update 2: It appears Schiaparelli has already been located by satellite. This still represents the first laser ranging retroreflector array deployed beyond the Earth-Moon system! So assuming it is now oriented such that the array can be seen from space - is anything else needed, or now that the position is know is it ready for science?

update: At the moment signal reception from Schiaparelli (ExoMars EDM) has not been re-established after the parachutes should have opened. Assuming it has landed right-side up (or at least close) can the retroreflector array still be used for science? Would imagery from orbit be able to eventually pinpoint the location so that it can be targeted by lasers from future satellites and meaningful measurements be performed?


Retroreflector arrays have many uses in space exploration and physics. See this answer, and here and here for examples.

The Schiaparelli Lander carries one that seems to be the first optical retroreflector to be deployed beyond Earth orbit.

This description lists examples of what it could be used for, but are there any specific plans to bounce beams off of it any time soon?

How can Schiaparelli's retroreflector array be used if communications is not established?

From: http://spaceflight101.com/exomars/schiaparelli-instrument-overview/

The INRRI Corner-Cube Retroreflector weighs under 25 grams, is 5.5 by 2.0 centimeters in size and is envisioned to be tracked by Mars orbiters capable of laser ranging or laser altimetry, or even laser communications. Its presence on Mars may also benefit future Martian geodesy or general relativity studies. INRRI has an aluminum body with eight fused silica Corner-Cube Reflectors within it, attached by a silicone rubber.

Installing a retroreflector on a rover or lander will enable precise georeferencing during the surface exploration activity. Having precise georeferenced data is useful in tracking sites that may be of interest for future exploration or sample return. Establishing a catalog of georeferenced sites of particular interest is a priority for NASA and ESA in the agencies’ long-term goals for Mars exploration.

The INRRI reflector is wavelength-independent, providing an initial platform to explore ranging on Mars, and prove the principles of laser communications between a surface vehicle and an orbiter.

enter image description here

  • If I read correctly, the orbiters actually don't have the instruments needed to use it (WTF?). The only laser range finder we tried to sent to mars was on the failed mars96 mission. – Antzi Oct 19 '16 at 9:13
  • @Antzi retroreflectors are incredibly useful. See my links - the ones that the Apollo astronauts set up on the Moon are still producing good science, as are the LAGEOS satellites. That they will be used, and be useful is certain! I'm just wondering if there is anything in the pipeline at the moment that is a candidate for the first use. – uhoh Oct 19 '16 at 9:23
  • Considering that the landing apparently failed, there may be no first use at all. – chirlu Oct 20 '16 at 8:42
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    You’ve now asked a different question. – chirlu Oct 20 '16 at 9:19
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    There's an excellent chance the lander exploded or broke up violently on impact. Thus a smaller chance of the retroreflector being visible/intact. – Organic Marble Oct 22 '16 at 16:48
up vote 1 down vote accepted

Probably not. As mentioned in the comment by @OrganicMarble, Schiaparelli fell without propulsion or parachutes for several kilometers and left a "crater" or at least a significant depression in the Martial soil, possibly accompanied by an explosion of the unused propellant.

Even individual corner reflectors - if separated - would probably be covered by debris or soil.

Here is "(t)he latest image... taken on 25 October by the high-resolution camera on NASA’s Mars Reconnaissance Orbiter." from here - cropped full size image, and the full reduced-file-size version.

enter image description here

enter image description here

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