Kathleen Howell is developing potential orbits around a Lagrange point.
Kathleen Howell never aspired to walk on the moon.
- Kathleen was more intrigued by the looping route that brought the Apollo 11 astronauts from Earth to the Sea of Tranquility and back.
- In 1982 Kathleen wrote a doctoral thesis on orbits in “multibody regimes” that earned her a PhD from Stanford.
- Howell’s life passion was Orbits. She soon received a Presidential Young Investigator Award.
- NASA has decided that a near-rectilinear halo orbit (NRHO)—a speciality of hers would be an ideal place to put the Lunar Orbital Platform-Gateway
- An NRHO can be slightly warped. It stands on end, almost perpendicular to an ordinary orbit—hence “near rectilinear.”
It’s quite possible to orbit around nothing, as long as that nothing is a Lagrange point.Howell, now a chaired professor at Purdue University
- In 1760 the Swiss mathematician Leonhard Euler theorized that for any pair of orbiting bodies, there are three points in space where gravitational and centrifugal forces precisely balance.
- Observation satellites have been positioned near Lagrange points, and sci-fi writers have imagined colonies stationed at them.
- Howell’s doctoral thesis explored a family of orbits around Lagrange points, called halo orbits because from Earth they appear to form a halo around the moon.
- The orbital math the Gateway will use is complex, because it must account not just for Earth and the moon, but the pull of the sun and even Jupiter.