The Chandrayaan-3 lunar lander that India launched July 13th (local time) has been smoothly conducting its mission, raising the farthest point (apogee) of its orbit in discrete engine burns since then. We learned today via Space.com that with July 20th as International Moon Day, the occasion was used to net a little publicity and attention for the mission by doing the next engine burn. The spacecraft moved into a 51,400 km x 228 km orbit, as planned.
That 2-3 PM IST window for the next firing is 0830-0930 GMT; 4:30-5:30 AM EDT. A translunar injection (TLI) burn will take place on July 31.
The Tweet also provided a graphic of the approach being used. By now, this general approach will be familiar.
I should point out that the highest orbit around Earth connects to the highest orbit around the moon and the next several engine burns will be to lower and circularize the lunar orbit.
As posted in the July 14 article here, it's expected to reach lunar orbit on August 5, then lower its apolune (highest point above the moon) in several engine burns. This could enable a landing attempt by the Vikram lander on August 23 or 24.
If touchdown is successful, the mission lander and rover will collect science data on the surface for up to 14 Earth days (a single day on the moon). The spacecraft are not expected to survive the deep cold of the lunar night.
They are exploiting the gravity assist maneuver to the hilt. “A gravity assist, gravity assist maneuver, swing-by, or generally a gravitational slingshot in orbital mechanics, is a type of spaceflight flyby which makes use of the relative movement (e.g. orbit around the Sun) and gravity of a planet or other astronomical object to alter the path and speed of a spacecraft, typically to save propellant and reduce expense.
ReplyDeleteGravity assistance can be used to accelerate a spacecraft, that is, to increase or decrease its speed or redirect its path. The “assist” is provided by the motion of the gravitating body as it pulls on the spacecraft.[1] Any gain or loss of kinetic energy and linear momentum by a passing spacecraft is correspondingly lost or gained by the gravitational body, in accordance with Newton’s Third Law. The gravity assist maneuver was first used in 1959 when the Soviet probe Luna 3 photographed the far side of Earth’s Moon and it was used by interplanetary probes from Mariner 10 onward, including the two Voyager probes’ notable flybys of Jupiter and Saturn.“
https://en.m.wikipedia.org/wiki/Gravity_assist