SpaceX brings its first astronauts to orbit: direct

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Today, Elon Musk’s private space company SpaceX will once again try to bring its first astronauts into orbit, after postponing a first launch on May 27th due to unfavorable weather conditions. The space mission is organized on behalf of NASA and will be the first to bring a crew into orbit from the United States for nearly ten years. It has not happened since July 2011, when the Space Shuttle Atlantis completed the last orbital flight of one of the most important and expensive space programs in the history of explorations beyond our atmosphere. Since then NASA has relied on the Russian space agency Roscosmos.

The launch is also considered historic for another reason: it will be the first to be managed by a private space company. This will deeply mark the next few years of space travel with astronauts, both in the event of success and in the event of a failure, which could have a strong impact on the activities of NASA and the International Space Station (ISS).

At 9:22 pm (Italian time) six years of SpaceX work – with not a few delays and some unexpected events – will be concentrated on the ramp of the John F. Kennedy Space Center launch complex 39A (Florida), the same from which the missions started to the moon over 50 years ago and space shuttles in more recent times. At that moment the Falcon 9 rocket will start its engines, pushing the Crew Dragon capsule into orbit with the astronauts Bob Behnken and Doug Hurley inside, for a rather thunderous start of their journey to the ISS about 450 kilometers away from ours heads. The capsule has already made some experimental flights – including one to the ISS last year – but always without humans on board.

In a sense, today’s will be “the test of the tests”, and for this it is eagerly awaited and accompanied by great expectations.

Live broadcast from NASA and SpaceX

Travel in orbit
The launch of the latest Space Shuttle on July 8, 2011 was accompanied by great doubts and uncertainties about the future of US space programs with astronauts. NASA was retiring one of its most successful spaceships, the only system capable of bringing its crews into orbit, and did not seem to have very clear ideas about what would replace it. The space agency had recently launched the “Commercial Crew Program” with the aim of involving private space companies, for the creation of new orbital transport systems, but it was immediately clear that the times would have been rather long and uncertain .

The last departure of the Space Shuttle Atlantis, in July 2011 (NASA)

Without its own spaceship and with the need to continue sending its astronauts to the ISS, for which periodic replacement of the crews is required, NASA decided to temporarily rely on the Russian space agency Roscosmos, making passages from its Soyuz orbital transport systems. Since 2011, all US astronauts (and not only) have therefore been able to reach the ISS only thanks to Roscosmos and at very high prices for each ticket: about 80 million dollars per person.

While NASA continued to pay for the salty steps offered by Russia, the Commercial Crew Program went ahead with its selection processes of the private companies deemed most suitable. SpaceX and Boeing were selected, with contracts worth over $ 3 billion and nearly $ 5 billion respectively to develop new transportation systems. In the following years the competition between the two companies would have become rather intense, with SpaceX which finally prevailed managing to finish its launch system first.

However, the Commercial Crew Program did not go smoothly as expected by NASA. Both SpaceX and Boeing have encountered numerous technical problems and delays in the development of their systems, in part due to requests for greater guarantees from the US space agency, which imposed very strict protocols before certifying the safety of the proposed systems. At the end of the project, both companies will be able to manage the transport of astronauts to the ISS, even if the timing is not yet clear for Boeing, due to further technical problems that emerged during the last unmanned experimental orbital flight.

On board
Today’s launch, unless further postponements for weather conditions, will take place from Cape Canaveral, the largest and most important launch base in the United States. About three hours after departure, Behnken and Hurley will be transported to the launch pad aboard a Model X, an electric car produced by Tesla, the car company owned by Elon Musk, who also holds control of SpaceX. The choice has raised some perplexity among the purists of NASA’s space launches, usually without any commercial reference, but it is a sign of private management and the fact that SpaceX is directly involved in many details.

Arrived near the launch pad, the two astronauts will use an elevator to climb the approximately 70 meters high Falcon 9, the large rocket that will take them into orbit. The elevator door will open onto a small corridor, similar to that of the gods finger of the airports, which will lead them to the entrance door of Crew Dragon, their space capsule located on the tip of the rocket.

Falcon 9 on the launch pad, with the finger leading to illuminated Crew Dragon (SpaceX)

Behnken and Hurley will go inside and perform the latest launch procedures. In the meantime, the ramp will be cleared and SpaceX will start a very delicate first task of the mission: refueling Falcon 9 with the insertion of oxygen in a liquid state at very low temperature (over -200 ° C) and kerosene (RP-1 ). It is immediately after this phase that the countdown on Wednesday 27 May was stopped, due to the adverse weather conditions around Cape Canaveral and in some of the sites scheduled for emergency ditches.

Refueling is one of the procedures that leaves NASA less relaxed, because it is usually done before astronauts are on board, so as to reduce the risks in the event that something goes wrong in the most catastrophic way, usually with a explosion. SpaceX has, however, perfected the use of its propellants at extremely low temperatures and therefore cannot refuel too early, compared to the time of launch. NASA in recent years has requested and obtained that SpaceX make numerous demonstrations on the security of the system, before authorizing the procedure with its astronauts on board.

The launch
At 9:22 pm (Italian time, 3:22 pm in Florida) the Falcon 9 will start its nine engines, detaching itself from the launch pad after a few moments to begin its journey to orbit. The procedure will be completely automatic, with Behnken and Hurley having to do nothing, apart from enduring for a few minutes the strong acceleration needed to overcome what usually holds us firmly on the ground. Starting the engines and starting will constitute another critical phase: a valve malfunction, a programming error in the on-board computer or a short circuit could end everything at a few hundred meters of altitude.

Crew Dragon is equipped with an emergency system, which is activated precisely in the event that something goes wrong in the huge rocket to which it is connected. On its sides, the capsule has a series of small thrusters (SuperDraco) designed to activate if the onboard computers detect serious failures and the risk of a Falcon 9 explosion. By activating, these engines separate Crew Dragon from the rest of the rocket and they make it move away quickly, so that it is at a safe distance from any explosions. The capsule then opens its parachutes and slowly descends to the Atlantic ocean where it can be retrieved by rescue teams.

The security system has been tested on several occasions with positive results, and resumes similar solutions adopted for some time by other rockets for the transport of astronauts, starting with the Russian Soyuz. The emergency procedure implies that for a few moments the crew is subjected to strong stresses due to acceleration, but nothing for which the astronauts were not trained in simulations on Earth before their launches.

Weather
Unlike other emergency systems that only work in the very first phase of the launch, SpaceX claims that Crew Dragon’s thrusters can be used at virtually any time of the rocket’s ascent to Earth orbit, thus offering additional guarantees. This implies that, in the event of a disaster, the capsule may end up at even very distant points of the Atlantic ocean with respect to Florida with the complications of organizing the rescue.

The distance of the return point in the event of an emergency adds some further complications on choosing the right time for the start of the mission. In general, space launches depend very much on weather conditions: winds at too high altitude can lead to the postponement of a departure, as well as excessively strong waves in areas where a capsule with a crew could fall.

For Crew Dragon, the weather conditions will need to be good in a large area of ​​Florida and the Atlantic, making it more likely to postpone the launch, as happened on May 27. In the event that SpaceX decides not to proceed today, a new opportunity would open on Sunday.

In orbit
From the moment of starting the engines, Behnken and Hurley will take about 12 minutes to reach Earth’s orbit: they will then have 19 hours before reaching the International Space Station. They will turn around the Earth several times, with periodic starting of the motors of their transport system, which will allow to reach ever higher orbits up to that of the ISS. Also in this case the procedures will be automatic, but some interventions are still foreseen by the astronauts to test the manual controls, collecting useful data for future Crew Dragon missions.

U.S. astronauts Bob Behnken and Doug Hurley in preparation for launch (SpaceX)

Near the ISS, the Crew Dragon automatic navigation system will do everything by itself, taking care of reaching one of the Station’s free docking points. The procedure will be totally automatic and is one of the most important functions of the onboard systems developed by SpaceX. The on-board computer will use video cameras and sensors to position the capsule in the right trajectory, to maintain its attitude and the proper speed to complete the docking.

International Space Station
After the docking procedure and some checks on the system’s watertight integrity, Behnken and Hurley will be able to open the lid of their capsule and enter the ISS, welcomed by the American astronaut Chris Cassidy and the two Russian cosmonauts Ivan Vagner and Anatoly Ivanishin, who are working on their mission on the Station for a few months.

It is not yet clear how long Behnken and Hurley will remain on board: originally NASA had thought about a stay of a few weeks, but things have changed after the delays accumulated by SpaceX and Boeing in the development of their systems of about three years. NASA is now running out of passes on Soyuz and would therefore like to immediately take advantage of the possibilities offered by Crew Dragon.

Barring changes in plans, Behnken and Hurley should therefore remain in orbit for a few months, participating in maintenance and research activities on the ISS. Their residence time will however be determined by some technical needs: part of Crew Dragon is covered with solar panels that serve to produce electricity for some on-board systems, but their exposure to the space environment determines their rapid deterioration. SpaceX estimates that they can still hold out for at least four months, so NASA could keep Behnken and Hurley on board the ISS for a few weeks.

Solar panels of Crew Dragon (SpaceX)

After their stay on the Station, the two astronauts will return to their space capsule, which will disconnect from the ISS to start the return to Earth procedure. Crew Dragon will make a turbulent return to the atmosphere and then open his parachutes, slowing down his descent to the Atlantic Ocean, off the coast of Florida. The sea rescue teams will then take care of the recovery of the capsule and provide assistance to Behnken and Hurley.

History and future
If everything works as expected, the mission that begins today will not have a historical significance only for its firsts: it will be the beginning of a new phase in the era of space exploration, in which large private companies will manage the launches with crews on behalf of NASA and other space agencies. Already in the fall, SpaceX is expected to manage a second mission to the ISS, transporting a crew of four astronauts.

By entrusting the management of transport to Earth orbit to private individuals, NASA will be able to concentrate its resources and research towards other objectives for the exploration of Deep Space with its probes and in the future with its astronauts. There is no shortage of things to discover out there.





Source link
https://www.ilpost.it/2020/05/30/spacex-lancio-astronauti-nasa-crew-dragon/

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