Your goal is first to learn about the breed. But at that point you will be in an information gathering stage so it won't matter whether the person has puppies available. Yes, you probably will need to talk to breeders to get the information. Theįirst list is things you should know before you focus on a particular breeder. To make things a little easier I've created a few separate lists. You will find that a lot of the answers will become obvious to you as you become more familiar with reading advertisements, and talking dogs with people. Use the questions to help you explore what it is that makes one breeder better than another. It isn't as though you need to spend two hours on the phone grilling the person with these questions. Oh, and don't have a heart attack at the length of this checklist. If you don't have any idea how to find the breeders to ask them the questions then take a look at the page on It is the overall picture that is important. Just because something is missing does not mean a person is not an ethical breeder. This checklist is only a guide, an ideal if you will. Part of being ethical is to avoid contributing to the problem and to contribute to the solutions. Note that these are not confined just to considering how healthy the dogs being bred are, but the contribution being made to the health and welfare of dogs generally. These are questions a person can consider in trying to evaluate the ethical qualities of a breeder.
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The first of seven Surveyor robotic spacecraft sent to collect data (in-cluding 11,000 photographs) over a period of 30 days for the proposed Apollo moon landing, Surveyor 1 was the first spacecraft to make a soft lunar landing, using retro-rockets to slow the lander from 6,000 to 3 mph for a soft touch-down. , Atlas Centaur AC-10 launches the Surveyor 1 spacecraft from Pad 36A at Cape Canaveral. The horse symbolized the Atlas 1-1/2 stage lower “workhorse” booster, while the man portion symbolized the “intelligent” upper stage. Ehricke, known as the father of Centaur, named his creation for the halfman / half-horse creature of Greek mythology. One or two Rocketdyne RL10 engines burning liquid oxygen (LOX) and liquid hydrogen (LH2) made Centaur the world’s first high-energy upper-stage rocket, one which enabled NASA to launch some of its most important scientific missions over the next 50 years. They all agreed that liquid oxygen (LOX) / liquid hydrogen (LA2) rocket engines were the most promising solution to the propellant question for “higher-end” applications.Ĭonvair’s second-stage concept, ushered into hardware by Ehricke, was basically a smaller version of the Atlas rocket itself, using the same pressurized balloon-tank concept. Ehricke also opined that Atlas would need a second-stage rocket in order to be useful for deeper space missions, so in 1956 he and a small group of Convair engineers began to study the problem in earnest. Ehricke, who had worked with Wernher von Braun at Peenemünde and later at Red Stone Arsenal, concluded that Atlas, based on the data, was capable of boosting itself into orbit, which it later did with the Project SCORE satellite. (Piction ID: 48063106 - Catalog: 14_025440)īack in 1954, Convair hired an ex-German V-2 rocket engineer named Krafft Arnold Ehricke (1917-1984) to perform conceptual studies of Atlas performance. Like Wernher von Braun, Ehricke was an alumnus of Hitler’s V-2 program but today is remembered as the father of the Atlas Centaur, a second-stage vehicle so versatile, reliable and efficient that variants are still in use 55 years later. This carefully staged publicity shot was probably conceived as PR “damage control” in the wake of Russia’s shocking success with Sputnik I, the world’s first artificial satellite, less than one week before this photo was taken. “See, we’re doing it, too!” Poker-faced rocketeer Krafft Ehricke with futuristic GD Astronautics satellite models on 10 October 1957. After Agena’s retirement in the summer of 1978, all Atlases were subsequently flown with the Centaur upper stage. It addition to the first five Mariner unmanned probes to Venus and Mars, the first interplanetary fly-bys, and the Ranger and Lunar Orbiter unmanned moon probes, Atlas Agena was used even more extensively for launching classified DoD payloads. Atlas Agena was launched 109 times during its 18-year career, with an 85 percent success rate. Agena sat atop an Atlas D lower “stage and a half” configuration and, combined, provided two and a half stages of rocket power. As of 2019, 251 Centaurs had flown.First launched in 1960, Agena was an expendable upper-stage launch system (ELS) developed by Lockheed Aircraft Corporation. 365 Agena stages were flown from 1959 to 1987. What made the Agena family less successful than the Centaur family?ĭepending on your metrics, it wasn't less successful. Solid rockets were considered to be much safer for carriage in the shuttle payload bay, and probably considerably cheaper. Instead, solid rocket stages (PAM, IUS, etc) were used to deploy high-energy spacecraft off the shuttle. There was a plan to launch Centaur from the shuttle but it was abandoned after the loss of Challenger. In contrast, Centaurs were used with the Space Shuttle I ran across a 1968 Bellcomm memo comparing possible unmanned lunar payload delivery systems from a Titan IIID, Centaur could put 75% more mass into a moon-bound trajectory than Agena. Centaur uses the RL10 hydrogen-oxygen engine, with specific impulse up in the 440-450 s range depending on version, but Agena used UDMH and nitric acid with a specific impulse of around 300. Agena is a much smaller and less powerful stage than Centaur.Īstronautix gives Agena-D a loaded mass of about 6.8 tons, as compared with around 23 tons for Centaur (though this varies quite a bit with version changes). |
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