Category Astronomy

The first space probe to complete its mission was Luna 2. It was launched by the USSR in 1959 and successfully landed on its destination — the Moon. Its predecessor, Luna 1, was launched towards the same target several months earlier but missed by 6000km (3730 miles).

Luna 1 (launched Jan. 2, 1959) was the first spacecraft to escape Earth’s gravity. It failed to impact the Moon as planned and became the first man-made object to go into orbit around the Sun. Luna 2 (launched Sept. 12, 1959) was the first spacecraft to strike the Moon, and Luna 3 (Oct. 4, 1959) made the first circumnavigation of the Moon and returned the first photographs of its far side. Luna 9 (Jan. 31, 1966) made the first successful lunar soft landing. Luna 16 (Sept. 12, 1970) was the first unmanned spacecraft to carry lunar soil samples back to Earth. Luna 17 (Nov. 10, 1970) soft-landed a robot vehicle, Lunokhod 1, for exploration. It also contained television equipment, by means of which it transmitted live pictures of several kilometres of the Moon’s surface. Luna 22 (May 29, 1974) orbited the Moon 2,842 times while conducting space research in its vicinity. Luna 24 (Aug. 9, 1976) returned with lunar soil samples taken from a depth of seven feet (about two metres) below the surface.

Luna 2 was the first object of human origin to make contact with another celestial body. The spacecraft scattered spherical emblems of the Soviet Union on the lunar surface. The spacecraft’s sensors found no evidence of a lunar magnetic field or radiation belt.

After an aborted launch on Sept. 9, the Ye-1A probe, also known at the time as the Second Soviet Cosmic Rocket, successfully lifted off on Sept. 12 (Sept. 13 Moscow time). When the spacecraft reached about 97,000 miles (about 156,000 kilometers) from Earth, it released one kilogram of sodium gas on Sept. 12 in a cloud that expanded to about 400 miles (650 kilometers) in diameter and was clearly visible from the ground.

Three days later, Luna 2 achieved escape velocity (the speed and direction required to travel beyond Earth’s gravity). This sixth Soviet attempt at lunar impact was much more accurate than its predecessors, and the spacecraft reached the surface of the Moon at 23:02:23 UT on Sept. 14, 1959, becoming the first object of human origin to make contact with another celestial body.

The probe collided with the moon at approximately 30 degrees north latitude and 0 degrees longitude on the slope of the Autolycus crater, east of Mare Serenitatis.

Luna 2 (as it was renamed in 1963) deposited Soviet emblems on the lunar surface carried in 9 x 15-centimeter metallic spheres. The spacecraft’s magnetometer measured no significant lunar magnetic field as close as 55 kilometers to the lunar surface. The radiation detectors also found no hint of a radiation belt.

Space probes are highly advanced robotic craft, often the size of a large car, launched into space to investigate celestial objects. They use radio transmitters to communicate with mission specialists on Earth. All probes have highly sensitive electronic equipment on board.

The accurate navigation of space probes depends on four factors: First is the measurement system for determining the position and speed of a probe. Second is the location from which the measurements are taken. Third is an accurate model of the solar system, and fourth, models of the motion of a probe.

For all U.S. interplanetary probes, the antennas of the Deep Space Network (DSN) act as the measurement system. These antennas transmit radio signals to a probe, which receives these signals and, with a slight frequency shift, returns them to the ground station. By computing the difference between the transmitted and received signals, a probe’s distance and speed along the line from the antenna can be determined with great accuracy, thanks to the high frequency of the signals and a very accurate atomic clock by which to measure the small frequency changes. By combining these elements, navigators can measure a probe’s instantaneous line-of-sight velocity and range to an accuracy of 0.05 millimeter-per-second and three meters respectively, relative to the antenna.

Many probes also carry cameras that are used to image the destination, whether it be a moon, planet or other body. During the final approach, these images are used when the distance becomes small. For example, the Cassini spacecraft’s camera provides an angular measurement with an accuracy of three microradians (three kilometers) at a distance of one million kilometers. The images complement the radio data and provide a direct tie to the target.

Calculation of the trajectory of a space probe requires the use of an inertial coordinate system as well, wherein a grid is laid over the solar system and fixed relative to the star background. For interplanetary missions, an inertial coordinate system with an origin at the center of mass of the solar system is used. Because the measurements provide information on the position of a probe relative to the antenna, knowledge of the antenna’s location relative to this inertial coordinate system is used to convert the measurements into elements in the system. Where the antenna is depends not only on its geographic location on Earth’s surface, but on Earth’s position relative to the solar system center of mass (known as the Earth ephemeris). Measurements of this ephemeris have an accuracy of about 0.5 kilometer and the location of the antenna is known to an accuracy of better than five centimeters.

Airlocks are vital for protecting the crew of a space-craft. In a submerged submarine, if there was no airlock, the vessel would instantly be flooded with water as soon as the hatch was opened. In the same way, a space station with no airlock would depressurize the instant the door was opened, killing anybody on board who was not wearing a spacesuit. This is because air always tries to remain at a level pressure. If the pressure inside a spacecraft is greater than the pressure outside, as soon as the hull is breached, air will rush out into outer space.

Airlocks, typified by the International Space Station’s (ISS) primary Quest Joint Airlock, are designed to permit safe passage of people and objects between a pressurised vessel and its surrounding environment. Further, they are designed to minimise pressure and air-level changes within the host craft.

The Quest airlock of the ISS is split into two main sections: an equipment chamber and crew lock chamber. The former connects to the ISS and supplies an auxiliary holding bay for any essential equipment, such as Extravehicular Mobility Units (EMUs – or spacesuits), as well as other key gear. It also supplies a staging area where astronauts can prepare for a spacewalk -namely get in and out of their spacesuits.

Connected to the equipment compartment is the crew lock, a smaller cylindrical chamber into which astronauts enter prior to any spacewalk. Once inside this section, the interior hatch between the equipment lock and the crew lock is shut. This provides a sealed environment for the suited astronaut and allows depressurisation to proceed. When the crew lock is fully depressurised, an external hatch becomes operational, providing an exit for the astronaut to enter space.

Importantly, before any spacewalk is attempted, astronauts must ‘camp out’ within the equipment chamber of the airlock in a reduced-nitrogen environment in order to purge nitrogen from their blood stream. This ensures that astronauts avoid decompression sickness in the low pressure experienced within the pure-oxygen atmosphere of the spacesuit. Nitrogen and oxygen are supplied and replenished via four externally mounted gas tanks, which ensures that the lock does not need to draw upon the host ISS’s own gas supplies.

Space probes are designed to do different jobs. Some fly by their target at a distance of several thousand kilometres, taking pictures of the planet’s surface and surveying its atmosphere. Other probes are designed to enter a planet’s orbit, which allows them to survey the planet in more detail. The probes that provide the most information about planets are called landers because they touch down on the planet’s surface.

This is a list of space probes that have left Earth orbit (or were launched with that intention but failed), organized by their planned destination. It includes planetary probes, solar probes, and probes to asteroids and comets, but excludes lunar missions, which are listed separately at Lunar proves and Apollo mission. Flybys (such as gravity assists) that were incidental to the main purpose of the mission are also included. Flybys of Earth are listed separately at Earth flybys. Confirmed future probes are included, but missions that are still at the concept stage, or which never progressed beyond the concept stage, are not.

Space probes are made to conduct science experiments. They do not have people on them. Space probes have helped scientists get information about our solar system. Most probes are not designed to return to Earth. Some have landed on other planets! Others have flown past the planets and taken pictures of them for scientists to see. There are even some space probes that go into orbit around other planets and study them for a long time. The information they gather is used to help us understand the weather and other changes which happen on planets other than the Earth. This information is important in helping to plan other space missions such as ones to Mars and to Saturn.

During the summer of 2003, NASA launched twin robotic rovers named Spirit and Opportunity. The rovers were launched approximately 3 weeks apart, but they had the same destination. Spirit and Opportunity were headed to Mars. The rovers landed in January of 2004 on different parts of the planet. They were sent to Mars to look for evidence of water. Each rover carried scientific instruments to help scientists explore the planet from Earth. The Earth-bound scientists tell the rovers where to go and what to examine. As the rovers move across the surface, they examine soil and rocks. This information is sent back to Earth. The rovers were built to last approximately 90 days. Spirit went silent on March 22, 2010. Opportunity is still working as of November 1, 2015! And they have found lots of evidence that water was once all over the surface of Mars!

The Cassini probe to Saturn was launched on October 15, 1997. It is the biggest and most expensive probe to ever visit another planet. The Cassini spacecraft went into orbit around Saturn in July 2004. It has studied the planet, its ring system, and many of its moons for more than ten years!

The New Horizons spacecraft was launched in 2006, and flew past Pluto in the summer of 2015. It was the first spacecraft to visit that dwarf planet, and is now moving farther away from our Sun to explore more distant objects for the first time.

The first human being to leave the confines of a spacecraft and take a “walk” in space was the Soviet cosmonaut Alexei Leonov. He crawled through the airlock of Voskhod 2 in 1965 and was so overwhelmed by the view that he shouted out the first words he could think of: “The Earth is round!” During his twenty minutes in space, Leonov’s spacesuit expanded, due to the lack of pressure, and he was barely able to fit back in the airlock.

Selected alongside Yuri Gagarin among the first 20 Soviet Air Force pilots to train as cosmonauts in 1960, Leonov flew twice into space, logging a total of 7 days and 32 minutes off the planet.

Launched on Voskhod 2, the world’s 17th human spaceflight, on March 18, 1965, Leonov made history as the first person to exit his spacecraft for an extravehicular activity (EVA).

“The Earth is round!” he exclaimed, as he caught his first view of the world. “Stars were to my left, right, above and below me. The light of the sun was very intense and I felt its warmth on the part of my face that was not protected by a filter,” said Leonov in a 2015 interview with the Fédération Aeronautique Internationale (FAI) on the 50th anniversary of his spacewalk.

After several minutes outside, his spacesuit ballooned, making it very difficult for him to maneuver. His crewmate, Pavel Belayev, unable to do anything to assist, Leonov made the decision to release air from his suit in order to be able to re-enter his capsule. “I decided to drop the pressure inside the suit … knowing all the while that I would reach the threshold of nitrogen boiling in my blood, but I had no choice,” Leonov told the FAI, the world governing body that certifies aviation and space records.

Ultimately, Leonov made it safely back inside after 12 minutes and 9 seconds floating outside his spacecraft. He and Belyayev returned to Earth the next day on March 19, 1965, having shown it was possible for a human to survive working in the vacuum in space.

Because astronauts can be in their spacesuits for up to seven hours, they need water to avoid dehydration. Spacesuits are equipped with the In-suit Drink Bag (IDB), a plastic pouch connected to the inside of the suit’s torso. It can hold nearly 2 litres (32oz) of water that can be accessed via a straw. The helmet also has a slot for rice-paper-covered fruit and a cereal bar, should the astronaut get hungry.

There is a slot in the hard upper torso (HUT) portion of the EMU for a rice paper-covered fruit and cereal bar. The bar is designed so that the astronaut can take a bite and pull the remainder up. The entire bar must be eaten at once to prevent crumbs from floating within the helmet. However, most astronauts prefer to eat prior to the spacewalk and not use this bar.

The space suit has the In-suit Drink Bag (IDB), which is a plastic pouch mounted inside the HUT. The IDB can hold 32 ounces or 1.9 liters of water and has a small tube (straw) that fits up next to the astronaut’s mouth. The astronaut can move his/her head within the helmet and suck water through the tube.

Each spacewalking astronaut wears a large, absorbent diaper called a Maximum Absorption Garment (MAG) to collect urine and feces while in the space suit. The astronaut disposes the MAG when the spacewalk is over and he/she gets dressed in regular work clothes.

Astronauts basically do the same thing when they go to space shuttle. Preparation varies with the food type. Some foods can be eaten in their natural forms, such as brownies and fruit. Other foods require adding water, such as macaroni and cheese or spaghetti. Of course, an oven is provided in the space station to heat foods to the proper temperature. There are no refrigerators in space, so space food must be stored and prepared properly to avoid spoilage, especially on longer missions.

Condiments, such as ketchup, mustard and mayonnaise, are provided. Salt and pepper are available but only in a liquid form. This is because astronauts can’t sprinkle salt and pepper on their food in space. The salt and pepper would simply float away. There is a danger they could clog air vents, contaminate equipment or get stuck in an astronaut’s eyes, mouth or nose.

Astronauts eat three meals a day: breakfast, lunch and dinner. Nutritionists ensure the food astronauts eat provides them with a balanced supply of vitamins and minerals. Calorie requirements differ for astronauts. For instance, a small woman would require only about 1,900 calories a day, while a large man would require about 3,200 calories. An astronaut can choose from many types of foods such as fruits, nuts, peanut butter, chicken, beef, seafood, candy, brownies, etc. Available drinks include coffee, tea, orange juice, fruit punches and lemonade.