Landing on Mars is never easy, as a record of failed missions has demonstrated. The gravity is fairly strong, but the atmosphere is thin. This pulls spacecraft in rapidly as they approach, but offers little natural means of slowing them down. Then there's the touchdown on rocky terrain, which can cause further problems.

Thus, mission planners try to settle their spacecraft down in fairly safe locations. The terrain needs to be flat, and it also helps if the landing site is at a fairly low altitude. This means there's more wispy carbon dioxide air to use for deceleration by parachute.

Getting to the high terrain on Mars is more difficult. It's no wonder that such areas are generally avoided by landers.

We're in the middle of a massive reshuffle of Mars exploration on a global scale. Programs in the USA and Europe face budgetary cutbacks. Some of the grand mission plans that were on the agenda could be infeasible, at least in the near future. It's time to consider some new options that could allow for interesting results at modest costs.

Let's consider sending some small probes to the highlands of Mars. These probes would not have the capability of a large rover, or even a Mars Pathfinder-style spacecraft. They will be modest in their performance, but the scientific returns could be more than we expect.

Just landing anything in some of the more geologically interesting regions of Mars would be an immediate payoff. We can see a lot from orbit, especially when we have a high-resolution camera on NASA's Mars Reconnaissance Orbiter. But nothing beats "ground truth".

Touching down a small instrument package to photograph the soil and rocks at close range, and see things from angles beyond the reach of an orbiting camera, would be useful. It would help to place our large pool of orbital data in better context. It would confirm some of our assumptions, and possibly challenge others.

A small instrument package could also yield some basic spectroscopic data, along with air pressure measurements.

How would we get there? Let's not place too much faith in parachutes. Instead, we should consider stronger deceleration during atmospheric entry. Engineers are making steady progress in the field of expandable heatshields. These can nestle a small lander like a shuttlecock, providing a large area for atmospheric drag with a relatively small mass.

A small rocket thruster could be fired immediately before impact, very close to the ground.

Shock absorbers would provide the final protection during impact. They may use compressible structures or gels. Some may even bounce. Airbags would probably not be useful for a small lander at a high velocity.

The lander itself would still need to be very rugged. But this can be done. Electronics and batteries can be highly robust. Delicate instruments and micro-rovers are probably off the manifest.

The lander could have a performance life of only a few hours, uplinking its data to an orbiter. The data set would not be large and could be transmitted in only a few passes.

Small landers could be launched in tandem with orbiters, and would separate as the spacecraft approached Mars. This could be one way of launching a "pathfinder" mission to demonstrate the landing technology.

Later, more landers could be launched in a group on a dedicated mission.

Plans have been drawn for penetrator missions that incorporate some of these principles. The best- known plan at the moment is the Finnish-Russian-Spanish MetNet mission plan.

Small spacecraft can still deliver useful results. Let's remember this in tough economic times.

Dr Morris Jones is an Australian space analyst and writer. Email morrisjonesNOSPAMhotmail.com. Replace NOSPAM with @ to send email.