It will be the first time in history that a rocket, ISRO’s PSLV, will be launching two rovers to the moon in a single mission.

In a first of its kind collaboration in a space-race to the moon, Japan’s Team HAKUTO has announced that their rover will be housed as a commercial payload onboard Bengaluru-based TeamIndus’s spacecraft. Along with the Japanese rover, called Moonraker, TeamIndus will also be carrying its own rover, Eca (pronounced “eeka”) – making this the first mission ever to carry two rovers to the moon. Shortly after touchdown on the satellite, scheduled to happen in early January 2018, the two rovers will be deployed.

The spacecraft housing the two rovers will be launched atop ISRO’s Polar Satellite Launch Vehicle (PSLV). Earlier this month, TeamIndus had announced a commercial launch contract with ISRO, a major milestone in its bid to become the first private entity to attempt to land on the moon.

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Both HAKUTO and TeamIndus are part of the $30-million Lunar XPrize, sponsored by Google. It is the largest incentivised competition in the world; to win it, a privately funded team has to soft-land a vehicle on the moon, move it to 500 m away from its landing site and then beam high-definition media back to Earth.

The partnership announcement has been met with a mix of elation and confusion because TeamIndus will now be carrying its competition along with its own rover. As of now, it is still unclear what the sequence of events will be after touchdown. The best guess would be that after landing on the Moon, the spacecraft will either open up a ramp for or drop the TeamIndus rover first and then the Team HAKUTO rover.

Team HAKUTO had previously designed their mission to carry two rovers, the other one being called Tetris, tethered to each other. It was expected that Moonraker would transmit images while Tetris would explore the lunar craters, fulfilling the optional science mission set out by the GLXP council. HAKUTO had also signed a collaboration with another team, Astrobotic, but which has since pulled out of the competition. As there has been no mention or design release of a second rover – or any update on their website – it would be fair to conclude that Moonraker is the only rover that will attempt to land on the Moon now.

The Japanese team is also in collaboration with the Japanese Space Agency (JAXA) to investigate radiation on the moon. In this joint research project, HAKUTO will demonstrate its ability to monitor radiation in real-time using a light and portable instrument. Its observations are planned to help JAXA improve its lunar radiation simulations as well as give missions of the future more information to work with. This is the first time JAXA is collaborating with a private entity, and has been listed as a “Supporting Company” on HAKUTO’s website.

The two rovers will be housed within the spacecraft atop the PSLV. The rocket will deploy the spacecraft at 70,000 km above Earth. The craft will then perform two gravity assists around Earth, flinging itself towards the Moon. Once it gets close enough, the craft will slow itself down through four orbit reduction manoeuvres before touching down. The entire process is expected to take 15 days.

The spacecraft’s weight is expected to be 600 kg, including all the payload and fuel. The dry mass alone is 175 kg. It’s payloads, the rovers Eca and Moonraker, are expected to weigh ten and four kilograms respectively. After landing, the craft’s computer will open a hatch beneath its body, either dropping or opening up the ramp (the design is yet to be finalised) for the first rover and then the second, once the first is out of the way.

Eca’s design has fared well on the overall cuteness meter on the internet. The rover’s “eyes” are cameras designed by the French space agency, CNES. This is the first time CNES is collaborating with a private company in India, though it has worked with ISRO in the past.

The landing site for TeamIndus is Mare Imbrium, the large plain visible to the naked eye on the top left part of the moon. The crater itself was created by a collision with an-other large body nearly 3.5 billion years ago. However, steady, now-extinct lava flow coated it enough to make the entire crater almost featureless. The biggest advantage such a geographical feature offers is a direct line of sight between a roving craft and the mothership.

Since the objective of the competition is to travel a fixed distance on the surface and transmit images, the rover will need to communicate with Earth all the time. This is achieved by having the rover send data to the craft and the craft relaying it to Earth. It is unclear whether Team HAKUTO’s rover will use the TeamIndus craft for communication as well.

The other GLXP incentives include ‘milestone’ prizes for demonstrating the ability to perform certain tasks grouped under the umbrella of ‘landing, mobility, and imaging’. Five teams have won these prizes, including TeamIndus – for demonstrating landing capability.

There are also two ‘Heritage Prizes’ that have drawn a lot of flak from the scientific community. These prizes will be awarded to rovers that can successfully reach and photograph heritage sites on the Moon – such as, for example, the places where the Apollo missions landed in the 1960s. These sites are widely regarded as being historically and culturally significant, and there is concern that rovers going there could deface the sites or damage leftover spacecraft parts. At the same time, Buzz Aldrin, the second human to step on the moon, and the surviving Apollo astronauts themselves have written in support of the Heritage Prize.

The deadline for teams to announce launch contracts is December 31, 2016. So far, three other teams – SpaceIL (Israel), Moon Express (US), Synergy Moon (international) – have also announced theirs. The PSLV rocket carrying the two rovers is expected to launch late December 2017 or early January 2018.

Sandhya Ramesh is a consultant with TeamIndus.

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