"Worked a minimum of 72 hours a week, they were fed 1,100 calories a day. Lung and heart disease was epidemic because of the dampness and intense air pressure. Deaths averaged 160 a day. When a deputation of prisoners petitioned for improved conditions, SS Brigadefuehrer Hans Kammler responded by turning machine guns on them, killing 80." -- Dr. A. Poschmann, chief medical officer to Albert Speer, Nazi minister of armament, at the Nuremberg trials.

This was life for the 52,000 inmates of concentration camp Dora who were forced to work inside the Mittelwerk, 1.2 million square feet of factory space in two tunnels dug out of a ridge in the Harz Mountains in what is now East Germany.

From April 1943 to April 1945, Dora's inmates built more than 6,000 V2 "vengeance" rockets that Adolf Hitler believed would save the Third Reich. More than 1,300 of the deadly rocket-bombs hit Britain in the waning months of the war, all fired from the Peenemunde base Hitler built on Germany's Baltic coast near the island of Ruegen.

The man who ran the production line in what Poschmann called "Dante's Inferno" is Arthur Louis Hugo Rudolph, who lived in the United States from 1945 until March of this year, when he renounced his U.S. citizenship and returned to Germany rather than face deportation.

"For two years, Arthur Rudolph was chief operations director for what has been described as a death factory," said Neal M. Sher, director of the Justice Department's Office of Special Investigations and the man who hounded Rudolph out of the United States after three years of investigation. "It is an awful irony that his experience and expertise in rocketry had to be used in this country over the bones of so many innocent victims of Nazi Germany's crime against humanity."

Not only did Rudolph live in the United States for almost 35 years, but he also designed the Pershing missile for the U.S. Army and supervised production of the Saturn 5 rocket that put the Skylab space station in orbit and 12 Apollo astronauts on the moon. For this, he shook the hands of three U.S. presidents and won the Distinguished Service Medal, the highest honor that can be bestowed by NASA.

Why was Rudolph allowed into the United States? Why was he allowed to stay so long? Were his crimes real? Or was he an unwitting pawn of Hitler's determination to produce the V2 rocket at any cost?

Some of the answers lie interred with the dead of the Mittelwerk, but a trail of facts also flows through the public records of the U.S. Army, the National Archives, the State Department's Berlin Document Center, Britain's Imperial War Museum and West German court proceedings. These documents reveal as tangled a web as any work of fiction written about Nazi Germany and the Cold War that followed its collapse.

Rudolph was brought to the United States by Project Paperclip, the secret Army operation that brought Wernher von Braun and his corps of more than 100 V2 experts to the United States. Not all the "Peenemundians," as they called themselves, were allowed to stay in the United States. The Mittelwerk director general, George Rickhey, Rudolph's superior, was ordered back to Germany to stand trial for war crimes. He was acquitted but was not invited back to the United States.

Why Rickhey and not Rudolph? There is no "smoking gun" in the public record, but U.S. Army documents suggest that Rickhey was expendable and Rudolph was not.

"Rickhey was an engineer, but he was more an engineering foreman than anything else," said one former Justice Department attorney who examined hundreds of Army documents. "Rudolph, on the other hand, was an expert in rocketry as well as being a very demanding production boss. He was somebody the Army wanted to keep in the United States."

The Justice Department said Rudolph renounced his citizenship rather than face a deportation trial. A Justice Department spokesman said that in his job as production boss at the Mittelwerk, Rudolph used as many as 10,000 slave laborers of 31 nationalities working "under the most inhumane conditions imaginable" to crank out V2 rockets. The department said at least 5,000 died at the Mittelwerk while Rudolph ran the production line.

The department said Rudolph was aware of every death, including as many as 87 Soviet workers who were hanged in four mass executions inside the tunnels.

How does the Justice Department know this? "Director Rudolph signed all the death certificates," a Mittelwerk secretary said after the war.

Rudolph said he had no knowledge of working conditions and was never aware of a single death inside the Mittelwerk. "Hard to tell," Rudolph told Army Maj. Eugene Smith, who asked him about slave labor conditions at the Mittelwerk a month after Rickhey was deported in May 1947. "It was not my department."

A graduate of the Engineering College of Berlin, Rudolph joined the Nazi Party in 1931, almost two years before Hitler came to power. He joined the paramilitary S.A. in 1933 and marched with the other "brown shirts."

When Rudolph arrived at the Mittelwerk in 1943, 10,000 inmates of the Dora camp still were digging the underground tunnels that SS Chief Heinrich Himmler turned over to Rudolph.

On May 6, 1944, Rudolph met in the Mittelwerk with SS leaders and V2 experts, including von Braun. The topic was stepped-up V2 production, especially of the electrically driven steering mechanisms that were to guide the V2s to their British targets.

SS Sturmbannfuehrer Otto Forschner, later hanged for war crimes, suggested using "Haeft-linge," in particular some 800 French political prisoners, some of them professors of physics and engineering. "French workers can only be used if they are clothed," Forschner said. The document did not mention any objections from Rudolph or von Braun.

"Clothed" was an SS euphemism for concentration camp prisoners, wearing the "striped pants and jackets" of inmates.

Other documents showed that less than a month after the Mittelwerk meeting attended by Rudolph and von Braun, more than 1,000 French prisoners were moved to Rudolph's assembly line. More than 700 died. When the war ended, the Mittelwerk was called "the French graveyard."

As head of production, Rudolph did more than supervise V2 output. When Smith interrogated Rudolph at Fort Bliss in 1947, the Army major repeatedly asked Rudolph about working conditions inside the tunnels. Twenty-seven times, Rudolph answered, "I don't know" or "I don't remember" or "I never noticed."

German documents show, however, that Rudolph requisitioned workers from the Dora camp and his 40 assistants helped train them. His minions also were in charge of clothing and feeding the workers. Their sleeping and toilet accommodations were his responsibility. When asked how long work shifts were, Rudolph replied, "I think it was 12 hours. It would be impossible for them to work any longer."

Rudolph told Smith that working conditions at the Mittelwerk "appeared good."

However, after his only visit to the Mittelwerk, Speer ordered a camp built for the prisoners to sleep outside the tunnels. Until the camp was built in late 1944, prisoners slept on the same wet ground where they worked. The death rate from pneumonia and tuberculosis reached epidemic proportions in the winter of 1944.

Meals were one bowl of watery soup twice a day. Their toilets were gasoline drums cut in half. Their clothes, Rudolph told the Army, were the "Haeftlinge uniform, long jacket and pants with stripes running vertical. For digging, it was surely enough to keep warm."

Perhaps the most telling case against Rudolph is made by documented reports of four mass hangings inside the tunnels. Two Soviet workers were hanged by SS guards when they discovered that the workers had stolen a piece of electrical wire to make a spoon for themselves. On another occasion, nine Soviets were hanged based on a sabotage report filed against them with the SS by Rudolph's office.

Hannelore Bannasch, Rudolph's secretary at the Mittelwerk, testified after the war, "I know there was a hanging early in 1945, about February. In Tunnel B. I know of 60 men. I believe they were Russians who planned an act of sabotage."

Rudolph told the Army he had "never seen anybody punished, beaten, hung or shot."

Smith asked, "Tell me about the day Rickhey ordered 12 men hung by a crane."

Rudolph replied, "The SS had control of things like that."

Smith said, "Rickhey could have stopped it, couldn't he?"

Rudolph replied, "I don't know."

Smith asked, "When did this happen?"

Rudolph replied, "I don't remember -- the fall of 1944."

Smith said, "Tell me about it."

Rudolph's reply was a key to the Justice Department case against him 40 years after the hanging.

"I got an order to stop all work," Rudolph said. "I don't remember who the order came from. I found out there was to be an execution from the same order. Then I told the department chiefs to stop the work and that all the Haeftlinge inside the tunnel had to assemble in the main assembly tunnel. The SS troops brought the Haeftlinge to the tunnel."

What did Rudolph see? "There was a rope about their necks and the rope was on the traverse of the crane."

Did they move? "I know that one lifted his knees."

Why were they hanged? "It was said they had a plot to blow up the underground plant. I don't know whether it was true."

Who were the men hanged? "I think they were Russians. Their hands were tied behind their backs, there was a piece of wood in their mouths to keep them from shouting. I don't remember about their feet."

One of the most damaging witnesses against Rudolph was Hans Friedrich, who also came from the Mittelwerk to Fort Bliss with Operation Paperclip.

"I telephoned Mr. Rudolph, who was technical director of the Mittelwerk, and asked him how long the crane would be out of work," Friedrich said. "He told me the men would be hanging there the last six hours of one work shift and the first six hours of the next work shift, so that all Haeftlinge could see.

"I asked some people why they were hung and why they had gags in their mouths. I was told they were hung because they plotted to sabotage the Mittelwerk on 9 November 1944, which is the date of a German holiday. I was told that the reason for the gags was that without them their tongues would come out."

From exile in Hamburg, Rudolph has told reporters that he was a scapegoat, that much of what has come out in the media against him is a "pack of lies."

Rudolph even has questioned the truth of a three-page news release on his departure for Germany by the Justice Department. But before he left, Rudolph initialed the release with his characteristic "Ru," indicating he approved of it.

Rudolph continues to collect the federal pension he accumulated in 35 years with the Army and NASA.