VMC Imaging Campaign – making the grade

Today’s blog post announces the list of proposals that have met the minimum requirements for consideration as VMC imaging targets.

As of 12:00CET today, the open period for VMC Imaging Campaign proposals is closed.

We are incredibly delighted with all the proposals (44 were submitted!), each of which demonstrated imagination and a real enthusiasm for Mars. Thank you to everyone who took the time to submit.

Of these 44, 25 have met the minimum requirements for consideration. Congratulations to those who made the grade! (The full list is at the bottom of this post.)

Making the grade

19 proposals have been rejected, as they failed to meet the minimum requirements, e.g., were not submitted by a group, or were submitted from someone from an ineligible country. We’ve already emailed some of those proposers to tell the news, but this blog post is the ‘official’ announcement: If your proposal is not in the listing below, then you have been rejected as failing to meet the minimum requirements.

Of the remaining 25 valid proposals, that is, the ones in the list below, we intend to try and accommodate as many as possible, but some may yet have to be dropped. This is not because of your efforts, but instead the decision will come down simply to us having a strictly limited observation period and various restrictions relating to spacecraft safety (see our earlier posts: Why conjunction frees up VMC time and VMC Imaging Campaign).

The next step for the Mars Express team is to assess the proposals that are considered to be the most promising (in terms of requested observation target and proposed group project) and work out how many of these observations we will be able to carry out.

How it’s done downtown

This is precisely what professional scientists face when requesting an observation from any spacecraft!

They submit their requests and the mission planners, flight dynamics teams and flight control teams try to carry out as many of these as possible.

As well as checking if a target is in view and safe to observe, there are other factors that have to be taken into account mostly to do with our ‘budgets’. Now by budget we don’t necessarily mean money – but the analogy is the same – you can only spend what is available. We have many budgets, but the main two in this case are the power budget and the data link budget.

To briefly explain these:

• Power Budget – as Mars in in a more elliptical orbit than Earth, its distance from the Sun varies significantly over the course of a Martian year (and, thus, so does that of Mars Express), meaning that our solar arrays generate less power and so less is available to supply the instruments at certain time.Also, reduced sunlight makes the spacecraft colder, meaning more power has to be supplied to the heaters, further reducing what is left. We also have eclipse seasons, where the spacecraft passes through the shadow of Mars. During these periods, MEX has to rely on batteries and then recharge them once it orbits back into sunlight. This further reduces the remaining margin.
• Link Budget – For communication purposes, we often talk about the distance between Mars and Earth in ‘one-way light time’. This is the amount of time our radio signals take to travel from Earth to Mars at the speed of light.As both planets circle the Sun at different rates, this can vary from about 5 to over 21 minutes. So how does this affect science? To use an analogy, if you stand close to someone, you can speak quite quickly and be understood — but if you are at opposite ends of the street, you’ll have to shout slowly to get your message across.It’s similar for us; at the farthest point from Earth, the MEX data rates can be 10x lower (than when nearest), meaning we either need 10x as much time to communicate with Earth, or produce only 1/10th of the science (or strike a balance in between).

Striking balances between the various budgets  is a big part of what our mission planners have to do and this observation campaign is no different. We’ll do our best but won’t be able to confirm anything for a few more weeks.

Accepted for planning consideration

Here’s the list of teams that we are going to advance to the next planning stage. Note that some of you have chosen similar targets, or observations that may be combined, which does make things easier from our side. Listing is in no particular order.

Well done to all of you for advancing to this stage and we hope to try and squeeze in as many of these observations as we can!

Announcement of accepted proposals

We are aiming to have the final list of accepted proposals ready to announce within approximately 8 May, and ideally even sooner than that. We’ll update you on planning progress in a couple weeks.

Watch this space!

And thanks again to everyone who submitted observation requests.