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2013-10-21 05:41:57
Richard Hollingham
Nasa's replacement for the Space Shuttle may have been in development for
almost 10 years but there s still one problem: no-one quite knows what it is
for.
Every organisation needs an ideas person. A maverick thinker. Someone who not
only thinks outside the box, but who considers replacing it altogether. For
Lockheed Martin s Human Space Flight Programme, that person is Josh Hopkins,
the company s Space Exploration Architect.
My role is to think big picture thoughts about what kinds of exploration
missions America and its international partners should be doing, Hopkins
explains. I am focused on human exploration, but also how that overlaps with
robotic spacecraft.
Hopkins may have the world s coolest job title but he has also got a problem.
Or, as he would probably prefer to put it, an exciting challenge: Orion,
America s replacement for the Space Shuttle.
It s not the delays and overruns besetting the $5 billion project that are
exercising Hopkins. Nor is it the multiple redesigns to the spacecraft since
President Bush gave the plan the go-ahead in 2004. The problem is that no-one
quite knows what Orion is for.
Resembling a supersized Apollo capsule, Orion will carry a human crew of four
on long duration missions into orbit and beyond. The programme has been one of
the most drawn-out in the history of human spaceflight, but it is finally
starting to come together. The first working prototype of the crew capsule has
been built by Lockheed Martin and is about to enter an intensive period of
testing, before an unmanned flight, currently slated for late next year.
When the Orion programme was first conceived a decade ago, the spacecraft was
destined to take astronauts back to the Moon. Today, Nasa s goals are so
shifting and ill-defined that it could end up heading for the Moon or a
(yet-to-be-identified) asteroid. Orion could be sent into deep space or simply
be used to shuttle supplies to the International Space Station (ISS). This is a
spacecraft in search of a mission.
To some extent that s true, admits Hopkins, and it has some obvious
disadvantages, but it also has some advantages in that we can design the
spacecraft to be flexible and have lots of different options for what we can
do.
As well as Nasa s current plans for a mission to an asteroid, these options
include some highly innovative ideas. We re looking at missions that could
orbit the Moon and have astronauts control rovers on the lunar far side, that
nobody s ever explored before, says Hopkins.
Mission impossible?
Combining the benefits of human exploration with the convenience, safety and
economy of robotics is a compelling idea. It would be considerably easier,
cheaper and safer than landing humans on the lunar surface. Parked in their
Orion capsule in lunar orbit, astronauts would be able to operate the rovers
like remote control cars, deciding where they should go in real-time. Nasa
astronaut Chris Cassidy recently tested the theory, successfully controlling a
rover in a simulated moonscape on Earth from the ISS.
It s different from how we traditionally control a rover, where you ve got
maybe a hundred people on Earth taking a long time to decide what to do says
Hopkins. In this scenario we have one or two astronauts making more real-time
decisions.
However, as the communications time delay between the Earth and the Moon is
only around two seconds (there and back), you could just as easily control a
rover from Earth. In fact the Soviet Union operated a couple of its lunar
rovers this way more than 40 years ago. Where this technology really starts to
make sense is for destinations much further away.
The big advantage of doing this at the Moon, says Hopkins, is that it s a
way to practice doing this for Mars.
Hopkins says that controlling rovers in almost-real-time would revolutionise
Mars exploration. What you might do for the first Mars missions is have the
astronauts orbit Mars and land on one of its tiny moons Phobos or Deimos
and from there they can control rovers on the Martian surface, he explains.
The people who operate the rovers on Mars today talk about the fact that a
professional geologist could do in one minute what it takes a rover a day to
do, so you explore much more effectively if you got rid of that huge time
delay.
Perhaps the biggest advantage is that this mission is possible with existing
technology. Landing on Phobos is relatively easy compared with landing and
leaving the surface of Mars, and well within the capabilities of an Orion
spacecraft fitted with landing gear or anchors. Phobos is so small (only around
15 km across) that it has practically no gravitational field, which means you
could land and take off using standard rocket thrusters. Mars, on the other
hand, would require some serious rockets and several tonnes of fuel to fire
them.
What s more, by landing on a Martian moon rather than simply staying in orbit
around the planet, you have a ready-made radiation shield. If you land your
spacecraft on one of these Moons, it is blocking half the sky from radiation,
says Hopkins. You could potentially use the sandy soil there to cover up your
spacecraft and provide even more radiation shielding.
The other advantage, of course, is that you can investigate the moons
themselves. Scientists want to discover whether Phobos and Deimos are captured
asteroids that Mars pulled into its orbit or whether they were blasted off the
surface of the planet by cosmic impact. There might even, adds Hopkins, be some
useful resources there. Perhaps we can make liquid oxygen rocket propellant on
those moons and then we wouldn t have to bring it all the way from Earth.
There are a lot of ifs , maybes and possibles in these concepts but, if
one of them was adopted, it would give the Orion programme a more compelling
ambition than the current vague notions of vague missions to vague asteroids.
With Orion counting down to its first launch, Nasa is close to regaining the
deep space capabilities it once had with Apollo. What the agency needs now is a
clear plan as to how it intends to use its shiny new spacecraft. A mission to
Phobos would be an endeavour with sound scientific purpose that would catch the
popular imagination.
That s why thinking outside the box is sometimes not enough. It might be time
to get a new box altogether.