Asteroid Adventure

THREEPIO: Sir, the possibility of successfully negotiating an asteroid field is approximately 3720 to 1!

HAN : Never tell me the odds!

Threepio's comment may be an example of how mathematics can be misleading. The odds he quoted may be those of a spaceship travelling straight through the asteroid field. (Robots tend to think linearly.) Fortunately Han and the Millenium Falcon can STEER, avoiding the biggest asteroids. Let us hope that people in science learn to think outside the box.

Earlier this year asteroids were the subject of a series of posts. In many ways an asteroid mission is easier than reaching the Moon, January 22. The DAWN mission will explore two of the largest asteroids, January 23. The lines between asteroids, comets and minor planets are becoming more blurred, January 24. In 2029 Apophis will pass closer to Earth than a communications satellite, January 29. A "gravity tug" could be used to deflect dangerous asteroids, January 30.

Last week the private company Digital Space released video of a notional asteroid mission. Darnell of Colony Worlds has posted the whole video here. Once a spacecraft achieves Earth escape velocity, reaching an asteroid is relatively easy. Unlike the Moon, there is no deep gravity well to descend into. A Orion spacecraft could virtually hover over an asteroid using thrusters. Digital Space envisions a landing craft based upon Lunar Surface Access Module designs. The spacecraft could "hop" from one landing site to another. The lower stage is designed to be left behind as a science station.

Check out those big old spacesuits! Using skintight suits could save 600-1200 pounds from the mission weight. When astronauts are ready to return home, the bulky outer layers could be left behind with the lower stage. Asteroids are probably dusty, and all that dust would be left behind too.

Concerning thrusters,Orion is still going through redesigns. As with many projects, weight is a growing problem. Like Apollo, Orion will now use hypergolic propellants for the thrusters. To save the mass of airbags, Orion is now planned to splashdown in the ocean. I hope they realise that the US has fewer aircraft carriers than in the 1960's. The Orion 3 unmanned mission is scheduled to land off the coast of Australia in September 2012. Watch out for the box jellies, and we'll put another shrimp on the barbie for you.

You're Going Out in That?

Check out the new Carnival of Space. You will see a fascinating article by Pamela Gay on interstellar jets, Brian Dunbar on Space Solar Power, even a few words on "dark energy."

Last week we saw a poor astronaut candidate Eaten Alive by the Mark III spacesuit. This suit is currently the favourite of NASA's Advanced Department. Like many artist's concepts it looks great in animations but is very cumbersome in reality. Seeing a need, NASA has solicited proposals from private industry.

Because very few companies are equipped to mass-produce spacesuits, participation is so far limited to the companies already making NASA suits. NASA has issued very specific requirements. They have specifically requested a single suit system adaptable for Low Earth Access, zero-G EVA, lunar and Mars excursions. They want to include water egress scenarios. They want a suit that one person could put on unassisted. So far the contractor community has not fulfilled NASA's wishes.

ILC Dover builds the Extravehicular Mobility Unit used in shuttle EVA's. The EMU weighs 310 pounds on Earth and is quite difficult to move in. Their I-1 suit has the most in common with the Mark III, with rotating bearings for mobility and a waist closure. Some weight has been saved by replacing heavy bearings with soft joints. This suit weighs more than 65 pounds not counting a PLSS backpack. It is difficult to imagine crews willingly wearing this during launch or descent.

The David Clark Company makes the orange "pumpkin suit" used for shuttle launch and Earth return. In an emergency involving decompression, air pressure in an inflated suit makes movement difficult. This is one more distraction for pilots struggling to control the vehicle during an abort scenario. This D-1 suit adds external cables to hopefully counteract the stiffness of pressurised joints. Unless this problem is solved, this suit would not be practical for EVA especially on the Moon or Mars.

Other players will shortly enter the stage. A startup called Orbital Outfitters, with experience building prop suits for many motion pictures, has recently signed a contract with private XCOR. The appearance of their suit is a closely guarded secret, but they promise it will be Hollywood-slick. Award of a contract for next-generation spacesuits depends the Constellation Program, which is slipping further into the future.

Despite the organisation's shortcomings, NASA personnel have always been dedicated to Space. They see a need to think outside the box, which has led to the Centennial Challenges Program. One of those challenges was the Astronaut Glove Competition, which this month awarded 200,000 dollars to inventor Peter Homer. A separate Challenge for a "Mechanical Counter-Pressure" glove had no entrants at all. NASA sees the need for new technology; it is up to citizens to answer it.

Eaten Alive

Today NASA released photos showing slow progress on hardware for the Moon. You can see the whole gallery here. The Orion CEV is a mockup made of wood and would not last one second in Space. The CEV and spacesuit are pictured in publicity paintings of people reaching the Moon.

Astronaut Andrew Feustel is eaten alive by the Mark III advanced space suit technology demonstrator. He is supported by cables and other devices because the suit is too heavy for a man to walk in. He seems to have no way of removing his helmet or even raising the visor. How many times have you seen astronauts raise their visors for comfort?

This month I hope you see a spacecraft technology that wil make human spaceflight safer, easier, and far more comfortable.