Editorial

by Jon Fairall

^{Landsat Woes}

At this writing – just before the Christmas break – engineers at NASA and the US Geological Survey were ‘cautiously optimistic’ that problems with Landsat-5 could be fixed. Quite correctly, staff at the Australian Centre for Remote Sensing, were viewing this announcement with some concern, and putting plans into place to deal with it.

In a sense however, Australians are reaping the rewards of two decades of sloth in the remote sensing field. It would be nice to think this could be a wake up call.

The problems began on 26 November when a device that points the solar array on Landsat-5 at the sun failed.

L-5’s solar array drive points the solar panels on the spacecraft at the sun. The arrays provide electricity for the spacecraft’s on-board batteries, which power all its systems. If the array does not point at the sun, the batteries will drain, and the communications link between the spacecraft and controllers on the ground will fail.

In order to keep the batteries working as long as possible, all non-essential systems on the craft, especially its imaging systems, have been shut down.

The drive that has developed problems is a back-up; the original failed in January 2004.

The Landsat community around the world has long feared this eventuality. Landsat-5 has exceeded its design life by 16 years. Landsat-6 was lost on launch. Landsat-7 is only partially operational. It produces images with many pixels missing. In Canberra, the head of the Australian Centre for Remote Sensing, Adam Lewis, says his organisation will move to using ‘L-7 composites’—a way of making up for the problems on L-7 –but he concedes this very much a band-aid solution. ‘It is obviously less convenient, but it can be used and there is a community of users who find this solution quite adequate,’ he said.

If the problem continues into February, ACRES will start looking to JAXA’s ALOS craft. ACRES will be the Oceania data node for ALOS, although it is not intended as an operational spacecraft, ACRES will be looking to it to take up some of the slack.

ACRES will also push the ASTER instrument carried on NASA’s Terra and Aqua. This data has the advantage that ACRES already downloads it in Alice Springs.

In the longer term, ACRES will switch to reliance on the Sino-Brazilian CBERS spacecraft. ACRES is also interested in access to the Indian IRS-P6 spacecraft.

In the very long term, ACRES will either be looking to the US to provide Landsat-8, or alternatively, will decide that the Brazilians, Indian and Chinese can, between them, supply the data we need.

Because need it we do. We can assume some certainties in the world, along with death and taxes. One is that the climate is changing. A second is that we will need to manage it. And a third is that we will need good data to do it.

Seen in that context, the ACRES data archives may well turn out to be one of the most important sources of information available to the government. It is the only truly objective measure of changes to Australian land cover.

Successive Australian governments have taken a pretty casual view of this resource. Essentially, the argument has been that we should use the investment other countries are prepared to make in space technology to acquire whatever data we need as cheaply as possible.

No doubt this is a very clever ploy, which has saved the public purse some few hundred million dollars over the last 20 years. But is it the right one?

Leaving aside the moral question of whether it is OK for Australia to bludge on the international system in this fashion, there are several reasons why it might not be so clever after all.

Australian scientists do not get invited to design meetings for these projects, so we never actually get satellites that measure precisely what we need. We don’t get to decide how significant border protection is, or land cover, or mineral exploration, or fire monitoring or a national mapping program. We just hope that foreigners make the right decisions for us.

We don’t get to decide how important data continuity is. National agendas change in foreign countries. We have little or no input into such debates. The current Landsat imbroglio, for instance, is due entirely to the fact that the US government has dithered over Landsat-8 for the best part of a decade. US decisionmakers are, quite rightly, totally indifferent to the views of Australians on this matter.

A third problem with the status quo is that we forgo all the training and technical transfer opportunities that sophisticated technology projects create. The Thais and Malaysians are both creating cadres of skilled technicians on the back of their national satellite programs. Australia produced a few PhDs out of its Fedsat program, but that is likely a thing of the past.

The government’s rejoinder will probably be that we can import skills if we need them. But it’s not clear that we can rely on this unless engineering salaries climb a lot higher than they are today. Whether business can afford them is a moot point.

Much of the problem seems to be that there is no part of the bureaucracy or academia prepared to argue for a space policy for Australia anymore. More’s the pity. The government is currently taking submissions for its National Collaborative Research Infrastructure Strategy to the tune of $542 million over seven years. In a rational world, a small but focused satellite program would be part of that.

JON FAIRALL is the Editor of Position

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(This page last modified on 1 February 2006)