Belitopia S1E4 – The Venus Flyby p2
Links and More InformationEpisode DetailsBelitopia Venus Flyby InformationWikipedia - Venus FlybyWikipedia - Apollo Applications ProgramOriginal 1967 NASA Venus Flyby Feasibility StudyPlease support our show.IntroductionIn the last episode of Belitopia, we started our story of the Venus 1 voyage. In this episode, we conclude our story of this historic voyage.Venus 1, a mission launched as part of the Apollo Applications Program, used Apollo technology with some necessary extensions in order to send a crew of two astronauts on the first ever flyby of another planet.This mission never happened in reality, but a version of this mission was in the planning stages before budgets were cut. But this is Belitopia. In our world, funding did occur, and the Venus Flyby mission actually occurred.We left off after part 1 in the middle of the mock documentary, “Our World in Space”, as it describes the Venus Flyby mission in greater detail. This fictional documentary takes place in the year 2040, 65 years after the mission took place.We left the documentary in part 1 after talking about the Christmas Miracle burn that saved the crew and mission in December of 1975. Now, let’s continue with our story. Let’s re-enter the documentary where we left off. We’ll talk about the flyby itself, the mission home, and the unprecedented and untried process used to slow down the ship in time for reentry into the earth’s atmosphere for a safe and slow splashdown.Now back to the voyage of Venus 1 — the Venus mission, in the world of Belitopia.Documentary — Our World in Space, 2040ADHello, and welcome to “Our World in Space — The Venus Flyby”. Part 2.The rest of the flight to Venus was, indeed, uneventful. After the Christmas Miracle burn on December 29, 1975, the next 43 days of the mission were busy preparing for the flyby. Long before the flyby itself would occur, many scientific experiments and studies were planned involving solar experiments with the sun, deep space experiments, and eventually Venus studies as the ship neared the flyby itself.The crew of Venus 1 was very busy.In fact, they were too busy to spend time thinking about what almost happened. They were too busy to think about what happened that resulted in the need for the Christmas Miracle burn in the first place, and how lucky they were that they were saved.Backlash from the CrisisThat wasn’t true on earth, however. On earth, there was significant discussions, among government leaders, NASA and AAP leaders, as well as among the general public. Their were two concerns.The first, would the STS engine continue to function for the rest of the trip, and can the mission end successfully as planned on day T+210? Most people were convinced that the engine would continue to work properly, but, there still were concerns.The second was a more actionable concern. While Venus 1 was in process, plans were progressing for a Venus 2 and Venus 3 flight. These two additional Venus flyby missions were similar in nature to Venus 1 using the exact same technology. The research and science they would perform would be different, but the basic flight plan was the same. Venus 2 was set to launch during the second planetary alignment window two years later in July of 1977. Venus 3 was scheduled to launch a year later in May 1978.However, the crisis on Venus 1 and the need for the Christmas Miracle brought heightened attention to the fact that there was only one main STS engine on the service module. If that engine were to fail, the mission would undoubtedly end in disaster. The engine was considered highly reliable, but still, it was a single point of failure. Unlike the Apollo moon missions, there was no free return trajectory that was available with the planned Venus missions profiles, so the engine would be required in order to safely return the spacecraft home.Given this concern, an unfortunate and unpopular decision was made. Apollo technology, as is, had insufficient safeguards built in to avoid any single point failure problems. Newer systems and better technology beyond Apollo was needed before we could safely attempt another mission beyond the moon. This effectively put an end to the planned Venus 2 and Venus 3 missions, and put to an end the development of a similar Mars 1 flyby mission that was still in the early planning stages. Those missions would have to wait for better technology, technology that would not be available for many years yet.The FlybyThe flyby itself was actually a very short window of visibility into Venus. Over 100 days into a 210 day mission, the flyby itself, the entire purpose of the trip, would occur during a very short two day period. After nearly 100 days in space, the entire purpose of the trip would be over in a matter of a few dozen hours.Planning was crucial to make sure that the ultimate advantage could be taken of the two day flyby. Sleep was minimal as the crew readied themselves for the flyby. There would be no sleep at all during the 48 hours of the flyby itself. Anticipation at its climax, the crew was getting ready.The flyby, adjusted for the changes caused by the Christmas Miracle burn, started officially at 15:35 hours on February 10, 1976 and ended at 8:12 hours on February 12th. The flyby of Venus, the planet named after the Roman Goddess of Love, occurred just two days before Valentines day, the holiday of love. This wasn’t the original plan. But, by, coincidence, coincidence created by the Christmas Miracle burn, the flyby would occur near Valentine’s Day. This was deemed a positive omen by the mainstream media and considered a good sign for the ongoing success of the mission. A sign of good luck that the crew — and those following on earth — desperately needed.United States President Gerald Ford, acting along with the congress of the United States, declared Valentines Day, February 14, 1976, an official day of celebration for the ongoing success of the Apollo Venus Flyby mission.And success it was.After the incredibly brief encounter with Venus, the ship was spun around by gravity and was now headed back on their four month return voyage home.Through March and April, the ship continued its trip to reach earth. Two Earth Assist Burns were needed. Nerves were fragile and everyone was at high alert as the first burn approached. After all, the SPS engine had not been used since the Christmas Miracle. If it failed again, all would be lost. It had to work.And it did work. It worked flawlessly. For over two months everyone was In a heightened state of anticipation to see what would happen when this burn occurred. Yes, all the experts said the engine was fine, but the proof was in the actual firing of the engine. Over two months after the Christmas Miracle, the STS engine worked perfectly and the crew was still on their proper course home.The second earth assist burn, EAB-II, occurred two months later and it too worked flawlessly. The crew of Venus 1 was perfectly aligned with earth and were heading home.All that remained now was to slow down enough to land safely.The SlowdownThe ship, after all, was traveling at unheard of speeds for previous manned space flight. The spacecraft was speeding toward earth at a relative speed of nearly 10,000 miles per hour. A significant amount of that speed needed to be shed before a reentry into the earth atmosphere could be considered.But how was this speed reduction going to occur? For the moon missions, this step was easy. While the ship was traveling at a high speed, the speed could be shed off by simply skipping into the earth atmosphere at such an angle that speed would be reduced by atmospheric friction, converting the speed to heat.For the Venus mission, though, the speed was too excessive to make that possible. If Venus 1 attempted to enter the atmosphere at the speed they were traveling, they would burn up in a matter of seconds, creating a fireball that could be seen for hundreds of miles.Before any attempt to enter the earth atmosphere could be contemplated, a significant amount of speed needed to be scrubbed. This speed reduction was accomplished by a series of maneuvers. These maneuvers involved the use of the gravity of the moon and the gravity of the earth to reduce that speed.The speed would be loss by a series of slowdown flybys of both the earth and the moon.The series of maneuvers were to occur over the last 14 days of the trip.This final stage of the voyage started on May 18, 1976, when the habitation module, which served as the crews primary home for the last 191 days, was undocked and left to float away. With most of the consumable resources consumed, the habitation module was no longer needed and would simply serve as a nuisance during the final maneuvers of the mission.So on May 18, the habitation module was separated from the ship and was sent into a trajectory that would send the spent module out past earth orbit and into deep space. The habitation module was the primary home for the two astronauts for the last seven months. It served its purpose near perfectly. Now, spent, it was abandoned.Meanwhile, the remaining Command-Service Module was sent onwards towards the second Lunar Flyby of the mission. This one, near the end of the mission, was designed to shed off a significant amount of excess velocity. The Lunar Flyby II occurred on May 19, 1976, and sent the ship on a quick 2 and a half day trip towards earth. The shortness of the trip to earth was because the ship still had too much velocity. While slower than its previous cruising velocity, if the ship were to try and re-enter now, it would still burn up.So, more speed needed to be shed. An additional burn of the service module engine occurred, and this burn aligned the spaceship into a position for a slingshot flyby past earth and back towards the moon. This earth flyby shed a significant amount of additional speed.On the way back to the moon, another minor course adjustment burn was performed, and Venus 1