Month: September 2021
Meet me up in space!
See the full article here:
https://blogs.ams.org/featurecolumn/2021/09/01/meet-me-up-in-space/
Rather than closing the distance, however, the target seemed to move down and away in defiance of everyday intuition…
David Austin
Grand Valley State University
Complex space missions rely on the ability to bring two spacecraft together, a procedure called orbital rendezvous. A spacecraft docking at the International Space Station is a typical example.
Historically, rendezvous was a vital component of the Apollo lunar missions. While three astronauts traveled to the moon in a single craft, the command module, two of them descended to the lunar surface in a second craft, the lunar excursion module (LEM). A successful mission required the ascending LEM to rendezvous with the command module before returning to Earth.
The first attempt at orbital rendezvous was one component of the Gemini IV mission in 1965 when the pilot James McDivitt tried to bring his Gemini capsule close to the spent booster that lifted them into orbit. Upon first seeing the booster at an estimated 120 meters, McDivitt aimed the capsule at the booster and thrusted toward it. Rather than closing the distance, however, the target seemed to move down and away in defiance of everyday intuition. He repeated this procedure several times with similar results.
NASA engineer André Meyer later recalled, “There is a good explanation [for] what went wrong with rendezvous.” Mission planners “just didn’t understand or reason out the orbital mechanics involved” due to competing mission priorities. That’s what we’re going to do here. This column will explain the relative motion of two spacecraft flying closely in Earth orbit and why that motion behaves in such a counter-intuitive way.
Read the rest of the story at
https://blogs.ams.org/featurecolumn/2021/09/01/meet-me-up-in-space/
Teaching Blog of Ioannis Souldatos 