Preparations for Artemis-1 launch are stacking up
The first part of the Space Launch System (SLS), NASA’s new heavy launch rocket, was stacked onto the mobile launcher at the end of November, in preparation for its inaugural test flight next year. Its twin solid rocket boosters are here shown being put together inside the Vehicle Assembly Building at Kennedy Space Center. Once constructed, the SLS will stand 111m high – taller than the Statue of Liberty – and generate 15 per cent more thrust at take-off than the Saturn V rocket, which launched the Apollo missions. The SLS will be used as part of the Artemis-1 mission, the first test of both NASA’s new launch vehicle and the Orion crew capsule, which the agency plans to use to return humans to the surface of the Moon.
> Read more about the Artemis-1 mission in our feature on page 29
of these TNOs. So how do you weigh the Kuiper Belt from over 6 billion km away?
Andrea Di Ruscio, at the Sapienza University of Rome, and his colleagues have used an ingenious method to tackle this. They used data from the Cassini probe to calculate the position of Saturn extremely accurately, and then used perturbations to this orbit to infer the cumulative mass of the TNOs.
With an intricate looping tour around Saturn and its moons for over 13 years, Cassini was one of the most complex space missions ever navigated. This required precise tracking of the spacecraft, and so for around six hours every day the Deep Space Network of radio dishes exchanged signals with Cassini. Distinct features of these signals allowed the Cassini team to track not only how far away the probe was (from the signal delay time), but also how fast it was travelling towards or away from Earth at the time (from the Doppler effect), and so reconstruct the spacecraft’s trajectory.
Pinpoint accuracy
Now, Di Ruscio and his team have reanalysed this heritage Cassini navigation data and referenced the measurements to Earth’s orbit in order to pinpoint the position
Runaway blue main-sequence stars at high Galactic latitudes. Target selection with Gaia and spectroscopic identification Read it online at: https://arxiv.org/abs/2011.08862