There is until 6 September for a third and final launch before the arrival of the storm period over Florida

NASA is taking a gamble on its next Artemis I liftoff attempt

photo_camera PHOTO/NASA-Cory Huston - NASA managers, engineers and technicians have rescheduled the second liftoff attempt of the Artemis I mission to the moon for Saturday, Sept.

The second liftoff attempt of NASA's mega space launcher is already set for 3 September, starting at 20:17 Spanish time (14:17 Eastern Daylight Time), with the launch window extending for the next two hours.

This was agreed by the Artemis programme management team at its meeting on 30 August. The extraordinary session was chaired by launch director Charlie Blackwell-Thompson who, for technical reasons, decided to abort the first flight attempt of the Artemis 1 mission to the Moon on 29 August.

In an official statement issued at 03:03 a.m. Spanish time (21:03 at the Kennedy Space Center in Florida), NASA confirms that during the first launch attempt, "crews were unable to cool the four RS-25 engines to approximately -250º Celsius and engine number 3 showed higher temperatures than the others". In addition, there was a hydrogen leak (...), which prompted Charlie Blackwell-Thompson's difficult decision to suspend liftoff. Vice President Kamala Harris was at the Kennedy Center to witness the important event live.

PHOTO/NASA-SSC - Uno de los cuatro motores potentes RS-25 de la etapa principal del lanzador SLS, que en su conjunto deben proporcionar cerca de un millón de kilos de empuje y que junto a los dos aceleradores laterales levantan 2.600 toneladas

According to data provided by NASA's manager for the SLS launcher, John Honeycutt, "three of the RS-25 engines, 1, 2 and 4, were down to about -245 degrees Celsius, but engine #3 was only down to about -230 degrees Celsius, according to temperature sensors". The main cause of the problem reported by the ground control engineering team is that the anomaly is "due to a faulty temperature sensor and not a decrease in the flow of liquid hydrogen into the engine". 

Blackwell-Thompson has indicated that replacing the sensor while the SLS rocket is on the launch pad is "probably not ideal" and could not be done before the end of the launch window, which ends on 6 September, before the start of the rainy and stormy period over Florida.

PHOTO/NASA-Kim Shiflett - Presidida por la directora de lanzamiento, Charlie Blackwell-Thompson, la reunión de gerentes del programa Artemis celebrada el 30 de agosto ha comprobado la falta de tiempo para reemplazar el sensor de temperatura defectuoso
NASA cannot afford failure

The decision has been made in accordance with the proposal of NASA's team of engineers and technicians and the prime contractor for the engines, Aerojet Rocketdyne. "The only thing I can do is replicate the success we had at Stennis Space Centre in early 2021," said John Honeycutt. It consists of modifying the established procedure, "move the test up in the timeline" and start flowing hydrogen into the four engines 30 to 45 minutes before liftoff. 

In the event that the same temperature problem arises again on 3 September and the engineers on the ground consider that the sensor is faulty and that engine No. 3 is cooling properly, it will be possible to continue with the countdown, provided that Charlie Blackwell-Thompson, as the person in charge of the launch, decides to do so.

The four RS-25s provide about one million kilos of thrust and together with the two solid fuel side boosters, together generate the 3,992 tonnes of thrust to lift the 2,600 tonnes of the 98.15 metre high SLS rocket off the ground.

PHOTO/NASA-Michoud - El responsable del lanzador SLS, John Honeycutt, ha informado que el criterio del equipo de ingenieros de control en tierra es que la causa principal del problema de temperatura en uno de los motores y no es una disminución del flujo de hidrógeno líquido

Neither NASA nor the Biden Administration can afford to fail the maiden flight of the first real integrated test of the SLS rocket, the Orion space capsule atop it and the ground systems that have been erected at Kennedy Space Center. The safety of the launch must be guaranteed in all its parameters.

The liftoff of the Artemis 1 mission marks the start of America's great space programme of the 21st century, the first stage of which is to return to the Moon. But the Artemis programme goes much further, and NASA considers it "the first step in the next era of human exploration". 

PHOTO/NASA-Bill Ingalls - La misión Artemis 1 significa el arranque del gran programa espacial del siglo XXI de Estados Unidos. Su primera etapa es regresar a la Luna y preparar los vuelos tripulados a Marte en un futuro cercano
A stepping stone to Mars

Tony Carro, who for many years and until recently has been NASA's representative in Spain, makes this desire to go further concrete. From his extensive knowledge of space science and technology and his many years at the Agency, he told ATALAYAR that the Artemis programme "is an essential step, the aim of which is to prepare for manned flights to Mars in the near future".

The US space agency's stated ambition is to realise this quantum leap 'together with commercial and international partners and establish a sustainable presence on the Moon to prepare for Mars missions'. And the launch infrastructure at Kennedy Space Centre, the SLS rocket and the manned Orion capsule - which ESA, the European Space Agency, has been involved in building - are the main instruments of the Artemis programme.

The Orion capsule will this time fly unmanned around the Moon and even 64,000 kilometres beyond, a much greater distance than has ever been reached by a manned spacecraft in outer space. But it will do so without astronauts, as the purpose of the Artemis I mission is to assess and verify that SLS and Orion meet the safety and reliability conditions for carrying astronauts to the Moon from 2025 onwards.

PHOTO/NASA-Kim Shiflett - La directora de lanzamiento, Charlie Blackwell-Thompson, se enfrenta a lluvias esporádicas durante la ventana de lanzamiento del 3 de septiembre, lo que de producirse impide el despegue mientras se prolonguen

The most critical moment for Orion is to bring the astronauts safely back to Earth. This is why it is crucial to test the reliability of the new heat shield that has been designed and manufactured to protect the capsule during its re-entry into the atmosphere, which will penetrate its upper layers at about 40,000 km/h. 

NASA's latest official statement indicates that military meteorologists at Space Launch Unit Delta 45 "are forecasting favourable weather conditions for Saturday, 3 September", although it also states that "rain is expected, which is expected to be sporadic during the launch window". Rain is a constraint to the launch, but if at any time the rain front passes, Charlie Blackwell-Thompson would be in a position to order a liftoff.

PHOTO/NASA-Bill Ingalls -  La vicepresidenta de Estados Unidos, Kamala Harris, se desplazó desde Washington hasta el Centro Espacial Kennedy para presenciar el despegue de la misión Artemis I, que finalmente fue aplazada

A failure to effectively start the Artemis programme would be devastating and would cast serious doubt on the reliability of the SLS launcher, whose development was approved by Congress in 2010; it has been delayed since 2017 and its inaugural launch is valued at more than $4 billion.

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