms (17,600 pounds). The R-7 was modifiable to be a multi-stage vehicle for translunar flight. None of the American rockets had that capability.

In March 1959, the Americans launched Pioneer-4 using a Juno-2 rocket and for the first time had the thrust capability to push a satellite beyond Earth orbit to an escape velocity that allowed it to pass within 60,000 kilometers (37,000 miles) of the Moon. The Juno-2 payload capability allowed for a 41 kilogram (90 pound) satellite in low-Earth orbit and could boost a 6 kilogram (13 pound) object into translunar flight and ultimately solar orbit.

American Lunar Exploration

In support of President Kennedy’s pursuit of a manned spacecraft landing on the Moon before 1970, the United States developed both the technology for getting there and doing scientific study as well as  surveying and photographing the lunar surface. To do this the Americans relied on three missions and spacecraft types, the first called Ranger, the second Surveyor and the third Lunar Orbiter.

Ranger

The Ranger series of spacecraft were missions designed to take close-up images of the Moon’s surface. Ranger spacecraft were built to crash onto the lunar surface while sending images back to Earth until impact. To launch the equipment needed to do this type of mission the Americans required a more powerful rocket than the Juno and Jupiter-C. They chose Atlas as the primary launcher (see picture above) for these missions. Atlas was far more powerful than its predecessors and could place a 327 kilogram (702 pound) payload into lunar trajectory. But early Ranger attempts failed to get beyond Earth orbit because of problems with the rocket’s upper stages. When Ranger-3 launched in January 1962 it was placed in low-Earth orbit before the upper stage rocket engines were successfully restarted to inject the spacecraft into a translunar flight. The spacecraft missed the Moon as did its sister, Ranger-4, in April 1962. Ranger-5 launched in October 1962 relayed pictures of the Moon but missed its target by 725 kilometers (450 miles). In January 1964 Ranger-6 successfully hit the target but failed to transmit pictures of its descent. Finally in July 1964 with Ranger-7, a 362 kilogram (798 pound) satellite, the Americans achieved both impact and pictures. Ranger-8 and Ranger-9 successfully followed in 1965.

Ranger-9's descent to the surface of the lunar highlands was relayed to Earth using six TV cameras transmitting in high-resolution. The pictures seen here represent a sequence of the spacecraft's approach to the surface before crashing. The Ranger transmissions were shown "live from the Moon" to millions of TV viewers. Source: Malin Space Science systems, Inc.

In the Ranger program the Americans, like their Soviet rivals, demonstrated that they could provide sufficient payload launch capability to achieve beyond-Earth space flight. They could operate multi-stage rockets that could be restarted in space. They could adjust flight paths, and could operate instrumentation in space and communicate back to Earth.

What remained on the shopping list of technological achievement included powered, controlled descent and soft landing, and orbital insertion capability around a non-Earth space object. These technological achievements were the goals of the other lunar programs that NASA launched after Ranger.

Surveyor

In Surveyor-1, in June 1966, the United States demonstrated a technological breakthrough. Only trailing the Soviet Luna-9 landing by four months, Surveyor-1 provided colour-television camera images of the lunar surface and relayed these back to Earth. Launched by Atlas-Centaur rockets between 1966 and 1968, five of the seven successfully soft-landed on the Moon and transmitted more than 88,000 pictures of their landing sites back to Earth. These sites were to be future landing sites for the Apollo Program. Surveyor-3 and Surveyor-7 included robotic soil scoopers for sampling lunar surface materials. The Surveyor landers from 5 through 7 included chemical analysis equipment and magnetometers to study lunar surface soils.

The Atlas-Centaur rocket could place 5,000 pound payloads into high-Earth orbit. It was really the mating of two very different rocket systems. The Atlas lower stage provided sufficient thrust to allow the Centaur stage, using liquid hydrogen as propellant, to become the workhorse upper stage for robotic spacecraft missions not only to the Moon but to a number of planetary missions in the 1970s.  Centaur technology packed a lot of punch for its size. That’s because liquid hydrogen proved to be a high-energy fuel source for rocket propellant, far more efficient than kerosene. Mastering the technical challenges posed by liquid-hydrogen rocket systems proved to be a significant achievement for the American space program.

This image shows the landing sites of Surveyor, Apollo and the Soviet Luna spacecraft. Surveyor and Apollo would not have been achievable without the development of liquid-hydrogen rocket systems first successfully demonstrated with Atlas-Centaur rockets and later with the Saturn family of Moon rockets.

Lunar Orbiter

The final piece of the puzzle fell into place for the American space program’s ambitious attempt to land a human on the Moon before the Soviet Union with the successful Lunar Orbiter missions in 1966 and 1967. From Lunar Orbiter-1 in August 1966 to Lunar Orbiter-5 in August 1967, the Americans demonstrated technology that produced high-resolution images of 99% of the Moon’s surface. What started as a low-orbit project to map and image suitable landing sites for Surveyor and Apollo spacecraft turned into a scientific mission with the last two Lunar Orbiter flights. Lunar Orbiter-4 flew a high-altitude polar orbit and photographed the entire Earth facing side of the Moon and 95% of the far side. Lunar Orbiter-5 provided medium resolution images of the far side and high-resolution of 36 specific lunar sites.

Lunar Orbiter-1 took the first images of the Earth from lunar orbit. This image taken in 1966 was digitally enhanced in 2008. Source: Lunar Orbiter Image Recovery Project

The unmanned robotic missions to the Moon by the United States proved a strong technical foundation for subsequent planetary exploration. The rocket systems developed continue to be the primary technology NASA continues to use for space flight.

Mastering Space Beyond Near-Earth – Part 1: How We Got Started – The Soviet Story

How do you tackle the subject of space, a significant contributor to our technological progress in the 20th and 21st century? In my previous blogs on space I have described the development of rocketry, a technology that gave us the means to reach beyond the outer atmosphere and establish our first human-inhabited and artificial robotic systems in near-Earth proximity.

But in treating the subject of space in the 21st century we need to look beyond the race to space, the Moon, and the planets, comets and asteroids of the Solar System. We need to understand what’s in it for us, why space and the technology we invent to explore it will be a driving force for innovation throughout the 21st century.

So how did we get started? It began with the Soviet Union and Sputnik-1, on October 4, 1957 and humanity has never looked back. Sputnik circled the Earth. We then launched many more satellites, some to spy on our neighbours, some to help us improve global communications, some to study the atmosphere, weather, our oceans, land use and more. What started as a two-nation duopoly in space has broadened to become a global adventure today. The United States and Russia have been joined by 48 other countries with satellites in orbit. Nine countries have launched satellites into near-Earth orbit. Six countries and Europe through the 18-member European Space Agency (ESA) have sent probes to explore Solar System neighbours. Business is getting into the act with the United States moving from a government-only contractor to a mixed economic model embracing for-profit companies working on sub-orbital and low-Earth orbit transportation systems.

In the articles that follow we look at the history of our outward urge, starting with the Moon and other nearby Solar System neighbours. We look at this from the perspective of technological accomplishments in achieving success beyond Earth orbit. In this immediate posting we focus on the Soviet Union’s contribution to escaping the bonds of Earth. They were the first to do it and it is a remarkable story.

The Technology to Leave Earth Orbit – The Soviet Union Came First

The launch of Luna-1 by the Soviet Union represented the first human-made object to escape Earth’s gravity.What did it take to send a satellite beyond Earth orbit? It meant developing a rocket capable of lifting a 361 kilogram (790 pound) object, Luna-1, into space traveling at a speed of 11.2 kilometers (7 miles) per second. That amounts to 40,234 kilometers (25,000 miles) per hour.

An augmented R-7 rocket, named Vostok, provided the launch capability. In an earlier blog we talked about the R-7 program, the most successful rocket launching system ever built. For the Soviets to turn it into an orbital escape booster they added a third-stage. This gave them capability to deliver 6-ton payloads into low-Earth orbit, and 1.5 ton payloads into trans-lunar trajectory. Luna-1 proved a remarkable achievement for technology in 1959, passing within 6,000 kilometers of the Moon before entering solar orbit. Its onboard instruments fed telemetry back to Earth providing measurements of our planet’s magnetic field.

A second 1959 triumph was Luna-2. It was the first probe to target and hit a non-Earth object, the lunar surface.  The Soviets recognized that reaching the Moon required longer duration power systems to keep instrumentation working. In Luna-3, launched a month after Luna-2, they incorporated solar cell technology to supplement the onboard batteries. When Luna-3 reached the Moon it circled it and returned to pass by Earth. During this elongated orbit of both Earth and Moon its onboard camera photographed 70% of the Moon’s unseen side. The  camera used standard 35 mm film. An onboard film laboratory developed the images which were then scanned by a television camera and transmitted using radio waves back to ground stations as the spacecraft approached Earth.

This map of the Moon's hidden far side was compiled from photographic images obtained by Luna 3. It represented the first map created from the observations and data collected by an artificial satellite of a Solar System object. Source: International Planetary Cartography Database

The Soviets Develop Robotic Systems for Planetary Exploration

Right from the start the Soviet Union made the Moon a target of its space program. When President Kennedy announced the Moon as the goal of the American space program in the 1960s he was abundantly aware of Soviet ambitions. The Soviets weren’t hiding anything. They had built heavy lift capacity in their rocket systems  far more than needed for ballistic missiles. But the Soviets needed much more than big rockets if they were to succeed. Their shopping list included:

1. Multi-stage rockets capable of being started and stopped in mid-trajectory flight
2. Satellite systems capable of adjusting flight paths and inserting themselves with pinpoint accuracy into orbit around another space object
3. Remote separation of sub-assemblies from the main satellite
4. Extended-range power supplies using solar, nuclear and improved battery systems
5. Powered controlled descent and soft landing systems for robotic probes
6. Mobile robots capable of navigating over uneven remote surfaces
7. Instrumentation that worked beyond low-Earth orbit and on remote planetary surfaces
8. Two-way communications systems working at never attempted distances

The Soviets mastered these skills but they came at great cost. In 1965 they made four failed attempts (Luna-5 through 8) to soft land Luna probes on the Moon. The technology included vernier rocket packs for controlled descent, nitrogen-bag inflation systems to cushion probeS on impact, and instrumentation shielding to achieve ambient temperatures (19 and 30 degrees Celsius, 66 to 86 Fahrenheit)in a space vacuum. These technologies worked to perfection in January 1966 with Luna-9 making the first powered descent to the Moon’s surface. Luna-9 incorporated a panoramic television camera onboard capable of 360 degree coverage.

This compiled picture from Luna-9 was the first set of images ever taken by a remote robot from the surface of another Solar System object.

Two months after Luna-9, the Soviets once again proved they had mastered another technological accomplishment, successfully placing a satellite into lunar orbit. Luna-10 achieved this feat using its course correction engines to slow the spacecraft sufficiently for lunar orbit insertion. The battery-operated instrumentation package included gamma radiation, electric and magnetic field, micro-meteoroid, and solar wind detectors. After 57 days and 460 orbits the batteries finally ran out and the Moon’s first artificial satellite ceased transmissions.

In 1966 the Soviets followed with two more Luna orbiters, Luna-12 providing television transmissions of the lunar surface back to Earth and Luna-13, deploying a lander with a penetrometer to dig 45 centimeters (18 inches) into the Moon surface to study its soil properties.

Luna-16, launched in 1970, after the first two Apollo Moon landings, incorporated robotic systems for descent, sample collecting of lunar surface materials, ascent and then return to Earth. In 1970, Luna-17 delivered a robotic rover to the Moon’s surface, Lunokhod-1.

In 1973, Luna-21 delivered a more sophisticated robotic rover to the Moon’s surface, Lunokhod-2. This rover traveled 37 kilometers during its mission, transmitting more than 80,000 and conducting over 700 lunar soil tests.

In 1973 the Soviets landed a robotic rover on the Moon, Lunokhod-2. Operating with guidance from Earth it travelled 37 kilometers over the lunar surface taking soil samples and television images and relaying the results to ground stations in the Soviet Union.

The last Luna probe, Luna-24 landed on the Moon in 1976 where it proceeded to take a 2.5 meter lunar core sample and return it to Earth.

The Soviets in their lunar exploration activity created all the technologies needed for planetary exploration beyond the Moon.

What were the Americans doing in parallel? Read the next blog.

Our 20th Century Space Legacy – Part 1: The Evolution of Rocket Technology

I grew up on a steady diet of science fiction where humanity travelled as freely through space as we do on Earth. Our venture into space so far does not reflect the science fiction I read as a young man. Where the 20th century launched us for the first time into and beyond our atmosphere, the 21st to date has largely remained near-Earth orbit experience for humans in space. Human-built robots have been the spacefarers exploring the planets of the Inner and Outer Solar System and with spacecraft launched in the 1970s reaching interstellar space.

Rockets are a Chinese invention with reference to them as useful for both military and celebratory purposes. The Chinese defended themselves against the 13th century Mongol invasion using rockets with little effect. Through trans-Asian trade, rockets were introduced to Europe in the 14th century. Rockets primarily were powered arrows at this time. In the 19th century the British Congreve rockets inspired Francis Scott Key in his writing of “The Star Spangled Banner,” the American national anthem. Rockets were used in whaling to enhance the power and distance harpoons could travel. Rockets attached to safety lines were used to reach ships in distress so that they could be towed to safety. The Katyusha rockets of World War II were the 20th century equivalent of the British Congreve rocket.

The image above is of two Congreve Rockets, similar to the ones that inspired Francis Scott Key to write the American national anthem. Source: The Smithsonian Institute

But the rockets that were to launch humans into Outer Space did not use the technology inspired originally by Chinese invention. In 1903, Konstantin Tsiolkovsky, a Russian school teacher, proposed liquid propellants as a rocket fuel because of the potential increase in exhaust velocity to drive rockets farther. In his writing Tsiolkovsky laid the theoretical groundwork for the rockets of Robert Goddard, an American, who built the first liquid-fueled rocket and launched it successfully. It didn’t go far but the technology he demonstrated became the basis for Germany’s emergence as the leader in modern rocketry.

Before World War II rocket clubs popped up throughout Europe, Japan and the United States. Rocket hobbyists were popular in Germany inspirted by the writings of Dr. Hermann Oberth, a Hungarian-born German, who wrote about rocket travel beyond Earth. An inspired Werner von Braun in 1930 began experimenting, building and firing liquid-fueled rockets built on Goddard’s designs. Von Braun eventually became the leader of the German rocket program that created the A-4, the rocket known to us as the V-2. The A-4 stood 14 meters in height (46 feet), burned alcohol combined with liquid oxygen, and could launch a  750 kg, (1,650 pound) payload. It had a range of 360 kilometers (225 miles). Several thousand A-4s with attached warheads were constructed and launched against British, French and Belgian targets from 1944 to early 1945 causing considerable destruction.

With the end of World War II both the United States and Soviet Union took an interest in the weapon systems designed by Germany. German scientists, remaining inventory of A-4  rockets, and the engineering tools and technology were spirited out of the country. The race to exploit and enhance this technology for war and science had begun.

Machines Enter Outer Space, Humans Soon Follow

Both the United States and Soviet Union assembled and test-fired the remaining inventory of A-4 rockets. Then they began building their own largely for war purposes. The dream of using rockets to put machines and humans into outer space seemed like an afterthought.

Exploration of near-Earth space soon followed with the launch of Sputnik, in October, 1957, the first artificial satellite placed in orbit. Weighing 84 kilograms (183 lbs.), Sputnik’s launch vehicle was the R-7.  R-7 technology directly evolved from the A-4. It burned kerosene and liquid oxygen. Today’s Russian space program continues to use the R-7.

To get to orbit rocket technology needed to achieve escape velocity. That meant building rockets with more power. More power required a larger amount of fuel. Both the Americans and Soviets approached this by developing multiple-staged rockets. With multiple staging a rocket could achieve orbit without carrying around any extra weight in the form of empty rocket casings. The approach to multi-staging, however differed dramatically. The Americans chose to build multi-stage rockets in a vertical-stack configuration. The Soviets built multi-stage rockets by strapping together each rocket. In the picture below you can see how the two designs differ. In the short-term the Soviet design made it possible to develop heavier lift capacity. The R-7 had three times the thrust and payload capacity of any of the American rockets. With limited thrust and capable of delivering only small payloads American satellite requirements stimulated integrated circuit development and the technology behind modern computing. But at the beginning of the Space Age, this need for light and small was not seen as an advantage.

The two rockets on the left are American. The Jupiter C resembled the A-4 in design. The Redstone and its successors were vertically stacked. The Soviet R-7 design straps multiple rockets together giving them initially a significant technological advantage in delivering large payloads into near-Earth orbit.

In space the Soviets surged ahead with heavy launch capacity and a program aimed at being first in all the key categories;

1. First artificial satellite (Sputnik 1) October 4, 1957
2. First animal sent into orbit (Sputnik-2 with the dog, Laika on board) November 2, 1957.
3. First satellite to orbit the Moon (Luna 1) January 2, 1959.
4. First satellite to send photographic images of  70% of the Moon’s far side (Luna 3) October 4, 1959
5. First animals sent into orbit and returned safely to Earth (Sputnik-5 with two dogs, Belka and Strelka on board) August 19, 1960.
6. First human to orbit the Earth and return safely (Yuri Gagarin in Vostok 1) April 12, 1961
7. First human to do multiple orbits of the Earth (Gherman Titov in Vostok 2) August 6, 1961
8. First multi-crew orbital flight (Vladimir Komarov, Konstantin Feoktistov, Boris Yegorov, in Voskhod 1) October 14, 1964.

For the American program the achievements were far more modest, the successful launch of a satellite, Explorer 1, January 31, 1958. Pioneer 4, launched in March 3, 1959, became the first American satellite  to pass the Moon and achieve solar orbit. On May 5, 1961, Alan Shepard became the first American to achieve suborbital flight. And on February 20, 1962, John Glenn became the first American to orbit the Earth.

The components for reasonably reliable rocket technology made these advances possible. All that was left was the imagination and determination of a government to set an achievement goal. That happened when President John F. Kennedy established a goal of landing a human on the Moon before 1970.

In our next blog we will look at the technology that created to achieve the Lunar landing of Neil Armstrong and Edwin Aldrin in Apollo 11.