tech2 News StaffAug 20, 2019 08:02:30 IST
The second moon mission from India, Chandrayaan 2, is expected to enter the moon's orbit today (20 August), one of the few remaining critical milestones in the mission before spacecraft attempts to soft-land on the moon's surface on September 7.
Currently, the Chandrayaan 2 composite is completing its lunar transfer phase, which will bring the spacecraft close enough to the moon that it can transition into the moon's orbit using power from its thrusters. This maneuver will allow it to escape Earth's gravitational pull and fall into the moon's gravity.
When the moon reached its apogee – its farthest point from Earth – the Chandrayaan 2 spacecraft's onboard thrusters will fire for a predetermined period, generating just enough thrust to slow themselves down for this'lunar capture'phase. This controlled transfer event – breaking free from the Earth's orbit of influence into the moon's – will unfold over several hours, estimated to end at 9.30 am IST on 20 August.
The critical step will require liquid apogee motors (thrusters) to be fired in the opposite direction to spacecraft's movement, thus slowing it down into what is known as "retrofiringThis allows spacecraft to come under the influence of the moon's orbit.
With the location of the moon relative to the Earth and the relative Earth to the Sun constantly changing, the intersection of Chandrayaan 2's path with the moon's was predicted and planned well ahead of time.
Once the lunar capture, or entry of spacecraft into the lunar orbit, is complete, the two-week (lunar-bound) phase of the mission will begin. This is an important part of the orbiter's mission: surveying its long-term home for the first time, ensuring that no damage was caused to its instruments thus far, and a thorough examination of Vikram Lander's landing site at Moon's South Polar region.
Chandrayaan 2 is expected to make its long-awaited powered descent and landing on 7 September in what the ISRO Chief described as'15 minutes of terror'.
While today's attempt will not be streamed live, you can follow live updates on our dedicated mission Chandrayaan 2 domain, ISRO's website, or Twitter page.
Find our entire collection of stories, in-depth analysis, live updates, videos & more on Chandrayaan 2 Moon Mission on our dedicated # Chandrayaan2TheMoon domain.