Seven things you didn’t know about Europe’s tug to Mars

Mars can be as far away from Earth as 400 million km. To make trips to the Red Planet more frequent and affordable for science and exploration, European engineers came up with a mission concept for a reusable tug, or interplanetary transfer service.

The martian tug promises to open a market of low-cost missions to Mars for a broader community. ESA calls it LightShip.

1. What is LightShip?

LightShip is an electric propulsive tug that will deliver one or more passenger spacecraft to Mars and offer communications and navigation services around the planet, as well as several seats for a range of scientific payloads.

Historically, a lightship is a vessel sent to remote, deep or dangerous waters to serve as a beacon for aiding navigation. In 1899, the captain of the East Goodwin lightship sent the first radio distress signal using Guglielmo Marconi’s wireless technology. The name LightShip is a tribute to the intrepid explorers that made use of these navigation beacons.

2. Why do we need LightShip?

Getting to Mars is not easy. LightShip provides a solution to two of the key challenges for Mars missions: firstly, delivery of passenger spacecraft to Mars, making the Red Planet more accessible; secondly, communications to and from Mars, providing a dedicated data relay service.

Additionally, the LightShip provides the first steps towards a global navigation satellite service (GNSS), like what we enjoy from smartphones on Earth, which would enable precise landing and operation at Mars.

 Improved navigation and communications will pave the way for future human missions.

3. How can LightShip lower the cost of a trip to Mars?

There are several ways in which LightShip could make trips to Mars more affordable and sustainable.

Its efficient electric propulsion system can deliver more mass to Mars than conventional chemical systems, and it could deliver multiple spacecraft to several orbits or entry trajectories.

With a reusable design, ESA plans to build several LightShips, which will lead to a lower cost per spacecraft.

4. What’s the science behind?

LightShip will host a payload devoted largely to atmospheric science. From a high orbit of nearly 6000 km above the martian surface, the LightShip science payload will monitor and measure atmospheric phenomena such as weather, wind and dust – all useful information for safe landing and operations on the martian surface.

Once several LightShips are operating at Mars, this would allow continuous monitoring weather systems around the whole planet.

The first passenger spacecraft to be carried to Mars by LightShip is dubbed SpotLight and primarily will aim to produce high resolution maps of the surface of the Red Planet from a low Mars orbit of approximately 300 km.

5. How do Mars explorers phone home?

LightShip offers a communication service that will allow future Mars landers and orbiters to deliver a huge amount of scientific data back to Earth, without having to embark heavy and costly direct-to-Earth communications systems of their own.

A robust Mars telecommunications relay network built with LightShip would support positioning, navigation and timing services for Mars orbiters, landers, rovers and aerobots.

The LightShip’s  Mars Communication and Navigation Infrastructure, or MARCONI, Service, is named after Guglielmo Marconi, an Italian inventor and electrical engineer known for his pioneering work on long-distance radio transmission, which was used to send the first distress signal on the East Goodwin lightship.

6. What can LightShip deliver to Mars?

The LightShip propulsive service is flexible and can drop passengers off during the transfer to Mars or deliver them door-to-door, depending on the propulsive capabilities of the passenger spacecraft.

Once LightShip has released its passengers to the desired orbits, it will transfer itself to its final operational orbit from which the MARCONI service can be delivered.

A range of different sizes of passenger spacecraft will be supported by LightShip, from small CubeSats to large platforms, with up to 12 passengers being delivered in any one mission.

7. When will all of this happen?

This mission concept is now entering a competitive Phase A/B1 study phase. Further development of the mission will depend on decisions made at the next ESA Council at Ministerial Level in November 2025.

If approved, the first LightShip mission is foreseen in 2032, with subsequent launch windows open in 2035 or 2037. Future LightShip missions will carry different passenger spacecraft to be decided by the science and exploration communities.