Nasa History

Margot Lee Shetterly's Hidden Figures reveals the struggle that African Americans faced during the time of the Space race and how they struggled to fight for their rights that they deserved. From the very start of the book, the struggles are introduced by Katherine Johnson's issues to get a job. When she gets a job at Langley air force base she is told that she wouldn't be there long as a computer. They try to get America first into space before the Soviet Union but they lose, in a manner of speaking. The Soviet Union was the first to get a satellite into space and the Americans were first to send a man into space and first to send a man to the moon. The United States spends so much money on going to space, and to a planet where there isn't any life at all. Yet the troubles in the nation were horrible, racism, discrimination, inequality. Many African Americans were concerned if they would ever get full rights, without discrimination or racism. Shetterly places the events in a greater context of history in the beginning of the book by starting in 1942, a few years after World War two had started. She starts explaining that even though it's about women working their way up in the social status, black people still get discriminated against. "Virginia's white teachers ranked in the bottom quarter in public school salaries, and their black counterparts might earn almost 50 percent less"(P. 11) The book then goes on to go into the context of around the end of the war and that America is modernizing itself because of the war. "there was a nursery school for the tinites tots, a boon to the mothers working six-day weeks during the war." (P. 63) Which shows that women were allowed to work

Electrical power is essential for the operation of a spacecraft. When that spacecraft must travel far from the Sun or operate for longer periods in hostile environments (such as the long lunar night or the dust storms of Mars) then nuclear power becomes enabling. In response to the need for long-lived, Sun-independent power, the US Atomic Energy Commission (AEC) initiated studies in the 1950s of both space nuclear reactors and space radioisotope power sources. These early concepts were designated by a SNAP number where SNAP stands for Systems for Nuclear Auxiliary Power. Even-numbered SNAP power sources were reactors and odd-numbered SNAP power sources were radioisotope power sources.

In recent years, three probes have been sent into outer space: Galileo, Ulysses and Cassini. Each has used for its electricity power source, a radioactive thermoelectric generator (RTG), heated by a source of plutonium 238. Cassini, launched in October 1997, will reach its scientific objective in late June or early July 2004, concurrent with PSAM7. The authors of this paper had the privilege of providing the final review of the Cassini safety assessments for the Office of Science and Technology of the President, before final approval by the President of the United States, as required by law and international treaty, before the launch of any nuclear device into space. In this paper, we will discuss the risk analysis carried out jointly by NASA and DOE and our assessment of their results. Since the United States has established a new initiative for space exploration using a nuclear fission device for exploration of the icy moons of Jupiter (JIMO), we believe the JIMO project can benefit from a critical review of the experience gained by past projects using RTGs, and in particular identification of those aspects which make the risk estimates plausible to the layman. There are several scenarios for possible adverse effects on public health. The probabilities for each scenario must be added to form a number for the overall risk. The probability of each scenario is a product of two basic terms: the probability of release of plutonium and the probability of an individual being hurt by the release. It is evident that the probabilities for the two terms are truly independent. For example, there is reason to believe that the probability of the space probe hitting the earth in a failed 'swing by' only has a connection with the stochastic probability of developing lung cancer by the amount of plutonium evaporated and not by the mechanism of cancer induction. Each probability is on the order of one in a million. Then it is easy to understand why the risk to an individual of a 'swing by' is less than one in 10 11 years, although the more complex NASA-DOE calculations, which allow for a reduction in the plutonium release for many possible reentry scenarios, puts it a factor of 50 smaller. We also comment on the procedures used for calculating the probabilities and consequences of these scenarios, on presenting these calculations to the public, on errors in various public comments on the Cassini Environmental Impact Statement, and on the comparative risks from RTGs and small nuclear reactors.

Experiments showing a seasonal variation of the nuclear decay rates of a number of different nuclei, and decay anomalies apparently related to solar flares and solar rotation, have suggested that the Sun may somehow be influencing nuclear decay processes. Recently, Cooper searched for such an effect in 238 Pu nuclei contained in the radioisotope thermoelectric generators (RTGs) on board the Cassini spacecraft. In this paper we modify and extend Cooper's analysis to obtain constraints on anomalous decays of 238 Pu over a wider range of models, but these limits cannot be applied to other nuclei if the anomaly is composition-dependent. We also show that it may require very high sensitivity for terrestrial experiments to discriminate among some models if such a decay anomaly exists, motivating the consideration of future spacecraft experiments which would require less precision.

Among these problem-solvers were a group of exceptionally talented African American women, some of the brightest minds of their generation. Originally relegated to teaching math in the South’s segregated public schools, they were called into service during the labor shortages of World War II, when America’s aeronautics industry was in dire need of anyone who had the right stuff. Suddenly, these overlooked math whizzes had a shot at jobs worthy of their skills, and they answered Uncle Sam’s call, moving to Hampton, Virginia and the fascinating, high-energy world of the Langley Memorial Aeronautical Laboratory.

The exploration of space both by humans and robots has been greatly enhanced and, in many cases, enabled by the use of radioiso-tope power sources (RPSs) to power and/or heat scientific instruments. Radioisotope power sources have enabled such breakthrough missions as the Pioneer flights to Jupiter, Saturn and beyond; the Voyager flights to Jupiter, Saturn, Uranus, Neptune, and beyond; the Apollo lunar surface experiments; the Viking Lander studies of Mars; the Galileo spacecraft that orbited Jupiter; the Ulysses mission to study the polar regions of the Sun; the Cassini spacecraft orbiting Saturn; and the recently launched New Horizons spacecraft to Pluto. Radioisotope heater units have enhanced or enabled the Apollo Early Scientific Experiment Package and the Mars exploration rover missions (Sojourner, Spirit and Opportunity). Since 1961, the United States has successfully flown 41 radioisotope thermoelectric generators (RTGs) to provide electrical power for 23 space missions. Published by Elsevier Ltd.

Nuclear power sources have enabled or enhanced some of the most challenging and exciting space missions yet conducted, including missions such as the Pioneer flights to Jupiter, Saturn, and beyond; the Voyager flights to Jupiter, Saturn, Uranus, Neptune, and beyond; the Apollo lunar surface experiments; the Viking Lander studies of Mars; the Ulysses mission to study the polar regions of the Sun; the Galileo mission that orbited Jupiter; the Cassini mission orbiting Saturn and the recently launched New Horizons mission to Pluto. In addition, radioisotope heater units have enhanced or enabled the Mars exploration rover missions (Sojourner, Spirit and Opportunity). Since 1961, the United States has successfully flown 41 radioisotope thermoelectric generators (RTGs) and one reactor to provide power for 24 space systems. The former Soviet Union has reportedly flown at least 35 nuclear reactors and at least two RTGs to power 37 space systems.

The general-purpose heat source radioisotope thermoelectric generator (GPHS-RTG), which was most recently flown on the New Horizons mission to Pluto, was originally conceived in 1979 and executed in a crash program to replace another RTG for the planned International Solar Polar Mission (ISPM). ISPM would later morph into the Ulysses mission to explore the polar regions of the Sun. When the benefits of the GPHS-RTG technology became apparent, the Galileo program also adopted the GPHS-RTG as the power source for orbital exploration of Jupiter. The GPHS-RTG then became the power source of choice for the Cassini mission to Saturn. The GPHS-RTG was designed such that it could produce 300 We at fueling with a mass of 55.9 kg, making the GPHS-RTG the most powerful RTG with the highest specific power ever flown.

Audiovisual records of a Project Mercury pilot's activities during an orbital flight indicate that his visor was left open during reentry and descent to the sea surface, phases of flight during which cabin pressure loss was to be mitigated by suit pressurization; however the suit could not have been pressurized with the visor open. Thus, for a presentlyunknown reason, a critical safety step-sealing the visor and making a pressure suit integrity test before re-entry-was overlooked in this flight, a fact itself unreported in any flight review or historical documents known to the author. The lesson is clear: even a highly-motivated, federally-funded project remains at base a collaboration of individuals, the project only being as strong as the proverbial weakest link. Attention to development of thorough and unambiguous procedural checklists is reiterated.

Pacific Spaceflight’s Mark II pressure garment (model Gagarin) was test flown to 17,200 feet MSL (5,242m) while worn and operated by Dr. C.M. Smith. The garment and its portable life support system (PLSS) maintained appropriate pressure, temperature and carbon dioxide levels throughout the 47-minute flight. The suit also provided sufficient elbow mobility, due to its convolute joints, for the suited person to operate the portable life support system’s manual suit pressure setting valve and the hand-held radio.