Bar Crobar

Putting mankind on Mars

At 120 metres high, Starship is the world's largest rocket. It is also the most powerful. SpaceX is counting on it to achieve its stated goal: to make humankind a multi-planetary species by putting it on Mars.

Its development is also very important for NASA, which is counting on this spacecraft to land its astronauts on the Moon during its mission. Artemis IIIscheduled for 2026.

The rocket has two stages: the Super Heavy propulsion stage and, above it, the Starship, which by extension gives its name to the entire rocket.

Two unsuccessful tests

The last test took place four months ago. The two stages of the rocket separated successfully in flight for the first time, but then both exploded. The flights lasted just four minutes in the first test and eight minutes in the second.

However, the spacecraft had reached an altitude of around 150 kilometres, crossing the boundary of space.

SpaceX then proposed 17 "corrective measures" to the US aviation regulator, the FAA, which had to be put in place in order to obtain a new flight licence, which was finally obtained on Wednesday.

"Ambitious objectives

For this third test, SpaceX had said it wanted to achieve several "ambitious objectives". One of these was to carry out a "controlled re-entry" of the spacecraft, which should have fallen back into the Indian Ocean to end the test after about an hour.

SpaceX also wanted to test the opening of the hatch, which could be used in the future to release cargo, such as satellites, into space.

The company also wanted to "demonstrate a fuel transfer" in flight. According to the specialist press, this transfer should have taken place between two tanks inside the spacecraft. Developing this function is essential, because to reach the Moon, Starship will have to refuel once in space, using a vessel that has already been filled by others, and acting as a kind of space service station.

In addition to its inordinate size, Starship's real innovation is that it should eventually be fully reusable. Currently, only the first stage of the Falcon 9 rocket returns to land after each launch to be reused.

Text by RTS afp/juma

The James Webb Space Telescope (JWST), awaited for thirty years by astronomers around the world to examine the Universe with unequalled resources, took off on an Ariane 5 rocket on Saturday to reach its observation station. It was successfully injected into its final orbit, announced the director of launch operations at the Guiana Space Centre.

"Good separation Webb telescope, Go Webb", announced Jean-Luc Boyer from the control centre in Kourou. After 27 minutes of flight, the upper stage of the Ariane rocket released the telescope, which will now take around a month to reach its observation post 1.5 million km from Earth.

His ambition: to shed light on the creation of the universe

The JWST will become the most advanced instrument ever sent into space to observe the cosmos. Its ambition is to shed more light on the two questions that plague humanity: "Where do we come from? and "Are we alone in the universe? And to catch a glimpse of the "cosmic dawn", when the first galaxies began to illuminate the universe from the Big Bang, 13.8 billion years ago.

It will enable us to better understand the formation of stars and galaxies, and to observe exoplanets, of which astronomers are discovering more and more specimens, with a view to perhaps one day identifying other Earths.

In the footsteps of Hubble

The James Webb will follow in the footsteps of the Hubble telescope, which revolutionised observation of the universe: it was thanks to the telescope that scientists discovered the existence of a galactic black hole at the centre of all galaxies, or water vapour around exoplanets.

Conceived by NASA when Hubble was launched in 1990, and built from 2004 onwards in collaboration with the European Space Agency (ESA) and the Canadian Space Agency (CSA), the JWST is different in more ways than one.

The size of its mirror, with a span of 6.5 metres, gives it a surface area and therefore a sensitivity seven times greater, sufficient to detect the thermal signature of a bumblebee on the Moon. Another difference is the way it is observed. Whereas Hubble observes space mainly in the visible light range, James Webb ventures into a wavelength that the eye cannot see: the near- and mid-infrared. This radiation is emitted naturally by all bodies, stars, humans and flowers.

This light will be studied by four instruments, equipped with imagers and spectrographs to better dissect it. Their development has mobilised a plethora of engineers and scientists, under the leadership of American and European laboratories and manufacturers.

Need cold to see clearly

The imperative condition for the JWST to function properly is an ambient temperature so low that it does not interfere with the examination of the light. Hubble is in orbit some 600 km above the Earth. At this distance, the JWST would be unusable, heated by the Sun and its reflection off the Earth and Moon. It will therefore be placed 1.5 million km away. And it will be protected from solar radiation by a heat shield made up of five flexible sails that will dissipate the heat, lowering the temperature (which is 80°C) to -233 degrees on the telescope side.

But before that could happen, the machine and its designers had to achieve a real feat: its flawless deployment, with a series of operations involving, for example, 140 opening mechanisms, 400 pulleys and almost 400 metres of cable for the shield alone. The observatory, 12 metres high and with a shield the size of a tennis court, had to be folded to fit inside the Ariane 5 fairing. The "encapsulation" was carried out using laser guidance to avoid any damage to the instrument, which cost some ten billion dollars to develop.

Absolutely clean

For these manoeuvres, NASA has also imposed draconian cleanliness measures to avoid any contamination of the telescope's mirror by particles or even contaminated breath. Finally, Arianespace has installed a customised fairing depressurisation system to ensure that no sudden change in pressure will damage the beast when it separates from the launcher at an altitude of 120 km. "An ESA official in Kourou explained on Thursday that "exceptional 'customers' require exceptional measures".

It will be several weeks before we know whether the telescope is ready for operation. Official commissioning is scheduled for June.

Text by Le Matin.ch (AFP)

Tag: Nasa

SpaceX's giant rocket, the third Starship test flight, has been "lost".