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Pushing Technological Limits: Post-Apollo Space Exploration
- Published On
June 11th, 2024
- Author
Saad Uppal
After the end of the space race and the subsequent retirement of the Apollo program, the world developed new technologies and spacecraft that would eventually expand humans’ understanding of outer space. This article will focus on 3 noteworthy programs which pushed technological boundaries: the space shuttle program, the Hubble Space Telescope, and the construction of the International Space Station, along with some other missions, such as the first landing on Mars and Venus.
The Infamous Space Shuttle
The space shuttle had a rich history, with almost 30 years of flight. The program was filled with achievements as well as tragedies. The shuttle came about after several designs and plenty of time spent on the drawing board. The unique challenge of building a reusable vehicle that took off like a rocket and landed like an airplane was immense. Engineers had to consider that the shuttle would have to be built in such a way that it could withstand the hypersonic speeds of liftoff and re-entry, while also being able to glide in sub-sonic speeds and eventually land on a runway.
The building of the space shuttle was entrusted to familiar names in the industry. Rocketdyne (now Pratt and Whitney) oversaw the development of the main engines of the orbiter, while Martin Marietta (now Lockheed Martin) built the iconic orange external tank. Finally, after many budget cuts and reiterations, in September of 1976, space shuttle ‘Constitution’ was unveiled. However, fans of a long-cancelled TV show ‘Star Trek’ wanted it called ‘Enterprise’ after the iconic ship featured in the TV show. In 1977, Enterprise was attached to a modified 747, with the goal of detaching at 15,000 feet and performing a landing in the Mojave desert’s lakebed. The test was a success, with 4 more tests carried out to validate the design and gather data.
The Space shuttle ‘Enterprise’ taking off aboard a modified Boeing 747 in 2015 (Photo Credit: NASA Government)
A new spaceworthy shuttle was designed and given the name ‘Columbia’. A new space worthy shuttle was designed and given the name ‘Columbia’. As expected, it was not all smooth sailing, with multiple challenges being faced by NASA. Most notably, the ceramic tiles on the underbelly of the ship, designed as a heat shield for re-entry, kept falling off. However, the fabrication process was modified, and the problem was overcome.
Finally, on April 12th, 1981, space shuttle ‘Columbia’ launched from launch complex 39-A and landed on Edwards Airforce Base with a total flight time of 2 days and 6 hours, carrying mission commander John W. Young and pilot Robert L. Crippen to orbit. Over the next 5 years, the shuttle served as a workhorse rocket, carrying multiple Comsats, some Department of Defense payloads, and many others in a total of 24 successful missions. However, disaster struck on January 28th, 1986, when space shuttle ‘Challenger’ exploded due to a leakage in one of the Solid Rocket Boosters (SRB), killing all 7 crew, including Christa McAuliffe, a high school teacher. It would be more than two years after the shuttle launched again.
In 1990, space shuttle ‘Discovery’ carried the Hubble Space Telescope (HST) to orbit. However, a design flaw prevented HST from capturing sharp images, thus five additional servicing missions had to be sent to correct the flaw. Then on June 27th, 1995, Space shuttle ‘Atlantis’ docked with the Mir space station (built by the Russians) and played a great role in reducing tensions with the former Soviet Union as cosmonauts and astronauts lived in harmony together. In total, the shuttle docked with Mir 11 times between 1994 and 1998. Towards the end of 1998, on the 4th of December, Space shuttle ‘Endeavour’ carried the Unity module of the International Space Station (ISS) and subsequently docked to the Zarya Module (launched by the Russians almost a month ago), forming the basis of the ISS. The shuttle would carry out a total of 27 assembly missions due to its large payload bay. Without the space shuttle, the ISS would have never left the drawing board. Disaster struck once again on 16th Jan 2003, when space shuttle ‘Columbia’ broke up on reentry, killing all seven crew. Finally, on 8th of July 2011, ‘Atlantis’ performed the last space shuttle flight, launching from LC-39A and landing in the Kennedy Space Center. Thus, bringing an end to a marvelous era of technological and aeronautical advancements.
The Hubble Space Telescope
The photograph captures Hubble's distinct structure, with its large cylindrical body, extended solar panels, and the open aperture that houses its powerful optics. (Imag Credit: NASA)
Most – if not all – of the people reading this article are familiar with the Hubble Space Telescope (HST). Hubble is mostly known for its large contributions to science and allowing humans a deeper view – literally and figuratively – into the beginning of the universe. However, with its achievements, it is easy to forget that Hubble was almost a failure.
Being a space telescope, Hubble bypassed a major flaw of ground-based telescopes, as light did not have to pass through the atmosphere to reach it, subsequently the rays were not distorted, leading to more accurate images of the universe. However, building Hubble was a challenge as well. It needed to remain still and point towards a part of the sky while taking a photo, while its natural tendency would be to flip around haphazardly, as it was orbiting Earth at almost 5 miles per second. To solve this, NASA teams installed 6 fine-tuned gyroscopes which spun 20 times per second and kept Hubble stable. After being constructed and assembled, Hubble was almost 44 feet (13.5 meters) long and weighed close to 12,000 kilograms (27,000 pounds), equipped with an 8-foot mirror, designed to reflect light into the many instruments on board. However, during the construction of the mirror, a crucial testing step was inadvertently skipped, resulting in a minor defect in the mirror.
After almost 15 years in development, Hubble was launched on 24th of April, onboard ‘Discovery’, the telescope was successfully deployed, and the shuttle came home. After almost 2 months, NASA director of astrophysics, Charlie Pellerin, was with Chief Engineer, Gene Oliver, when Hubble sent back its first images. Charlie pointed out a fuzzy spot, however Gene convinced him that only a minor technical adjustment must be made. However, the team later realized that they had launched Hubble with a spherically aberrated mirror. When the news was heard nationwide Hubble quickly became the butt of jokes. Charlie Pellerin said,
“When I realized what happened, I didn’t believe my personal reputation was in danger, I believed it was ruined.”
Thankfully though, the NASA team realized the problem: one edge of the mirror was off by about 50th of a human hair, thus NASA built COSTAR (Corrective Optics Space Telescope Axial Replacement) consisting of 5 motorized mirrors effectively serving as optical glasses to correct the defect. It was installed in one of Hubble’s instrument bays in 1993 on one of the shuttle missions. After it was installed, it would take time to calibrate, so the shuttle crew landed without knowing whether their mission had been successful. 11 days later, the calibrations were completed, and images were transmitted to mission control. COSTAR had been successful and fixed the problems with the mirror, everyone was spellbound by the images being sent back.
This sharp and colorful close-up of the dying star’s nebula was recorded in 2009 by the Hubble Space Telescope’s Wide Field Camera 3, installed during the final shuttle servicing mission. (Photo Credit: NASA)
Hubble paved the way for humans to understand the beginning of the universe by essentially looking back at time. It has captured images of galaxies as far away as 13.4 billion light years away, meaning that we can see how the universe looked and behaved only 400 million years after the big bang.
The International Space Station
The International Space Station (ISS) weighed approximately 420 tonnes and measures 74 meters long by 110 meters wide. Astronauts living on the ISS stay in the modules, which are pressurized with air to breathe, providing comfortable living conditions and protection from the vacuum of space. Each module has one or more berthing ports that can be used to connect it with other parts of the station. It also has two main sections: the Russian orbital segment (built in Russia) and the American orbital segment (built in America, Japan, and parts of Europe). Both sections are slightly different and use different technologies and methods to achieve the same goal. For example, the design of the berthing ports is different, thus a special adapter called the Pressurized Mating Adapter (PMA) had to be used to connect two modules from the different world powers.
The International Space Station (ISS) is a monumental feat of engineering and international collaboration, with its various components built by different countries and companies. (Photo Credit: ESA)
Most of the modules were sent up by the space shuttle because of its large payload area. However, some were also sent up by the Russians. In fact, the first module for the ISS, Zarya, was sent up by Russia. Zarya was originally built to be part of the Mir space station, but it didn’t fly due to the end of the program. Thus, it was modified and launched on 20 November 1998 aboard a Proton rocket from the Baikonur Cosmodrome in Kazakhstan, with 6 berthing ports to connect it with future modules. The previous century, in 1900, all theories convinced that light was a wave, but in the 20th century, all were coming towards its particle nature
Next, space shuttle ‘Endeavor’ was launched a month later, carrying the Unity module. On day 3 of the mission, the Canadarm on the space shuttle grabbed onto unity was attached with the orbital docking system on the shuttle. Then, on the 4th day of the mission, the shuttle slowly approached Zarya and docked with it. It would take a few more days of preparation before the crew could enter the space station. On the 8th day of the mission, the hatch was opened, and the astronauts went inside the station, they only stayed for a day before departing. In that time, 3 EVAs (Extra Vehicular Activities) were carried out to finalize the installation and add communication devices along with some extra cables.
The third major module added to the ISS was the Zvezda (meaning “star” in Russian) service module with a total of 4 berthing ports. It was launched on 12th July 2000 aboard a Proton rocket and docked to the Zarya module 2 weeks later. Zvezda was important in the sense that it carried the main life support systems and electrical systems for continued human presence in space. Zvezda is still an integral part of the ISS and is usually the assembly area for crew during meetings or emergencies.
The first module dedicated solely to research in the ISS was America’s, Destiny lab. It was launched in February 2001 aboard the space shuttle ‘Atlantis’. The mission lasted for 12 days while the shuttle remained docked to the ISS for only 6. After docking with Unity’s nadir (pointing towards the Earth) port, the Canadarm was used to move Destiny and connect it with Unity’s forward-facing berthing port, this process took hours to complete and very careful movement to ensure nothing was damaged.
The next day, the latches were opened, and the crew entered the lab for the first time. A total of 3 separate EVAs had to be done to connect and install items and cables outside the laboratory.
Many more modules were sent up, like the Columbus and Harmony module. The ISS was built over a decade and 30 missions were launched to assemble all the modules and another instruments. It is a testament to what humans can achieve if they put aside their differences and collaborate to achieve a joint goal, aiming for the prosperity of humankind.=
Other Missions
The Soviet Mars 3 mission launched on May 28, 1971, aboard a Proton rocket. The spacecraft consisted of a lander and an orbiter designed to orbit Mars after the lander separated. The lander attempted a soft landing on Mars on December 2 of the same year; the first ever to do so. However, it failed 110 seconds after landing, with no experiments being carried out, and only transmitted a gray image with no detail. The orbiter continued to perform nominally and stayed in service for eight months, carrying out experiments and sending images back to Earth.
The Soviet Venera 9 mission was the first to orbit and land on Venus. The spacecraft was launched on June 8, 1975, aboard a Proton rocket. The probe entered Venus’s orbit on October 20, 1975. The lander was then separated from the orbiter module and landed on Venus two days later. This mission gave humans the first pictures – albeit black and white – taken from the surface of another planet.
Each image transmitted from Vinera 9 provided valuable insights into the geology and atmosphere of Venus, shedding light on its complex and hostile environment. (Photo Credit: NASA Science)
The Cassini probe (built by NASA) was the fourth spacecraft to perform a flyby of Saturn and the first to enter its orbit. It launched on October 15, 1997, aboard a Titan IV rocket. After nearly seven years and four gravity assists from Venus, Earth, and Jupiter, Cassini entered Saturn's orbit on July 1, 2004. A lander named “Huygens” performed a soft touchdown on the largest of Saturn’s moons – Titan. Cassini remained in orbit for more than 13 years and performed a controlled descent into the gas giant’s thick atmosphere, where it burned up after transmitting data taken from the upper parts of Saturn’s atmosphere.
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